Article

Depositional sequences in the Kimmeridgian of the Voconian Basin (France) controlled by carbonate export from shallow-water platforms

November 2003
Geobios 36(6)

DOI:10.1016/j.geobios.2003.03.004

Authors:

Claude Colombié

Claude Bernard Lyon 1 University

Andreas Strasser

University of Fribourg

Detailed sedimentological analyses and sequential and cyclostratigraphic interpretations in the Kimmeridgian of the Swiss Jura and the Vocontian Basin lead to a high-resolution correlation from the platform to the basin where the biostratigraphy is well established. Several orders of depositional sequences are defined. Their duration is estimated from the time frame given in the sequence-chronostratigraphic chart of Hardenbol et al. (1998). It is suggested that an elementary sequence formed in tune with the 20 ky precession cycle. Small-scale and medium-scale sequences correspond to the 100 and 400 ky eccentricity cycles, respectively. The platform-to-basin correlation shows that the composition of the hemipelagic and pelagic deposits depends to a large part on cyclical variations of carbonate production in shallow-marine environments and subsequent export to the basin. The distribution of thick versus thin marl-limestone alternations and carbonate-dominated versus marl-dominated intervals observed in the basinal sections is explained by the superposition of high- and low-frequency sea-level changes that controlled the carbonate productivity on the platform and the export potential of carbonate mud to the basin.

High-resolution cyclostratigraphic analysis from magnetic susceptibility in a Lower Kimmeridgian (Upper Jurassic) marl–limestone succession (La Méouge, Vocontian Basin, France)

Article

Jan 2008
SEDIMENT GEOL

High-resolution magnetic susceptibility (MS) analysis was carried out on a Lower Kimmeridgian alternating marl–limestone succession of pelagic origin that crops out at La Méouge (Vocontian Basin, southeastern France). The aim of the study was to characterize the strong, dm-scale sedimentary cyclicity of the succession at a very high resolution, and to analyze the cycles for evidence of astronomical forcing. From marl to limestone, MS varies progressively and closely tracks the highest frequency cyclicity corresponding to the basic marl–limestone couplets. Long-term wavelength cycling modulates the high-frequency cyclicity (couplets), and appears to be controlled by clay content. Spectral analysis of the MS record reveals the presence of the complete suite of orbital frequencies in the precession, obliquity, and eccentricity (95–128 ka and 405 ka) bands with very high amplitude of the precession index cycles originating from dm-scale couplets. 405 ka-eccentricity cycles are very pronounced in the MS maxima of the marl members of the couplets, suggesting eccentricity-driven detrital input to the basin. 405 ka-orbital tuning of the MS maxima further sharpens all of the orbital frequencies present in the succession. These results are similar to those of previous studies at La Méouge that used carbonate content observed in field. Our results are also in accordance with cyclostratigraphic studies in Spain and Canada that report dominant precession index forcing. By contrast, in the Kimmeridge Clay (Dorset, UK), obliquity forcing dominates cyclic sedimentation, with weaker influence from the precession index. Ammonite zone duration estimates are made by counting the interpreted precession cycles, and provide an ultra-high resolution assessment of geologic time. In sum, this study demonstrates the power of the MS as a proxy in characterizing the high-resolution cyclostratigraphy of Mesozoic sections, particularly in alternating marl–limestone successions, and for high-resolution correlation and astronomical calibration of the geologic time scale.

Tethyan-to-boreal correlation in the Kimmeridgian using high-resolution sequence stratigraphy (Vocontian Basin, Swiss Jura, Boulonnais, Dorset)

Article

Full-text available

Jun 2007

Ammonite biostratigraphy plays a central role in the definition of Jurassic stratigraphy. Nevertheless, the strong provincialism of European ammonite species during the Kimmeridgian is a long-standing problem in correlation attempts between the boreal and Tethyan faunal realms. Moreover, the sequence-stratigraphic interpretations for northern and southern Europe given in the Jurassic chronostratigraphic chart of Hardenbol et al. in SEPM Publ. 60 (chart) (1998) are different. The present study aims to resolve this correlation problem in order to better understand the connections between the boreal and the Tethyan realms during the Kimmeridgian. A sedimentological and high-resolution sequence-stratigraphic interpretation is presented for two unpublished sections (Cras d’Hermont and Roche de Mars) in the northern Swiss Jura, where recently discovered ammonites display both boreal and Tethyan influences. Then, these sections are correlated with the same time interval in the central Swiss Jura and Vocontian Basin, which belong to the Tethyan realm. Lastly, a long-distance transect is constructed between the Vocontian Basin, Swiss Jura, northern France, and southern England, the last two areas being part of the sub-boreal realm. The main results of this work are that: (1) third-order depositional sequences, and also higher-frequency sequences, can be correlated from the Tethyan to the boreal realm; (2) the sequence-stratigraphic interpretation given by Hardenbol et al. in SEPM Publ 60 (chart) (1998) for northern Europe seems to be accurate and agrees with the sequence-stratigraphic framework established in the Swiss Jura; (3) the Late Kimmeridgian of the Swiss Jura displays boreal influences; (4) integrated high-resolution sequence-stratigraphic and cyclostratigraphic studies are a valuable approach for bridging the correlation gap between northern and southern Europe.

Orbitally forced climate and sea-level changes in the Paleoceanic Tethyan domain (marl–limestone alternations, Lower Kimmeridgian, SE France)

Article

Jun 2010
PALAEOGEOGR PALAEOCL

High-resolution analysis of multiple climatic proxies was carried out on a ∼ 8.5-m Lower Kimmeridgian interval of a pelagic marl–limestone succession at Châteauneuf-d'Oze (Vocontian Basin, southeastern France). The aim of the study was to characterize the orbitally controlled sedimentary cyclicity and to decipher paleoclimatic and paleoceanographic changes. All analysed proxies (magnetic susceptibility, carbonate content, manganese content, and bulk carbon and oxygen stable isotopes (δ13C and δ18O) respond in synchrony to orbitally forced climate change. Precession index cycles modulated by short (∼ 100 kyr) eccentricity cycles are strongly expressed in magnetic susceptibility, carbonate and Mn contents but less so in δ18O. Obliquity cycles are expressed in manganese and particularly in δ13C. The orbital forcing was conferred to these rhythmic pelagic sediments via paleoclimatic and paleoceanographic changes as follows. Detrital input and marine carbonate production are recorded by the magnetic susceptibility and carbonate signals with strong precession cyclicity. Calcareous nannofossil analysis shows the omnipresence of coccoliths and debris of coccoliths in the marls and limestones, suggesting that the carbonate production was in largest part in situ. Precession index may exert oscillations in the antagonist marine surface productivity and detrital flux processes via solar radiation change. Oxygenation of the seafloor leading to redox cycles is detected in the manganese signal and supported by the δ13C record, with a strong expression of the obliquity. Finally, paleotemperature variations were deduced from the δ18O record, although this latter has been in part perturbed by diagenesis.

Carbon- and oxygen-isotope records of palaeoenvironmental and carbonate production changes in shallow-marine carbonates (Kimmeridgian, Swiss Jura)

Article

Jan 2010
GEOL MAG

Carbon- and oxygen-isotope ratios are commonly used to correlate shallow- and deep-marine successions. Carbon- and oxygen-isotope analyses were performed on bulk-carbonate samples from two Kimmeridgian sections of the Swiss Jura platform in order to correlate them with biostratigraphically well-dated coeval sections in the adjacent basin. On the platform, a general decrease in δ¹³C and δ¹⁸O values from the base to the top of the studied interval is measured, whereas time-equivalent pelagic–hemipelagic carbonates record an increase in carbon- and oxygen-isotope ratios. Moreover, the measured δ¹³C and δ¹⁸O values are generally lower than those indicated for the Kimmeridgian open ocean and show high-frequency variations superimposed on the general trend. Samples were screened for diagenetic alteration using optical and cathodoluminescence petrography and coupled carbon- and oxygen-isotope and trace-element analyses. Some observations favour a role for diagenetic alteration, but isotopic and elemental trends as well as sedimentological evidence suggest that the more negative values of δ¹³C and δ¹⁸O relative to Kimmeridgian seawater are also due to local environmental conditions. High-frequency changes in δ¹⁸O and δ¹³C values most likely result from variations in salinity and carbonate production and accumulation rates. These variations were produced by different water masses that were isolated from the open ocean and developed their own geochemical signatures. Repeated isolation was induced by high-frequency sea-level fluctuations and helped by irregular platform morphology. Consequently, carbon- and oxygen-isotope records in shallow-marine carbonates can be used for stratigraphic correlation only if their origin is well known.

Facies, cycles, and controls on the evolution of a keep-up carbonate platform (Kimmeridgian, Swiss Jura)

Article

Dec 2005

During the Late Jurassic, accelerated ocean-floor spreading and associated sea- level rise were responsible for a worldwide transgression, which reached its maximum in the Late Kimmeridgian. In many Western European basins, this major sea-level rise led to the formation of marly and condensed sections. In the Swiss Jura, however, a shallow carbonate platform kept growing and only subtle changes in the stratigraphic record suggest an increasingly open-marine influence. Field observations and thin-section analyses reveal that the central Swiss Jura was at that time occupied by tidal flats and by more or less open marine lagoons where shoals and bioherms developed. The evolution through time of sedimentary facies and bed thicknesses permits the definition of small-, medium-, and large-scale depositional sequences. The diagnostic features of these sequences are independent of scale and seem largely controlled by the Kimmeridgian second-order transgression. A high-resolution sequence- stratigraphic correlation with biostratigraphically well-dated hemipelagic and pelagic sections in the Vocontian Basin in France reveals that: (i) The most important increase in accommodation recorded in the Kimmeridgian of the central Swiss Jura occurs in the Eudoxus ammonite zone (Late Kimmeridgian) and corresponds to the second-order maximum flooding recognized in many sedimentary basins. (ii) The small- and medium-scale sequences have time durations corresponding to the first and second orbital eccentricity cycle (i.e. 100 and 400 ka, respectively), suggesting that sedimentation on the platform and in the basin was at least partly controlled by cyclic environmental changes induced by insolation variations in the Milankovitch frequency band. The comparison of the high-resolution temporal framework defined in the Swiss Jura and Vocontian Basin with the sequence- stratigraphic interpretation realized in other Western European basins shows that the large-scale sequence boundaries defined in the Kimmeridgian of the Swiss Jura appear in comparable biostratigraphic positions in most Western European basins. Discrepancies that occur are probably because of local or regional tectonics.

A Jurassic record encodes an analogous Dansgaard–Oeschger climate periodicity

Article

Full-text available

Feb 2022

Earth’s past climate exhibits short-term (1500-year) pronounced fluctuations during the last glacial period, called Dansgaard–Oeschger (DO) glacial events, which have never been detected in pre-Quaternary times. The record of DO equivalent climate variability in Mesozoic strata can provide constraints on understanding these events. Here we highlight a prominent 1500-year cyclicity in a Jurassic (~ 155 Ma) ice-free sedimentary record from the Tethyan Basin. This Jurassic 1500-year cyclicity is encoded in high-resolution magnetic susceptibility (MS) proxy data reflecting detrital variations, and expressed as marl-limestone couplets. Additionally, MS data detect the modulation of these DO-scale couplets by supercouplet sets, reflecting the precession and its harmonics. We suggest that this Jurassic DO-like cyclicity may originate from paleo-monsoon-like system, analogous to the record of DO events in the Pleistocene East Asian monsoon archives. Paleogeographic reconstructions and atmosphere–ocean simulations further support the potential existence of strong, ancient monsoon circulations in the Tethyan Basin during the Jurassic.

