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Peter F Rawson - One of the best experts on this subject based on the ideXlab platform.
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interhemispheric radio astrochronological calibration of the time scales from the andean and the tethyan areas in the valanginian Hauterivian early cretaceous
Gondwana Research, 2019Co-Authors: Beatriz Aguirreurreta, Mathieu Martinez, Mark D Schmitz, Marina Lescano, Julieta Omarini, Maisa Tunik, Henning Kuhnert, Andrea Concheyro, Peter F RawsonAbstract:An integrated radio-astrochronological framework of the Agrio Formation in the Andean Neuquen Basin of west-central Argentina provides new constraints on the age and the duration of the late Valanginian through Hauterivian stratigraphic interval. A CA-ID TIMS U-Pb age of 126.97 ± 0.04(0.07)[0.15] Ma is presented here from the upper Hauterivian Agua de la Mula Member of the Agrio Formation. Biostratigraphic data from ammonoids and calcareous nannofossils and this high precision new radioisotopic age, together with three former ones from the same Agrio Formation are combined with new astrochronological data in the Andes. These are correlated with modern cyclostratigraphic studies in the classical sections of the Mediterranean Province of the Tethys, supporting detailed interhemispheric correlations for the Early Cretaceous. We also provide new δ13C data from the Agrio Formation which are compared with records from the classic Tethyan sections. According to our calibration, the minimum in the values in the mid-Hauterivian appears to be synchronous and, thus, another important stratigraphic marker for global correlation. A new duration of 5.21 ± 0.08 myr is calculated for the Hauterivian Stage, starting at 131.29 ± 0.19 Ma and ending at 126.08 ± 0.19 Ma. The difference between the duration of the Hauterivian in GTS2016 and in this study is 1.32 myr while the base and top of the GTS2016 Hauterivian differ respectively by 3.40 and 4.69 myr.
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a high precision u pb radioisotopic age for the agrio formation neuquen basin argentina implications for the chronology of the Hauterivian stage
Cretaceous Research, 2017Co-Authors: Beatriz Aguirreurreta, Mark D Schmitz, Marina Lescano, Maisa Tunik, Andrea Concheyro, Peter F Rawson, Mariano Buhler, Victor A RamosAbstract:Abstract A new CA-ID TIMS U–Pb age of 130.39 ± 0.16 Ma is presented here from the Pilmatue Member of the Agrio Formation, lower Hauterivian of the Neuquen Basin in west-central Argentina. This high precision radioisotopic new age, together with the two former ones from the upper Hauterivian Agua de la Mula Member of the Agrio Formation and modern cyclostratigraphic studies in the classical sections of the Mediterranean Province of the Tethys indicate that the Hauterivian Stage spans some 6 Ma, starting ca. 132 Ma and ending ca. 126 Ma. These radioisotopic ages are tied to ammonite biostratigraphy and calcareous nannofossil bioevents and biozones recognized in the Neuquen Basin which in turn are correlated with the Mediterranean standard zones. A new geological time scale for the Valanginian–Hauterivian stages in the Mediterranean region integrating astrochronological and radiochronological data differs with the current official geological time scale which still maintains poorly constraint absolute ages for the Berriasian-Aptian interval.
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lower cretaceous ammonites from the neuquen basin argentina the Hauterivian genus spitidiscus
Cretaceous Research, 2012Co-Authors: Peter F Rawson, Beatriz M AguirreurretaAbstract:Abstract Spitidiscus is a widely-distributed Hauterivian genus that briefly invaded the Neuquen Basin, Argentina, in mid Hauterivian times, well after it first evolved in the west Tethyan area. Its appearance in Argentina is linked with a globally-significant mid Hauterivian sea-level rise. This is marked in the basin by a sharp facies change in the Agrio Formation, from non-marine sandstones of the Avile Member to marine sediments, often laminated black shales, with Spitidiscus at the base of the overlying Agua de la Mula Member. Our extensive field work has shown that Spitidiscus occurs across the whole basin, where it is represented by two species, Spitidiscus riccardii Leanza and Wiedmann and Spitidiscus kilapiae sp. nov. For most of its vertical range Spitidiscus occurs alone, characterising the S. riccardii Zone. But at the top of its range it is joined by the first crioceratitid ammonites, their appearance marking the base of the Crioceratites schlagintweiti Zone.
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lower cretaceous ammonites from the neuquen basin argentina the neocomitids of the pseudofavrella angulatiformis zone upper valanginian
Cretaceous Research, 2010Co-Authors: Maria B Aguirreurreta, Peter F RawsonAbstract:Abstract The Pseudofavrella angulatiformis Zone (upper Valanginian) of the Agrio Formation in the Neuquen Basin, Argentina, is characterized exclusively by a complex sequence of neocomitid faunas that are sandwiched between the olcostephanids of the underlying Viluceras permolestus Subzone beneath and the holcodiscid faunas of the Holcoptychites neuquensis Zone above (lowermost Hauterivian). Three successive neocomitid genera, Pseudofavrella, Chacantuceras and Decliveites gen. nov., characterize three subzones. Over half the taxa are new: Pseudofavrella robusta, P. sp. nov. 1 and 2, Chacantuceras casanuestraense, Chacantuceras coniunctum, Decliveites crassicostatus, and Decliveites agrioensis.
