Andrés Maldonado's research while affiliated with Instituto Andaluz de Ciencias de la Tierra and other places

Publications (77)

Article
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Ona Basin, the westernmost oceanic basin in the southern Scotia Sea, is affected by the opposite flows of Circumpolar Deep Water (CDW) and Weddell Sea Deep Water (WSDW); thus, it represents a key location for exploring seafloor morphologies influenced by bottom currents. The present study aims to capture the spatial arrangement of recent subsurface...
Article
The Scotia Sea is a complex geological area located in the Southern Ocean which evolution is closely linked to the opening of the Drake Passage. Structural highs of continental nature derived from the former continental bridge between South America and the Antarctic Peninsula surround the abyssal plains of the Scotia Sea, restricting small isolated...
Article
A detailed morphologic and seismic stratigraphic analysis of the continental margin offshore of Adelaide Island on the Pacific Margin of the Antarctic Peninsula (PMAP) is described based on the study of a regular network of reflection multichannel seismic profiles and swath bathymetry. We present an integrated study of the margin spanning the shelf...
Article
The spatial distribution and temporal occurrence of mass transport deposits (MTDs) in the sedimentary infill of basins and submerged banks near the Scotia-Antarctic plate boundary allowed us to decode the evolution of the tectonic activity of the relevant structures in the region from the Oligocene to present-day. The 1020 MTDs identified in the av...
Article
Dove Basin, a small oceanic domain located within the southern Scotia Sea, evidences a complex tectonic evolution linked to the development of the Scotia Arc. The basin also straddles the junction between the main Southern Ocean water masses: the Antarctic Circumpolar Current (ACC), the Southeast Pacific Deep Water (SPDW) and the Weddell Sea Deep W...
Article
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The aim of the present study was to characterise the morpho-sedimentary features and main stratigraphic stacking pattern off the Tierra del Fuego continental margin, the north-western sector of the Scotia Sea abyssal plain (Yaghan Basin) and the Malvinas/Falkland depression, based on single- and multi-channel seismic profiles. Distinct contourite f...
Article
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The Powell Basin is one of the few present-day examples of a small isolated ocean basin largely surrounded by blocks of continental crust. The continental blocks in this basin result from the fragmentation of the northern Antarctic Peninsula. This basin was created by the eastward motion of the South Orkney microcontinent relative to the Antarctic...
Article
Sedimentary processes in small, isolated oceanic basins that form adjacent to continental margins but detached from continents remain poorly understood. This work describes two such basins located in the southern Scotia Sea, the Protector and Pine basins. We analysed multichannel seismic profiles to interpret morphostructural features and stratigra...
Article
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Analysis of a new regional compilation of magnetic anomalies from marine, aeromagnetic and satellite data reveals the main structural/tectonic elements of the Scotia Arc. The most relevant magnetic anomaly in the continental crust, the Pacific Margin Anomaly (PMA), is related to composite magmatic arc batholiths. It was emplaced by subduction proce...
Article
The N-S trending Scan Basin is the easternmost deep basin north of the South Scotia Ridge, which is a geologically complex structural elevation that hosts the strike-slip boundary between the Scotia and Antarctic plates. We characterized the main morpho-structural features of the basin by analyzing the available multichannel seismic reflection prof...
Article
The southern margin of the Scotia Sea hosts the convergent boundary between the Scotia and Antarctic plates where a number of small basins are sitated. Mass transport deposits (MTDs) within two of these small basins, Dove and Scan basins, reveal the importance of seismicity, slope instabilities and depositional processes in their growth patterns. S...
Article
The Scotia Arc, situated between South America and Antarctica, is one of the Earth’s most important ocean gateways and former land bridges. Understanding its structure and development is critical for the knowledge of tectonic, paleoenvironmental and biological processes in the southern oceans and Antarctica. It extends from the Drake Passage in the...
Article
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Ona Basin is a small intra-oceanic basin located in the southwestern corner of the Scotia Sea. This region is crucial for an understanding of the early phases of opening of Drake Passage, since it may contain the oldest oceanic crust of the entire western Scotia Sea, where conflicting age differences from Eocene to Oligocene have been proposed to d...
Article
1] The Drake Passage is considered a gateway for oceanic and asthenospheric flows since its opening, entailing widespread consequences for climate and plate tectonics, respectively. Both the surface and the 50 km upward continued Bouguer anomaly maps of the Scotia Sea and surrounding areas, based on Gravity Recovery and Climate Experiment gravity s...
