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Deep structure of the Mid Black Sea High (offshore Turkey) image by multi-channel seismic survey (BLACKSIS cruise)
Abstract
The Black Sea is considered to be a Mesozoic–Early Cenozoic marginal basin related to the north-dipping subduction of Tethys beneath Europe. However deformation of this basin during the successive Eocene to Neogene collisions of African-derived continental fragments (Kirshehir and Arabian micro plates) remains poorly understood. A multi-channel seismic survey conducted in the central part of the Black Sea has shed light on the superimposed tectonic fabrics of the Central Ridge (the Mid Black Sea High, MBSH) in response to these successive collisions. The MBSH is formed by a series of large NW–SE trending anticlines and synclines, and possible northeast-verging thrusts were identified at the boundary with the deep East Black Sea Basin northeast of the ridge. These buried folds and thrusts, blanketed by 3 to 8 s TWT of undeformed sediments, are interpreted as the offshore extension of the Early Cenozoic tectonic belt resulting from the collision between the Pontides in the north and the Kirshehir block to the south. The offshore part of the belt forming the ridge could have then collapsed when collision ended. Neogene structures also affect the MBSH. A recent graben (the Sinop Trough) extends between this central high and mainland Turkey. This graben could have been formed during the late Miocene incipient dextral strike slip motion of the North Anatolian Fault that was initiated during extrusion of the Anatolian microplate. Active tectonic inversion of deep-seated normal faults present along the Pontides passive margin was also observed along the northeastern flank of the Eastern Pontides. This deformation is the westernmost extension of the Lesser Caucasus front that outlines the suturing of the Eastern Black Sea Basin in easternmost Turkey and in Georgia.
... The formation history and dynamics of the Black Sea have been discussed by several studies based on multichannel seismic reflection and refraction, gravity and magnetic data, providing different interpretation of the structural features present in the western and eastern halves of the basin (e.g., Adamia et al., 1974;Letouzey et al., 1977;Tugolesov et al., 1985;Finetti et al., 1988;Okay et al., 1994;Spadini et al., 1996;Rangin et al., 2002;Egan and Meredith, 2007;Edwards et al., 2009;Shillington et al., 2009;Sheremet et al., 2016;Sydorenko et al., 2017). ...
... The origin and kinematic evolution of the EBSB has been under investigation since the publication of regional seismic lines for the entire Black Sea area in the 1980's (Tugolesov et al., 1985;Finetti et al., 1988;Belousov et al., 1988). From that moment, numerous studies have attempted to unravel the timing and kinematics of EBSB opening (e.g., Finetti et al., 1988;Görür, 1988;Graham et al., 2013;Nikishin et al., 2003;Okay et al., 1994;Rangin et al., 2002;Robinson et al., 1996;Shillington et al., 2008;Stephenson and Shellart, 2010;Sydorenko et al., 2017). However, the limited constraint over the deep, syn-kinematic and early post-kinematic stratigraphic record of the basin complicates geodynamic reconstructions. ...
... Early insights into the geological evolution of the Black Sea came from regional seismic lines (Belousov et al., 1988;Finetti et al., 1988;Tugolesov et al., 1985). Since then, researchers have attempted to unravel the kinematics, mechanisms and timing for the opening of the EBSB (e.g., Finetti et al., 1988;Görür, 1988;Graham et al., 2013;Nikishin et al., 2003;Okay et al., 1994;Rangin et al., 2002;Robinson et al., 1996;Shillington et al., 2008;Stephenson & Shellart, 2010). In addition, crustal-scale industry seismic datasets have been acquired due to the growing interest in the EBSB as a region with high hydrocarbon potential, related to the presence of a regionally distributed source-rock, the Maykop Formation (e.g., Graham et al., 2013;Robinson et al., 1996;Stovba et al., 2009). ...
One of the key elements in passive continental margins and basins research is the understanding of how extensional processes initiate and evolve from rifting to breakup stage. These processes may vary spatially and temporally as result of the complex trade-off between spreading rates, lithospheric compositional variations, and along-axis changes in melt supply. Thus, extension may focus over one conjugate margin resulting in an along-axis change in rifting style. Lower crust and/or mantle exhumation may occur at hyper-extended areas, and along-axis changes in melt supply during spreading may result in varying amounts of magmatic intrusions within a highly extended continental crust. The resulting crustal structure and composition at rifted margins may therefore present a geophysical signature differing from what is normally expected for continental and oceanic crust, making it difficult to define the transition from the late stages of continental rifting to initial oceanic accretion. Nevertheless, a clear understanding of the stages defining passive continental margins and extensional basins evolution is key to unravel the mechanisms driving lithospheric extension, as well as the present-day configuration at these settings. Sedimentary basins formed in continental rifts and rifted margins also contain some of Earth�s major hydrocarbon fields. Constraining the evolution and dynamics of these fields gives insight into the timing of basin formation, sedimentation, trap formation, and heat-flow evolution, which are crucial for efficient hydrocarbon exploration. Passive continental margins are also relevant to the study of gas hydrates deposits, which are of interest not only for their potential as a future energy resource, but also for their implications on seafloor stability and their contribution to climate change. However, the dynamics driving their formation and evolution along passive margins is yet to be fully understood. This study provides an integrated geophysical investigation at one of the currently most debated extensional regions, the Eastern Black Sea Basin (EBSB). Here, the timing and dynamics of rifting and breakup processes and the resulting crustal configuration are still poorly constrained. This is due to the deep water setting and thick sedimentary infill, limiting direct sampling of deep sedimentary units and the ability of imaging the deep basin structures using conventional seismic imaging. The EBSB is also a frontier for oil and gas exploration due to the presence of a regional source-rock, the Oligocene-lower Miocene Maykop Formation. Thus, untangling the stages in basin evolution and defining the extent of different crustal basements is essential for modelling the maturity of the hydrocarbon systems in place. This study uses high-resolution, 2D long-offset seismic reflection data by Geology Without Limits (GWL) to investigate the deep tectonostratigraphic elements of the basin and the morphological character of its basement. Magnetic anomaly data are integrated to complement and guide seismic interpretation, defining the magnetisation character of morphologically different crustal domains. The combined analysis of tectono-stratigraphic and magnetic anomaly results provides new insights on the present-day crustal configuration, and on the timing and kinematics of rifting and breakup processes across the EBSB. The Black Sea is characterised by thermo-dynamic conditions which make this area favourable to gas hydrate formation. Gas hydrates have long been known in this area, with related evidence for Bottom Simulating Reflectors (BSRs) predominantly found in the western part of the basin (WBSB). Seismic data used in this study reveal new evidence for multiple BSRs along the NE margin of the EBSB, thus providing a new case study to investigate the physical nature of the identified BSRs, the presence and distribution of gas hydrates and/or free gas zones, and the mechanism(s) driving multiple BSRs generation. The long-offset nature of the seismic acquisition provides both reflected and refracted travel-time information that can be used in a tomographic approach, aiming to define a 2D velocity model within the shallow sedimentary section. To improve refracted arrivals, downward continuation is also applied to the seismic data. Results help to constrain velocity changes in sediments across the BSRs, which are interpreted as indicative for the presence of free gas and gas hydrate in the area. Velocities defined form travel-time analysis are also used to provide estimates of free gas and gas hydrate saturation in sediments using a forward effective-medium modelling approach. Results from this thesis contribute to the understanding of rifting evolution on both small-scale basins, such as the Black Sea, and fully developed passive continental margins. Similarly, results also contribute to the general understanding of gas hydrate evolution in the Black Sea as well as along other well-known gas hydrate regions.
... Early insights into the geological evolution of the Black Sea came from regional seismic lines (Belousov et al., 1988;Finetti et al., 1988;Tugolesov et al., 1985). Since then, researchers have attempted to unravel the kinematics, mechanisms, and timing for the opening of the EBSB (e.g., Finetti et al., 1988;Görür, 1988;Graham et al., 2013;Nikishin et al., 2003;Okay et al., 1994;Rangin et al., 2002;Robinson et al., 1996;Shillington et al., 2008;Stephenson & Schellart, 2010). In addition, crustal-scale industry seismic data sets have been acquired due to the growing interest in the EBSB as a region with high hydrocarbon potential, related to the presence of a regionally distributed source-rock, the Maykop Formation (e.g., Graham et al., 2013;Robinson et al., 1996;Stovba et al., 2009). ...
... Seismic data have also been used to define the presence and distribution of the synrift in the EBSB, but imaging is often limited by attenuation through the thick basin infill (e.g., Finetti et al., 1988;Rangin et al., 2002;Shillington et al., 2008). In fact, in most studies, synrift geometries (e.g., fanning reflector geometry toward fault planes) are not clearly observed in seismic data (e.g., Nikishin et al., 2015a;Shillington et al., 2008). ...
... Sinop-1, 5,531 m deep, was drilled on a structural high of Andrusov Ridge, targeting a synrift of Aptian to Albian age (e.g., Tari & Simmons, 2018;Figure 1b). The sediment cover above the MBSH and the Shatsky Ridge has been described by using extensive academic and industry seismic reflection data (e.g., Belousov et al., 1988;Nikishin 2015aNikishin , 2015bRangin et al., 2002;Robinson et al., 1996;, crustal scale wide-angle seismic data (e.g., Shillington et al., 2017;Yegorova et al., 2010), and seafloor dredging (Rudat & MacGregor, 1993). Chronostratigraphic charts have been compiled to illustrate the different ages and litho-stratigraphy elements of the Black Sea region and EBSB (Adamia et al., 2017;Shillington et al., 2008;Sydorenko et al., 2017;Tari & Simmons, 2018). ...
The age and distribution of the synrift and early postrift infill records the spatial and temporal distribution of extension and breakup processes in a rift basin. The Eastern Black Sea Basin (EBSB) is thought to have formed by back‐arc extension during Cretaceous to Early Cenozoic time. However, a lack of direct constraints on its deep stratigraphy leaves uncertainties over the time, duration, and location for rifting and breakup processes in the basin. Here we use the enhanced imaging provided by 2‐D long‐offset seismic reflection profiles to analyze the deep structural and stratigraphic elements of the EBSB. Based on these elements, we infer the presence of two distinct Late Cretaceous synrift units, recording initial extension (rift stage 1) over the continental highs (Shatsky Ridge and the Mid Black Sea High), followed by strain localization along the major basin‐bounding faults and rift migration toward the basin axis (rift stage 2). Overlying these units, Palaeocene(?)‐Eocene and Oligocene units show a synkinematic character in the NW, with evidence for ongoing extension until Oligocene time. Toward the SE, these sequences are instead postkinematic, directly overlaying a basement emplaced during breakup. We interpret the Palaeocene(?)‐Oligocene units to record the time spanning from the initiation of breakup (Late Cretaceous‐Palaeocene, in the SE) to the end of extension (Oligocene, in the NW). The first ubiquitously postrift infill is the Lower Miocene Maykop Formation. Our results highlight the along‐strike temporal variability of extension and breakup processes in the EBSB.
... The northward-sloping Pontide orogenic wedge is located between the Central Anatolian Plateau and the Black Sea Basin where the northward-convex bend of the NAFZ occurs (Meijers et al., 2010;Yıldırım et al., 2011) (Fig. 1). The Pontides comprise Triassic to Paleocene island-arc rocks and Eocene flysch units related to the Alpidic orogeny (Ş eng€ or and Yılmaz, 1981;G€ orür, 1988;Okay and Tüysüz, 1999;Stephenson and Schellart, 2010;Tüysüz, 1999;Rangin et al., 2002;Nikishin et al., 2015). ...
... 6 km SW of Bafra (Demir, 2005;U guz andSevin, 2007, 2009). These Eocene units are normal-faulted, but structural reconstructions and seismic reflection profiling have shown that these old anisotropies are being inverted during the present-day tectonic regime (Robinson et al., 1996;Rangin et al., 2002). ...
... The fault corresponds with a distinct lineament and coincides with the transition between the different uplifted delta deposit levels and the rugged high topography to the south. A neotectonic offshore graben, the Sinop Trough (Rangin et al., 2002), is a major structure immediately north of the Kızılırmak Delta. The bounding normal faults strike NW-SE, parallel to the Bafra Fault, and record activity until the Pliocene (Rangin et al., 2002). ...
We analysed the interplay between coastal uplift, sea level change in the Black Sea, and incision of the Kızılırmak River in northern Turkey. These processes have created multiple co-genetic fluvial and marine terrace sequences that serve as excellent strain markers to assess the ongoing evolution of the Pontide orogenic wedge and the growth of the northern margin of the Central Anatolian Plateau. We used high-resolution topographic data, OSL ages, and published information on past sea levels to analyse the spatiotemporal evolution of these terraces; we derived a regional uplift model for the northward-advancing orogenic wedge that supports the notion of laterally variable uplift rates along the flanks of the Pontides. The best-fit uplift model defines a constant long-term uplift rate of 0.28 ± 0.07 m/ka for the last 545 ka. This model explains the evolution of the terrace sequence in light of active tectonic processes and superposed cycles of climate-controlled sea-level change. Our new data reveal regional uplift characteristics that are comparable to the inner sectors of the Central Pontides; accordingly, the rate of uplift diminishes with increasing distance from the main strand of the restraining bend of the North Anatolian Fault Zone (NAFZ). This spatial relationship between the regional impact of the restraining bend of the NAFZ and uplift of the Pontide wedge thus suggests a strong link between the activity of the NAFZ, deformation and uplift in the Pontide orogenic wedge, and the sustained lateral growth of the Central Anatolian Plateau flank.
... Early insights into the geological evolution of the Black Sea came from regional seismic lines (Belousov et al., 1988;Finetti et al., 1988;Tugolesov et al., 1985). Since then, researchers have attempted to unravel the kinematics, mechanisms, and timing for the opening of the EBSB (e.g., Finetti et al., 1988;Görür, 1988;Graham et al., 2013;Nikishin et al., 2003;Okay et al., 1994;Rangin et al., 2002;Robinson et al., 1996;Shillington et al., 2008;Stephenson & Schellart, 2010). In addition, crustal-scale industry seismic data sets have been acquired due to the growing interest in the EBSB as a region with high hydrocarbon potential, related to the presence of a regionally distributed source-rock, the Maykop Formation (e.g., Graham et al., 2013;Robinson et al., 1996;Stovba et al., 2009). ...
... Seismic data have also been used to define the presence and distribution of the synrift in the EBSB, but imaging is often limited by attenuation through the thick basin infill (e.g., Finetti et al., 1988;Rangin et al., 2002;Shillington et al., 2008). In fact, in most studies, synrift geometries (e.g., fanning reflector geometry toward fault planes) are not clearly observed in seismic data (e.g., Nikishin et al., 2015a;Shillington et al., 2008). ...
... Sinop-1, 5,531 m deep, was drilled on a structural high of Andrusov Ridge, targeting a synrift of Aptian to Albian age (e.g., Tari & Simmons, 2018;Figure 1b). The sediment cover above the MBSH and the Shatsky Ridge has been described by using extensive academic and industry seismic reflection data (e.g., Belousov et al., 1988;Nikishin 2015aNikishin , 2015bRangin et al., 2002;Robinson et al., 1996;, crustal scale wide-angle seismic data (e.g., Shillington et al., 2017;Yegorova et al., 2010), and seafloor dredging (Rudat & MacGregor, 1993). Chronostratigraphic charts have been compiled to illustrate the different ages and litho-stratigraphy elements of the Black Sea region and EBSB (Adamia et al., 2017;Shillington et al., 2008;Sydorenko et al., 2017;Tari & Simmons, 2018). ...
p>Estimating the degree of lithospheric stretching, and identifying the distribution of crustal types, are important elements in oil and gas exploration activity, because this information is used for thermal modelling of hydrocarbon maturation. The Eastern Black Sea Basin (EBSB) is a frontier basin for hydrocarbon exploration, but the deep-water setting (∼2200 m) and the presence of a thick sedimentary sequence (∼10 km) limit conventional seismic imaging. The EBSB is considered to be partially underlain by oceanic crust, but the distribution of crustal types and the structures accommodating the stretching are still poorly known. We use long-offset reflection seismic data, acquired in 2011 by Geology Without Limits and ION GXT, to image key elements of rift-basin settings such as thinned continental crust, tilted fault-blocks, syn- and post-kinematic sequences, the top of the acoustic basement and Moho. We differentiate the basement by examining seismic reflectivity patterns as an indicator of crustal type. We interpret variations in basement morphology to indicate the presence of a continent-ocean transition of enigmatic nature. This information will be used to further investigate the nature and thickness of the crust and to provide insights into mechanisms of continental extension and rifting in back-arc settings.</p
... In the deep-water part magnetic susceptibility information is not available. In another way, values of magnetic susceptibility of samples can be used from the adjacent onshore because marine seismic stratigraphy is similar to that exposed on land [see for example, Rangin et al., 2002;Khriachtchevskaia et al., 2009;Hippolyte et al., 2010;Georgiev, 2012]. They do not exceed mostly (30-40) 10 5 SI on the conjugate margins of the Black Sea in the Pon and Cr [Kaymakci et al., 2003;Guzhikov et al., 2012]. ...