Comment on "Orbitally forced climate and sea-level changes in the Paleoceanic Tethyan domain (marl–limestone alternations, Lower Kimmeridgian, SE France) " by S. Boulila, M. de Rafélis, L. A. Hinnov, S. Gardin, B. Galbrun, P.-Y. Collin [Palaeogeography Palaeoclimatology Palaeoecology 292 (2010) 57–70]

Article

Jun 2011
PALAEOGEOGR PALAEOCL

A recent paper by Boulila et al. (2010) reports on orbitally-forced cycles recorded as marl-limestone alternations in one Lower Kimmeridgian section, Chateauneuf d'Oze (SE France, Tethyan domain). In an attempt to illustrate the in situ (i.e., pelagic) origin of carbonates in marls and limestones, the authors challenged the results of previous work concerning sections from other Tethyan areas of similar age, which demonstrate that nannofossil abundance is originally higher in marls than in limestones. Boulila et al. (2010) present data acquired with optical and Scanning Electron microscopes estimating nannofossil contribution to the rocks. However, their selected illustrations do not support a high contribution of the nannofossils to the carbonate fraction of their samples or their interpretation of the finest fraction of the rocks (micarbs). Furthermore, according to their data on carbonate content of the rocks, they did not analyse true marl-limestone alternations, but slightly argillaceous limestones and limestones. Boulila et al. (2010) also criticize earlier work providing a sequence stratigraphy interpretation of the Chateauneuf d'Oze section. However, contrarily to these earlier works, they did not consider platform-to-basin correlations that are essential in order to understand the sedimentary dynamics at the basin-wide scale. This comment challenges the work by Boulila et al. (2010) that largely underestimates the role of carbonate production on shallow platforms and its subsequent export basinwards as a major mechanism controlling the sedimentation in epicontinental basins.

Reply to the comment on "Orbitally forced climate and sea-level changes in the Paleoceanic Tethyan domain (marl–limestone alternations, Lower Kimmeridgian, SE France)" by S. Boulila, M. de Rafélis, L. A. Hinnov, S. Gardin, B. Galbrun, P.-Y. Collin [ Palaeogeography Palaeoclimatology Palaeoecology 292 (2010) 57–70]

Article

Jun 2011
PALAEOGEOGR PALAEOCL

In their comment on our paper (Boulila S. et al. 2010 — Orbitally forced climate and sea-level changes in the Paleoceanic Tethyan domain, marl–limestone alternations, Lower Kimmeridgian, SE France, Palaeogeog. Palaeoclim. Palaeoecol., 292, 57–70), Mattioli and co-authors (E. Mattioli et al., Comment on "Orbitally forced climate and sea-level changes in the Paleoceanic Tethyan domain (marl–limestone alternations, Lower Kimmeridgian, SE France) " by S. Boulila, M. de Rafélis, L. A. Hinnov, S. Gardin, B. Galbrun, P.-Y. Collin [Palaeogeography Palaeoclimatology Palaeoecology 292 (2010) 57–70], Palaeogeography Palaeoclimatology Palaeoecology, this issue) criticize our depositional model of Lower Kimmeridgian marl-limestone alternations in the Vocontian Basin (SE France) and contest the nannofossil contribution to the build-up of micritic limestones. The model that we proposed links maxima of orbitally forced insolation with high sea-level, weaker continental erosion, and reduced detrital input, and insolation minima to low sea-level, increasing erosion of detrital materials and their transport to the basin. This involves a competition between multiple variable fluxes, and is supported by a multi-proxy study (magnetic susceptibility, weight percent carbonate, manganese content coupled with cathodoluminescence analysis, oxygen and carbon stable isotopes, and calcareous nannofossil analysis) on a 8.5-m thick interval from a ~ 40 m-thick section at Châteauneuf-d'Oze (SE France). This differs substantially from previous models suggesting that detrital input to this part of the Vocontian Basin constitutes ‘background noise’, and that the main mechanism inducing the marl–limestone rhythms was orbitally forced carbonate mud export from the Jura Platform.

Tectonic and eustatic control on a mixed siliciclastic–carbonate platform during the Late Oxfordian–Kimmeridgian (La Rochelle platform, western France)

Article

Jan 2010
SEDIMENT GEOL

Facies analysis and correlation of high-order sequences in middle-outer ramp successions: Variations in exported carbonate on basin-wide δ13Ccarb (Kimmeridgian, NE Spain)

Article

May 2005

Carbonate mud that accumulated in the deep parts of a late Kimmeridgian carbonate ramp (Iberian Basin, NE Spain) was partly derived by resedimentation from shallow water production areas. High-frequency sea-level changes, probably driven by climatic changes in tune with precession and short-eccentricity cycles, affected carbonate production and the amount of exported sediment. Facies analysis and correlation of three outcrops located in middle and outer ramp settings allows a comparison of high-order sequences (bundles of beds and sets of bundles) across a ramp transect and an assessment of the carbonate factory. Analysis of the storm deposits found in middle ramp settings identifies deepening to shallowing high-frequency cycles based on the level of exported carbonate. In outer ramp areas, many of the bundles exhibit a thinning trend, indicating a progressive decrease of carbonate production and hence, carbonate export during periods of high-frequency sea-level rise. δ13Ccarb values show a gradual increase through the studied long-term transgressive interval ranging from 1·5‰ to 2·8‰. Within this long-term evolutionary trend, short-term δ13Ccarb fluctuations occur that correspond with some of the high-order cycles defined from sedimentary facies analysis. These short-term δ13Ccarb shifts are interpreted as shifts in carbonate export from shallow reef regions to the outer ramp. A consequence of this study is that variation in δ13Ccarb can be used for correlation in outer ramp successions, at least on a basin-wide scale.

Benthic biota (nummulites) response to a hyperthermal event: Eccentricity-modulated precession control on climate during the middle Eocene warming in the Southern Mediterranean

Article

Jul 2023
PALAEOGEOGR PALAEOCL

The Kimmeridgian of the south-western margin of the Holy Cross Mts., central Poland: stratigraphy and facies development. Part I. From deep-neritic sponge megafacies to shallow water carbonates

Article

Dec 2020

Andrzej Wierzbowski

Inverted Responses of the Carbon Cycle to Orbital Forcing in Mesozoic Periplatform Marginal Basins: Implications for Astrochronology

Article

Full-text available

Jun 2020

Astrochronology depends on the faithful record of insolation forcing in climatic proxies, including the carbon isotope composition measured on bulk carbonates (δ¹³Ccarb). In marginal basins close to carbonate platforms, the source of carbonate is varied, which can impact the record of the astronomical cycles in the δ¹³Ccarb signal. We compare here the δ¹³Ccarb values together with detrital and weathering proxies before and during a crisis in the platform carbonate production (Weissert event, Valanginian, ~135 Ma) to document how a change in the carbonate source can affect the record of the orbital forcing by the carbon isotope system. The level of burial diagenesis was insufficient to alter the clay mineral assemblages, which are linked to cyclic changes in weathering conditions. The δ¹³Ccarb values correspond to the values measured in other parts of the basin, which experienced various levels of burial diagenesis, suggesting that they also reflect a paleoenvironmental signal. In marl beds, the δ¹³Ccarb values increase with detrital and kaolinite content, suggesting that humid/arid cycles controlled the evolution of the δ¹³Ccarb signal in marl beds. Before the Weissert event, the δ¹³Ccarb values in the limestone beds increase with CaCO3 content and arid conditions. This can reflect the change of type of carbonate produced in shallow‐marine environments and exported to the basin. These environmental changes disrupted the record of the eccentricity cycles in the δ¹³Ccarb signal. The sources of carbonate must therefore be clearly identified and documented before using the δ¹³Ccarb series for orbital tuning in hemipelagic areas close to carbonate platforms.

Sedimentology and carbon isotope stratigraphy of the Rhaetian Hochalm section (Late Triassic, Austria)

Article

May 2020
GLOBAL PLANET CHANGE

The Rhaetian (201–209 Ma, the latest stage of the Triassic) is an important time-interval for the study of environmental changes preceding the End-Triassic Mass extinction. A detailed sedimentological and chemostratigraphic study was conducted in the lower Kössen Formation at Hochalm (Austria), the type-section of the Hochalm Member (Mb). This section exposes mid-Rhaetian sediments deposited in an intraplatform shallow marine basin on the north-western margin of the Tethys. The study highlights eight apparent shallowing-upward sequences from the middle of Unit 2 to Unit 4 of the Hochalm Mb stacked within the long-term transgression that characterizes the Kössen Formation. Both the bulk carbonate and the bulk organic matter δ¹³C records indicate the presence of a distinct increase in carbon isotope values in the lower part of the lower Hochalm Mb. This excursion might represent a new chemostratigraphic marker that could be used for refining the Rhaetian stratigraphy and represents another important Late Triassic carbon-cycle perturbation prior to the major disturbance associated with the End Triassic biotic crisis.

Facies Architecture in Carbonate Ramps: Learned Lessons from Jurassic Cases Studies in the Iberian Basin: IEREK Interdisciplinary Series for Sustainable Development

Chapter

Jan 2019

Beatriz Bádenas

Mechanisms of Preservation of the Eccentricity and Longer-term Milankovitch Cycles in Detrital Supply and Carbonate Production in Hemipelagic Marl-Limestone Alternations

Article

Jan 2018

Mathieu Martinez

Mechanisms of Preservation of the Eccentricity and Longer-term Milankovitch Cycles in Detrital Supply and Carbonate Production in Hemipelagic Marl-Limestone Alternations

Chapter

Jan 2018

Mathieu Martinez

The Down-dip Preferential Sequence Record of Orbital Cycles in Greenhouse Carbonate Ramps: Examples From the Jurassic of the Iberian Basin (NE Spain)

Chapter

Jan 2018

Field-trip to the excavations in the Late Jurassic along the future Transjurane highway near Porrentruy (Canton Jura, NW Switzerland): dinosaur tracks, marine vertebrates and invertebrates

Article

Full-text available

Jan 2009

This one-day field-trip (21.08.2009) to the Late Jurassic palaeontological excavations sites along the future course of the federal highway A16 “Transjurane” near Porrentruy (Canton Jura, NW Switzerland) accompanies the 5th International Symposium on Lithographic Limestone and Plattenkalk. First, we will visit the excavations in the Late Kimmeridgian Marnes à virgula. These claystones are extremely rich in small oysters (“Exogyra virgula”, Nanogyra sp.) and they frequently bear marine vertebrates, notably fishes, turtles and crocodilians. Besides remains of marine vertebrates, the under- and overlying (marly) limestones yield a diverse and rich invertebrate fauna, which was first described by Thurmann & Etallon (1861-1864). It is thus possible to collect typical Jura fossils such as Ceratomya sp., Homomya sp., Pholadomya sp., Sellithyris sp., and others on the excavation sites. Afterwards, we will move to two dinosaur tracksites, which are situated in immediate geographic and stratigraphic proximity to the Marnes à virgula excavations. The tracksites are located in two different laminite intervals of slightly different age at the transition from the Early to the Late Kimmeridgian. Tracks of sauropod and theropod dinosaurs will be observed during daylight and after dinner at night. Therefore, we will install a special nocturnal illumination; so don’t forget to bring your camera! Because the visited sites are located close to active highway construction sites we will have to provide you with safety vests, and we recommend you to wear good (closed) shoes.