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belemnites of valanginian Hauterivian and barremian age sr isotope stratigraphy composition 87sr 86sr δ13c δ18o na sr mg and palaeo oceanography
Palaeogeography Palaeoclimatology Palaeoecology, 2004Co-Authors: J.m. Mcarthur, Jorg Mutterlose, Alastair Ruffell, Peter F Rawson, G D Price, M.f. ThirlwallAbstract:We present new data on 87Sr/86Sr, δ13C and δ18O, and elemental compositions of belemnites from 85 m of Valanginian, Hauterivian and Barremian strata at Speeton, Yorkshire, eastern England. The 87Sr/86Sr data provide a global standard for 87Sr/86Sr isotopic dating, and correlation to the biostratigraphic schemes of NW Europe. Values of 87Sr/86Sr increase from 0.707380±0.000003, at the base of the Hauterivian, to 0.707493±0.000004 in the earliest Late Barremian Paracrioceras elegans ammonite Zone before decreasing thereafter towards an Aptian minimum. The downturn in the elegans Zone coincided with the onset of volcanism on the present Ontong Java Plateau. A linear interpretation of the 87Sr/86Sr profile shows that the relative durations of ammonite zones differ by a factor ≤18. The basal Hauterivian unconformably overlies Valanginian strata; the discontinuity in 87Sr/86Sr across this surface represents a gap in sedimentation of 2.0 myr. In our belemnites (mostly of the genera Hibolites, Acroteuthis, and Aulacoteuthis) the absence of a correlation between δ18O and δ13C suggests that strong non-equilibrium fractionation has not affected the isotopic composition of the calcite. Our δ18O values therefore approximate to a valid record of marine palaeo-temperatures. Specimens of the genus Hibolites have δ18O values that are 0.4‰ more positive than those of co-occurring specimens of the genus Acroteuthis. This offset may be explained as resulting from small (0.4‰) departures from equilibrium during precipitation of calcite, different depth habitats, or changing temperature in the Speeton sea in the time that elapsed between deposition of our individual belemnites. The averaged belemnite record of δ18O through the section shows that seawater warmed from around 11°C at the base of the Hauterivian to a maximum around 15°C in the middle of the Hauterivian regale Zone, and returned to a cooler temperature of around 11°C by the middle of the overlying inversum Zone, a temperature that persisted to the basal Barremian. Through the Barremian, temperature increased to a peak of 20°C in the early Late Barremian elegans Zone then, in the same zone, precipitately and temporarily decreased to around 14°C at about the time of onset of volcanism on the Ontong Java Plateau, before they returned to around 16°C in the uppermost part of the section. In specimens of Aulacoteuthis and Acroteuthis, a good correlation between δ18O and the content of Na, Sr, and Mg suggests that incorporation of these trace elements in these genera is largely controlled by temperature. The dependency of concentration on temperature ranges from 7 to 20% per degree Celsius, if equilibrium fractionation of oxygen isotopic composition is assumed, so the Mg, Na and Sr content of these genera may be used as palaeo-temperature proxies. The trace element content of Hibolites shows no relation to stable oxygen isotopic composition and so does not record palaeo-temperature.
Karl B. Föllmi - One of the best experts on this subject based on the ideXlab platform.