... The circular OSO southeastern offset results from general dextral shift along the OSO zone parallel to the Middle Alpine thrust belt bounded the Eastern Pon on the north [Nikishin et al., 2003]. In whole, the OSO zone follows the strike of the North Anatolian Fault [Rangin et al., 2002] and the NA thrust front [Finetti et al., 1988] and is consis-tent with their dextral motions. In turn, the Neo thrust front extends on the direct continuation of the TTZ and its trend is clearly sub-parallel to that of faults in the crystalline crust of the Black Sea (e.g. the OSO fault zone). ...
... The AB zone and the southeastern setoff of the OSO fault are not manifested themselves in the feature of the Pon and A-T zone being limited by Middle Alpine thrust front [Finetti et al., 1988;Rangin et al., 2002]. ...
... The northward-sloping Pontide orogenic wedge is located between the Central Anatolian Plateau and the Black Sea Basin where the northward-convex bend of the NAFZ occurs (Meijers et al., 2010;Yıldırım et al., 2011) (Fig. 1). The Pontides comprise Triassic to Paleocene island-arc rocks and Eocene flysch units related to the Alpidic orogeny (Ş eng€ or and Yılmaz, 1981;G€ orür, 1988;Okay and Tüysüz, 1999;Stephenson and Schellart, 2010;Tüysüz, 1999;Rangin et al., 2002;Nikishin et al., 2015). ...
... 6 km SW of Bafra (Demir, 2005;U guz andSevin, 2007, 2009). These Eocene units are normal-faulted, but structural reconstructions and seismic reflection profiling have shown that these old anisotropies are being inverted during the present-day tectonic regime (Robinson et al., 1996;Rangin et al., 2002). ...
... The fault corresponds with a distinct lineament and coincides with the transition between the different uplifted delta deposit levels and the rugged high topography to the south. A neotectonic offshore graben, the Sinop Trough (Rangin et al., 2002), is a major structure immediately north of the Kızılırmak Delta. The bounding normal faults strike NW-SE, parallel to the Bafra Fault, and record activity until the Pliocene (Rangin et al., 2002). ...
The Kızılırmak River (1355 km) is the longest river of Anatolia. It traverses the Central Pontides and forms deep bedrock gorges, fluvial and deltaic terraces along its lower stream and a large delta into the Black Sea. The Central Pontides is an actively deforming and uplifting mountain range located at the northern margin of the Central Anatolian Plateau (CAP). The presence of strath terraces and uplifted paleo-delta levels along the lower course of the river indicates a response of Kızılırmak to active uplift of the Central Pontides and sea-level fluctuations of the Black Sea. To understand the Quaternary tectonic, climatic and sea level impacts on the lower stream and delta of the Kızılırmak River, we carried out geologic and geomorphic mapping of several fluvial and deltaic terraces in order to date 5 levels by optically stimulated luminescence dating (OSL) method. Our results indicate accelerated regional uplift since Middle Pleistocene in the eastern part of the Central Pontides with uplift rates varying between about 0.07 and 0.3 m/ka. The delta terraces at 103 and 123 m above mean river level on the western side of Kızılırmak River uplifted presumably faster than the terraces at 58 and 87 m above mean river level on the eastern side by 0.2-0.3 m/ka. Since MIS 9 the western and eastern delta platforms uplift coherently with 0.2 m/ka or less. The southern part of the delta is delimited by Alaçam Segment of the Erikli Fault. The area south of the Alaçam segment of the Erikli Fault is uplifting faster than the region to the north of it (0.07 m/ka) since Middle Pleistocene. This indicates a tectonic interaction between the positive flower structure of the North Anatolian Fault Zone and an active rifting of the Sinop Graben over the Erikli Fault system.
... The northward-sloping Pontide orogenic wedge is located between the Central Anatolian Plateau and the Black Sea Basin where the northward-convex bend of the NAFZ occurs (Meijers et al., 2010;Yıldırım et al., 2011) (Fig. 1). The Pontides comprise Triassic to Paleocene island-arc rocks and Eocene flysch units related to the Alpidic orogeny (Ş eng€ or and Yılmaz, 1981;G€ orür, 1988;Okay and Tüysüz, 1999;Stephenson and Schellart, 2010;Tüysüz, 1999;Rangin et al., 2002;Nikishin et al., 2015). ...
... 6 km SW of Bafra (Demir, 2005;U guz andSevin, 2007, 2009). These Eocene units are normal-faulted, but structural reconstructions and seismic reflection profiling have shown that these old anisotropies are being inverted during the present-day tectonic regime (Robinson et al., 1996;Rangin et al., 2002). ...
... The fault corresponds with a distinct lineament and coincides with the transition between the different uplifted delta deposit levels and the rugged high topography to the south. A neotectonic offshore graben, the Sinop Trough (Rangin et al., 2002), is a major structure immediately north of the Kızılırmak Delta. The bounding normal faults strike NW-SE, parallel to the Bafra Fault, and record activity until the Pliocene (Rangin et al., 2002). ...
From Late Miocene to present, Anatolia's rapid counterclockwise movement, which increases in velocity towards the Hellenic Arc, has formed the North Anatolian Fault (NAF), a dextral transform fault along the Anatolia-Eurasia plate boundary and the northern margin of the Central Anatolian Plateau (CAP). A zone of transpression referred to as the Central Pontides exists between the broad restraining bend of the NAF and the Black Sea Basin, uplifting what is interpreted as a detached flower structure. Dating of Quaternary landforms in the eastern flank of the Central Pontides has helped to understand its recent deformation. However, in the western flank of the Central Pontides there is an absence of Quaternary studies, relatively quiet modern seismicity, and difficulties locating or observing fault scarps. This led us to use optically stimulated luminescence dating (OSL-dating) of fluvial terrace sediments and the study of geomorphic features to gain insight into the influence of climate and tectonics on landscape evolution of this area. In this area, the Filyos River crosses the Karabük Fault (reverse fault) and deeply incises a gorge through the Karabük Range before flowing towards the Black Sea. In the gorge an abundance of indicators of tectonic deformation were mapped, such as hanging valleys, wind gaps, bedrock gorges, landslides, steep V-shaped channels, tilted basins, as well as fluvial strath terraces. In particular, strath terraces of at least 8 levels within just 1.5 km of horizontal distance were examined. We used OSL-dating to estimate five deposition ages of fluvial strath terrace sediments, leading to an estimation of incision and uplift rates over time. Using three samples per terrace with strath elevations of 246 ± 0.2 m, 105.49 ± 0.2 m, 43.6 ± 0.2 m, 15.3 ± 0.2 m and 3.6 ± 0.2 m above the Filyos River, we determined corresponding ages of 841 ± 76 ka, 681 ± 49 ka, 386 ± 18 ka, 88 ± 5.1 ka and 50.9 ± 2.8 ka. Incision rates over time (oldest terrace to youngest) suggest uplift of 0.29 ± 0.03 mm/y, 0.16 ± 0.01 mm/y, 0.10 ± 0.01 mm/y, 0.17 ± 0.01 mm/y and 0.07 ± 0.004 mm/y. Collectively, our ages infer decelerating fluvial incision and rock uplift rates in the Karabük Range of the Central Pontides. The highest rate that belongs to oldest terrace level (841 ± 76 ka) also implies long-term mean uplift, which is well correlated with long term (∼350 ka) mean uplift rate obtained from fluvial terraces in the eastern flank of the (Gökırmak Basin) Central Pontides. These results indicate Quaternary activity of the Karabük Fault despite the fact that very low modern seismicity and partition of strain in the north of the North Anatolian Fault.
... The offshore areas of the central Black Sea Basin comprise two major (western and eastern) subbasins separated by the mid-Black Sea High (Okay et al., 1994;Robinson et al., 1995;Görür and Tüysüz, 1997;Tüysüz, 1999;Meredith and Egan, 2002;Rangin et al., 2002;Cloetingh et al., 2003;Nikishin et al., 2003;Hippolyte et al., 2010) (Figure 1). Despite the absence of subduction-related arc magmatism in the Lower Cretaceous (Tüysüz, 1999;Hippolyte et al., 2010), the Black Sea Basin is commonly considered as a back-arc basin that was formed by the extension of northward subduction of the Neotethys Ocean (Hsu et al., 1977;Letouzey et al., 1977;Zonenshain and Le Pichon, 1986;Görür, 1988Görür, , 1997Görür and Tüysüz, 1997). ...
... Older sediments are deformed by the late Eocene fold-thrusts and probably inverted by extensional faults in the Sinop Trough and the mid-Black Sea High. Later sediments consist of undeformed Oligocene-Miocene to Pliocene-Quaternary sediments formed by abrupt subsidence caused by flexural loading and associated regional subsidence (Robinson et al., 1995Meredith and Egan, 2002;Rangin et al., 2002;Cloetingh et al., 2003;Nikishin et al., 2003) (Figures 1, 8). Figure 3 for sample locations. **TOC = total organic carbon; S 1 = the amount of volatile organic compounds in the sample; S 2 = the amount of hydrocarbon compounds generated from the thermal cracking of the kerogen; S 3 = the amount of CO 2 generated from the kerogen; T max = pyrolysis temperature at the maximum rate of kerogen conversion; HI = hydrogen index; OI = oxygen index; PI = petroleum index; RC = residual carbon; PC = pyrolyzed carbon; MINC = mineral carbon; N/A = wrong data caused by weak S 2 and HI. ...
... A seismic line and its interpretation shows the offshore area of the central Black Sea of Turkey (modified fromRobinson et al., 1996;Meredith and Egan, 2002;Rangin et al., 2002) (seeFigure 1for location). ...
The central Black Sea Basin of Turkey is filled by more than 9 km (6 mi) of Upper Triassic to Holocene sedimentary and volcanic rocks. The basin has a complex history, having evolved from a rift basin to an arc basin and finally having become a retroarc foreland basin. The Upper Triassic-Lower Jurassic Akgöl and Lower Cretaceous Çaǧlayan Formations have a poor to good hydrocarbon source rock potential, and the middle Eocene Kusuri Formation has a limited hydrocarbon source rock potential. The basin has oil and gas seeps. Many large structures associated with extensional and compressional tectonics, which could be traps for hydrocarbon accumulations, exist. Fifteen onshore and three offshore exploration wells were drilled in the central Black Sea Basin, but none of them had commercial quantities of hydrocarbons. The assessment of these drilling results suggests that many wells were drilled near the Ekinveren, Erikli, and Ballifaki thrusts, where structures are complex and oil and gas seeps are common. Many wells were not drilled deep enough to test the potential carbonate and clastic reservoirs of the Inalti and Çaǧlayan Formations because these intervals are locally buried by as much as 5 km (3 mi) of sedimentary and volcanic rocks. No wells have tested prospective structures in the north and east where the prospective Inalti and Çaǧlayan Formations are not as deeply buried. Untested hydrocarbons may exist in this area. ©2013. The American Association of Petroleum Geologists. All rights reserved.
... The Sinop Basin was filled with Pliocene and Quaternary sediments that lie in harmony with the basement (Meredith and Egan 2002). Rangin et al. (2002) suggested that the Sinop Basin was formed with relation to the recent movements of the North Anatolian Fault. Based on the interpretation of high-resolution seismic data, Dondurur and Çifçi (2007) pointed out that the tectonic situation of the upper and middle continental slope of the Central Black Sea basin is controlled by the Archangelsky Ridge. ...
... These were interpreted as the discontinuity boundaries of other units dominating the region. On the other hand, they have been shown by many researchers in seismic sections and tectonic sections obtained as a result of basin modeling (Meredith and Egan 2002;Rangin et al. 2002;Finetti et al. 1988;Cloetingh et al. 2003;Robinson et al. 1995Robinson et al. , 1996Dondurur and Çifçi 2007). Maden and Dondurur (2012) found the depth of the Cretaceous sedimentary basin in Sinop Graben as approximately 4 km. ...
To investigate the crustal structure of the Archangelsky Ridge, gravity data obtained from the World Gravity Map (WGM2012) were analyzed using Total Horizontal Derivative (THD), Parker-Oldenburg (PO) inversion and Normalized Full Gradient (NFG) techniques. The THD method was applied to the Bouguer gravity after band-pass filtering in order to image the discontinuities. The maximum amplitude values of the THD were used to reveal the discontinuities caused by the density difference in the Archangelsky Ridge and its vicinity. In addition, the basement upper surface topography of the region was calculated and mapped with the inverse solution. Moreover, the presence of an uplift area in the northeast of the study area, as well as the elevation of the Archangelsky Ridge was determined. The depth to the Cretaceous aged sedimentary basement in the Sinop basin and on the Archangelsky Ridge approximately reaches 4 km and 1.6 km, respectively. The average upper surface depth of the basement is calculated as 5 km under the Eastern Black Sea Basin (EBSB). Finally, depth calculations were made using NFG method for the selected profiles and correlated with gravity inversion results. The depth results of the basement upper surface topography obtained from NFG and inversion methods are compatible with each other within ± 0.1 km error limits.
... For example, minor counterclockwise rotation and eastward drift of the Mid-Black Sea (Andrussov-Arkhangelsky) ridge with thrusts at the toe of its NE flank (Rangin et al., 2002) could represent equal to the Apennines chain relative motion, and well-known manifestations of strike-slip tectonics in the Pyrenees can be scalably observed in the Dobrogea and the NW shelf and Crimea. It should be mentioning also the important role of the Late Cimmerian tectonism and Late Variscan tectonic lines as well in controlling the Alpine structural style and evolution of the NW shelf. ...
... Structure of the Mid-Black Sea ridge and East Black sea basin (Rangin et al., 2002) vs. Apennines alochthonous and Bradanic foredeep (Benetatos et al., 2015). Analyzing the role of strike-slip tectonics for the origin of fault-and-fold pattern of the structural units tracing from Romanian offshore to the Plain Crimea and comparing their essential details with its equivalents from the Pyrenees and surrounding areas it has been found many direct analogies that testify an existence of similar driving mechanisms and topological constraints for structural anatomy of these regions. ...
An analysis of comparative tectonic evolution of two entailing regions of the Alpine belt - Black Sea and Western Mediterranean - reveals profound analogies and homologues in their structure and development. Though both back-arc basins under comparison have many distinctions and differ each from other due to their linear dimensions (nearly twofold), a certain time shift for the lithological spectra during some epochs, present state of volcanic activity etc., they, nevertheless, reveal a striking morphological coincidence and notable genetic analogy in their spatial, kinematic, undercrustal, palaeogeographic, and other features. The above comparison allows consideration of the circum-Black Sea region as a minor and simplified tectonic copy of the Western Mediterranean area being evolved in similar way and caused by similar tailoring of its structural units that stipulated by uniform stress/fault pattern inherited from the MesoTethys tectonic realm demonstrating kind of self-similarity or crustal scaling effect. Two prominent mega-sutures, the Teisseyre-Tornquist Zone and South Armorican Shear zone, represent axial alignments along which a distorted symmetry could be traced for both basins under comparison. The above similarities can help elaborate new trends for oil and gas exploration in the circum-Black Sea basin using geological knowledge on the Western Mediterranean and vice versa.
... The Black Sea is a semi-isolated extensional basin surrounded by thrust belts and is considered to be a Mesozoic-Early Cenozoic marginal back-arc basin generated by the northwards subducting Tethys Ocean (e.g., Zonenshain & Le Pichon 1986;Rangin et al. 2002). The Black Sea basin comprises western and eastern Black Sea subbasins, which are separated by a regional high, the Mid Black Sea Ridge, which is divided into two parts, the Andrusov Ridge in the north and the Archangelsky Ridge in the south (Figure 1). ...