Excursion dans le du bassin subalpin (20-23 septembre 2013). Turbidites et brèches carbonatées (Jurassique et Crétacé du bassin subalpin)

Article

Full-text available

Sep 2013

Kimmeridgian epeiric sea deposits of northeastern Spain: Sedimentary dynamics of a storm-dominated carbonate ramp

Chapter

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Jan 2008

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Crussol 2010

Data

Full-text available

Feb 2015

Sedimentology and sequence stratigraphy from a mixed (carbonate-siliciclastic) rift to passive margin transition: The Early to Middle Cambrian of the Argentine Precordillera

Article

Nov 2014
SEDIMENT GEOL

Cyclostratigraphy of an orbitally-driven Tithonian–Valanginian carbonate ramp succession, Southern Mendoza, Argentina: Implications for the Jurassic–Cretaceous boundary in the Neuquén Basin

Article

Jan 2015
SEDIMENT GEOL

Detailed sedimentological, sequence stratigraphical and cyclostratigraphical analyses have been made from four lower Tithonian–lower Valanginian sections of the Vaca Muerta Formation, exposed in the southern Mendoza area of the Neuquén Basin, Argentina. The Vaca Muerta Formation is characterized by decimetre-scale rhythmic alternations of marls, shales and limestones, and consists of five facies associations, which reflect different paleoenvironmental conditions: basin to restricted outer ramp, outer ramp, and middle ramp. Vertical organization within the Vaca Muerta Formation shows a well-ordered hierarchy of cycles, where elementary cycles, bundles and superbundles with frequencies within the Milankovitch band have been recognized. According to biostratigraphic data, elementary cycles have a periodicity of ~ 20 ky, which correlates with the precession cycle of Earth's axis. Spectral analysis based on series of cycle thickness allows us to identify frequencies of about 400 ky and 90–120 ky, which we interpret as the modulation of the precessional cycle by the Earth's orbital eccentricity. Cycles are probably driven by variations in carbonate exportation, as fluctuations in shallow-water carbonate production involve modifications in carbonate basinward exportation. Cyclostratigraphic data allowed us to build a floating orbital scale for the Tithonian–lower Valanginian interval in the Neuquén Basin. Correlation between studied sections allowed us to recognize a discontinuity between the Substeueroceras koeneni and Argentiniceras noduliferum ammonite zones in the Malargüe Anticline area. Orbital calibration of these sections is consistent with Riccardi's biostratigraphic scheme, wich place the Jurassic-Cretaceous boundary within the Substeueroceras koeneni ammonite Zone. On the other hand, the base of the Vaca Muerta Formation (Virgatosphinctes mendozanus ammonite Zone) would be probably placed in the base of the middle Tithonian rather than the lower Tithonian, which is also consistent with our preliminary palaeomagnetic data.

Turbidites et brèches carbonatées (Jurassique et Crétacé du bassin subalpin)

Book

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Sep 2013

ISSC Report Catuneanu et al 2011

Data

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Dec 2013

Magnetic susceptibility and spectral gamma logs in the Tithonian–Berriasian pelagic carbonates in the Tatra Mts (Western Carpathians, Poland): Palaeoenvironmental changes at the Jurassic/Cretaceous boundary

Article

Jun 2013

Integrated stratigraphy of the Lower and Middle Cenomanian in a Tethyan section (Blieux, southeast France) and correlations with Boreal basins

Article

Full-text available

Mar 2013

A detailed stratigraphic analysis was carried out on the Lower–Middle Cenomanian hemipelagic deposits of the Blieux section (Alpes-de-Haute-Provence; southeast France) in order to identify the Middle Cenomanian event I (MCE I) in the Vocontian Basin. These deposits are represented by five bundles composed of limestone–marl alternations that are separated by thick marly intervals. The Blieux section, which is well exposed, very thick, continuous and relatively rich in macrofauna, provides an ideal succession for an integrated approach. Biostratigraphy by ammonoids and sequence stratigraphy have been established for the whole succession whereas calcareous nannofossil and geochemical analyses have been carried out on a restricted interval across the Lower/Middle Cenomanian boundary. The uppermost part of the Mantelliceras mantelli Zone, the Mantelliceras dixoni Zone and the lower part of the Acanthoceras rhotomagense Zone have been recognized. The appearance of the genus Cunningtoniceras (C. inerme or C. cunningtoni) is used to place the base of the A. rhotomagense Zone and the Lower/Middle Cenomanian boundary. This boundary is also well characterized by the presence of nannofossil Subzone UC2C. Two orders of hierarchically stacked depositional sequences have been identified. Medium- and large-scale sequences correspond to 400 ky eccentricity cycles and to third-order cycles, respectively. The duration of the interval studied (from the uppermost part of the M. mantelli to the lower part of the A. rhotomagense zones) is estimated to be 2.8 my. Carbon-isotope values determined from bulk carbonate sediments show a first positive excursion (+0.6‰) corresponding to the MCE Ia, in the lower part of the A. rhotomagense Zone. A subsequent increase (+1.1‰) is recorded and could correspond to MCE Ib, but a sharp return to baseline values as expected in an excursion is not observed. The duration of the MCE I is estimated to be less than 400 ky. The Blieux section is correlated with some classical sections of the Anglo-Paris (Southerham, Folkestone, Cap Blanc-Nez) and Lower Saxony (Baddeckenstedt and Wunstorf) basins using ammonoid biostratigraphy, sequence stratigraphy, and chemostratigraphy. It is proposed as a candidate for the Middle Cenomanian GSSP (Global Boundary Stratotype Section and Point).

Shallow-water marl-limestone alternations in the Late Jurassic of Western France: Cycles, storm event deposits or both?

Article

Oct 2012
SEDIMENT GEOL

The contribution of event deposits to various basin fills can be very significant, higher than 90% in some cases. Events may lead to the formation of marl–limestone alternations, which can also result from cyclic changes in sea level or climate, for example. The marl–limestone alternations of the Late Jurassic of western France contain abundant coarse-grained accumulations that resemble storm deposits described in other western European successions. The detailed analysis of facies evolution and hierarchical, high-frequency stacking pattern of depositional sequences of the Phare de Chassiron section (Ile d'Oléron, western France) allows the controls on marl–limestone formation to be defined. This section contains nearshore and shallow-marine mud deposits that were exposed to high-energy events. Elementary, small-, and medium-scale depositional sequences are defined. The stacking-pattern and the duration of these sequences suggest an orbital control on sedimentation. Precession (20 ka) cycles notably controlled the formation of elementary sequences that correspond to marl–limestone alternations. The deposition of marly or carbonate mud occurred in this storm-dominated system because of muddy sea beds, the gentle slope of the shelf, and the great amount of particles in suspension, which reduced water energy resulting from storms. Sediment supply was also sufficient to limit bioturbation and favour the preservation of numerous storm deposits. The production of carbonate mud was localised on positive structures and partly controlled by Milankovitch-scale sea-level cycles. Transport by storms of carbonate mud to the adjacent marly depressions during high carbonate production periods led to the formation of calcareous beds. Marl–limestone alternations in the Late Jurassic of western France therefore result from the combined effects of cyclic changes in carbonate production and high-energy, episodic events.

Crussol 2010

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Aug 2013

Sedimentary evolution of an Upper Jurassic carbonate ramp (Iberian Basin, NE Spain)

Article

Full-text available

Apr 2010

A synthesis of the sedimentary evolution of the Upper Jurassic carbonate epeiric ramps that developed in the northern part of the Iberian Basin (NE Spain) is presented. The facies distributions reconstructed from the analysis of a 200 km-long transect, show a transition from shallow to relatively deep sedimentation sites. The studied carbonate ramps record major long-term transgression, from mid-Oxfordian to mid-Kimmeridgian followed by progressive basinwards coastal shift until the major regressive event around the mid-Berriasian. Subsidence was relatively homogeneous across the northern Iberian Basin during most of the studied interval. Major episodes of differential subsidence occurred around the Oxfordian-Kimmeridgian transition and onwards from the mid-Tithonian. The sedimentary evolution and particular facies types of the successive Iberian carbonate ramps is described, considering five depositional sequences that have a long-term transgressive-regressive evolution. The Oxfordian sequence shows a sharp transition from shallow to deep ramp areas: from mixed siliciclastic-carbonate (ooidal, skeletal, peloidal) facies to condensed (i.e. spongiolithic, peloidal, glauconitic) facies in the open platform domain. In the two Kimmeridgian sequences (Kim1 and Kim2), the transition between shallow and deep areas is more gradual and thickness distribution across the ramp is more homogeneous. Coral-microbial reefs and oolitic-peloidal-skeletal shoals characterized the shallow areas. Towards the offshore domain, these facies grade rapidly to a tempestite-dominated lith of acies and then into thick lime mudstone successions (i.e. rhythmic marls-mudstone alternations). Shallow oncolitic-peloidal and skeletal facies covered wide areas of the carbonate ramp during the early Tithonian (Ti1 sequence) and graded basinwards to thick successions of well-bedded micrites. The middle Tithonian to lower Berriasian platform (Ti2 sequence) is only partly exposed and formed during a stage of more heterogeneous subsidence. It is characterized by a thick succession with metre-scale shallowing-upward sequences with local development of peritidal, algallaminated caps. The factors that controlled the sedimentary evolution and major facies changes across the successive epeiric carbonate ramps are discussed by comparison to other Upper Jurassic platforms developed in the western Tethyan realm.

Facies and depositional sequence evolution controlled by high-frequency sea-level changes in a shallow-water carbonate ramp (late Kimmeridgian, NE Spain)

Article

Full-text available

Nov 2004
GEOL MAG

The outcrops of the Sierra de Albarracín (NE Spain) allow a precise reconstruction of the shallow sedimentary domains of a late Kimmeridgian carbonate ramp, developed in western marginal areas of the Iberian Basin. The sedimentary record shows a hierarchical sequence stratigraphic organization, which implies sea-level changes of different frequencies. The studied succession is arranged in a long-term transgressivemicrobial reefs (pinnacles up to 16 m in height). The increased production rates were able to fill part of the accommodation created during the early stage of high-frequency sea-level rise and the shallow platform was eventually exposed to subaereal erosion and meteoric cementation.

Facies distribution and long-term sequences in an Upper Jurassic epeiric carbonate platform (NE Spain).