Article
The sedimentary record in the vicinity of the triple junction at the southern Drake Passage is analyzed in order to decode the palaeoceanographic evolution and the influence of tectonic events. The break-up of the last connection between South America and Antarctica led to the circulation of important oceanographic bottom flows, including the Antar...
Article
An international 3-day meeting in which participants discussed geodynamic and multidisciplinary topics related to the evolution of the Scotia Arc was held at the Andalucía Institute of Earth Sciences (Spanish Research Council (CSIC)/University of Granada (UGR)) in Granada, Spain. The Scotia Arc encompasses southern South America, the Antarctic Peni...
Article
Identification of the pre-glacial, transitional and full glacial components in the deep-sea sedimentary record is necessary to understand the ice sheet development of Antarctica and to build circum-Antarctic sediment thickness grids for palaeotopography/-bathymetry reconstructions, which constrain palaeoclimate models. A ~ 3300 km long Weddell Sea...
Article
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Initial stages of oceanic spreading in the Bransfield Rift from magnetic and gravity data analysis, Tectonophysics (2012), doi: 10.1016/j.tecto.2012.09.016 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will unde...
Data
The deep sea sedimentary record is an archive of the pre-glacial to glacial development of Antarctica and changes in climate, tectonics and ocean circulation. Identification of the pre-glacial, transitional and full glacial components in the sedimentary record is necessary for ice sheet reconstruction and to build circum-Antarctic sediment thicknes...
Article
Multibeam echosounder data and TOPAS seismic reflection profiles collected during the AntPac 1997, Scan 2004, and Scan 2008 cruises aboard the RV Hespérides reveal a host of surficial geomorphological features as yet poorly investigated in the Scan Basin, south-central Scotia Sea. This area represents one of the deep gateways between the Weddell Se...
Article
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The study of more than 500 single- and multichannel seismic records enabled the generation of a detailed palaeo-bathymetric map of the Messinian surface over most of the Alboran Basin, Western Mediterranean. This regional surface is characterized by several erosional features (channels, terraces and canyons) and topographic highs (structural, volca...
Article
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The analysis of multichannel seismic profiles reveals that the distribution of sedimentary depocenters within the Protector and Pirie basins of the southern Scotia Sea, close to the Scotia-Antarctica plate boundary, is largely due to the morpho-structural control of the basement and influenced by the distribution of bottom currents. Both basins con...
Chapter
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Una revisión de la base de perfiles sísmicos existente en el sector septentrional de la plataforma continental del Golfo de Cádiz ha permitido identificar y caracterizar una serie de fallas normales que afectan a las unidades sedimentarias del Cuaternario superior. En el margen Bético, zona comprendida entre las localidades de Chipiona y Conil de l...
Article
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The Powell Basin is a small oceanic basin located at the NE end of the Antarctic Peninsula developed during the Early Miocene and mostly surrounded by the continental crusts of the South Orkney Microcontinent, South Scotia Ridge and Antarctic Peninsula margins. Gravity data from the SCAN 97 cruise obtained with the R/V Hespérides and data from the...
Article
The opening of oceanic basins constitutes one of the key features of Plate Tectonics because it determines the rifting and displacement of the continental crustal blocks. Although the mechanisms of development of large oceans are well known, the opening and evolution of small and middle size oceanic basins have not been studied in detail. The Prote...
Conference Paper
Bransfield Basin is located at the Pacific margin of the Antarctic Peninsula and constitutes an incipient oceanic back-arc basin. This basin developed as a consequence of the separation of the South Shetland Blockfrom the Antarctic Peninsula. Analysis of multichannel seismic profiles from Brazilian, Spanish, Japanese and Chinese cruises allows the...
Conference Paper
Discovery Bank is located at the eastern end of the South Scotia Ridge. The new geophysical data point that this bank is continental in nature and may be a former fragment of the continental bridge that connected South America and the Antarctic Peninsula before the Oligocene and is located at the Scotia-Antarctic plate boundary along the South Scot...
Chapter
Multichannel and high resolution seismic profiles from the central Scotia Sea and northern Weddell Sea show a sequence of seismic units interpreted to be the result of high-energy bottom currents. The seismic character of the units is indicative of active bottom flows, which developed extensive drifts under the influence of the Weddell Sea Bottom W...