... The Cretaceous sequence is about 700 m thick on the ridge and is extensively affected by normal fault systems in the deeper parts of the sedimentary sequence, i.e. in the northern and southern flanks of the Archangelsky Ridge (Meredith & Egan 2002). The Sinop Basin is located between the Archangelsky Ridge and the Turkish coastline ( Figure 1) and has been affected by late Miocene normal faults along the Turkish margin and the Archangelsky Ridge (Rangin et al. 2002). The shelf break is located at a water depth of about 300 m. ...
Some strong reflections about 3 to 5 m thick were observed at depths of 25-60 metres below the sea floor using deep-towed, 5 kHz subbottom profiler data in the Turkish shelf and upper slope of the Eastern Black Sea at water depths of 250 to 700 m. Strong reflections of this kind are generally attributed to shallow and localized gas accumulations. We, however, observed that the reflection polarity of these strong reflections was positive, suggesting that they do not correspond to reflections from the upper boundary of a possible gas front. In this study, we evaluate these reflections to determine if they represent hydrogen sulphide-rich shallow gas hydrate layers, which would be an unusual gas hydrate occurrence in a shallow marine environment. The existence of gas hydrate formations in thermobaric conditions, as in our study area (shallower water depths and relatively higher temperatures), depends completely on the gas composition in the hydrate structure; it is possible for gas hydrates to be stable only if they are formed by a certain amount of hydrogen sulfide together with methane. We closely examined the hydrogen sulphide potential of the area and found that the maximum total hydrogen sulfide concentration in the surficial sediments in the area was, at 5550 ppm, enough to produce hydrogen sulphide-rich gas hydrates. Using geoacoustic and geochemical data, we propose a conceptual model for the formation of shallow hydrogen sulfide-rich gas hydrates. According to this model, conjectural gas hydrate layers in the area should be formed along the boundary between a sulphate-reducing zone and an underlying carbonate reducing zone, where methane comes into contact with hydrogen sulphide. We also propose that the strongly reflective appearance of these layers on the subbottom profiler data indicates that the hydrate zone consists of a number of gas hydrate sheets with a decreasing thickness towards the seabed, interbedded with non-hydrate-bearing sediments.
... The southern shore of the Black Sea region is a suture zone, where closely related species meet and hybridize following post-glacial range expansion (Bilgin, 2011), including other amphibians, like banded newts in genus Ommatotriton Kalaentzis et al., 2023). Additionally, the studied region is a central unit of the eastern Pontides (Yilmaz et al., 2000;Rangin et al., 2002). This region, including Artvin and Rize provinces, is also a crossing point between populations from Anatolian and Caucasian refugia. ...
Hybrid zones are geographic areas where individuals from distinct taxa meet, mate, and hybridize. These zones may have complex histories, but many of them originated relatively recently, during climatic oscillations in the Quaternary, following range shifts of formerly isolated, well-differentiated lineages. The Bufo bufo species group comprises four species distributed over the Western Palearctic. Whereas the contact zone between Bufo bufo and B. spinosus in western Europe has been well characterized, little is known about other species contacts. Here we focused on the contact between B. verrucosissimus and B. bufo in northeastern Türkiye, using mtDNA and microsatellite markers to describe genetic structure and patterns of admixture in the hybrid zone based on Bayesian clustering and cline analyses. Both species meet in a narrow contact zone at Rize province, with restricted introgression suggesting barriers to hybridization consistent with species status. Spatial population genetic analyses of microsatellite data pinpoint a possible enclave population of B. bufo at the Borçka district in Artvin province, isolated within the B. verrucosissimus range. The centers of the microsatellite and mtDNA-based clines are slightly displaced, with B. verrucosissimus mtDNA introgressing about 33 km W of the nuclear contact. Hybrid zone dynamics seem to be associated with range shifts mediated by Pleistocene glacial cycles and/or sex-biased dispersal.
... Possible modification of the model of Okay et al. [1994]. Almost every publication on the tectonic structure of the Black Fig. 4. Pull-apart structures in the dextral shear OSO zone: 1 -faults (a -first rank, b -branch); 2 -over thrust [Rangin et al., 2002]; 3-5 -NAF position (3 - [Gürbüz, 2010], 4 - [Meijers et al., 2010a], 5 - [Eyuboglu et al., 2012]); 6 -derived from Bouguer gravity anomaly map of Turkey [Ates et al., 2012]; 7 -zones of Late Cretaceous volcanism ; 8 -positive magnetic anomalies; 9 -pull-apart structures; 10 -Andrusov Ridge; 11 -boundary of supposed West Black Sea rift; 12 -borders of subbasins. Sea mentions that it consists of two subbasins separated by the MBSH, which includes the Andrusov and Arkhangelsky ridges. ...
We present an integrated analysis of the geophysical parameters of the lithosphere of Black Sea basin obtained as a result of the interpretation of magnetic, gravity, thermal, deep seismic sounding and seismic-tomographic data. It first demonstrates inherent significant differences in geophysical parameters of lithosphere in the Western and Eastern Black Sea subbasins existing from the prerift stage. The set of reviewed parameters responsible for formation of the present-day lithosphere includes types of crust, depths to acoustic basement, configuration of subbasins, depths to Moho, heat flow and relief of the thermal-asthenosphere boundary (LAB), trends of main deep faults of the crystalline crust, their kinematic types, occurring linear magnetic anomalies, velocity pattern of subcrustal mantle. The above-mentioned parameters of the lithosphere are indicators of the age, geodynamics and driving mechanisms for opening of a subbasins. Oblique trends of the subbasins and the topography of Moho discontinuity in the west and east domains, oblique striking of pre-rifting Istanbul zone and the Shatsky Ridge and different trends of deep faults in the crystalline crust suggest distinct lithospheric structure existing from pre-opening of the Black Sea subbasins and different geodynamical conditions of its formation. The Odesa-Sinop-Ordu deep fault zone as a direct continuation of the Golovanivskaya suture zone of the Ukrainian shield and its slope, probably is of the Precambrian age. So it could be the tectonic boundary between two segments of pre-rift continental crust and between future subbasins. The examples illustrate how indicated parameters of the lithosphere can geophysically confirm the basic ideas of available models for geodynamics of the Black Sea.
... This uncertainty in the time of rifting is due to the anomalously thick sediments (~8-14 km) infilling the basin, preventing a study of the deeper parts of this succession and basement from drilling as well as limiting seismic imaging without reliable age calibration (e.g. Finetti et al., 1988;Rangin et al., 2002;Shillington et al., 2008;Nikishin et al., 2015a;Nikishin et al., 2015b;Sydorenko et al., 2017;Tari and Simmons, 2018). It is likely that rifting of the Black Sea basin was probably diachronous, and thus the Western and Eastern Black Sea basins probably have a different geodynamic history (e.g. ...
Resolving the time of rifting of the Black Sea basin is critical to reconstructing the tectonic evolution of the Pontides arc in northern Turkey. U–Pb geochronology of detrital zircons from Middle Jurassic, Upper Cretaceous, and lower Eocene formations in the Eastern Pontides (NE Turkey), as well as published data from circum-Black Sea terranes, reveals that sediments preserved along with the northern (East European Craton-Scythian Platform) and southern (Eastern and Central Pontides-southern flank of the Greater Caucasus-Transcaucasus) margins of the Eastern Black Sea basin display distinct detrital provenances. The U–Pb detrital zircon ages of the sedimentary samples from the Eastern Pontides have distinct populations with ages of ∼650–540, ∼200, ∼170, ∼80, and ∼50 Ma. In contrast, the ages of the sedimentary samples from the northern Black Sea terranes are characterized by age peaks of ∼1400 and ∼1100 Ma compared to those of the Eastern Pontides. Only a few detrital zircons in the range of ∼650–540 Ma and <200 Ma are identified in the sedimentary samples from the northern Black Sea terranes. This contrast in detrital zircon ages, together with modal analysis of the samples and published paleocurrent data, suggests that Middle Jurassic–lower Eocene sedimentary samples in the Eastern Pontides were locally sourced from Gondwana affinity crustal basement rocks and associated Mesozoic–Cenozoic igneous rocks. Furthermore, there was no exchange of detritus across the Eastern Black Sea basin during the Middle Jurassic–early Eocene. These inferences require the Eastern Black Sea basin to have rifted in a back-arc setting behind the Eastern Pontides arc by the Middle Jurassic or survived as a relict basin of the Paleotethys.
... Bu faylardan yaklaşık 1000 km uzunluğunda olan Kuzey Anadolu Fay hattı ve yaklaşık 400 km uzunluğunda olan Doğu Anadolu Fay hattı ülkeyi doğu-batı ve güneydoğu-kuzeydoğu ekseninde çevrelemektedir [1]. Şekil 1'de Türkiye'deki önemli fayları ve Türkiye sınırlarındaki plakları gösteren harita verilmiştir [2]. Bu faylar üzerinde önemli aktif tektonik hareketler tarih boyunca ülkemizde önemli depremler meydana getirmiştir. ...
Günümüzde inşaat alanında meydana gelen teknolojik gelişmeleri uygulamada aktif ve doğru bir şekilde kullanabilmek için ülkemizde 2007 yılında yürürlüğe giren ‘Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik’ yerini 1 Ocak 2019 tarihi itibariyle ‘Türkiye Bina Deprem Yönetmeliği’ne bırakmıştır. Türkiye sınırları içerisinde yoğun olarak aktif tektonik faylar bulunmasından dolayı depreme dayanıklı yapı tasarımı büyük önem arz etmektedir. Depreme karşı tasarımda yapılara etkiyecek deprem yüklerinin tespitinde tasarım ivme spektrumları kullanılmaktadır. Bu çalışmanın amacı, 2007 Türk deprem yönetmeliğinden 2018 Türk deprem yönetmeliğine geçilirken meydana gelen deprem hesap esaslarındaki değişimin incelenmesidir. Bu çalışmada 2007 Türk deprem yönetmeliğine göre iki farklı deprem bölgesinde yer alan Bingöl ve Elazığ il şehir merkezlerinin, 2007 ve 2018 Türk deprem yönetmeliklerine göre ivme spektrumları karşılaştırılmıştır. Çalışma kapsamında ele alınan bölgeler için farklı deprem yer hareket düzeylerine göre ivme spektrumlarının, köşe periyotlarının, koordinata dayalı spektrum katsayılarının farklı zemin sınıflarına göre değişimi irdelenmiştir. 2007 deprem yönetmeliği ile 2018 deprem yönetmeliği karşılaştırıldığında, 2007 deprem yönetmeliğinde ivme spektrumları bölgesel olarak farklılık göstermez iken, 2018 yönetmeliğinde Afet ve Acil Durum Başkanlığı’nın oluşturduğu Türkiye Deprem Tehlike Haritalarından alınan ivme parametrelerinin koordinat odaklı değişimi bölgesel bir farklılık göstermesinden kaynaklı olarak ivme spektrumlarında farklılıklar meydana geldiği görülmüştür. Deprem tasarım esaslarında koordinata bağlı çalışan 2018 Türk deprem yönetmeliğinde ivme spektrumları kullanılacağı konumuna göre değişiklik göstermektedir. 2007 Türk deprem yönetmeliğinde ise ivme spektrumları konuma göre değişiklik göstermemektedir. Bu nedenle deprem tasarım esasları açısından, 2018 Türk deprem yönetmeliğindeki ivme değerlerinin, 2007 Türk deprem yönetmeliğindeki sabit ivme değerlerine kıyasla ekonomik ve emniyetli bir durum gösterdiği söylenebilir.
... In this triangle, Bingöl province is limited to the Erzincan pull-apart basin along the North Anatolian Fault in the north, and on the south to the rising Gökdere elevation in the compression jump zone between the Eastern Anatolian Fault and Palu-Bingöl. In the East-West direction, the effective section of Fig. 3 shows the tectonic map and study area of Bingol (Rangin et al. 2002). ...
Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and
the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic
seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It
occurred since 1900; the seismicity of the region was obtained statistically by considering the
earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study,
magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time
periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may
affect the peak ground acceleration according to various attenuation relationships are calculated and
using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were
determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a
probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that
the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5,
7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability
of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03g, 0.58g
and 0.24g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is
high and the importance of considering the earthquake effect during construction is emphasized for this
region.
... The Black Sea is a marginal sea located at Alpine orogenic belt, and surrounded by the compacted tectonic belts, the Pontides orogeny in the south, the Caucasus in the north, and the Crimean Territory in the north (Günay et al,2003). It is located on the western side of the active Arabia-Eurasian conflict and North Anatolian Fault (KAF), which allows tectonic to escape from Anatolia (Rangin et al., 2002). The Black Sea consists of two main expansion basins, these are western and eastern Black Sea lower basins (Figure 1). ...
In this study, Cellular Neural Network (CNN) method is applied to the magnetic anomaly map of Black Sea. It is compared with the structure boundaries and tectonic structure of the Black Sea and surrounding region. Thus, the tectonic structure of the zone is tried to be clarify by the tectonic information with the CNN output of the magnetic anomaly map.
... The sediment cover above these ridges has been described by extensive academic and industry seismic reflection data (e.g. Belousov et al. 1988;Robinson et al. 1996;Rangin et al. 2002;Nikishin et al. 2015a, b), crustal-scale wide-angle seismic data (e.g. Edwards et al. 2009;Shillington et al. 2017), regional potential field data (e.g. ...
The Rioni Basin is an underexplored petroliferous basin located at the Georgian margin of the Black Sea flanked by two folded belts (the Greater Caucasus and the Achara-Trialet Belt). Whereas the stratigraphy of the northern onshore Rioni Basin has elements which are common with that of the offshore Shatsky Ridge, the southern onshore Rioni Basin segment is both stratigraphically and structurally akin to the offshore Gurian folded belt in the eastern Black Sea. In the northern basin segment, the existing oil fields (East and West Chaladidi) and an undeveloped oil discovery (Okumi) are related to either post-salt or pre-salt antiformal traps in detachment folds or in poorly understood stratigraphic pinchouts beneath a regional Upper Jurassic evaporite sequence. In the southern Rioni Basin, the oil in existing fields has either anticlinal four-way closures (Supsa) or a subthrust trap (Shromisubani) related to the leading edge of the north-vergent Achara-Trialet folded belt. Despite the long history of petroleum exploration in the Rioni Basin, these proven plays are not fully understood and systematically explored using modern technology. The existence of an Upper Jurassic regional evaporite seal highlights the possibility of pre-salt plays in the northern part of the basin.
... The prominent NW-SE structural trend of syn-rift highs in the centre of the basin was long known (e.g. Tugolesov et al. 1985;Finetti et al. 1988;Robinson et al. 1996;Rangin et al. 2002) as a potential exploration trend. Therefore, a joint venture between Petrobras, TPAO and ExxonMobil spudded the Sinop-1 well in February 2010 in a water depth of 2182 m, practically at the basin floor of the Black Sea (Fig. 6). ...
Deepwater hydrocarbon exploration drilling only began in the Black Sea less than 20 years ago, primarily because of the economical/technological challenges associated with mobilizing suitable rigs through the Bosporus. However, to date (end 2017), c. 20 deepwater wells have now been drilled, targeting a large variety of plays in this underexplored basin. The deepwater wells drilled to date are categorized by their main play objectives, within either the sag/post-rift or syn-rift basin fill of the Black Sea. The sag/post-rift play types have proven to be more successful, finding either biogenic gas in Miocene to Pliocene reservoirs associated with the Paleo-Danube and Paleo-Dnieper/Dniester or oil in Oligocene deepwater siliciclastic systems. Syn-rift or early postrift plays, in contrast, assumed mostly shallow water carbonate reservoir targets. Only one well targeted pre-rift stratigraphy. Most of the exploration failures to date are directly related to the lack of reservoir at the targeted stratigraphic levels. However, the recent discoveries have underlined the presence of at least two active and effective petroleum systems that cover large parts of the deepwater Black Sea Basin.