Chapter

Full-text available

Apr 2010

Provenance of microcrystalline carbonate cement in limestone-marl alternations (LMA): Aragonite mud or molluscs?

Article

Full-text available

Jan 2008

Aragonite derived from marine molluscs is evaluated as the source for microcrystalline carbonate cements of limestone-mar] alternations (LMA). Calculations demonstrate that extremely low levels of mollusc-derived aragonite, well below the production rates of molluscs in modem marine settings, could have provided sufficient carbonate to cement examples of Ordovician, Silurian and Jurassic LMA in non-tropical or tropical settings. It is likely that even in the Palaeozoic molluscs provided sufficient carbonate entirely to source microcrystalline cements of LMA. Autochthonous molluscan aragonite is the only viable aragonite precursor for LMA microcrystalline cements of cool-water settings where temperatures precluded calcified algae and abiotic carbonate precipitation. In 'calcite seas' where Mg:Ca ratios inhibited both abiogenic aragonite precipitation and aragonite generation by calcified algae, molluscan aragonite was again the most likely main contributor. In some epeiric seas where brackish wedges switched off the shallow-water carbonate mud factories molluscan aragonite is the parsimonious source of carbonate for LMA microcrystalline cements.

Dynamic sedimentary conditions during periods of enhanced sequestration of organic carbon in the central southern Tethys at the onset of the Cenozoic global cooling

Article

Full-text available

May 2013
SEDIMENT GEOL

Stagnant bottom-water conditions (e.g., low and stable redox potential, long-water residence time) is an assumption commonly used to explain the preservation and burial of high amounts of organic carbon (Corg) in marine sediments. Rather than stagnant conditions, the evidence presented here from north-central Tunisia supports dynamic conditions during formation of variably Corg-rich, outermost shelf carbonates of the early-middle Eocene. The dynamic conditions are inferred by the deposition of four distinct lithofacies in this outermost shelf setting. Shedding of carbonate (i.e., mud and fragmented bioclasts) from the shallower source areas controlled the distribution of all lithofacies, with higher amounts of transported benthic debris occurring in the most proximal lithofacies and vice versa. This carbonate shedding also controlled the deposition of three orders of lithological cycles, from limestone/marly limestone couplets grading to cycles made up of groups of couplets. Bottom-water redox potential varied in intensity throughout this depositional setting, with moderate oxygen depletion (suboxic conditions) in the southern sector of north-central Tunisia and much higher oxygenation in the northern area. Evidence for suboxic bottom waters in the southern sector (higher Corg contents) is provided by higher trace metal (Cu, Ni, Zn, Cr, Mo, U and V) enrichments than in the northern area. Regionally heterogeneous primary productivity of surface waters is suggested to have caused a higher Corg burial flux in the southern sector compared to the north, a situation interpreted to have been related to varying upwelling patterns due to the effects of regional palaeogeography and the dominant wind patterns.

The lost paleosols: Masked evidence for emergence and soil formation on the Kimmeridgian Jura platform (NW Switzerland)

Article

Full-text available

Apr 2013
PALAEOGEOGR PALAEOCL

Lagoonal carbonates of Kimmeridgian age in NWSwitzerland formed in a tropical epeiric sea and exhibit indicators of subaerial emergence such as tidal biolaminites, desiccation cracks, flat pebble conglomerates, and fenestral structures. Additionally, 30 dinosaur tracksites from at least six stratigraphic intervals indicate repeated formation of land bridges between the platform and adjacent massifs. Populations of herbivorous and carnivorous dinosaurs necessitate substantial vegetation and consequently a soil cover, but no striking evidence of paleosols have been found within the track bearing sequences. However, two stratigraphic levels exposed in nine outcrops exhibit distinctive hardgrounds that experienced early meteoric diagenesis during times of emergence. Initial induration beganwith the precipitation of thin micriticmeniscus cements. Contemporaneously meteoric waters completely dissolved all aragonite leaving large voids. Iron-hydroxides were precipitated in the uppermost 7–10 cm where they impregnated the porous micrite and constituted a separate cement generation, which caused a penetrative dark red staining. These aspects are suggestive of the formation of Mediterranean-type red soils on the emerged platform. During transgression, the soil was eroded and wavecut hardgrounds were superimposed on the hardgrounds formed during regression. Erosion is evidenced by micro-karst, truncated Gastrochaenolites isp. borings and the physical removal of steinkerns. The eroded material including floral remains provided surplus nutrients leading to eutrophication. This food-rich environment supported the mass-occurrence of gastropods in the nerineoid limestones and oysters (Nanogyra sp.) in the Virgula Marls.

Sedimentary and chemostratigraphic record of climatic cycles in Lower Pliensbachian marl-limestone platform successions of Asturias (North Spain)

Article

Dec 2012
SEDIMENT GEOL

A combined sedimentological, lithological and chemostratigraphical (Mg/Ca, δ13C, δ18O) analysis of the Lower Pliensbachian marl–limestone platform successions exposed along the Asturias coastline (northern Spain) has resulted in the characterization of high-frequency cycles. The highest-order sedimentary cycles (i.e. elementary cycles) are centimeter- to deciemeter-thick alternations of bioclastic and muddy laminated/burrowed facies, which do not match the marl–limestone couplets. They encompass three sedimentary stages: deposition from storm-density currents (bioclastic facies), dominant lateral advection of continental terrigenous mud accumulated on to an oxygen-deficient seafloor (laminated facies), and recovery of bottom oxygenation involving the burrowing of laminated sediments (burrowed facies). The close match between the number of elementary cycles recorded during the Jamesoni Subzone in Asturias and Yorkshire (Northern England) gives support to the idea of the influence of a regional climatic factor (i.e. millennial-scale cyclicity).

Sedimentary vs. diagenetic control on rhythmic calcareous successions (Pliensbachian of Asturias, Spain)

Article

May 2009
TERRA NOVA

The diagenetic overprint in rhythmic hemipelagic successions can either enhance or change the original distribution of CaCO3, but it is difficult to evaluate its effect because in most field examples, it is not possible to distinguish between sedimentary and diagenetic features. The rhythmic succession of the Pliensbachian of Asturias (Spain) shows alternation of bioclastic and laminated/burrowed intervals. The original content of carbonate brought by storms from shallow areas was larger in the bioclastic horizons. However, there is a widespread mismatch between facies alternations and the observed lithological rhythms. The diagenetic redistribution of CaCO3 resulted in successive limestone–marl/clay couplets that do not match (either in number or in the location of the boundaries) the sedimentary cycles defined by facies alternations. We conclude that interpreting the limestone–marl rhythms as a direct response to primary changes is highly questionable, unless there is unequivocal proof of a sedimentary origin of the alternation of the two lithologies.

Kimmeridgian protoglobigerinids (Foraminifera) from Crussol (SE France)

Article

Full-text available

Apr 2010

A detailed investigation of the protoglobigerinids from the Kimmeridgian section of the Montagne de Crussol, SE France is presented. This monotonous succession of predominantly carbonate beds represents peri-platform hemipelagic deposits, well dated by ammonites. Three species were determined in thin sections and in isolated forms after extraction by acetolysis. Favusella? parva (Kuznetsova) is the most common species occurring in almost the entire succession from the Orthosphinctes to the Beckeri zones. Favusella hoterivica (Subbotina) has been retrieved less frequently from the Platynota to the Beckeri zones, and it is its oldest occurrence. The rare Globuligerina bathoniana (Pazdrowa) occurs only in the Late Kimmeridgian. Based on our study and the review of the literature a palaeogeographical map was plotted, showing that most of the protoglobigerinid occurrences are in deep water facies of the northern margin and central part of the Tethys. These records demonstrate the presence of Globuligerina bathoniana, G. oxfordiana (Grigelis), Favusella hoterivica, F.? parva and Compactogerina stellapolaris (Grigelis) in the Kimmeridgian. KeywordsProtoglobigerinids-Conoglobigerinidae-Favusellidae-Late Jurassic-Palaeogeography-SE-France

Planktonic versus benthic foraminifera response to Milankovitch forcing (Late Jurassic, Betic Cordillera): Testing methods for cyclostratigraphic analysis

Article

Jul 2010

Foraminiferal assemblages from the Bifurcatus Zone (Oxfordian, Upper Jurassic) are studied in the Navalperal section (Betic Cordillera, southern Spain). A total of 24 sampling stations and around 5,700 specimens of foraminifera were recognized on thin-section analysis and classified into two major categories: planktonic and benthic. The abundance of foraminifera (number of specimens/cm2) was calculated for both categories and the cyclic pattern was studied by spectral analysis, considering the autochthonous and para-autochthonous character of the studied assemblages. The Lomb-Scargle periodogram together with a permutation test were tested for performing the high-resolution spectral analysis, being particularly well suited for working with short time series and uneven sampling. Spectral analysis reveals the influence of orbital-scale Milankovitch cyclicity at the eccentricity, obliquity, and precession bands. Moreover, this incidence is significantly different depending on the analyzed group (benthic versus planktonic). Whereas the long-range eccentricity band is not distinguishable from a trend and the short-range eccentricity band is not statistically significant (at 90% confidence level), the obliquity band is better represented in the planktonic component and the precession band is better developed in the benthic group. Variations in temperature affecting upper waters, determined by obliquity-scale fluctuations, could be responsible for changes in the planktonic foraminiferal assemblage, while changes in nutrient availability and substrate oxygenation, as a consequence of input variations from source areas at the precession-scale cycles, could affect the benthic foraminiferal assemblage. KeywordsPlanktonic and benthic foraminifera-Lomb-Scargle periodogram-Milankovitch cycles-Betic Cordillera-Oxfordian

Taphonomic windows and molluscan preservation

Article

Dec 2008
PALAEOGEOGR PALAEOCL

Recent studies on silicified fossil biotas have suggested that substantial skewing of the molluscan record resulted from early aragonite dissolution in mid-outer carbonate ramp settings. If those rare skeletal lagerstätten are representative, then the quality and completeness of the molluscan record are thrown into doubt. Yet database studies suggest that the bivalve fossil record is actually relatively complete. If so, then biodiversity must be captured by other processes that preserved shells vulnerable to early dissolution, and which operated on a relatively high frequency, i.e., less than the species duration for bivalves.