Article
Multichannel and high-resolution seismic profiles complemented with swath bathymetry show a variety of contourite deposits in the northern Weddell Sea resulting from the interaction between bottom currents and the seafloor physiography. Seven types of contourite drifts are identified based on the seismic signature, reflector configuration and geome...
Article
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The opening of Southern Ocean gateways was critical to the formation of the Antarctic Circumpolar Current and may have led to Cenozoic global cooling and Antarctic glaciation. Drake Passage was probably the final barrier to deep circumpolar ocean currents, but the timing of opening is unclear, because the Shackleton Fracture Zone could have blocked...
Article
The Bransfield Basin is located off the northern tip of the Antarctic Peninsula. The analysis of multichannel seismic reflection profiles allows the shallow structure of the Bransfield Basin and its eastwards prolongation through the Scotia Sea to be imaged. The Bransfield Basin is asymmetrical, with most of the sediment input coming from the passi...
Article
Mass-movement is an important process controlling the sedimentary structure and growth patterns of the Ebro continental slope during recent time (at least Quaternary). About 37% of the slope surface is affected by mass-movement features, which are variable in distribution, size and morphology. The northern and central sectors are mainly affected by...
Article
The lateral ending of the South Shetland Trench is analysed on the basis of swath bathymetry and multichannel seismic profiles in order to establish the tectonic and stratigraphic features of the transition from an northeastward active to a southwestward passive margin style. This trench is associated with a lithospheric-scale thrust accommodating...
Article
New swath bathymetry with multichannel and high resolution seismic profiles shows a variety of contourite drift, sediment wave morphologies, and seismic facies in the central Scotia Sea. The deposits are to be found at the confluence between the two most important bottom current flows in the southern ocean: the eastward flowing Antarctic Circumpola...
Article
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New bathymetric and magnetic anomaly data from the Phoenix Ridge, Antarctica, show that extinction of all three remaining segments occurred at the time of magnetic chron C2A (3.3 ± 0.2 Ma), synchronous with a ridge-trench collision south of the Hero Fracture Zone. This implies that the ultimate cause of extinction was a change in plate boundary for...
Article
The Shackleton Fracture Zone, which forms the boundary between the Antarctic and Scotia plates in the Drake Passage, is characterized by a present-day left-lateral motion. The West Scotia Ridge, an extinct spreading centre, formed the oceanic crust of the western Scotia Plate and intersects the Shackleton Fracture Zone in a complex deformed area. M...
Article
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New swath bathymetric, multichannel seismic and magnetic data reveal the complexity of the intersection between the extinct West Scotia Ridge (WSR) and the Shackleton Fracture Zone (SFZ), a first-order NW-SE trending high-relief ridge cutting across the Drake Passage. The SFZ is composed of shallow, ridge segments and depressions, largely parallel...
Article
Ten seismic facies assemblages organized into architectural elements have been identified on the basis of multichannel seismic profiles in the Powell Basin. These facies include: sheet drapes with parallel high-amplitude reflectors, sheet drapes with cyclic reflectors, sheet drapes with chaotic and moderate-amplitude reflectors, broad lenses with c...
Article
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The study of the Gulf of Cadiz on the basis of multichannel seismic profiles and wells illustrates the stratigraphy and tectonics. The evolution of the southern Iberian margins was more complex than in most North Atlantic margins since it entailed several phases of rifting, convergence and strike-slip motions. Three main tectonic provinces surround...
Article
Grain size of 294 samples and mineralogical analysis of 364 surface samples from the Spanish continental shelf and upper slope of the Gulf of Cadiz delineate four sediment facies that derive mainly from siliciclastic sources. The northern area is formed by the mud-rich prodelta of the Guadalquivir River, parallel to the coast and progradational tow...
Article
The Cadiz continental margin of the northeastern Gulf of Cadiz off Spain was selected for a multidisciplinary project because of the interplay of complex tectonic history between the Iberian and African plates, sediment supply from multiple sources, and unique Mediterranean Gateway inflow and outflow currents. The nature of this complex margin, par...
Article
The late Quaternary pattern of sedimentary facies on the Spanish Gulf of Cadiz continental shelf results from an interaction between a number of controlling factors that are dominated by the Atlantic inflow currents flowing southeastward across the Cadiz shelf toward the Strait of Gibraltar. An inner shelf shoreface sand facies formed by shoaling w...