... The nature of the entire PE is not well known, but it appears to be a reverse fault zone that controls morphologically the southern continental slope of the Black Sea. It constitutes a western continuation of the Lesser Caucasus thrust in the Eastern Black Sea basin, having wellknown recent seismic activity (Zonenshain and Le Pichon 1986;Robinson et al. 1996;Okay and Ş ahintürk 1997;Rangin et al. 2002). We assumed that the PE is a compressional tectonic structure bounding Pontide terrain uplifted from Late Eocene to Recent. ...
GIRIŞ
Türkiye Alp-Himalaya Sıradağı içinde Doğu Akdeniz bölgesinde bulunur. Batı Avrupa’dan Asya’ya yaklaşık 9 bin km uzunluktaki bu sıradağın oluşumu günümüzde de devam etmektedir. Bu oluşum sırasında meydana gelen tektonik olaylar nedeniyle Alp-Himalaya Sıradağı dünyanın en aktif deprem kuşaklarından birisidir. Türkiye’nin sismotektonik özellikleri içinde bulunduğu Doğu Akdeniz bölgesindeki güncel levha tektoniğiyle doğrudan ilişkilidir. Bu bölgede dünya ölçeğindeki litosferik levhalar birbiriyle etkileşim içinde bulunurlar.
Bunlardan Arabistan ve Avrasya levhalarının çarpışması sonucu ortaya çıkan Anadolu levhası etrafında veya içinde meydana gelen tektonik deformasyonlar ve bunların neden olduğu deprem etkinliği Türkiye’nin sismotektoniğini doğrudan kontrol etmektedir.
Anadolu levhası Doğu Akdeniz bölgesinde devam eden levha kinematiği içinde saatin tersi yönünde dönerek batıya doğru hareket eder ve litosferik Afrika levhası üzerine itilir. Bu tektonik süreçte meydana gelen deformasyonların çoğunluğu Anadolu levhasını kuzey ve güneyden sınırlayan levha içi transform fayları tarafından karşılanır. Bu transform faylar, sırasıyla, Kuzey Anadolu Fayı (KAF) ve Doğu Anadolu Fayı (DAF) olarak adlandırılır. Diğer taraftan Akdeniz’de Anadolu ile Afrika levhaları arasındaki yitimi karşılayan Ege ve Kıbrıs yayları ile Afrika ve Arabistan levhaları arasında transform sınır oluşturan Ölü Deniz Fay (ÖDF) zonu bölgenin diğer deprem kaynağı olan devasa yapısal unsurlardır.
Türkiye ve yakın çevresinde tarihsel ve aletsel dönemlerde çok sayıda deprem kayıt altına alınmıştır. Anadolu’da 1900 öncesi tarihsel dönemde 200’den fazla yıkıcı depremin meydana geldiği ve bazı medeniyetleri ciddi şekilde etkilediği, hatta yıkılmalarına neden olduğu bilinmektedir. Benzer şekilde aletsel dönemde 1900-2012 yılları arasında Türkiye ve yakın çevresinde 203 büyük deprem (Mw ≥ 6,0) kaydedilmiştir. Bu depremler bölgede 90 binden fazla kişinin ölümüne neden olmuş, ülke ekonomisini etkileyecek düzeyde 50 milyar dolardan fazla zarara yol açmıştır. Bu afetlerin toplum üzerinde yaratmış olduğu psiko-sosyolojik etki ise çok daha büyük ve ölçülemeyecek boyuttadır.
2009 yılında Afet ve Acil Durum Yönetimi Başkanlığı’nın kurulması ülkede meydana gelen doğa-afetlerinin etkisini azaltma konusunda yeni bir yapılanmayı, mevcut politika ve planların gözden geçirilmesi gerekliliğini de beraberinde getirmiştir. Bu bağlamda önceki ulusal planların deneyimi ışığında yeni bir Ulusal Deprem Stratejisi ve Eylem Planı (UDSEP-2023) oluşturulmuştur. UDSEP-2023 planı 2011 yılında Afet Yüksek Heyeti tarafından imzalanmış ve ülkede deprem zararlarının azaltılması çalışmalarında izlenecek resmi bir belge niteliğini kazanmıştır. UDSEP-2023’te deprem afeti nedeniyle meydana gelen kayıp ve zararların azaltılmasında gerek duyulan bilgi alt yapısının oluşturulması için deprem kaynağı diri fayların yeniden değerlendirilmesinden bunların neden olabilecekleri tehlikenin tanımlanmasına uzanan bir dizi araştırma başlatılmıştır. Deprem jeolojisi ve sismoloji konularında başlatılan bu araştırmalar; Türkiye diri fay, sismotektonik ve deprem tehlike haritalarının hazırlanması, ülke genelindeki diri faylarda paleosismolojik araştırmaların tamamlanması, depremle tetiklenen sıvılaşma ve tsunami konularında temel bilgi altyapısının oluşturulması için araştırmaların yapılması olarak sıralanabilir.
Sismik tehlike değerlendirmeleri depreme dayanıklı tasarım politikaları, risk analizleri ve arazi kullanım planlamaları için vazgeçilmezdir. Bu değerlendirmelerin temel aşaması olan sismik tehlike haritalarının hazırlanabilmesi için yeni teknoloji ve bilgi birikimine dayalı hazırlanmış veya güncellenmiş sismotektonik bilgi alt yapısını gerektirmektedir.
Sismotektonik harita ve ilgili veri tabanı deprem tehlike analizlerinde gerekli jeolojik ve sismolojik bilgileri sağlar. Bunlarla birlikte çok disiplinli bir yaklaşım gerektiren deprem tehlike analizlerinin başarısını arttırmak amacıyla, bu harita veya veri tabanlarına diğer jeofizik, jeodezik ve benzeri her türlü bilgi de eklenmektedir. Türkiye için sismik tehlike modelleri öneren çalışmalar sınırlıdır (Yarar vd., 1980; Erdik ve Öner, 1982; Erdik vd., 1982, 1985, 1999; Kayabalı, 2002). Son yıllarda sismik tehlike durumunu Avrupa boyutunda ele alan SHARE projesi (Woessner vd., 2015) ve Orta Doğu bölgesinin sismik tehlikesini araştıran EMME projesi (http://www.emme-gem.org/) ortak ülke olarak bulunduğumuz bölgesel ölçekte yapılan sismik tehlike çalışmalarına örnek olarak gösterilebilir.
Bu araştırmada ulusal bir katılımla hazırlanan Türkiye Sismotektonik Haritası ve Veri Tabanı tanıtılmaktadır. Türkiye sismotektonik veri tabanı oluşturulması ve ilgili haritaların hazırlanması UDSEP-2023 kapsamında Maden Tetkik ve Arama (MTA) Genel Müdürlüğü sorumluğunda gerçekleştirilmiştir. Projede Afet ve Acil Durum Yönetimi Başkanlığı (AFAD), Kandilli Rasathanesi ve Deprem Araştırma Enstitüsü (KRDAE) ve Harita Genel Komutanlığı (HGK) kurumsal ortaklar olarak katkı koymuşlardır. Ayrıca üniversitelerden konularında uzman araştırıcılar projeye kişisel katılımlarla katkı koymuşlardır. Proje kapsamında hazırlanan veri tabanı jeolojik, jeofizik, sismolojik ve jeodezik bilgilerden oluşan beş veri grubunu kapsar. Bunlar diri faylar, aletsel ve tarihsel deprem katalogları, moment tensör kataloğu ve kabuk kalınlığı bilgileridir. Bu veri tabanı kullanılarak 18 paftadan oluşan 1:500.000 ölçekli Türkiye Sismotektonik Haritası hazırlanmıştır. Bunların dışında 1:1.250.000 ölçekli ülkenin tamamını bir bütün olarak gösteren Türkiye Sismotektonik Haritası da hazırlanmıştır. Türkiye sismotektonik haritası ve ilgili veri tabanı ülkede sismik tehlike analizlerinde gerekli bilgileri sağlamaktadır. CBS ortamında hazırlanmış olan bu veri tabanı sistematik veri eklenebilir ve yenilenebilir bir bilgi altyapısıdır.
... See Fig. 1 for other symbols. Fig. 8. Pull-apart structures in the dextral shear OSO zone: 1 faults (a the first rank, b accompanying; 2 overthrust faults [Rangin et al., 2002]; 35 NAF position (3 [Gürbüz, 2010], 4 [Meijers et al., 2010], 5 [Eyuboglu et al., 2012]); 6 derived from Bouguer gravity anomaly map of Turkey [Ates et al., 1999]; 7 zones of Late Cretaceous volcanism , 8 positive magnetic anomalies; 9 pull-apart structures; 10 Andrusov Ridge; 11 borders of sub-basins. ...
The results of the international "Geology without Limits" project unequivocally confirmed the faults pattern in the crystalline crust of the Black Sea delineated from gravity and magnetic data. The locations of 135 from among ca. 150 faults on its surface derived from the seismic sections of this project completely coincide with those of the present study used. For the first time, we introduced clear evidence for the decisive role of the crystalline crust faults in the opening of the Black Sea. The long-lived Odessa-Sinop (OS) fault zone of the Precambrian origin was of prime importance for this process. It separated the рге-rift continental crust into two blocks with a different geological structure definitely recognized by an integrated geophysical analysis. The West Black Sea and East Black Sea Basins opened by two distinct mechanisms. The western basin, except its eastern part, opened behind a continental fragment that orthogonally rifted and moved towards the southeast along two parallel deep fault zones: the sinistral OS (together with the West Crimean — Pontides) and dextral Balkanides — Pontides (BP) faults. The rest of the Black Sea Basin has originated through the anticlockwise rotating of a large continental block that produced the breaking of the EBSB rift and forming Odessa-Sinop-Ordu (OSO) fault zone. The dextral strike-slip faults in this zone caused the opening of eight local pull-apart basins in the southeastern West Black Sea Basin. The OS fault system, as a long-term feature appears to control the strikes of the Western and Eastern Pontides and the present-day obliquity between the main rift axes of the Black Sea sub-basins. The direct southeastern prolongation of the OS fault forms the western boundary of the pre-Cretaceous strata of the Eastern Pontides.
... The nature of the entire PE is not well known, but it appears to be a reverse fault zone that controls morphologically the southern continental slope of the Black Sea. It constitutes a western continuation of the Lesser Caucasus thrust in the Eastern Black Sea basin, having wellknown recent seismic activity (Zonenshain and Le Pichon 1986;Robinson et al. 1996;Okay and Ş ahintürk 1997;Rangin et al. 2002). We assumed that the PE is a compressional tectonic structure bounding Pontide terrain uplifted from Late Eocene to Recent. ...
Turkey is located in one of the most seismically active regions in the world. Characterizing seismic source zones in this region requires evaluation and integration of geological, geophysical, seismological and geodetical data. This first seismotectonic database for Turkey presented herein was prepared, under the framework of the National Earthquake Strategy and Action Plan—2023. The geographic information system (GIS)-based database includes maps of active faults, catalogues of instrumental and historical earthquakes, moment tensor solutions and data on crustal thickness. On the basis of these data, 18 major seismotectonic zones were delineated for Turkey and the surrounding region. The compilation and storage of the seismotectonic data sets in a digital GIS will allow analyses and systematic updates as new data accrete over time.
... The regional geological structure of the Black Sea has been under investigation since the 1980s, when regional seismic lines for the entire area were published (Tugolesov et al. 1985;Finetti et al. 1988;Belousov & Volvovsky 1989). More recent seismic data acquired in the EBS and adjacent areas have been published by Robinson et al. (1996), Afanasenkov et al. (2007), Shillington et al. (2008), Rangin et al. (2002), Khriachtchevskaia et al. (2010), Stovba et al. (2009), Nikishin et al. (2010), Mityukov et al. (2012), Almendinger et al. (2011), TPAO/BP Eastern Black Sea Project Study Group (1997), Gozhyk et al. (2010) and Graham et al. (2013). A set of long regional deep seismic lines acquired in 2011 in the framework of the international project Geology Without Limits allowed a new map of the acoustic basement for the whole Black Sea to be proposed (e.g. ...
The margin of the northeastern Black Sea is formed by the Crimea and Kerch peninsulas, which separate it from the Azov Sea to the north. The age and architecture of the sedimentary successions in this area are described from exploration reflection seismic profiling acquired in the area, in addition to the regional DOBRE-2 CDP profile acquired in 2007. The sediments range in age from Mesozoic to Quaternary and can be divided into five seismo-stratigraphic complexes linked to the tectono-sedimentological evolution of the area. The present regional basin architecture consists of a series of basement structural highs separating a series of sedimentary depocentres and is mainly a consequence of the compressional tectonic regime affecting the area since the Eocene. This has focused shortening deformation and uplift along the axis of the Crimea–Caucasus Inversion Zone on the Kerch Peninsula and Kerch Shelf of the Black Sea. Two major sedimentary basins that mainly formed during this time – the Sorokin Trough in the Black Sea and the Indolo-Kuban Trough to the north of the Kerch Peninsula in the Azov Sea – formed as marginal troughs to the main inversion zone.
... The prominent NW-SE structural trend of syn-rift highs in the centre of the basin was long known (e.g. Tugolesov et al. 1985;Finetti et al. 1988;Robinson et al. 1996;Rangin et al. 2002) as a potential exploration trend. Therefore, a joint venture between Petrobras, TPAO and ExxonMobil spudded the Sinop-1 well in February 2010 in a water depth of 2182 m, practically at the basin floor of the Black Sea (Fig. 6). ...
The numerous, mostly untested deepwater Black Sea play types can be subdivided into syn-rift and post-rift plays. The largest targets are synrift fault blocks, such as the Andrusov and Tetyaev highs in Turkey and Ukraine, respectively. Although their internal stratigraphy is poorly constrained (i.e. proportion of pre-rift and syn-rift versus basement) translating to not only reservoir risk but also to reservoir quality risk, the trap sizes are very large. Also, the assumed lateral charge from the Miocene-Oligocene Maikop Formation and perhaps even from Eocene sources makes these structures extremely attractive. The overall structure of the Shatsky Ridge is not as clear as it has elements of an extremely large carbonate platform on top. The Polshkov High is unique in the sense that it represents a large rotated syn-rift fault block along the lower plate edge of the Western Black Sea in Bulgaria. On the conjugate upper plate margin, very large inverted syn-rift structures, such as the Kozlu Anticline, are recognized in the Turkish sector.
On top of most of the syn-rift highs described above, various typical carbonate geometries can be interpreted on seismic data such as backreef pinnacles, lowstand buildups, raised rims, backstepping, aggradation and prograding clinoforms. These syn-rift to post-rift carbonate platforms tend to grow on footwall blocks of syn-rift faults and can reach more than 800 meters in thickness. The age of these carbonate features is poorly constrained at present as to the exact opening age of the Black Sea basins, i.e. anywhere between Jurassic to Eocene.
Several intra-Tertiary reservoirs could be targeted in the compactional anticlines above the large syn-rift highs. Another play associated with Tertiary sands is that of the deepwater extension of the Subbotina discovery in Ukraine. The Subbotina structure is a compressional anticline situated in a dominantly Miocene, south-vergent folded belt offshore Kerch Peninsula. Similar folded belts are also known in the Russian, Georgian, Turkish and Bulgarian sectors of the Black Sea. Also, pure stratigraphic traps may exist in a widely recognized Eocene low-stand wedge along the basin margins. However, reservoir quality is a definite risk for the Tertiary reservoir intervals in certain segments of the Black Sea as the function of the provenance area(s).
... The interpretation is consistent with the paleomagnetic data of Bazhenov and Burtman (2002), supporting the oroclinal bending model in the LC. Based on numerous geological studies in the investigation area, it was accepted that the northwards subduction and the finally consumption of the northern branch of Neotethys ocean led to collision of the EP to the north with the Taurus Platform to the south during the Paleocene-Eocene (Ş engör and Yılmaz, 1981;Okay and Ş ahintürk, 1997;Okay and Tüysüz, 1999;Rangin et al., 2002;Boztug, 2009). The later collision which occurred between the Arabian platform and the Taurides during the Oligocene was marked by the stepwise consumption of the southern branch of the Neotethys (Ş engör and Yılmaz, 1981;Robertson and Dixon, 1984;Yılmaz, 1993;Robertson et al., 2007) (Fig. 14a). ...