Sedimentology and Carbonatogenesis of the Upper Campanian Limestones in Jebel Berda (South Central Tunisia)

Article

Jun 2021
J Afr Earth Sci

The Berda Formation corresponds to an inner-shelf stratigraphic equivalent of the Campanian-Maastrichtian outer-shelf Abiod Formation of Tunisia. The present work aims to carry out a sedimentological study of the lower unit (Upper Campanian) of Berda Formation limestones in order to interpret the limestone depositional environment and the origin of the associated micrite particles. This work is based on the study of a geological section surveyed in the Jebel Berda, typic locality, completed by microscopic observation of thin sections that allowed us identifying different carbonate facies and interpreting their depositional environments. The micrite particles have been examined with the SEM. The mineralogical and geochemical proportions and the magnetic susceptibility of the Berda Formation limestone, have been evaluated using respectively XRD, Atomic Absorption Techniques and KLY-3 Kappabridge susceptometer. The studied succession of Berda Formation includes five carbonate facies that developed within different depositional environments (1) calcisphere-rich bioclastic mudstone-wackestone within a circalittoral environment, (2) echinoderm-rich bioclastic wackestone-packstone within a shallow-marine environment (3) bioclastic rudstone within an open-marine environment, (4) peloid-rich bioclastic grainstone within high energy littoral shallow-water marine environment and (5) bioclastic dolomicrite-dolomicrosparite within a continental to marine transition environment. The studied limestones are composed of two kinds of micrite particles, (1) irregularly shaped particles resulting from fossils and micro-fossils desintegration and (2) regularly shaped polyhedral particles resulting from inorganic chemical precipitation. The carbonate facies are arranged into shallowing-up parasequences. The sedimentary facies variation and carbonate accumulation are controlled by eustatic sea-level fluctuation. In this way the biodetrital micrite occurred mainly during the transgressive intervals whereas the inorganic chemical micrite is related to the regressive intervals. Key words: Carbonate facies, carbonatogenesis, Campanian, Jebel Berda, southern central Tunisia

Sedimentology and depositional sequences of a Kimmeridgian carbonate ramp system, Lower Saxony Basin, Northern Germany

Article

Full-text available

Jan 2018

Shallow-marine Kimmeridgian (Late Jurassic) deposits in the Lower Saxony Basin (LSB) composed of alternating limestone, marl and claystone attract great palaeontological interest due to their rich invertebrate and vertebrate assemblages. Unfortunately, the absence of open-marine marker fossils and numerous sedimentary gaps in combination with lateral facies changes hamper the precise stratigraphic correlation of these strata on both a local and global scale. Here, an integrated approach combining carbonate microfacies analysis, ostracod biostratigraphy and high-resolution sequence stratigraphy is applied to two Kimmeridgian sections (Langenberg and Bisperode, 60 km apart) in the southeastern LSB. High-resolution carbonate microfacies analysis enables the definition of 19 microfacies types and seven microfacies associations, which can be arranged into facies belts along a carbonate ramp. Vertical microfacies, bed thickness and diagnostic surfaces define stacking patterns that are interpreted as small-, medium- and large-scale sequences. The ostracod biostratigraphic framework established in this study provides the required stratigraphic control. Correlation of the two studied sections reveals a more proximal setting for Bisperode than Langenberg and an overall shallowing-up trend from mid-ramp to proximal inner ramp developed in both sections. Furthermore, the majority of the medium-scale sequence boundaries defined in this study can be found in similar biostratigraphic positions in other European basins. Synsedimentary tectonics combined with high sediment accumulation rates can be identified as important controlling factors for the distribution and composition of the Kimmeridgian deposits in the LSB based on detailed correlation on both a regional and super-regional scale.

Palynofacies and calcareous nannofossils in the Upper Kimmeridgian, southeastern Paris basin (France)

Article

Full-text available

Nov 2005

The Upper Kimmeridgian Members “Calcaires blancs supérieurs” and the “Marnes à exogyres supérieures” of the southeastern Paris basin were investigated for their palynofacies and calcareous nannofossils. These members display alternating limestone-marl lithotypes and represent shallow marine palaeoenvironments. The lower carbonate member is interpreted as a proximal palaeoenvironment (palaeobathymetry = 5 to 10 m), where storm and swell deposits were prevalent and the salinity was occasionally weak. The relative richness of brown phytoclasts in this part is favoured by good preservation related to restricted conditions. These conditions would explain the dominance of the nannofossil Cyclagelosphaera margerelii in the nannofossil assemblages. The palynological data as those of the nannofossil assemblages show variations in the shift from carbonate member to marly member. The dominance of brown phytoclasts over black phytoclasts, the presence of amorphous organic matter (AOM), and the highest abundance and diversity observed within the nannofossil assemblages suggest that the maximum of distality occurred during this transition, at the basal part of the Marnes à Exogyres supérieures. The upper part of the section (marly member) characterized by storm deposits and storm-coquina beds is deeper (palaeobathymetry probably between 10 and 40 m depth) than the lower part. Oxidizing depositional conditions prevailed and explained the abundance of black particles found in this upper part, while proximate cysts and elevated non-placolith coccolith abundances indicate that relationships with the open sea were probably more significant compared to the lower part. Towards the top of the section, recurrences of restricted conditions are reflected by relatively elevated amounts of AOM and the abundance peak of the nannofossil Biscutum ellipticum. This study shows that micropalaeontological signals can be well recorded in vast lagunal domains. We speculate that salinity, nutrient supply, and oxygenation of the waters control microfossil associations. In shallow environments, these parameters are particularly fluctuating, especially when freshwater dilutes marine waters in surface, on the occasion of rainy periods or of intense arrival of continental waters.

Cyclostratigraphy and the Astronomical Time Scale

Article

Jan 2007

An important innovation in the International Geologic Time Scale 2004 is the use of astronomically forced stratigraphy, or cyclostratigraphy, to define geologic time over 0 to 23.03 Ma, much of it at an unprecedented resolution of 0.02 myr. In addition, 'floating' astronomical time scales with 0.10 to 0.40 myr resolution are defined for entire epochs and stages in the Paleogene and all three Mesozoic periods. Some of these calibrations use a new astronomical model with an hypothesized high accuracy over 0-250 Ma. These accomplishments have motivated the International Commission on Stratigraphy to complete a continuous Astronomical Time Scale ('ATS') for the past 250 Ma, and to initiate a coordinated prospecting for astronomical-like signals in Paleozoic cyclostratigraphy. Astronomically calibrated geologic time with a 0.02 to 0.40 myr resolution is a major breakthrough for the geosciences. Chronostratigraphy between widely spaced horizons dated with high-precision radioisotope geochronology suffers total loss in precision and accuracy; a continuous ATS between horizons can restore this hard-won precision and accuracy. Consequently, estimates of rates and magnitudes for a wide range of Earth system processes that can be examined only in the context of Earth history, e.g., paleoclimatology, geochronology, geodynamics, structural geology, geochemical cycles and biotic evolution, will be improved up to an order of magnitude over what is possible today.

Nature and origin of carbonate particles along a transect the western margin of Great Bahama Bank (Middle Miocene): Sedimentary processes and depositional model

Article

Full-text available

May 2008

During ODP Leg 166, Middle Miocene sediments were collected along the western margin of the Great Bahama Bank (GBB) at four sites, distributed along a proximal-distal transect. Site 1006 is located in the basin, Site 1007 at the toe-of-slope and Sites 1003 and 1005 on the mid and upper slope. The carbonate slope deposits of GBB consist of periplatform oozes, an admixture of platform-derived aragonite and high-magnesium calcite particles, and pelagic low-magnesium calcite. An assessment of carbonate sedimentation is made in order to estimate the proportion of platform-derived versus pelagic components. The originality of this study is based on the application of a separation method giving access to homogeneous granulometric fractions, ranging from 63 to 3 mu m in grain diameter. This method, associated with a multidisciplinary approach (micropaleontology, optical and electronic microscopy, mineralogy - X-ray diffractometry, and trace elements geochemistry - strontium and magnesium), allows the quantification and characterization of different kinds of carbonate particles. In Miocene sediments, three types of particles display a biogenic structure: planktonic foraminifera, calcareous nannofossils and fragments of neritic organisms. Two types of particles do not exhibit any structures that allow for a determination of their origin. Based on their size and their mineralogy, we have distinguished macroparticles (calcite and dolomite) and microparticles (calcite and aragonite). The detailed study of the composition of the separated fractions highlights major differences in carbonate ooze composition between the different sites along the transect. The unlithified samples of Sites 1006 and 1007 are dominated by pelagic components (planktonic foraminifera and calcareous nannofossils) and contain aragonite microparticles. In contrast, lithified sediments of Sites 1003 and 1005 (and 1007) are characterized by higher proportions of neritic debris and particles without biologic structure, the pelagic phase is impoverished and aragonite needles are absent. The origin of particles without biological structure has been demonstrated by their spatial distribution and by mineralogical as well as geochemical criteria. The rhombohedral calcitic microparticles mainly occur at slope sites. Their high magnesium contents support a formation on the bank implying an allochthonous origin. This suggests that calcitic microparticles correspond to the bank micrite exported towards slope environments. Rhomboedral calcitic macroparticles, which fill sediment voids, originate from in situ transformations of metastable carbonates due to pore fluids, which preferentially flow in the slope permeable sediments. Two sedimentary sources are proposed: 1) an autochthonous pelagic source with low-magnesium calcitic components and 2) an allochthonous neritic source with both aragonitic and calcitic components. Export and depositional processes can be differentiated for the allochthonous particles. The neritic debris and calcitic microparticles in slope Sites 1003 and 1005 (and less frequently in Site 1007) were probably exported by gravity currents whereas the aragonite microparticles, due to their shape and granulometry, were perhaps transported as suspension and deposited at the distal Sites 1006 and 1007.

Paleoceanography of Lower Cretaceous Alpine platform carbonates

Article

Jan 2013

Shallow‐water carbonate platforms evolve in an interplay of local, regional and global dynamics, thereby generating a detailed record of environmental conditions. Platform sediments constitute important archives of past environmental change and, as such, they are increasingly analysed for the information they contain on wider‐scale patterns. The integration of this information with palaeoceanographic data obtained from deeper‐water sediments provides a powerful tool to develop a more diverse and complete image of past environmental change. In this contribution, the remains of the northern Tethyan carbonate platform of Early Cretaceous age cropping out in the western Swiss Jura and the Helvetic Alps are used to illustrate the advantage of a palaeoceanographic approach in their interpretation. The tools applied are biostratigraphy and chemostratigraphy (carbon and strontium isotopes) in order to obtain a precise age model for correlation with (hemi‐)pelagic sediments in adjacent basins, sequence stratigraphy as a means to reconstruct the impact of sea‐level change, phosphorus stratigraphy as a proxy for trophic levels, facies and microfacies analyses as a gateway to gain better insight into the carbonate factory, and the detailed analysis of platform‐drowning unconformities as an indicator of wider‐scale palaeoenvironmental change. It is shown that changes from periods of predominantly photozoan to predominantly heterozoan carbonate production near the Berriasian–Valanginian boundary and middle early Aptian coincided with substantial increases in phosphorus burial rates and major carbon‐isotope excursions. Furthermore, the majority of the platform‐drowning episodes occurred just prior to and during episodes of major palaeoenvironmental change and, last but not least, the platform itself may have influenced the chemistry of adjacent basins and the carbon‐isotope composition of associated carbonates by the export of periplatform ooze.