Article
This study provides an integrated view of the growth patterns and factors that controlled the evolution of the Gulf of Cadiz continental margin based on studies of the tectonic, sedimentologic and oceanographic history of the area. Seven sedimentary regimes are identified, but there are more extensive descriptions of the late Cenozoic regimes becau...
Article
Seismic facies and Quaternary depositional systems of the Gulf of Cadiz have been characterized by means of high-resolution seismic profiles (airguns, Geopulse and ORE 3.5 kHz). A total of 11 Pleistocene and two Holocene sequences separated by type-1 or type-2 discontinuities were identified. The age of the depositional sequences was determined bas...
Article
The Gulf of Cadiz is located at the boundary between the Eurasian and African plates in the southwestern margin of Iberia, and it straddles a place of major tectonic events since the Mesozoic. The Gibraltar belt migrated westward into the Gulf of Cadiz during the Miocene, while a north–south trending margin was built upon allochthonous formations a...
Article
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An area of mudwave development has been identified from the northwestern Powell Basin, northern Weddell Sea, Antarctica. The wave-field is located near the base of the continental slope in water depths of 2800–3100 m, along the pathway of Antarctic Bottom Water (AABW) flow from the Weddell Sea. The waves are presently active, migrating up a low ang...
Article
The Pliocene—Quaternary pattern of contourite deposits on the eastern Gulf of Cadiz continental slope results from an interaction between linear diapiric ridges that are perpendicular to slope contours and the Mediterranean undercurrent that has flowed northwestward parallel to the slope contours and down valleys between the ridges since the late M...
Article
Base-of-slope aprons that lack significant channel development and are fed by multiple sediment sources (i.e., numerous slope failures or debris chutes) represent an alternative facies organization to submarine fans that possess channels and are fed by canyon point sources of allochthonous sediment. Two styles of base-of-slope apron deposition are...
Article
Seven sediment types are identified from the analysis of 60 piston cores in the Ebro turbidite systems (1200–1800 m deep) between the Ebro shelf and the Valencia Trough in the northwestern Mediterranean Sea. These sediments are grouped into five facies associations: channel floor of erosive-depositional channel-levee complex, levee of erosive-depos...
Article
The Ebro continental margin sedimentation system originated with a Messinian fluvial system. This system eroded both a major subaerial canyon cutting the margin southeastward from the present Ebro Delta and an axial valley that drained northeastward down Valencia Trough. Post-Messinian submergence of this topography and the Pliocene regime of high...
Article
The eastern and southeastern margins of Iberia were affected during Neogene time by a rifting tectonic process superimposed on the Alpine structures. The Valencia Trough, situated off the northeastern coast of Iberia, has been defined as a rift system that began its activity in late Oligocene-Early Miocene time. The opening of the Valencia Trough p...
Article
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The Pliocene and Pleistocene deposits of the Spanish Ebro margin overlie a regional unconformity and contain a major disconformity. These unconformities, named Reflector M and Reflector G, mark the bases of two seismic sequences. Except for close to the upper boundary where a few small channel deposits are recognized, the lower sequence lacks chann...
Article
The Ebro continental margin from the coast to the deep sea off northeastern Spain was selected for a multidisciplinary project because of the abundant Ebro River sediment supply, Pliocene and Quaternary progradation, and margin development in a restricted basin where a variety of controlling factors could be evaluated. The nature of this young pass...
Article
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The Valencia Valley is a Quaternary, 200 km long deep-sea valley in the Valencia Trough, Western Mediterranean Sea. A swathmapping survey approximately mid-way along the valley length, where the floor has an average gradient of 1:250 (0.2), shows valley walls that rise 200 to 350 m above the valley floor, with slopes of 2 to 18. Sediment forming th...
Article
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The northern continental slope off the Ebro Delta has a badland topography indicating major slope erosion and mass movement of material that deposits sediment into a ponded lobe. The southern slope has a low degree of mass movement activity and slope valleys feed channel levee-complexes on a steep continental rise. The last active fan valley is V-s...
Article
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The Valencia Fan, one of the larger deep-sea depositional systems in the western Mediterranean Sea, developed in the large depression between the Valencia Trough and the Balearic Basin Plain. Six main lithoseismic units are identified and sedimentary processes inferred from 6000 km of sparker profiles. This fan is largely formed by channeliz