Palaeomagnetic studies of the Neogene–Quaternary rocks of Anatolia have been mostly interpreted in the light of its westward escape as a result of the collision between the Arabian and Eurasian plates along the Bitlis–Zağros suture during the Neotectonic period. However, within the collision zone, in East Anatolia, palaeomagnetic data are not available. In order to help understand the deformational history of Eastern Anatolia during the Neotectonic period, we have carried out a palaeomagnetic study of Miocene–Quaternary volcanic rocks from 100 sites, selected on the basis of their geographical position and known age. The results indicate that the study area can be divided into five principal tectonic blocks, based on earthquake activity and the rotation that the blocks underwent. These blocks are the Van Block (VB), the Kars Block (KB), the Anatolian Block (AB), the Pontide Block (PB), and the Arabian Block (ARB). The largest counterclockwise (CCW) tectonic rotations were encountered in the AB and PB, whereas the largest clockwise (CW) rotations were recorded in the VB. The sinistral East Anatolian Fault and the Erzurum Fault Zone form the present boundary of these two contrasting, CW and CCW-rotating domains. Both the AB and the PB exhibit similar amount of rotation until the Quaternary, during which the AB rotated 13° CCW while the PB remained stable. The Quaternary rotation of the AB is attributed to the activity of the North Anatolian Fault. The KB shows the smallest amount of CW rotation during all of the time intervals studied. All of the blocks studied indicate an acceleration in the amount of rotations during the Quaternary, which was preceded by a period of relative tectonic stability during the Late Pliocene. Following the collision of the Arabian Plate with the Eurasian Plate during the Mid-Miocene, the crust was initially thickened by thrusting and folding. This was followed by lateral extrusion and differential rotation of the crustal blocks during Late Miocene–Pliocene in response to ongoing indentation of the Arabian Plate. Our data show that strike-slip faults that commonly separate wedge-shape crustal blocks are the most significant means of accommodating the tectonic escape and rotation of crustal blocks in East Anatolia. Delamination of the lower crust and the lithospheric mantle may have contributed to the deformation by thermally weakening the crust.
... The pre-existence of an oblique weak zone along an extensional graben favours the localization of deformation along the intermediate transfer zone (Fig. 6b). Its geometry points to the formation of large-scale triangle zones composed of thrusts that truncate the margins of the pre-existing graben (e.g., structure IV, Fig. 6e), which is compatible with the transitional area of the main Crimean thrust over the Mid Black Sea High (e.g., Finetti et al., 1988) and the geometry of the extensional structures (Archangelsky, Andrusov horsts and the Mid-Black Sea High, Fig. 10a, Rangin et al., 2002). ...
... Stratigraphic schemes for the Black Sea have already been presented in numerous publications (Tugolesov et al., 1985;Finetti et al., 1988;Robinson et al., 1996;Dinu et al., 2005;Afanasenkov et al., 2007;Shillington et al., 2008;Rangin et al., 2002;Khriachtchevskaia et al., 2009Khriachtchevskaia et al., , 2010Munteanu et al., 2011;Menlikli et al., 2009;Stovba et al., 2009;Tari et al., 2009;Stuart et al., 2011;Nikishin et al., 2009Nikishin et al., , 2010Nikishin et al., , 2012Mityukov et al., 2012;Almendinger et al., 2011;Georgiev, 2012; TPAO/BP Eastern Black Sea Project Study Group, 1997;Gozhik et al., 2010). Based on the interpretation of new seismic data, we are suggesting a revised stratigraphic scheme for the pre-Oligocene section. ...
A new lithostratigraphy scheme has been compiled for the Western Black Sea Basin and a new geological history scheme from Middle Jurassic till Neogene is suggested for the entire Black Sea Region. Continental rifting manifested itself from the Late Barremian to the Albian while the time of opening of the basins with oceanic crust was from Cenomanian till mid Santonian; origination of the Western and Eastern Black Sea Basins took place almost simultaneously. During Cenozoic time, numerous compressional and transpressional structures were formed in different part of the Black Sea Basins. It is shown that in Pleistocene-Quaternary time, turbidities, mass-transport deposits and leveed channels were being formed in the distal part of the Danube Delta.
Focal mechanism solutions of the earthquakes that occurred in the Black Sea in the last 100 years show that thrust and strike-slip faults are predominantly active in the region. One of these clusters is developing off the coast of Samsun where the submarine Sinop basin is located. In order to investigate the seismic sources of earthquakes in this area, 14 high-resolution multi-channel seismic sections and multi-beam bathymetric data were processed and evaluated. The oldest seismic stratigrafic units (U4) is referred to as coustic basement with wavy reflectors, while its top is marked by high ampitude reflection indicating an unconformity. This uniconformity is overlain by parallel or less parallel Unit 3 deposits. Upper surface of Unit 2 is marked by an erosional surface which is overlain by parallel reflector of Unit 1. Unit 1 is the youngest sediments and truncated by Yeşilırmak canyon. Three fault types of different ages were determined. The oldest fault could reach only top of unit 4 has been interpreted as inactive fault. Faults that border the Sinop basin and reach the sea floor by cutting all seismic units are considered in the active fault class. However, the faults that remain within Unit 1 and do not reach the seafloor are considered as faults that are coeval with sedimentation. According to these data, faulting in the Central/Eastern Pontide structural block should be reconsidered in the context of the seismic activity of the region and re-evaluated as an earthquake hazard that will pose a risk in the future.
The Black Sea is a sea among continents. The connection with oceans is being through the Turkish straits. The sea has a basin hydrological characteristic for the rivers falling inside it. These streams are Danube, Dnieper, Bug, Dniester, Don, Kuban, Rion, Çoruh, Kızılırmak, Yeşilırmak and Sakarya. The part of streams which is left in water track is the Black Sea. The Black Sea coast is divided among Ukraine, the Russian Federation, Georgia, Turkey, Bulgaria, and Romania. The countries like Turkey, Georgia, Russia, Ukraine, Belarus, Poland, Czech Republic, Germany, Italy, Swiss, Liechtenstein, Slovenia, Austria, Slovakia, Hungary, Croatia, Bosnia, Herzegovina, Serbia, Kosovo, Montenegro, Macedonia, Romania, Moldova, Bulgaria are taking place in this Black Sea. In terms of geopolitical theories this field has an extremely important strategic location. This study aimed to analyze the position of this area, its importance, human and physical characteristics.
Yeni yapılacak olan veya mevcut binaların güçlendirilmesinde deprem ivme hareketleri önemli bir rol oynamaktadır. Bu nedenle, modern deprem tasarım kodları, uygulama mühendislerine, farklı zemin sınıfları için standart tasarım davranış spektrumu sağlamaktadır. Bu çalışmada, yüksek depremselliğe sahip Kocaeli bölgesindeki EC8 ve TBDY tasarım davranış spektrumu uygulamaları değerlendirilmektedir. Bu amaçla, öncelikle Kocaeli bölgesinin depremselliği, 17 Ağustos 1999 (Kocaeli) depremini de dikkate alarak, sunulmuştur. İkinci olarak, bu iki kodun tasarım davranış spektrumları birbirleriyle ve dört farklı zemin sınıfında kaydedilen gerçek ivme hareketlerinin spektral davranış eğrileri ile karşılaştırılmıştır. Daha sonra iki betonarme bina modelleri davranış spektrum analizleri ile incelenmiştir. Geçmiş sismik hareketler göz önüne alındığında, bölgenin her zaman büyüklüğü 5.0'den büyük olan deprem olaylarına eğilimli olduğu görülmektedir. Ayrıca Kocaeli deprem ivme hareketlerinin zemin özelliklerine bağlı olarak değiştikleri gözlemlenmiştir. Bunun yanında, her iki deprem tasarım kodları da Kocaeli bölgesindeki her zemin sınıfında gerçek spektral değerlerini kapsayan tasarım davranış spektrumu sağlamaktadır. Bina analizlerinin sonuçları, EC8 tasarım tepki spektrumları ile elde edilen kesme kuvvetlerinin TBEC ve gerçek deprem spektral ivme değerlerinin kullanıldığı durumda elde edilen kesme kuvvetlerinden daha muhafazakar sonuçlar verdiği görülmektedir.
For the first time the monograph presents the results of the study the heterogeneity of the Earth's crust of Ukraine and adjacent regions based on detailed three-dimensional gravity models of separate tectonic structures and regions. They were calculated using the automated program complex GMT-Auto for the interpretation of potential fields. Essentially new information has been obtained on the detailed 3D distribution of unified density in the crustal blocks, the layers that compose them, and fault zones.
The density distribution schemes have been compiled for the entire crust at certain depths (surface of the basement, 10, 20, 30 km, Moho discontinuity). The thickness was determined for conditionally distinguished "granite", "diorite", "basalt" layers of the Earth's crust and crust-mantle mixture within the whole study region. Its values are graphically represented by isolines on the respective schematic maps. The granitic, granitic-diorite, dioritic and basaltoid types of the crust were identified that for the first time made it possible to delineate the areas of different composition in the present - day consolidated crust of the entire study region.
For specialists who study the deep structure of the lithosphere, as well as graduate students and students of geological faculties of higher education.
Several models exist concerning the deformation history of the Pontides in North Anatolia during the Cretaceous period, which vary depending on the positions of the Istanbul and Sakarya zones, the consumption of the northern branches of the Neotethys ocean and the rifting of several sub-basins. Notably, the early Cretaceous tectonic history of the Pontides involved the closure of the northern Neotethys ocean (Intra-Pontide ocean), and the collision between the Istanbul and Sakarya zones, producing thrust structures along the collisional front. The lack of palaeomagnetic data providing evidence for this deformation pattern demonstrates that further investigation is required, particularly focusing on the Lower Cretaceous strata in the Pontides. Thus, this study aimed to examine samples from a total of 78 sites from the Lower–Upper Cretaceous sedimentary rocks, and Middle Eocene to Middle Miocene sedimentary and volcanic rocks. Results of this study indicated large counterclockwise rotations up to R±ΔR = −73.9°±9.1°, and small clockwise rotations of R±ΔR = 14.2°±12.2° in the Istanbul and Sakarya zones, during the Early Cretaceous and Late Cretaceous periods. These rotation patterns are accompanied by the closure of the Intra-Pontide ocean, and the collision between the Istanbul and Sakarya zones during the Early and Late Cretaceous periods. On the other hand, in the Middle Eocene, small counterclockwise rotations of R±ΔR = −6.4°±13.9° and 4.6°±12.9° along the western coastline of the Pontides indicated that the northern margin of the Pontides was stable during this period.
The geographic range of a species is crucial for obtaining information on the exact distribution of the species. The geographic data are important for delimiting distinct species or exploring the degree of differentiation among different populations of a species. The local details of species boundaries facilitate the study of the importance of phylogeographic background, secondary contacts, and hybrid zones, along with the relations between the species and its extrinsic environmental factors. In the present study, the range boundaries of Bufo bufo and Bufo verrucosissimus in the north-eastern region of Türkiye were delineated using an integrative taxonomic approach that utilized a combination of molecular and morphological data. According to the mtDNA results of the present study, B. bufo inhabits a single distribution from İyidere town to Çayeli town in Rize, while B. verrucosissimus is distributed from Şavşat town of Artvin to Ardeşen town in Rize. In addition, the two species coexist in Pazar, Hemşin, and Çamlıhemşin towns in Rize. The demographic analyses indicated a distinct population expansion for the B. verrucosissimus species after the Last Glacial Maximum, while the same did not occur for B. bufo. The univariate and multivariate statistical analyses conducted for the morphological data of the two species corroborated the presence of a putative contact zone between B. bufo and B. verrucosissimus. In summary, the present study resolved the non-distinct geographic boundaries between B. bufo and B. verrucosissimus species and also revealed the easternmost distribution of B. bufo in Türkiye. In addition, important evidence on the putative contact zone between the two species was indicated using an integrative taxonomic approach.
The origin and development of the Black Sea Basin (BSB) remain controversial. In this study, we determined the main tectonic features of the BSB using satellite gravity, heat flow, and seismological data. Positive gravity anomalies are observed in the arc region due to high-density material, while negative gravity anomalies are seen in the trench region owing to the mass deficiency and sediments. The trench region has a relatively low heat flow anomalies along the Black Sea coasts.
The Moho depth increases from 18.11 km in the Eastern Black Sea Basin (EBSB) to 51.83 km in the Eastern Anatolia Plateau (EAP) with an average of 34.13 ± 6.15 km. The lithosphere thickness changed between 78.48 km beneath Anatolia and 120.57 km below the EBSB with an average of 99.17 ± 8.17 km. The low heat flow and Moho temperature values indicate that the lithosphere is strong and cold beneath the BSB. The numerical results, therefore, provide evidence for southward subduction of the Tethys oceanic lithosphere below the Anatolian plate during the late Mesozoic-Cenozoic. Considering all geophysical and geological data, we conclude that the Black Sea Basin represents a relict basin, rather than a back-arc basin.
The Black Sea has undergone several limnic and marine stages due to fluctuations in the global sea level. The exchange of saline water from the Mediterranean Sea to the Black Sea through the Bosporus Strait was interrupted when the sea level dropped below the Bosporus sill. This induced limnic conditions, while marine conditions were established after the reconnection to saline Mediterranean seawater. Extended river fan systems developed during sea level low-stands, providing large amounts of organic material being buried by rapid sedimentation on the slopes of the Black Sea margins. The biogenic degradation of this material produces most of the methane gas expelled into the anoxic water column today. This largely happens by ubiquitous cold vents at ~700 m water depth (i.e. at the stability boundary of methane hydrates) and by mud volcanoes in ~2000 m water depth. A significant amount of gas is expected to accumulate in the sediment within the methane hydrate stability zone. However, bottom-simulating reflectors, the seismic indicator for gas hydrates, are not found everywhere along the margin. Recent analyses of the Danube and Dniepr fans have revealed a discontinuous gas hydrate formation in an area with no active seeps, while areas of active seepage located in the vicinity of BSR reflections held no gas hydrates. In addition, the ongoing diffusion of salt into the uppermost Black Sea sediment pore space since the last glacial maximum further reduces the volume of the gas hydrate stability zone. Estimates of the total amount of gas stored in gas hydrates therefore require a detailed structural analysis prior to regional- or basin-scale modelling attempts.
The Black Sea is an oval basin with an area of 423.000 km2, a volume of 534.000 km3 and a maximum depth of 2206 m. It is connected to Atlantic Ocean by Mediterranean Sea-Aegean Sea-Turkish Straits System (The Sea of Marmara and the straits of Bosphorus and Dardanelles) and it is also connected to Sea of Azov by the Kerch strait. The mean sea level at the Black Sea is about 55 cm higher than the level at the Aegean Sea. The maximum development of the Black Sea shelf is at the west of Crimean peninsula, where it is more than 190 km wide. Along the Turkish coast, Russian coast and south of the Crimean peninsula, the shelf exceeds 20 km in width in only a few places. The widths of about 40 km are found off the Bulgarian coast and south of the Sea of Azov.
The Black Sea opened as a back-arc and/or intra-arc basin to the north of Pontide magmatic belt. It is seperated by the mid-Black Sea Ridge (comprising Andrusov and Archangelsky ridges). Western Black Sea Basin (WBSB) and Eastearn Black Sea Basin (EBSB) have different time and mechanisms of opening.
The study area is located on the southern margin of the WBSB, on the fragment called Istanbul Zone (which is delimited by the Intra-Pontid suture in the south and by the WBSB to the north) and its offshore area. WBSB opened as a back-arc basin behind the southwards-moving Istanbul Zone and collided with the Sakarya Zone along the Intra-Pontide Suture during the Eocene. Istanbul Zone rifted off from its original location around the present Odessa Shelf during the early Cretaceous, and started to move southwards along the West Black Sea and West Crimean transform faults. The emplacement of the Istanbul Zone into its present position was possibly during the late Albian.
Geophysical data have become increasingly important for rapidly developed tectonic research since 1960s. Seismic reflection method is the most effectively used geophysical method for investigation of the deep structure and the geological features beneath the sea floor. From the middle of 1990's to present, in spite of well-rounded but non-utilizable data of commercial two dimensional (2D) and three dimensional (3D) seismic studies of petroleum companies, the number of scientific studies and publications for academic purposes, revealing the geological structure beneath Turkish sector of the WBSB using marine seismic reflection data, has been increasing. Especially, there is a considerable amount of scientific articles focused on various subjects (such as mass wasting, sedimentation, sea-level fluctuations, BSR, Messinian events etc.) presenting detailed seismic sections and providing a good definition of the structural properties beneath the shelf and the continental slope of the southern part of the basin along Turkish margin.