Sequence Stratigraphy: Methodology and Nomenclature

Article

Full-text available

Nov 2011
NEWSL STRATIGR

The recurrence of the same types of sequence stratigraphic surface through geologic time defines cycles of change in accommodation or sediment supply, which correspond to sequences in the rock record. These cycles may be symmetrical or asymmetrical, and may or may not include all types of systems tracts that may be expected within a fully developed sequence. Depending on the scale of observation, sequences and their bounding surfaces may be ascribed to different hierarchical orders. Stratal stacking patterns combine to define trends in geometric character that include upstepping, forestepping, backstepping and downstepping, expressing three types of shoreline shift: forced regression (forestepping and downstepping at the shoreline), normal regression (forestepping and upstepping at the shoreline) and transgression (backstepping at the shoreline). Stacking patterns that are independent of shoreline trajectories may also be defined on the basis of changes in depositional style that can be correlated regionally. All stratal stacking patterns reflect the interplay of the same two fundamental variables, namely accommodation (the space available for potential sediment accumulation) and sediment supply. Deposits defined by specific stratal stacking patterns form the basic constituents of any sequence stratigraphic unit, from sequence to systems tract and parasequence. Changes in stratal stacking patterns define the position and timing of key sequence stratigraphic surfaces. Precisely which surfaces are selected as sequence boundaries varies as a function of which surfaces are best expressed within the context of the depositional setting and the preservation of facies relationships and stratal stacking patterns in that succession. The high degree of variability in the expression of sequence stratigraphic units and bounding surfaces in the rock record means ideally that the methodology used to analyze their depositional setting should be flexible from one sequence stratigraphic approach to another. Construction of this framework ensures the success of the method in terms of its objectives to provide a process-based understanding of the stratigraphic architecture. The purpose of this paper is to emphasize a standard but flexible methodology that remains objective.

Orbital calibration of the Early Kimmeridgian (southeastern France): Implications for geochronology and sequence stratigraphy

Article

Sep 2008
TERRA NOVA

Classic stratigraphic methods rarely provide high-resolution correlations between intrabasinal sedimentary sequences, which are important to understand the origin of sedimentation process and its environmental change. In this study, we investigate high-resolution cyclostratigraphic correlation from magnetic susceptibility in two Early Kimmeridgian pelagic marl-limestone successions, at La Méouge and Châteauneuf-d'Oze, southeastern France. Spectral analysis reveals the complete suite of orbital frequencies (precession, obliquity, and eccentricity) with the marl-limestone couplets being primarily precession-driven. Frequencies detected by the spectral analysis are similar between the sections, but their relative amplitudes are somewhat different, linked to the palaeoenvironmental position and the completeness of the sections. High-resolution correlation reveals two significant hiatuses at Châteauneuf-d’Oze. Early Kimmeridgian Platynota, Hypselocyclum, and Divisum ammonite zones were orbitally calibrated for an ultra-high resolution assessment of geological time. Finally, strong 405-kyr eccentricity cycles are recorded as third-order depositional sequences.

Interactions between environmental change and shallow water carbonate buildup along the nortern Tethyan margin and their impact on the Early Cretaceous carbon isotope record

Article

Full-text available

Mar 2006

The evolution of the Early Cretaceous, northern Tethyan carbonate platform was not only influenced by changes in sea level, detrital influx, and surface water temperature but also by changes in trophic levels. We distinguish between phases of carbonate production dominated by oligotrophic photozoan communities and by mesotrophic and eventually colder-water heterozoan communities. Superimposed on this bimodal trend in platform evolution were phases of platform demise for which we provide improved age control based on ammonite biostratigraphy. The initial phase of these episodes of platform demise corresponds in time to episodes of oceanic anoxic events and environmental change in general. On the basis of a comparison between the temporal changes in an Early Cretaceous, ammonite-calibrated δ¹³C record from southeastern France and coeval changes in the platform record, we suggest that the history of carbon fractionation along the northern Tethyan margin was not only influenced by changes in the oceanic carbon cycle such as in the rate of production and preservation of organic and carbonate carbon and in the size of the oceanic dissolved inorganic carbon reservoir, but it was also influenced by the above-mentioned changes in the ecology and geometry of the adjacent carbonate platform. Phases of photozoan carbonate production induced positive trends in the hemipelagic carbonate δ¹³C record. Phases of heterozoan carbonate production pushed the δ¹³C system toward more negative values. Platform drowning episodes implied an initial increase in δ¹³C values, followed by a longer-term decrease in δ¹³C values.

Eustatic controls on the depositional evolution of Upper Tithonian and Berriasian deep-water carbonates (Vocontian Trough, SE France)

Article

Full-text available

Jan 1993

Sedimentology and sequence stratigraphy of Upper Tithonian and Berriasian carbonate beds and carbonate-marlstone alternation have been studied at three different localities in the realm of the Vocontian Trough (SE France). The carbonate rocks yield an unequivocal hemipelagic to pelagic fossil assemblage. They can be subdivided into three facies types: facies type I: fossil wackestones (periplatform ooze); facies type IIm/IId: intraclastic-fossil wackestones/floatstones ; facies type III: intraclast-fossil grainstones/rudstones (grain flows). Facies type I represents autochthonous deep-marine deposits, whereas the monomictic mass-flow breccias (facies types II and III) record the collapse of the carbonate slope during relative sealevel lowstands. The sedimentological and sequential development of the studied formations is mainly controlled by third-order sea-level variations and, in some cases, also by synsedimentary tectonics. from Authors

Depositional sequences in deep-shelf environments formed through carbonate-mud import from the shallow platform (Late Oxfordian, German Swabian Alb and eastern Swiss Jura)

Article

Full-text available

Jan 1998

Upper Oxfordian deposits in southern Germany exhibit limestone-marl alternations typical of deep-shelf depositional environments. These deposits contain varying amounts of brachiopods, echinoderms, foraminifera (mainly represented by Spirillina, Lenticulina, Usbekistania, Bigenerina, Glomospira and Reophax), cephalopods, sponges and associated encrusters, and scarce bivalves, ostracods and gastropods. Fragments of reworked microbialites (tuberoids, Tubiphytes, nubecularians, bryozoans, serpulids, and Terebella), and glauconite also occur in variable quantities. In one section of the proximal shelf area (eastern Swiss Jura) there is interfingering of facies dominated by platform-derived elements (ooids, oncoids, coral fragments, peloids, bivalves, ostracods, gastropods) and of facies related to a more parautochthonous, distal sedimentation (Rhaxella and other sponge-spicules, brachiopods, Lenticulina, Spirillina). The complete record of each ammonite zone as well as the recognition of different ammonite horizons suggest that no important sedimentary gap is present. For the deep-shelf deposits of southern Germany, statistical analysis shows that the higher the total percentage of particles is in a sample, the more frequent are glauconite, bioturbation, nodularization, cephalopods, sponges, and microbial crusts. Wackestone and packstone samples thus generally correspond to lower sedimentation rates than mudstones that reflect a high carbonate-mud sedimentation rate. The carbonate mud is thought to be exported from the shallow platform because scarce nannofossils and/or insignificant bioerosion in sponge reefs exclude the possibility of relating carbonate-mud variations to changes in autochthonous productivity. Variation in carbonate-mud exportation from the platform towards the deep shelf has thus been implied from the relative abundance of particulate elements (fauna, tuberoids) which are considered as mainly autochthonous or parautochthonous. Consequently, changes in carbonate-mud content in the studied deep-shelf settings may be related to carbonate production on the shallow platform and to the export dynamics from the platform to deeper sedimentary environments. Variation in carbonate sedimentation rate has been used to interpret depositional sequences in terms of sequence stratigraphy and cyclostratigraphy: constrained by a detailed bio- and chronostratigraphical framework, a correlation of these sequences is proposed between the sections in southern Germany and the eastern Swiss Jura.

Chronology of fluctuating sea levels since the Triassic (250 million years ago to present)

Article

Full-text available

Jan 1987

Sequence stratigraphy and changes in the ammonite fauna (Upper Jurassic, S-E France)

Conference Paper

Full-text available

Nov 1989

Kimmeridgian/Tithonian eustacy and its imprints on carbonate rocks from the Dinaric and the Jura carbonate platforms

Article

Full-text available

Jul 1991

The Upper Jurassic stratigraphy and the facies development of the Dinaric carbonate platform of Slovenia (northwest Yugoslvaia) are compared with the Jura carbonate platform of southern Jura (southeast France). The similar facies development between the two platforms during the Kimmeridgian and the Tithonian, as well as a pronounced discontinuity in the same stratigraphical position (controlled by dasycladacean algae and/or ammonites), made it reasonable to correlate the two regions. This discontinuity is marked by a bauxite horizon and a karst breccia in south Slovenia (inner platform), and by a black-pebble conglomerate (inner platform) and a reef breccia (outer platform) in the southern Jura. These features are interpreted as type 1 sequence boundaries related to a global fall of sea level. -from Authors

Fazies-, Sequenz-, und Gamma-Ray-Analyse im h??heren Malm der Schw??bischen Alb (SW-Deutschland) mit Bemerkungen zur Rohstoffgeologie (hochreine Kalke)

Article

Full-text available

Jan 2001

Thomas Pawellek

Sequenzielle Faziesentwicklung der Karbonatplattform des Schweizer Jura im Späten Oxford und Frühesten Kimmeridge

Thesis

Full-text available

Jan 2003

Wolfgang A. Hug

Zugl.: Fribourg, Univ., Diss., 2003.

Subaerial exposure environment. AAPG Mem

Chapter

Full-text available

Jan 1983

Carbonate depositional sequences and systems tracts - Responses of carbonate platform to relative sea-level changes

Article

Full-text available

Jan 1993

Fundamental carbonate-depositional principles and geologic-based observations were used to construct depositional sequence and systems tract models for a variety of rimmed shelves and ramps. The models show how, for example, depositional sequences made up of (1) carbonate, (2) carbonate-siliciclastic, or (3) carbonate-evaporite-siliciclastic facies are produced by depositional systems responding to lowstand, transgressive, and highstand conditions. -from Authors

High resolution correlations and genetic stratigraphy: an integrated approach[Correlations haute resolution et stratigraphie genetique: une demarche integree]

Article

Full-text available

Jan 1992

The aim of this paper is to provide a guide to one of the more practical applications of genetic stratigraphy, that of high resolution correlation between vertical stratigraphic sections obtained from outcrop or from subsurface data. The method requires knowledge of primary depositional features and comprises two phases. The first phases put the information together as a vertical "log'; the second phases correlate between the various vertical sections produced in phase one. The method is illustrated by two examples. The first concerns correlation at the reservoir scale, while the second applies this sort of correlation to unravel the evolution of the intracratonic Paris Basin during the Jurassic. -from English summary

A U-Pb and 40 Ar/ 39 Ar time scale for the Jurassic

Article

Full-text available

Jun 2000
CAN J EARTH SCI

Published time scales provide discrepant age estimates for Jurassic stage boundaries and carry large uncertainties. The U-Pb or ⁴⁰Ar/³⁹Ar dating of volcaniclastic rocks with precisely known stratigraphic age is the preferred method to improve the calibration. A radiometric age database consisting of fifty U-Pb and ⁴⁰Ar/³⁹Ar ages was compiled to construct a revised Jurassic time scale. Accepted ages have a precision of ±5 Ma (2σ) or better and are confined to no more than two adjacent stages. The majority of these calibration points result from integrated bio- and geochronologic dating in the western North American Cordillera and have not been previously used in time scales. Direct dates are available only for the Triassic-Jurassic boundary and the initial boundary of the Crassicosta chron and the Callovian stage. The chronogram method was used to estimate all Early and early Middle Jurassic zone boundaries (attempted here for the first time), late Middle Jurassic substage boundaries, and Late Jurassic stage boundaries. Significant improvement is achieved for the Pliensbachian and Toarcian, where six consecutive zone boundaries are determined. The derived zonal durations are disparate, varying between 0.4 and 1.6 Ma. The latest Jurassic isotopic database remains too sparse, therefore chronogram estimates are improved using interpolation based on magnetochronology. The initial boundaries of Jurassic stages are proposed as follows: Berriasian (Jurassic-Cretaceous): 141.8+2.5 1.8 Ma; Tithonian: 150.5+3.4 2.8 Ma; Kimmeridgian: 154.7+3.8 3.3 Ma; Oxfordian: 156.5+3.1 5.1 Ma; Callovian: 160.4+1.1 0.5 Ma; Bathonian: 166.0+3.8 5.6 Ma; Bajocian: 174.0+1.2 7.9 Ma; Aalenian: 178.0+1.0 1.5 Ma; Toarcian: 183.6+1.7 1.1 Ma; Pliensbachian: 191.5+1.9 4.7 Ma; Sinemurian: 196.5+1.7 5.7 Ma; Hettangian (Triassic-Jurassic): 199.6 ± 0.4 Ma.