In tectonics, researchers search for ways to predict the time and location of damaging tectonic events such as earthquakes and tectonically induced events. To be neotectonically useful, the predictions must be precise enough to alleviate the loss of life and property. This quest for prediction techniques also involves the investigation of active tectonics. The earthquake occurred on October 15, 2016 (Ml=5.0) re-attracted attention to the tectonic activity of WBSB. This earthquake took place at 11:18 local time and lasted 7-8 seconds. It was felt in the cities of Istanbul, Kocaeli, Duzce, Sakarya, Zonguldak and even in the Bulgarian cities Varna and Bourgas. The epicenter of the earthquake was at a point 195 km north-east of Istanbul and 124 km north-west of Zonguldak. This earthquake with a shallow epicenter (11.4 km below the surface) was one of the rare instrumentally recorded strong earthquakes occured at the southern part of the WBSB.
The Bartın Earthquake of September 3, 1968 (MS=6.6) is the strongest instrumentally recorded earthquake along the Turkish margin of Black Sea. This earthquake was the first seismological evidence of active thrusting occuring at the southern margin of the Black Sea and its fault-plane solution indicated a thrust mechanism which emphasized a different behaviour from the right-lateral strike-slip North Anatolian Fault. Focal mechanism derived from the solution of the moment tensor for the October 15, 2016 Black Sea earthquake, revealed another clue for the active thrusting at the WBSB with a very similar focal mechanism solution of Bartin Earthquake.
The central and the deepest parts of the Black Sea was believed to be aseismic but, with the recent studies, the researchers showed that there are a significant number of earthquakes in the Black Sea, mostly of magnitude Mw=4.0 or smaller. They also revealed that the seismicity increases towards the margins of the Black Sea, with the largest events at the margins. The researchers also emphasized that, in southern Black Sea and the middle part, especially offshore of Bartın and Samsun, the earthquakes which have the reverse faulting component dominated solutions, are related with the compressional tectonic regime and the strikes of these earthquakes generally lie parallel to the basin. These earthquakes show that the region is not aseismic and produces earthquakes from time to time, though not very frequently.
The folds are commonly accompanied by reverse faulting and many of these reverse faults are low angle and are called thrust faults. Some of the thrust faults and high-angle reverse faults may break the surface, but many others remain hidden within the cores of anticlines and are termed buried reverse faults. Buried active faults present a significant earthquake hazard-that large damaging earthquakes can occur on faults located entirely beneath or within folded rocks. The tips of such faults may be buried at depths of several kilometers, and when they rupture during earthquakes, uplift and folding occur at the surface. In this study, the fault structures that are considered to be formed by the effect of compressional tectonic regime and the structures formed by the activities of these faults beneath the shelf and slope areas between the region offshore Akçakoca-Cide at the southern part of the WBSB, revealed by using marine seismic reflection data.
The marine seismic reflection data used in this study were collected by the collaboration of General Directorate of Mineral Research and Exploration (MTA), Cambridge University and Istanbul Technical University (ITU) in September, 1998. R/V MTA Sismik-1 was used to collect data on 14 seismic lines with a total length of 460 km. All necessary and some optional processes of typical marine seismic data processing sequence were applied to raw data to obtain time-migrated seismic sections. From the time-migrated seismic sections, to give examples for thrust fault structures and folds formed by the activities of these faults became possible. These images were beneficial to clarify the presence of the compressional regime effecting the study area.
Available onland and offshore geological exploratory well data of Akçakoca-1, Akçakoca-2, Ereğli-1, Filyos-1, Bartin-1, Ulus-1, Amasra-1, Cakraz-1 and Gegendere-1 are obtained from General Directorate of Petroleum Affairs (PIGM) and used to correlate with seismic sections. Seismic markers of the time-migrated seismic sections were dated by referencing to Akcakoca-1 and Akcakoca-2 wells.
Also in this study, the land-offshore geological sections prepared by means of the geological sections given by previous geological studies and the information about the continuation of the geological features from land to offshore in the study area was presented. These geological sections also give quite beneficial new evidences for the presence of the compressional tectonic regime in the study area.
The important findings of this study were to give another clue for the presence of the compressional tectonic regime effecting the basin by using the outcomes of seismic reflection studies and to reveal the continuation of the thrust related geological features from land to offshore. The results obtained, agrees with the opinion that Black Sea is being compressed in N-S direction.
An integrated approach to the processing of sapropel with the use of supercritical CO2 extraction of bioactive substances with carbon dioxide at the first step of the process is discussed. The dependences of the yield and composition of extracts (8-35 MPa, 50 °C) and features of sapropel are established. Further carbonization of the solid residue remaining after extraction results in organic-rich products (phenol and its mono, dialkyl and methoxy derivatives, hydrocarbons C14-C22) and carbon-mineral materials with a total pore volume of 0.681-1.211 cm³ g⁻¹. It was found that the introduction of the initial stage of treatment with supercritical CO2 allows not only extracting valuable amino acids, but also affects the yield, composition and properties of liquid and solid sapropel transformation products at subsequent stages of heat treatment.
High-resolution 3D seismic data in combination with deep-towed sidescan sonar data and porewater analysis give insights into the seafloor expression and the plumbing system of the actively gas emitting Kerch seep area, which is located in the northeastern Black Sea in around 900 m water depth, i.e. well within the gas hydrate stability zone (GHSZ). Our analysis shows that the Kerch seep consists of three closely spaced but individual seeps above a paleo-channel-levee system of the Don Kuban deep-sea fan. We show that mounded seep morphology results from sediment up-doming due to gas overpressure. Each of the seeps hosts its own gas pocket underneath the domes which are fed with methane of predominantly microbial origin along narrow pipes through the GHSZ. Methane transport occurs dominantly in the form of gas bubbles decoupled from fluid advection. Elevated sediment temperatures of up to 0.3 °C above background values are most likely the result of gas hydrate formation within the uppermost 10 m of the sediment column. Compared to other seeps occurring within the GHSZ in the Black Sea overall only scarce gas indications are present in geoacoustic and geophysical data. Transport-reaction modeling suggests that the Kerch seep is a young seep far from steady state and probably not more than 500 years old.
The Central Pontides of N Turkey represents a mobile orogenic belt of the southern Eurasian margin that experienced several phases of exhumation associated with the consumption of different branches of the Neo-Tethys Ocean and the amalgamation of continental domains. Our new low-temperature thermochronology data help to constrain the timing of these episodes, providing new insights into associated geodynamic processes. In particular, our data suggest that exhumation occurred at (1) ~110 to 90 Ma, most likely during tectonic accretion and exhumation of metamorphic rocks from the subduction zone; (2) from ~60 to 40 Ma, during the collision of the Kirşehir and Anatolide-Tauride microcontinental domains with the Eurasian margin; (3) from ~40 to 25 Ma, either during the early stages of the Arabia-Eurasia collision (soft collision) when the Arabian passive margin reached the trench, implying 70 to 530 km of subduction of the Arabian passive margin, or during a phase of trench advance predating hard collision at ~20 Ma; and (4) ~11 Ma to the present, during transpression associated with the westward motion of Anatolia. Our findings document the punctuated nature of fault-related exhumation, with episodes of fast cooling followed by periods of slow cooling or subsidence, the role of inverted normal faults in controlling the Paleogene exhumation pattern, and of the North Anatolian Fault in dictating the most recent pattern of exhumation.
In the past few decades, the Black Sea has been the subject of intense geological and geophysical studies, including deep seismic sounding, reflection profiling, gravity and magnetic surveys for scientific and petroleum exploration purposes (Nikishin et al. 2010; Soson et al. 2010; Stephenson and Schellart 2010).
The Mid Black Sea High comprises two en echelon basement ridges, the Archangelsky and Andrusov ridges, that separate the western and eastern Black Sea basins. The sediment cover above these ridges has been characterized by extensive seismic reflection data, but the crustal structure beneath is poorly known. We present results from a densely sampled wide-angle seismic profile, coincident with a pre-existing seismic reflection profile, which elucidates the crustal structure. We show that the basement ridges are covered by approximately 1–2 km of pre-rift sedimentary rocks. The Archangelsky Ridge has higher pre-rift sedimentary velocities and higher velocities at the top of basement (c. 6 km s−1). The Andrusov Ridge has lower pre-rift sedimentary velocities and velocities less than 5 km s−1 at the top of the basement. Both ridges are underlain by approximately 20-km-thick crust with velocities reaching around 7.2 km s−1 at their base, interpreted as thinned continental crust. These high velocities are consistent with the geology of the Pontides, which is formed of accreted island arcs, oceanic plateaux and accretionary complexes. The crustal thickness implies crustal thinning factors of approximately 1.5–2. The differences between the ridges reflect different sedimentary and tectonic histories.
GIRIŞ
Türkiye dünyanın en aktif deprem kuşaklarından biri olan Alp-Himalaya dağ sırası içinde, Doğu Akdeniz bölgesinde bulunur. Türkiye ve yakın çevresinde son yüzyılda büyüklüğü 6,0 ve üzeri olan 203 deprem kayıt edilmiştir (Kadirioğlu vd., 2016). Bu depremler arasındaki 72 yıkıcı deprem, bu coğrafyada yaşayan 90 binden fazla kişinin ölümüne ve tahmini 50 milyar doların üzerinde ekonomik zarara yol açmıştır. Bunların yanı sıra bu depremlerin yaratmış olduğu psiko-sosyolojik etki ise çok daha fazla olmuştur.
Deprem zararlarının azaltılması çalışmalarının ilk ve temel aşaması depremi oluşturan diri fayların mekânsal dağılımları ve özelliklerinin ortaya konmasıdır. Diri fayların mekânsal dağılımları haritalama çalışmalarıyla belirlenir. Amaca yönelik olarak farklı ölçeklerde hazırlanabilen diri fay haritalarında fayların aktiviteleri (yaş), ayrıntılı geometrik, yapısal ve kırılma mekanizması özellikleri verilmelidir. Bu özelliklerin tanımlanabilmesi ise ancak jeoloji, jeofizik, sismoloji ve jeodezi gibi farklı disiplinlere dayanan yöntem ve bilgilere dayalı yapılabilmektedir.
Günümüzde deprem tehlike analizlerinde ihtiyaç duyulan gereksinimleri karşılamak amacıyla, diri fay haritalarında parametrik fay bilgileri de diri fay bilgi alt yapısının temel bileşenleri olarak sunulmaktadır. Bu parametreler; fayın uzunluğu, niteliği, geometrik özellikleri ve segment yapısı, kırılma zonunun derinliği ve genişliği, uzun ve kısa dönem kayma hızı, deprem tekrarlanma aralığı, tek bir depremde meydana gelebilecek olan yer değiştirmenin miktarı gibi bilgilerden oluşmaktadır. Bu parametrelerin elde edilebilmenin ilk aşaması diri fayların orijinal geometrik özelliklerini gösteren ayrıntıda (ölçeklerde) haritalama yapılması ve fay parametreleri hakkında sistematik veri toplanmasıdır.
Diri fay haritaları deprem sırasında yüzey kırığı oluşturan, dolayısıyla jeolojik ve morfolojik olarak izler bırakan fayların haritalanmasına dayanır. Bu kapsamda hazırlanan haritalardaki diri faylar, çizgisel deprem kaynağı olarak tanımlanır. Çizgisel deprem kaynakları, olasılıksal deprem tehlike analizlerinde hedef yüzey yırtılması oluşturabilecek ve gerçekte üç boyutlu olan fay düzleminin, yer yüzeyindeki izinin, harita üzerinde gösterilmesidir. Çizgisel kaynaklar oluştukları veya etkisi altında oldukları tektonik rejime göre normal, doğrultu ve ters/bindirme mekanizmalarda olabilirler. Faylanma genelde tek bir mekanizmada meydana gelmemekte, çoğunlukla bir diğer mekanizmayı da bileşen olarak bünyesinde bulundurmaktadır. Örneğin; ters atım bileşenli sağ yanal doğrultu atım, normal atım bileşenli sol yanal doğrultu atım gibi.
Çizgisel kaynakların yanısıra benzer sismik özellikler gösteren bölgeler, alansal kaynaklar olarak tanımlanmaktadır. Benzer veya farklı mekanizmalarda olan fay sistemi, zonu veya demetleri bir alansal kaynak olarak bir arada değerlendirilebilmektedir. Bununla birlikte, jeolojik ve morfolojik bilgilere dayalı herhangi bir diri fay (çizgisel kaynak) haritalanamayan alanlarda güncel sismik aktivitenin meydana geldiği bölgeler de bulunmaktadır. Bu durum yüzeye ulaşamamış (kör) bir kırılmadan kaynaklanabileceği gibi, kabuk içindeki gerilmelere bağlı herhangi bir alanda meydana gelen enerji boşalması gibi nedenlerden de kaynaklanabilmektedir. Söz konusu bu sismik aktivitelerin meydana geldiği alanlar, doğrudan yüzeyde jeolojik ve morfolojik izlere dayalı haritalanabilen bir diri fay ile ilişkilendirilemezse de alansal bir kaynak olarak tanımlanabilmektedir.
Sismotektonik model, sismik tehlike analizlerinde depremin kaynağı olan çizgi veya alan kaynakların mekânsal dağılımları ve karakteristik özelliklerin tanımlanması olarak kabul edilir. Bu özellikler depremin oluştuğu sismojenik kabuğun özellikleri ve meydana gelen depremin zamansal - mekânsal oluşma olasılıkları hakkında istenilen düzeyde bilgi sağlamalıdır. Maden Tetkik ve Arama (MTA) Genel Müdürlüğü tarafından 1992 yılında basılan 1:1.000.000 ölçekli Türkiye Diri Fay Haritası (Şaroğlu vd., 1992), ülke genelindeki deprem kaynağı diri fayların belirli bir standart kapsamında gösterildiği ilk veri kaynağıdır. Bu haritada sunulan diri fay bilgileri yayımlandığı tarihten itibaren Türkiye ve yakın çevresinin güncel tektoniği ve depremselliği üzerine yapılan çok sayıdaki bilimsel araştırmalarda ve ülkedeki deprem tehlikesinin belirlenmesi çalışmalarında kullanılan temel başvuru kaynaklarından birisi olmuştur. Ancak, deprem jeolojisindeki hızlı ilerlemeye bağlı olarak sahip olunan bilgi birikimi, deprem tehlike ve risk araştırmalarında yeni analiz tekniklerinde, daha kapsamlı fay parametre bilgilerine ihtiyaç duyulması bu haritanın yenilenmesi ihtiyacını gündeme getirmiştir.
Bu ihtiyacı karşılamak amacıyla, 2004 yılında MTA Genel Müdürlüğü, Jeoloji Etütleri Dairesi Başkanlığı tarafından, deprem jeolojisindeki güncel yaklaşımlar ışığında, 1992 basımı Türkiye Diri Fay Haritası’nın yenilenmesi amacıyla “Türkiye Diri Fay Haritası’nın Güncellenmesi ve Diri Fay Veri Tabanı Oluşturulması” adlı bir araştırma programı başlatılmıştır. Program amacı doğrultusunda, 2004–2011 yılları arasında, Türkiye anakarasının tamamında ayrıntılı diri fay araştırmaları yürütülmüş ve farklı ölçeklerde diri fay haritaları hazırlanmıştır (Emre vd., 2013).
Bu çalışmada, Türkiye kara alanındaki diri fayların özellikleri ayrıntılı olarak sunulmuştur. Bu amaçla Türkiye’nin diri fayları tanıtılırken kapsamlı bir literatür değerlendirmesinden daha çok, belirli bir standart kapsamında 10 yılı aşan arazi çalışmalarına dayalı hazırlanan yenilenmiş Türkiye Diri Fay Haritası (Emre vd., 2013) bilgilerine ağırlık verilmiştir. Bununla birlikte, Türkiye’nin depremselliğini doğrudan ilgilendiren yakın çevredeki tektonik yapılar da mevcut literatür bilgilerine dayalı olarak tanıtılmıştır. Burada sunulan bilgilerin Türkiye ve yakın çevresinde deprem tehlikesi değerlendirmelerinde, aktif tektonik araştırmalarında, bölgesel planlamalarda yönlendirici ve sismotektonik bilgi alt yapısında önemli katkısı olacağı düşünülmektedir.