Systematic position and palaeoecology of the Upper Jurassic to Tertiary alga Marinella lugeoni PFENDER

Article

Full-text available

Jan 1993

The alga Marinella lugeoni Pfender commmonly occurs in Upper Jurassic and Lower Cretaceous sediments, and is known until the Oligocene. Features detected in the rich material from the Portuguese Upper Jurassic support a red algal character and reveal close relationships to the corallinaceans. The simple structure of most of the thallial tissue and the radial arrangement of cell threads in Marinella are also features of solenoporacean red algae. Marinella occurs in a wide variety of marine shallow-water environments, but is most frequent in particle-rich, partly clayey limestones. It also occurs in settings of fluctuating salinities, where it indicates the more marine phases. -from Authors

The Geology of Stratigraphic Sequences

Book

Jan 1997

Andrew D. Miall

Major Transgressive/ Regressive Cycles: The stratigraphic signature of European Basin Development

Article

Jan 1998

Facies models: response to sea level change

Article

Jan 1992

A.D. Miall

Limestone-Marl alternations – an overview

Article

Jan 1991

Subaerial exposure environment

Article

Jan 1983

Facies Models: Response to Sea-Level Change

Article

Jan 1992

Integrated Stratigraphy of the Oxfordian and Kimmeridgian (Late Jurassic) in northern Switzerland and adjacent southern Germany

Book

Jan 2000

Reinhart A. Gygi

1. 1 Geographical and 1. 2 Previous work palaeogeographical setting Stratigraphic exploration of the Swiss Jura range began before The measuring of detailed sections and the excavation of fossils 1820. MERIAN (1821) described the Jurassic sediments in the ar- were done in an area which is confined to the west by a line be- ea of Basel for the first time and gave a short and appropriate tween Boncourt in Canton Jura and Biel in Canton Bern description of the principal lithostratigraphic units. Merian (fig. 1). The belt of outcrops becomes narrower towards the east was aware that fossils were a means for correlation, but he stated and then runs northeast from Canton Aargau to Mohringen on that fossils were not known well enough at the time for this the Danube river in southern Germany. This whole area is purpose. Therefore he correlated strictly lithostratigraphically. where the Burgundy platform (PuRSER 1979) interfingers with He correlated the marls of the Biirschwil Formation of the early sediments of the rhodano-swabian epicontinental sea which and middle Oxfordian in the central Jura with the marls of the was situated adjacent to northern Tethys (fig. 63). The whole Effingen Member of the middle and late Oxfordian in the east- area was transformed into an epicontinental sea (fig. 2) by the ern Jura range (fig. 3).

Layering: the origin and environmental significance of lamination and thin bedding

Article

Jan 1977

Introduction to carbonate and evaporite facies models

Article

Jan 1992

Tidal flat environment

Article

Jan 1983

E.A. Shinn

Sur les Songiofaunes de l'Oxfordien supérieur et du Kiméridgien du Portugal

Article

Jan 1985

Palynology, ammonites and sequence stratigraphy fromtethyan middle oxfordianto lower kimmeridgian, S-E France comparison with the boreal realm

Article

Jan 2000

Roger Jan Du Chene

The results presented in this paper have to be considered as a contribution to an important project whose aim is the geological study and global sequence stratigraphie correlation (multidisciplinary approach) of the Middle Oxfordian to Tithonian of different French areas, from the Sub-Boreal sections of Boulonnais, Normandy, Charente, Quercy, to the Tethyan sections of the Vocontian Trough. The review includes shallow water as well as deep water sections. The concept of this project is similar to the SE France Berriasian study published by the same working group (JAN DU CHÊNE et al., 1993). A dinocyst stratigraphie distribution chart zone is proposed between the Middle Oxfordian Transversarium Zone and the basal Upper Kimmeridgian Acanthicum of the Mesogean deep water reference sections of Vergons and Châteauneuf-d'Oze (Vocontian Trough; SE France). The two sections studied are rich in ammonites and are there-fore easily correctable with other Vocontian Trough sections to propose a sequence stratigraphic break-up primarily based on bed geometry, lithofacies and stratonomic observation, complemented by palynological and geochemical data, such as Mn content. The 3rd order sequences are stratigraphically calibrated using biostratigraphic information based on ammonites and dinocysts. From Sequence Ox 5 to Kim 3, most of the 3rd order sequences proposed by HARDENBOL et al. (1998) are stratigraphically recognised correctly with the exception of Kim 2. Data given by different geological tools as well as from other areas (particularly from the north of the Aquitaine Basin) suggest a double sequence Kim 2. To avoid any confusion with the HARDENBOL et al. cycle chart, the sequences proposed in this paper are called Kim 2' and Kim 2" respectively at the base and at the top of the interval. Correlation with the Boreal and Sub-Boreal realms are also proposed. The correlation takes into account recent papers on ammonite distribution at the Oxfordian-Kimmeridgian boundary. The joint occurrence of both Amoeboceras bauhini(a boreal species common in the base of the Baylei Zone) and Taramelliceras hauffianum (a Mesogean species) in outcrops of South Germany strongly suggests that the base of the Baylei Zone (and consequently the Oxfordian-Kimmeridgian boundary) corresponds to the base occurrence of T. hauffianum in the uppermost part of the Hauffianum subzone in the Tethyan realm. Most of the important dinocyst species have been observed in fairly comparable stratigraphic position to those known in the Boreal and Sub-Boreal realms. Additional information will be given in the near future by integrated studies presently in progress along the Upper Jurassic margins of the Aquitaine Basin (Quercy and Charente) and in Normandy.

Stratigraphy and mineralostratigraphy of the Kimmeridgian in the central Jura Mountains of Switzerland and eastern France

Article

Jan 1998

P.O.J. Mouchet

The microfacies, micropaleontology, mineralogy and sedimentology of the series of the Reuchenette Formation (Kimmeridgian), introduced by Thalmann (1966) to replace the Kimmeridgian auctorum, have been studied and compared with other series in the Swiss and French Jura Mountains. The studied area corresponds to a shoal environment separating the Tethys (S) and the Paris Basin (N). The depositional environments represent three major domains: intertidal/supratidal domain, internal platform and external platform (margin and slope). Field observations and microfacies analysis revealed two major discontinuities. Clay-mineralogy data show that kaolinite can be used as a stratigraphical marker. Both methods, microfacies and clay-mineralogy, allowed to establish correlations in an area where the biochronological markers are extremely rare. The two major discontinuities can be correlated with series described by Bernier (1984), Chevallier (1989) and Strohmenger et al. (1991) in the Jura of SE France (Jura meridional) and can be tied to the global eustatic curve established by Haq (1991).

Cretaceous sequence stratigraphy, Chart 4, Mesozoic and Cenozoic Sequence Stratigraphy of European Basins

Article

Jan 1998

Shallow platform carbonates, in walker, r.gjames, n.p., eds

Article

Jan 1992

The stratigraphic signatures of tectonics, eustasy and sedimentology: Cycles and events in stratigraphy [J]

Article

Jan 1991
AAPG BULL

Anatomy of a Modern Carbonate Tidal-flat, Andros Island, Bahamas

Article

Jan 1976

SEQUENCE STRATIGRAPHY OF THE OXFORDIAN AND KIMMERIDGIAN STAGES (LATE JURASSIC) IN NORTHERN SWITZERLAND

Chapter

Jan 1998

The Oxfordian and Kimmeridgian exposures of the Jura of northern Switzerland show a transition from a shallow-water carbonate platform to a deeper marine basin. The carbonate platform was well established in the northern part of the Jura by Middle Oxfordian time and continued to develop through Late Oxfordian and Kimmeridgian time. The platform is characterized by shallow-water carbonates, sometimes rimmed by coral reefs. The basinal sediments grade distally from marls or turbiditic carbonates into condensed, highly fossiliferous limestones or ironstones. The study is based upon 220 sedimentary logs and utilizes a very detailed chronostratigraphic framework established from a combination of ammonite biostratigraphy and clay mineralogy. Sequence stratigraphic analysis of the succession reveals that the Oxfordian sediments as a whole represent a 2nd-order regressive-transgressive cycle, punctuated by eight 3rd-order cycles. The onset of the 2nd-order transgression is coincident with a change in the morphology of the carbonate platform from a rimmed-shelf to an epeiric carbonate platform. The lower Kimmeridgian sediments represent a minor 2nd-order regressive cycle, punctuated by three 3rd-order scale cycles. This was followed by a 2nd-order transgression, the base of which is dated as eudoxus Zone. The Oxfordian sequence boundaries are denoted O1 to O8, and the Kimmeridgian sequence boundaries are denoted K1 to K3. Relative sea-level changes are supported by the progradational, aggradational and retrogradational relationships of the facies within the sequences and by detailed study of the genesis and correlation of the key stratigraphic surfaces. Periods of relative sea-level fall are mainly characterized by progradation of the carbonates basinward and renewed influx of terrigenous siliciclastics. The start of transgression is marked by a decrease in the terrigenous influx and retrogradation of the carbonate facies across the carbonate platform. Maximum flooding is characterized by a slowdown or even termination of the growth of coral reefs on the platform, condensation of the beds and sometimes by the deposition of a condensed fossiliferous horizon in the basin. The sequence stratigraphic method allows further refinement of correlations between the basin and carbonate platform, and provides an explanation and framework for the complexity of carbonate facies.

A Triassic, Jurassic and Cretaceous time scale

Article

Jan 1995

Microfacies Analysis of Limestones

Book

Jan 1982

Erik Flügel

Fossil Calcareous Dinoflagellate Cysts

Chapter

Jan 1991

Helmut Keupp

Present knowledge of fossil calcareous dinoflagellate cysts is summarized briefly. All genera of the cyst family Calciodinellaceae Deflandre 1947, including most of the Mesozoic “Calcisphaerulidae” Bonet 1956, known from the fossil record since the late Triassic, are listed here and subdivided into three subfamilies. Several specimens show a more or less complete paratabulation which is expressed by different modes. A monophyletic character of the traditional peridinian family can be proposed owing to a corresponding tabulation pattern (ortho-hexa-tabulation of the general formula 4′,3a,7″, 4-6c,5‴,2‴). A more or less strong control over cyst morphology by environmental factors is pos-tulated due to the quasi-extracellular mineralization. This is obviously problematic for sys-tematics. But on the other hand, these mineralization features can be used for environmental and stratigraphic interpretations. Two new names (Pentadinellum, Wallidinellum) are introduced here for the calcareous cysts of Recent Ensiculifera cf. mexicana and Scrippsiella sweenyae.

Parasequence stacking patterns, third-order accommodation events, and sequence stratigraphy of Middle to Upper Cambrian platform carbonates, Bonanza King Formation, Southern Great Basin

Article

Jan 1993

The jurassic Lithocodium aggregatum-Troglotella incrustans foraminiferal consortium

Article

Mar 1996

Lithocodium aggregatum, an enigmatic micro-encruster widespread in Mesozoic shallow marine carbonates, was considered to be a codiacean alga but can now be identified from Upper Jurassic examples as loftusiid foraminifer (Order Lituolida, Superfamily Loftusiacea). The microgranular wall may also contain detrital quartz, a feature which excludes any codiacean affinity. The complex, alveolar though imperforate, wall structure is identical to that of other loftusiid foraminifers; the only difference is the encrusting life habit of Lithocodium. The foraminifer is coiled in juvenile growth stages but subsequently developed irregular growth, making it possible for it to contribute to the formation of oncoids and reefal biotic crusts. The numerous alveolar structures, which are covered by only a very thin outer wall, suggest that these alveoli were containers for photoautotrophic symbionts. Lithocodium and Bacinella are not parts of one single organism, although phrenotheca-like structures crossing parts of the chambers partly resemble the latter. In the Upper Jurassic material, nearly every specimen of Lithocodium includes bubble-like structures, formerly interpreted as algal sporangia. These structures are identified here as the foraminifer Troglotella incrustons. During its later growth, Troglotella developed an irregular shape and grew into the alveoli of the Lithocodium walls. This may be interpreted as a commensal relationship, with Troglotella feeding on the carbohydrates synthesized by the Lithocodium symbionts.

An Upper Jurassic sponge- algal buildup from the northern Frankenalb, West Germany.

Article

Jan 1981

During Upper Jurassic time (middle-upper Oxfordian) a number of relatively small organic buildups, principally composed of siliceous sponges and algae, developed in S.Germany. This study concentrates on one of these organic structures, the Mullersfelsen buildup (near Streitberg). This developed during cyclic stages in relatively deeper water subtidal depositional environments, without strong current and wave action. 3 facies types are recognized: 1) sponge-crust boundstone facies characterized by micritic boundstone rich in calcified siliceous sponges, 2) lithoclastic packstone facies allochems, 3) tuberolitic wackestone facies. The spatial distribution of these microfacies indicate that the sponge-crust boundstone facies is the mound constructional facies, whereas both wackestone and packstone facies are only developed in areas marginal to the main organic buildup.-from Authors

Geochemical characterization (Mn content) of third order eustatic sequences in Upper Jurassic pelagic carbonates of the Vocontian Trough (SE France)

Article

Jan 2001
Eclogae Geol Helv

The manganese contents of the Oxfordian-Kimmeridgian pelagic carbonates in the section at Châteauneuf d'Oze (Vocontian Basin, Hautes Alpes, France) are used to define 11 geochemical units. These units are interpreted in terms of sequence stratigraphy and grouped into 6 third-order sequences, which then are compared with those of the sequence-chronostratigraphic chart of Hardenbol et al. (1998). Using this approach, two modifications to the chart are proposed: (i) the Oxfordian-Kimmeridgian boundary in the Tethyan realm should be set in the upper part of the Hauffianum subzone, as clearly proposed by biostratigraphic studies from Wierzbowski (1991), Atrops et al. (1993), and Schweigert and Callomon (1997). (ii) a new sequence (Kim2′) should be introduced in the Hypselocyclum zone, and the sequence Kim2″ (Hypselocyclum - Divisum zones) becomes the equivalent of the cycle chart Kim2 sequence.

Der bauhini-Faunenhorizont und seine Bedeutung für die Korrelation zwischen tethyalem und subborealem Oberjura

Article

Jan 1997

La sous-famille des Ataxioceratinae (Ammonitina) dans le Kimméridgien inférieur du Sud-Est de la France. Systématique, évolution, chronostratigraphie des genres Orthosphinctes et Ataxioceras

Article

Jun 1979

François Atrops

Mineralostratigraphy, litho- and biostratigraphy combined in correlation of the Oxfordian (Late Jurassic) formations of the Swiss Jura range

Article

Jan 1986

An Upper Jurassic reef complex from Slovenia, Yugoslavia.

Article

Jan 1981

An Upper Jurassic (Oxfordian and lower Kimmeridgian) reef complex is well exposed in the area of Slovenia, northwestern Yugoslavia. This reef complex is though to be a barrier-reef that developed along the shelf-margin of an ancient carbonate platform. From basin to lagoon the following subdivisions have been delineated: a fore-reef area characterized by carbonate breccias and blocks of reef debris; a central reef area with abundant hydrozoans and corals that can be further subdivided into actinostromariid and parastromatoporid zones; and, a back-reef area with locally developed lagoons and patch-reefs defined as the Cladocoropsis zone.-Authors

Forced regressions in a sequence stratigraphic framework: Concepts, examples, and exploration significance

Article

Jan 1992
AAPG BULL

Sequence stratigraphic concepts suggest that stratal geometries develop and are largely controlled by changes in relative sea level. On the shelf, low-stand deposits, which form during falls and subsequent stillstands of relative sea level, can be recognized by the presence of an unconformity at the base, the isolated and basinward position relative to the previous shoreline, and the abrupt seaward translation of shallow-water and shoreline facies into the basin across an unconformity surface. This seaward translation of facies and shoreline regression in a response to relative sea level lowering is termed a "forced regression'. Certain shelf sands, previously interpreted as offshore or mid-shelf sand bodies, can be reinterpreted as stranded lowstand shorelines associated with forced regressions. This alternative interpretation has economic significance insofar as it suggests different subsurface correlations and reservoir geometries. Examples of forced regression are described. -from Authors

Interactions between tectonics and eustasy during the Upper Jurassic and lowermost Cretaceous. Examples from the south of Iberia

Article

Jan 1991

Describes the organization and correlation of sedimentary bodies deposited on the South Iberian margin during the Upper Jurassic (mainly Oxfordian Kimmeridgian) and lowermost Cretaceous (intra Berriasian), which are significant with regard to 3rd order eustatic cycles. Particular interest has been raised by the comparison of the sedimentary record of the epicontinental shelves, with that of the distal areas of the paleomargin. Twelve discontinuities have been identified and analysed between the Middle Oxfordian and the Middle Berriasian. Of the 12 unconformities examined, at least 8 can be recognised in South Iberia and 5 can be correlated with the records in other sectors of the Iberian and northwest African margins. It has been possible to infer the interactions between tectonics and eustasy and to calibrate the intervals of instability, which have been characterised according to their duration. -from Authors

Shallow water sediments of late Jurassic age from northwestern Switzerland dated by ammonites[Datierung von Seichtwassersedimenten des Spaten Jura in der Nordwestschweiz mit Ammoniten]

Article

Jan 1995
Eclogae Geol Helv

R.A. Gygi

The last gap in the ammonite zonation of the Oxfordian of northern Switzerland could be closed with cardioceratids of the Costicardia Subzone from the upper Renggeri Member. The Cordatum, the Densiplicatum and the lower part of the Antecedens Subzones are represented in the Terrain a Chailles Member. In the upper part of the St-Ursanne and the Pichoux Formations there are ammonites of the upper Antecedens and the Parandieri Subzones. Ammonites of the Bifurcatus Zone and the Hypselum Subzone occur in the Gunsberg Member. A Ringsteadia from the most proximal part of the upper Geissberg Member indicates that probably the whole of this member belongs to the Hypselum Subzone. -from English summary

The carbonate feedback system: Interaction between stratigraphic accommodation, ecological succession and the carbonate factory

Article

Jan 1996

Peter Homewood

The carbonate factory, as defined by geologists, is that essentially subtidal community on shallow marine shelves which produces large volumes of skeletal carbonate. Carbonate reefs are an obvious example to illustrate major skeleal production, and fossil associations of reef building organisms have seen successful application of the ecological concept of community succession. The stratigraphic context of any given accumulation indicates a geological time period with its specific palaeontological associations, major climatic features and the palaeogeography as determined by plate tectonics. Dynamic and sequence stratigraphic analysisof the strata reveal changes in sea-level and positions of shoreline with displacements of facies tracts, transgressions and regressions. In this paper, the analysis of carbonate depositional systems, using high resoulation sequence stratigraphy, studies the ratio between change in accommodation space and skeletal carbonate production. This approach establishes the concurrent change in nature of facies belts (expansion, retraction and type) and fossil communities, within the detailed time frame of change in accommodation. Carbonate production is generally considered to be a fairly simple funcion of environmental conditions such as climate and water depth. However, data form several case studies also show a covariance between change in stratigraphic achitecture of catbonate system (the seaward or landward stepping stacking patterns of stratigraphic units) and change in facies. Case studies include Carboniferous algal mound development in the Paradox Basal (USA), Devonian stromatoporoid reef development in Alberta (Canada), and Cenomanian rudistid shoal development i Oman. The hypothesese are tested on cases taken from the literature, including Oxfordian reefal development in the Jura, and nummulite population change in the Carbières (France). Facies changes record significant modification in the type and amounts of carbonate skeletal material produced in shallower water environments by prevalent communities within the ecosystem. The analysis of carbonate system within the hierarchical framework and detailed time frame of high resolution (genetic) stratigraphy suggests that a causal link exists between changes in stratigraphic accommodation and changes in ecosystem, the two being linked with the carbonate factory. The causal link is deduced to be a complex feedback system within a given climate and palaeogeographic setting. The feedback system would involve nutrients, reproductive strategies, ecosystem and production of carbonate or organic matter. The concept of a carbonate feedback system, involoving the parameters listed above, may help to explain paradoxes such as the drowning of carbonate platform and the vulnerability of mature or climax communiteis. It should also allow to improve prediction of carbonate reservoir distribution and properies for hydrocarbon exploration, and to lay the ground for improved algorithms of carbonate sediment production to be used in stratigraphic forward modelling.

Black Shales

Article

Feb 1995

Nutrient Excess and the Demise of Coral Reefs and Carbonate Platforms

Article

Aug 1986

Because rates of carbonate production and bioerosion are similar, even modest increases in nutrient avalability can shift a reef community from net production to net erosion. In the geologic record, drowned reefs and carbonate platforms typically exhibit evidence of nondeposition, bioerosion, and reduced redox potential, which indicate excess nutrient availability during drowning. -from Authors

Seismic stratigraphy and global changes in sea level, Parts 1 and 2.

Chapter