In central eastern Anatolia which is located between Eurasia and Africa, the study of basin developments between late Eocene and early Miocene is of great importance for understanding the process of the closure of the Neo-Tethys Ocean and the formation of strike-slip faults and regional uplift. To study these, three basins were selected: the Sivas-Erzincan, Gürün-Akkisla-Divrigi (GAD), and Malatya basins. The study proposes that the opening of the GAD basin played a key role in the formation of the Ecemis fault, which started developing at the end of early Miocene, and in mountain uplift. All these basins are situated on continental blocks and oceanic crust, arranged from north to south as the Sakarya continent, the Izmir-Ankara-Erzincan ocean (Northern Neo-Tethys), the Kirsehir continent, the inner Tauride ocean, the Munzur-Binboga block, the Maden (=Berit) ocean, the Bitlis-Pütürge block, the Çüngüs ocean and the Arabian continent.
The findings indicate that late Eocene-early Miocene successions in these basins were not deposited in foreland basins formed in front of the thrust faults associated with the closure of the ocean, as stated in previous studies. Rather, they were deposited in forearc and backarc basins related to the subduction which was effective until the end of early Miocene. The Sivas-Erzincan and Malatya basins, located on the inner Tauride and Maden (=Berit) oceans, were forearc basins, while the GAD basin situated on the Munzur-Binboga block was a backarc basin. These basins have parallel developments up to the end of early Miocene. While marine sediments were deposited in the Malatya and Sivas-Erzincan basins between late Eocene and early Miocene, terrestrial units began to settle in the GAD basin from the late Eocene and the deposition there is continuous until the end of the early Miocene.
Collision of the Arabian and the Anatolian plates at the end of early Miocene (16-18 Ma) produced the left-strike slip Ecemis fault zone, which caused the lateral slip of sedimentary units in the Sivas-Erzincan and GAD basins over hundreds of kilometers. This event produced the first westward tectonic escape of the Anatolian plate prior to the north Anatolian fault (NAF) and the east Anatolian fault (EAF). The Gürün region located in the GAD basin was exhumed in late Miocene and this basin was broken. The Gürün region, which remains on the rising part of the Munzur-Binboga block, is not a different basin as stated earlier, but it is a part of the GAD basin, representing the central part of the GAD basin lake, as indicated by the fine grained deposits (limestones and clay) that occur in the Gürün area.
The architecture of sedimentary basin is the result of the interplay
between deep-seated tectonic processes at lithospheric or crustal scale creating or
reducing the accommodation space, and the near-surface processes taking place in
the source and depositional areas. Understanding the evolution of the
sedimentary basin requires, therefore, an integrated study of the coupling
between sediment routing and lithospheric processes that are responsible for
basin formation, evolution and, ultimately, for its closure by complete stages of
regressive basin fill, or inversion and exhumation.
This thesis is focused on understanding the mechanism controlling the
tectonic and sedimentary evolution of back-arc basins, from their opening to
subsequent inversion. During the quest of understanding the particular type of
basin formation and subsequent inversion in the Black Sea Basin, two main
objectives were pursued.
The first objective is related to understanding the role played by inherited
extensional rheology in far-field transmission and localization of compressional
deformation driven by an active orogenic area into a pre-existing back-arc domain.
Back-arc contractional geometries are not necessarily controlled by major internal
asymmetries, such as active subduction zones. Therefore, the presence of
inherited rheologically weak zones controls the vergence of thrusting systems
during back-arc inversion. The lateral variability of such weakness zones may
create a contractional polarity change, which is a change in the thrusting vergence
along the strike of the back-arc basin where its opposite margins act as indenters.
This type of change, critical for understanding a number of worldwide basins, such
as the Black Sea or the Huon-Finisterre arc, has received little attention so far in
phenomenological studies.
The second objective of the thesis is to understand the effects of large sea level
variations in the depositional architecture and sedimentary exchange
between basins connected through a shallow marine barrier. The objective is
studied in the context of the Late Miocene-Quaternary sediment fluxes between
the Carpatho-Balkans source area, the Dacian marginal basin and the Black Sea
main sink by the means of seismic sequence stratigraphic analysis calibrated by
wells in both basins.
The thesis is organized in two main sections. Following a brief introduction
in Chapter 1, two observational studies in Chapters 2 and 3 analyze the geometries
and effects of Black Sea Basin back-arc opening and inversion, and the effects of
the large scale sea-level drop recorded during the Messinian Salinity Crisis of the
Paratethys. These observational studies form the base of the phenomenological
process-oriented studies in Chapters 4 and 5 that analyze the mechanisms of backarc
basin inversion by the means of analogue modeling. The thesis ends with the
conclusions of Chapter 6.
Architecture of the sedimentary basin fills reflects the tectonic processes that created enlarged and subsequent closed sedimentary basins. Depicting the geometry and litho-stratrigraphy of basin fills can provide useful insights for unraveling the tectonic evolution of both the basins and the adjacent orogen where the direct observation is hampered by uplift and erosion, such as in the case of back-arc domains.
Back-arc basin evolution is driven by processes active at the main subduction zone typically assuming the transition from an extensional back-arc, during the roll-back of a mature slab, to a contractional basin, during high-strain collisional processes. A similar type of transition is observed in the Black Sea Basin evolution, from an extensional domain during Cretaceous-Early Paleogene resulting from the roll-back of a mature slab associated with the N-ward subduction of Neothetys Ocean under the Rhodope-Pontides Arc, to a gradually inverted basin during Late Paleogene – Pliocene times after the collision between Pontides and Taurides continental units.
The Cretaceous-Paleogene extension resembles in a series of graben, tilted block and prograding passive margin like structures, with associate wedge shape geometry of the syn-extensional deposits. Basinward these deposits are younger in age, demonstrating the migration of extension from basin margin (offshore Romania-Ukraine shelf in the North and onshore Pontides in the South), towards basin center (offshore Bulgaria and Turkey). This extensional geometry played an important role in the subsequent inversion, which transformed the Black Sea into a compressional back-arc basin.
The shortening started during Late Eocene gradually affected all areas of the Western Black Sea Basin during Oligocene and Pliocene times as reveled by syn-tectonic sedimentation, on its western margin. In terms of sediments lithology this marks a shift form carbonate passive margin to a clastic “foreland” like sedimentation, such as in the case of Kamkya (Late Eocene-Lower Miocene) and Histria (Oligocene-Upper Miocene) depressions. The mechanism of this generalized inversion was the transmission of strain from the collision recorded in the Pontides –Balkanides orogens into the Black-Sea back-arc basin.
The architecture of the “anomalous” thick uppermost Miocene-Pliocene sedimentary pile on the north-western part of the basin, shows the far field effect of two tectonic processes; one that provide the sediments related with uplift and erosion of the Carpathian Orogen, and the second one which created the accommodation space and was related with continuous subsidence in the Western Black Sea center.
A new satellite laser ranging/Global Positioning System solution at seven sites in Anatolia and Aegea is used to obtain a better definition of the extrusion motion of the Anatolian-Aegean block with respect to Europe. This motion can be described in a first approximation by a counterclockwise rotation which transfers most of the motion of Arabia to Anatolia. Displacement vectors obtained at common points of two triangulation nets measured in central Greece in 1895 and 1975 are combined with the SLR/GPS measurements to compute the velocity field over Greece with respect to Europe. These measurements indicate that central Greece is a zone of extension between the Anatolian-Aegean counterclockwise rotation to the south and the northern Greece clockwise rotation to the north. It is shown that the collision between the Mediterranean ridge and Africa began 3-6 Ma, and the modifications that this collision has produced on the kinematic pattern both in Aegea and on the Mediterranean Ridge are described. -from Authors
The Black Sea consists of two oceanic basins separated by the mid-Black
Sea ridge. The east-west-oriented west Black Sea basin opened as a
back-arc rift in the Cretaceous by tearing a Hercynian continental
sliver, the Istanbul zone, from the present-day Odessa shelf. The
Istanbul zone, which was initially contiguous with the Moesian platform
in the west, moved south during the Late Cretaceous-Paleocene with
respect to the Odessa shelf along two transform faults: the dextral west
Black Sea and the sinistral west Crimean faults. It collided in the
early Eocene with a Cimmeride zone in the south, thereby ending the
extension in the western Black Sea and deactivating both the west Black
Sea and the west Crimean faults as strike-slip faults. The east Black
Sea basin opened as a result of the counterclockwise rotation of an east
Black Sea block around a rotation pole located north of the Crimea. This
block was bounded by the west Crimean fault, the southern margin of the
eastern Black Sea, and the southern frontal thrusts of the Greater
Caucasus. The rotation of the east Black Sea block was contemporaneous
with the rifting of the west Black Sea basin but lasted until the
Miocene, resulting in continuous compression along the Greater Caucasus.
This study focuses on the presence of a major strike-slip fault system in the Thrace basin. This new discovery is important for the geology of the Thrace basin and also brings a new perspective to petroleum exploration. The wrench fault system is named the Thrace strike-slip fault system (Perincek, 1988). Similarities with the North Anatolian fault zone prompted an investigation of the relationship between these two fault system.s The study area covers most of the Thrace region of Turkey. The purposes of this paper are (1) to outline the geometry of the Thrace fault system, (2) to demonstrate its tectonic relation with other major structures of the region, (3) to define the age of its inception, and (4) to discuss possible magnitudes of the lateral displacement. The interpretation is based mainly on seismic data consisting of 180 seismic reflection profiles that have a total cumulative length of 2,800 km. Seismic data are complemented with subsurface control from 54 wells.
We use a new satellite laser ranging/Global Positioning System (SLR/GPS) solution at seven sites in Anatolia and Aegea to obtain a better definition of the extrusion motion of the Anatolian-Aegean block with respect to Europe. We show that this motion can be described in a first approximation by a counterclockwise rotation which transfers most of the motion of Arabia to Anatolia. We combine 78 displacement vectors obtained at common points of two triangulation nets measured in central Greece in 1895 and 1975 with the SLR/GPS measurements to compute the velocity field over Greece with respect to Europe. These measurements indicate that central Greece is a zone of extension between the Anatolian-Aegean counterclockwise rotation to the south and the northern Greece clockwise rotation to the north. This extension is principally localized within the Gulf of Corinth to the east but is distributed to the west. We then extrapolate this velocity field to the whole Aegea and western Anatolia using recently published GSP results as well as the SLR results. The narrow dextral North Anatolian fault, which limits the velocity field to the north, progressively gives way to a much wider boundary zone where extension becomes dominant. We show that the collision between the Mediterranean Ridge and Africa began 3-6 Ma, and we describe the modifications that this collision has produced on the kinematic pattern both in Aegea and on the Mediterranean Ridge.
We present and interpret Global Positioning System (GPS) measurements of crustal motions for the period 1988-1997 at 189 sites extending east-west from the Caucasus mountains to the Adriatic Sea and north-south from the southern edge of the Eurasian plate to the northern edge of the African plate. Sites on the northern Arabian platform move 18+-2 mm/yr at N25+-5W relative to Eurasia, less than the NUVEL-1A circuit closure rate (25+-1 mm/yr at N21+-7W). Preliminary motion estimates (1994-1997) for stations located in Egypt on the northeastern part of Africa show northward motion at 5-6+-2 mm/yr, also slower than NUVEL-1A estimates (10+-1 mm/yr at N2+-4E). Eastern Turkey is characterized by distributed deformation, while central Turkey is characterized by coherent plate motion (internal deformation of <2 mm/yr) involving westward displacement and counterclockwise rotation of the Anatolian plate. The Anatolian plate is de-coupled from Eurasia along the right-lateral, strike-slip North Anatolian fault (NAF
The Western Black Sea Basin began opening as a back-arc basin by the rifting of a juvenile continental margin magmatic arc during the Aptian. Its southern continental margin succession is well exposed in the Western Pontides, Northwest Turkey. This succession consists predominantly of volcanogenic coarse clastic rocks, shales, and carbonates with a deepeningupward character. The volcanogenic clastic rocks are mostly turbidites and mass-flow deposits in places with huge exotic blocks. The volume and nature of this clastic material were controlled by both relief of nearby sediment sources and arc volcanism, whereas the carbonates depended on ocean circulation and surface organic productivity. The Aptian to lower Cenomanian part of the succession formed during the synrift stage, whereas the rest accumulated during the postrift stage. The synbreakup stage is marked by the upper Cenomanian to Campanian sedimentary faciès. The synrift sediments commence locally with Aptian lagoonal black shales, rich in organic matter. They pass laterally and upward into an Albian unit, comprising marginal marine glauconitic sandstones succeeded by siliciclastic turbidites, marls, sandy limestones, and blue to black shales with abundant glauconite. This unit includes several levels of mass-flow deposits, comprising mostly conglomerates and olistoliths of various sizes, ranging from a few centimeters to hundreds of meters in diameter. The synrift sediments end with a Cenomanian succession of blue to black shales and clayey limestones, in part with exotic blocks derived from the underlying rocks. The postrift sediments at the base of upper Cenomanian to Campanian consist of pelagic red micrites and marls followed by mainly volcanogenic (both andesitic and basaltic) terrigeneous and carbonate turbidites and deepwater sediments, ranging from Turonian to lower Eocene. The basal pelagic carbonates rest with a slightly angular unconformity on the synrift deposits and represent the breakup facies. Facies analyses of the rift succession indicate that the Western Black Sea Basin was isolated during its synrift stage from free interchange with the Intra-Pontide Ocean to the south, and therefore was euxinic. During the riftdrift transition in the late Cenomanian, the euxinic conditions largely disappeared, and the water column above the arc margin of this basin became well mixed. The volcanic activity in the arc also increased in intensity soon after this transition, and largely controlled the postrift sedimentation.
The southern continental margin of the Black Sea back-arc basin is represented predominantly by a thick clastic sequence of Aptian to Recent age. Potential source, reservoir, and cap rocks are common in various stratigraphie levels of this sequence. The most prospective source and reservoir rocks appear to have been deposited in the synrift stage of the basin. During this stage, the rift trough was probably relatively shallow and restricted from free interchange with the Neotethys Ocean in the south. During the postrift stage, a thick sequence of volcaniclastic turbidites and subordinate pelagic limestones, with limited source and reservoir potential, accumulated. This accumulation was interrupted at the end of the early Eocene by compressional tectonics, which resulted from the closure of the Neotethys. The postrift sedimentation probably carried the earlier source rocks into the hydrocarbon generation window, while the Eocene compressional tectonics generated the main prospective traps.
Strike slip on various scales and on faults of diverse orientations is one of the most prominent modes of deformation in continental convergence zones. Extreme heterogeneity and low shear strength of continental rocks are responsible for creating complex 'escape routes' from nodes of constriction along irregular collision fronts toward free faces formed by subduction zones. The origin of this process is poorly understood. The 2 main models ascribe tectonic escape to buoyancy forces resulting from differences in crustal thickness generated by collision and to forces applied to the boundaries of the escaping wedges. Escape tectonics also creates a complicated geological signature, whose recognition in fossil examples may be difficult. We examine the Neogene to present tectonic escape-dominated evolution of Turkey both to test the models devised to account for tectonic escape and to develop criteria by which fossil escape systems may be recognized.-from Authors
The North Anatolian transform fault is a morphologically distinct and seismically active strike-slip fault which extends for about 1200 km from Karliova to the Gulf of Saros along the Black Sea mountains of N. Anatolia. It takes up the relative motion between the Black Sea and the Anatolian plates, thereby connecting the E. Anatolian convergent zone with the Hellenic Trench through the complex plate boundary zone of the Aegean. For most of its length, the transform has a typical strike-slip fault zone morphology, characterized by narrow ‘rift zone,’ offset, captured and dammed streams, sag ponds and other deformed morphological features. The fault zone is a broad region of extensively crushed country rock cut by a number of parallel and/or anastomosing strike-slip faults. The transform has periods of seismic activity the last of which, from 1939 to the present, is characterized by frequent 6 ≤ M≤7earthquakes; these are separated by quiet periods of about 150 years. The crust along the fault zone is thinner than normal. The transform probably originated some time between the Burdigalian and the Pliocene and has an offset of about 85 km. Whether the offset of the fault changes systematically along its strike is not known. The North Anatolian transform fault seems to have originated as a consequence of the Arabia-Anatolia collision durmg the late (?middle) Miocene, when the Anatolian Plate originated and was wedged out into the oceanic tract of the E. Mediterranean from the converging jaws of Arabia and Eurasia to prevent excessive crustal thickening in E. Anatolia. The westerly motion of Anatolia with respect to Eurasia and Africa caused a great change in the tectonic evolution of the eastern Mediterranean, giving rise to the Aegean extensional regime and to internal deformation of Anatolia.
We present new evidence for the propagation processes of the North Anatolian fault. Folding in the Dardanelles Straits region allows us to document the timing of the deformation preceding, and the finite displacement after, the passage of the propagating tip of the fault. The accuracy of the observations is due to interplay between deformation and the sea-level changes in the Mediterranean (the well-known Messinian regression followed by the Pliocene transgression). The long-term kinematics around the Sea of Marmara pull-apart (total displacement of about 85 km over the past 5 m.y.) is similar to the present-day kinematics deduced from space geodesy. At a larger scale, westward propagation of the North Anatolian fault over nearly 2000 km in the past 10 m.y. appears to be associated with strain recovery, suggesting that the continental lithosphere retains long-term elasticity.
The motion of the Somalia plate relative to the Nubia (Africa), Arabia and Antarctica plates is re-evaluated using a new inversion method based on a Monte Carlo technique and a least absolute value misfit criterion. A subset of the NUVEL 1 data set, with additional data along the Levant Fault and in the Red Sea is used. The results confirm that the motion of Arabia with respect to Africa is significantly different from the motion relative to Somalia. It is further shown that the data along the SW Indian Ridge are compatible with a pole of relative motion between Africa and Somalia located close to the hypothetical diffuse triple junction between the ridge and the East African Rift. The resulting Africa-Somalia motion is then compatible with the geological structures and seismological data along the East African Rift system. Assuming a separate Somalia plate thus solves kinematic and geological problems around the Afar triple junction and along the East African Rift.
A recent marine geophysical survey in the northern Molucca Sea revealed the structure to be that of a classical active convergent margin. We observe from west to east a volcanic arc (Sangihe), a forearc basin resting on an outer ridge (the Molucca ridge), which serves as a buttress for an accretionary wedge, and a composite downgoing plate (Snellius Ridge and Philippine Sea Basin). Gravity modeling indicates a strong negative anomaly above the wedge, which cannot be explained with reasonable density values. Modeling imposes a basement deepening and a rupture of the 700-km-long subducting lithosphere. This process individualized the lithospheric slab from the Snellius Ridge, which in turn was separated recently from the south Philippine Basin by the incipient Philippine Trench. This induces a deformation of the forearc region with backthrusting of the outer ridge and forearc basin, visible on bathymetry and seismic data. We extrapolate the tectonic emplacement of such oceanic blocks to the Oligocene times in order to explain the origin of the Pujada Miangas outer ridge as a sliver previously incorporated to the margin, and we discuss the possibility of this deformation process being fabric for terrane accretion.
The ideas of Hess and Dietz on seafloor spreading were principally concerned with the production of ocean floor on the axes of oceanic rifts. The continents were believed to move with the surrounding ocean floor, and to remain undeformed during their motion. These are also the ideas on which plate tectonics depends, though it differs from earlier theories by imposing rather severe restrictions on the possible relative motions. The basic assumption in plate tectonics is that the surface of the Earth may be divided into many rigid aseismic plates in relative motion. The boundaries of the plates are defined by the seismic zones of the world, earthquakes being the expression of the relative motion between neighbouring plates. Since the relative motion of any two plates may be completely described by a rigid body rotation of one about some axis through the centre of the Earth, all problems concerned with present-day continental drift and tectonics reduce to the problem of determining the axes of relative rotation and angular velocities of all pairs of plates in contact. There is now abundant evidence to show that the basic assumption of plate tectonics is correct (McKenzie & Parker 1967; Morgan 1968; Le Pichon 1968; Isacks et al . 1968). The evolution of the Red Sea and the Gulf of Aden is a consequence of the motions of at least four plates: Arabia, the north-west Indian Ocean, Africa east of the rift and Africa west of the rift. The motion between Arabia and east Africa is well determined from observations in the Gulf of Aden, but that between Arabia and west Africa must be obtained by fitting Arabia on to Africa by closing the Red Sea. The motion on the Ethiopian rift can then be calculated.
The goal of this study was to use the tectonic framework of European craton to constrain our understanding of the sedimentary basins of Europe. An understanding of the amalgamation of the crustal blocks of Europe during the Caledonian, Hercynian, and Alpine orogenies was accomplished using an Evans and Sutherland system. Paleogeographic maps were ;made and integrated with the plate reconstruction with an eye toward how regional plate-scale events affect play elements in the basins. Europe is an artifact of Phanerozoic tectonic history, an amalgamation of crustal blocks without a precambrian nucleus of it own. This is in direct contrast of Africa, Asia, and North America. Multiple riftings and collisions created extremely complex mountain building during the Caledonian, Hercynian, Cimmerian, and Alpine orogenies. Basins are diverse, superimposed, and have long-lived tectonic histories with complex structuring and highly variable play elements. The Hercynian orogene set up the framework for northern European hydrocarbon systems. Its collapse set up the Apulian Mesozoic hydrocarbon system. Alpine deformation and tectonically related extension in turn set up the Neogene hydrocarbon systems of the Carpathians Pannonian basin and the Apennines. Eleven paleogeographic maps were completed at a scale of 1:5,000,000. There are four for the Paleozoic to show the Hercynian orogeny and its subsequent foredeeps, and four for the Mesozoic, showing Tethyan rifting and associated subsidence, as well as the Cimmerian orogenies and start of Alpine deformation. The three time slices in the Cenozoic show the Alpine orogene and its foredeeps and the tectonically related extensional basins.
The Black Sea comprises two extensional basins formed in a back-arc setting above the northward subducting Tethys Ocean, close to the southern margin of Eurasia. The two basins coalesced late in their post-rift phases in the Pliocene, forming the present single depocentre. The Western Black Sea was initiated in the Aptian, when a part of the Moesian Platform (now the Western Pontides of Turkey) began to rift and move away to the south-east. The Eastern Black Sea probably formed by separation of the Mid-Black Sea High from the Shatsky Ridge during the Palaeocene to Eocene. Subsequent to rifting, the basins were the sites of mainly deep water deposition; only during the Late Miocene was there a major sea-level fall, leading to the development of a relatively shallow lake. Most of the margins of the Black Sea have been extensively modified by Late Eocene to recent compression associated with closure of the Tethys Ocean. Gas chromatography—mass spectrometry and carbon isotope analysis of petroleum and rock extracts suggest that most petroleum occurrences around the Black Sea can be explained by generation from an oil-prone source rock of most probably Late Eocene age (although a wider age range is possible in the basin centres). Burial history modelling and source kitchen mapping indicate that this unit is currently generating both oil and gas in the post-rift basin. A Palaeozoic source rock may have generated gas condensate in the Gulf of Odessa. In Bulgarian waters, the main plays are associated with the development of an Eocene foreland basin (Kamchia Trough) and in extensional structures related to Western Black Sea rifting. The latter continue into the Romanian shelf where there is also potential in rollover anticlines due to gravity sliding of Neogene sediments. In the Gulf of Odessa gas condensate has been discovered in several compressional anticlines and there is potential in older extensional structures. Small gas and oil discoveries around the Sea of Azov point to further potential offshore around the Central Azov High. In offshore Russia and Georgia there are large culminations on the Shatsky Ridge, but these are mainly in deep water and may have poor reservoirs. There are small compressional structures off the northern Turkish coast related to the Pontide deformation; these may include Eocene turbidite reservoirs. The extensional fault blocks of the Andrusov Ridge (Mid-Black Sea High) are seen as having the best potential for large hydrocarbon volumes, but in 2200 m of water.
We review the geological and geophysical structural framework of the deep Black Sea and Caspian Sea basins. Based on seismic evidence and subsidence history, we conclude that the deep basins have an oceanic crust formed in a marginal sea environment. We propose that the present deep basins are remnants of a much greater marginal sea formed during three separate episodes during the Mesozoic: in the Middle Jurassic, Upper Jurassic and Late Cretaceous. A tentative sketch of the geologic evolution of the area is presented. The marginal sea reached its greatest extent in the Early Tertiary when it was about 900 km wide and 3000 km long. The central part of the marginal sea has since disappeared during the collision between the Arabian promontory and the Eurasian margin.
The Tasova–Erbaa and Niksar basins are two adjacent pull-apart basins along the North Anatolian Fault Zone (NAFZ). Within the Tasova–Erbaa basin, sedimentary lithofacies of the Upper Pontus Formation (Plio-Pleistocene) are asymmetrically distributed, with laterally derived alluvial fans, coarse braid plain deposits, and axial braided stream deposits dominating the northern and western parts of the basin. The basin has gently dipping sediments locally affected by pervasive extensional (T) faulting. Isolated compressional structures are associated with master faults (deformation zone width ≤500 m). Pervasive extensional faults (T and R?) and late-stage PDZ-parallel compressional faults are also present. An additional set of extensional faults trends perpendicular to the PDZ, accommodating secondary pull-apart stretching within the basin. The distribution of sedimentary facies and structural styles is consistent with that predicted by models for pull-apart basins. The adjacent Niksar basin is an active pull-apart basin, possibly as young as 0.5–1 Ma. Its modern drainage and sedimentary facies are symmetrically arranged. Adding the lengths of the Tasova–Erbaa and Niksar basin suggests ∼80 km total displacement along the North Anatolian fault, which is consistent with Seymen (ITU Ph.D. Thesis, 1975), Sengor [J. Geol. Soc. 136 (1979) 269–282] and Armijo et al. [Tectonophysics 243 (1999) 135–154], who observed about 85±5 km total displacement along the North Anatolian fault. The change in course of the North Anatolian fault, marked by the formation of the Niksar–Ezinepazari segment, and this new geometry suggest that the Anatolian block is rotating anticlockwise by having two separate poles: one located near Damascus and the other occurring north of the Sinai peninsula. This change may also mark the transfer of the Anatolian triple junction from Erzincan to Karliova about 1 Ma ago. Furthermore, it appears that while the fault shortcuts the older basin, a new generation of pull-apart basins is formed due to changes of boundary conditions along the fault zone.
Petroleum geology of the Black Sea The North Anatolian transform fault; its age, o¡set and tectonic signi¢cance Strike-slip faulting and related basin for-mation in zones of tectonic escape; Turkey as a case study. Strike-slip deformation, basin formation, and sedimentation
- A G Robinson
- J H Rudat
- C J Banks
- R L F Wiles
Robinson, A.G., Rudat, J.H., Banks, C.J., Wiles, R.L.F., 1996. Petroleum geology of the Black Sea. Mar. Pet. Geol. 13, 195^223. S °engo « r, A.M.C., 1979. The North Anatolian transform fault; its age, o¡set and tectonic signi¢cance. J. Geol. Soc. London 136, 269^282. S °engo « r, A.M.C., Go « ru « r, N., S °arog ›lu, F., Biddle, K.T., Chris-tie-Blick, N., 1985. Strike-slip faulting and related basin for-mation in zones of tectonic escape; Turkey as a case study. Strike-slip deformation, basin formation, and sedimentation. Soc. Econ. Paleontol. Mineral. Spec. Publ. 37, 227^264.
Kinematic his-tory of the opening of the Black Sea and its e¡ect on the surrounding regions Analyse tectonique et e ¤tats de contraintes ce ¤nozo| «ques dans la zone centrale de la faille Nord Ana-tolienne. The 'se de doctorat Turkey: An interpretation
- A I Okay
- A M C «r
Okay, A.I., S °engo « r, A.M.C., Go « ru «r, N., 1994. Kinematic his-tory of the opening of the Black Sea and its e¡ect on the surrounding regions. Geology (Boulder) 22, 267^270. O º ver, S., 1996. Analyse tectonique et e ¤tats de contraintes ce ¤nozo| «ques dans la zone centrale de la faille Nord Ana-tolienne. The 'se de doctorat, Universite ¤ Paris Sud-Orsay, 260 pp. O º ver, S., Bellier, O., Poisson, A., Andrieux, J., 1997. Late Cenozoic stress change along the central North Anatolian fault zone (Turkey). Ann. Tecton. 11, 75^101. Perinc °ek, D., 1991. Possible strand of the North Anatolian Fault in the Thrace Basin, Turkey: An interpretation. Am. Assoc. Pet. Geol. Bull. 75, 241^257.
Anon-ymous, 1993. Tectonic evolution and paleogeography of Eu-rope. AAPG international conference and exhibition
- P O Y|lmaz
- D A Leary
- I O Norton
- R J Chuchla
Y|lmaz, P.O., Leary, D.A., Norton, I.O., Chuchla, R.J., Anon-ymous, 1993. Tectonic evolution and paleogeography of Eu-rope. AAPG international conference and exhibition, 77, p. 1677.
Active slivering of oceanic crust along the Molucca ridge (Indonesia^Philippines). Geodynamic implication. Tectonics 18
- A G Bader
- M Pubellier
- C Rangin
- C Deplus
- R Louat
Bader, A.G., Pubellier, M., Rangin, C., Deplus, C., Louat, R.,
1999. Active slivering of oceanic crust along the Molucca
ridge (Indonesia^Philippines). Geodynamic implication. Tectonics 18, 606^620.
Recent temporal change in the stress state and modern stress ¢eld along the North Anatolian fault zone (Turkey)
- O Bellier
- S Ver
- A Poisson
- J Andrieux
Bellier, O., O º ver, S., Poisson, A., Andrieux, J., 1997. Recent
temporal change in the stress state and modern stress ¢eld
along the North Anatolian fault zone (Turkey). Geophys. J.
Int. 131, 61^86.
The development of the Red Sea and Gulf of Aden in relation to plate tectonics
- D P Mckenzie
McKenzie, D.P., 1970. The development of the Red Sea and
Gulf of Aden in relation to plate tectonics [abstr., with dis-
Analyse tectonique et e ¤tats de contraintes ce ¤nozo| «ques dans la zone centrale de la faille Nord Anatolienne. The 'se de doctorat
- S O º Ver
O º ver, S., 1996. Analyse tectonique et e ¤tats de contraintes
ce ¤nozo| «ques dans la zone centrale de la faille Nord Anatolienne. The 'se de doctorat, Universite ¤ Paris Sud-Orsay,
260 pp.
Late Cenozoic stress change along the central North Anatolian fault zone (Turkey). Ann. Tecton. 11, 75^101. Perinc °ek, D., 1991. Possible strand of the North Anatolian Fault in the Thrace Basin, Turkey: An interpretation
- S O º Ver
- O Bellier
- A Poisson
- J Andrieux
O º ver, S., Bellier, O., Poisson, A., Andrieux, J., 1997. Late
Cenozoic stress change along the central North Anatolian
fault zone (Turkey). Ann. Tecton. 11, 75^101.
Perinc °ek, D., 1991. Possible strand of the North Anatolian
Fault in the Thrace Basin, Turkey: An interpretation. Am.
Assoc. Pet. Geol. Bull. 75, 241^257.
The North Anatolian fault zone Major active faults of the world; results of IGCP Project 206. Final meeting of IGCP Project 206, ‘A worldwide comparison of the characteristics of major active faults
- A A Barka
- R C Buckman
- P L Hancock
Barka, A.A., Buckman, R.C., Hancock, P.L., 1992. The North
Anatolian fault zone Major active faults of the world; results of IGCP Project 206. Final meeting of IGCP Project
206, 'A worldwide comparison of the characteristics of major active faults', 6, Suppl., pp. 164^195.
Analyse tectonique et états de contraintes cénozoı̈ques dans la zone centrale de la faille Nord Anatolienne
- S Över
Regional and petroleum geology of the Black Sea and surrounding region
- N Görür
- O Tüysüz
The development of the Red Sea and Gulf of Aden in relation to plate tectonics [abstr., with discussion]. A discussion on the structure and evolution of the Red Sea and the nature of the Red Sea, Gulf of Aden and Ethiopia rift junction
- McKenzie
Regional and Petroleum Geology of the Black Sea and Surrounding Region
- C J Banks
- A G Robinson