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mercury anomalies volcanic pulses and drowning episodes along the northern tethyan margin during the latest Hauterivian earliest aptian
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Guillaume Charbonnier, Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract The latest Hauterivian-earliest Aptian time interval includes three episodes of significant environmental change (Faraoni, late early-Barremian, and Taxy Episodes). This time interval appears to partially overlap with large-scale volcanic activity related to the Tristan da Cunha plume along the Rio Grande Rise, High Arctic large igneous province volcanism, and the early phase in the formation of the greater Ontong Java LIP in the Pacific. The establishment of exact temporal relationships between volcanic activity and environmental change remains, however, a major challenge, due to the scarcity of numerical ages for the Early Cretaceous. We report mercury (Hg) contents in uppermost Hauterivian-lowermost Aptian marl/limestone alternations from seven sections along a N S transect in the Western Tethys. The Hg contents in marl samples display rather scattered records, which are generally well correlated with the total organic carbon (TOC) records. In associated limestone beds, five distinct spikes in Hg concentrations occur in three intervals (latest Hauterivian, early Barremian, and latest Barremian). The small amounts of organic matter (
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early cretaceous late berriasian to early aptian palaeoceanographic change along the northwestern tethyan margin vocontian trough southeastern france δ13c δ18o and sr isotope belemnite and whole rock records
Cretaceous Research, 2009Co-Authors: Stéphane Bodin, Nico M.m. Janssen, Alexis Godet, Nicolas Fiet, Virginie Matera, Stephane Westermann, Arnaud Clement, Peter Stille, Karl B. FöllmiAbstract:Stable carbon, oxygen, and strontium isotope records were obtained from uppermost Hauterivian to lowermost Aptian belemnite rostra, which were collected in well-dated sections from the Vocontian Trough (southeastern France). This data set complements previously published belemnite-isotope records from the uppermost Berriasian-Hauterivian interval from the same basin. The belemnite carbon and oxygen isotope record is compared to the carbonate bulk-rock isotope record from the same sections, and from additional Italian sections. With regards to their long-term trends, both belemnite and whole-rock δ18O records are well correlated, except for the uppermost Hauterivian-lower Barremian interval, within which they deviate. This discrepancy is interpreted to be linked to the latest Hauterivian Faraoni oceanic anoxic event and its early Barremian aftermath. The Faraoni level is characterized by enhanced sea-water stratification, probably induced by the onset of a warmer and more humid climate along the northern Tethyan margin. The early Barremian was characterized by stronger vertical sea-water mixing reflected by a decrease in density contrast between sea-surface and deeper waters. The belemnite oxygen isotope record shows a more stable evolution with smaller fluctuations than its bulk-rock counterpart, which indicates that deeper water masses were not as much subjected to density fluctuations as sea-surface water. The comparison of belemnite and bulk-rock carbon isotope records allows observing the impact of regional influence exerted by platform carbonate ooze shedding on the carbon cycle. Discrepancies in the two records are observed during time of photozoan carbonate platform growth. The strontium isotopic record shows a gradual increase from the uppermost Berriasian to the uppermost lower Barremian followed by a rapid decrease until the uppermost Barremian and a renewed small increase within the lowermost Aptian. The major inflection point in the uppermost lower Barremian appears to predate the onset in the formation of the Ontong-Java volcanic plateau.
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platform induced clay mineral fractionation along a northern tethyan basin platform transect implications for the interpretation of early cretaceous climate change late Hauterivian early aptian
Cretaceous Research, 2008Co-Authors: Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract High-resolution clay-mineral analyses were performed on upper Hauterivian to lower Aptian sediments along a platform-to-basin transect through the northern Tethyan margin from the Neuchâtel area (Switzerland), to the Vocontian Trough (France) in order to investigate links between climate change, carbonate platform evolution, and fractionation patterns in clay minerals during their transport. During the Hauterivian, the northern Tethyan carbonate platform developed in a heterozoan mode, and the associated ramp-like topography facilitated the export of detrital material into the adjacent basin, where clay-mineral assemblages are dominated by smectite and kaolinite is almost absent, thereby suggesting dry-seasonal conditions. During the Late Hauterivian Balearites balearis ammonite zone, a change to a more humid climate is documented by the appearance of kaolinite, which reaches up to 30% of the clay fraction in sediments in the Vocontian Trough. This prominent change just preceded the Faraoni Oceanic Anoxic Event and the onset of the demise of the Helvetic Carbonate Platform, which lasted to the late early Barremian. From the Late Barremian onwards, the renewed growth of the northern Tethyan carbonate platform in a photozoan mode and the associated development of a marginally confined platform topography fractionated the clay-mineral assemblages exported into hemipelagic settings: kaolinite particles were preferentially retained in proximal, platform settings, due to their size and their relatively high specific weight. In the inner platform environment preserved in the Swiss Jura, an average of 32% of kaolinite in the clay fraction is observed during the latest Barremian–earliest Aptian, whereas clay-mineral assemblages of coeval sediments from deeper depositional settings are dominated by smectite and show only minor amounts of kaolinite. This signifies that besides palaeoclimate conditions, the morphology and ecology of the carbonate platform had a significant effect on the distribution and composition of clay assemblages during the Late Hauterivian–Early Aptian along the northern Tethyan margin.
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enrichment of redox sensitive trace metals u v mo as associated with the late Hauterivian faraoni oceanic anoxic event
International Journal of Earth Sciences, 2007Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Silvia Gardin, Thierry Adatte, Rodolfo Coccioni, Virginie Matera, Philipp Steinmann, Karl B. FöllmiAbstract:The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.
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Biostratigraphy, sedimentology and sequence stratigraphy of the latest Hauterivian - Early Barremian drowning episode of the Northern Tethyan margin (Altmann Member, Helvetic nappes, Switzerland)
Eclogae Geologicae Helvetiae, 2006Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Pascal Linder, Karl B. FöllmiAbstract:During the Early Cretaceous, major palaeoceanographic changes are mirrored on the northern Tethyan carbonate platform by changes in the carbonate factory and by platform drowning. The Altmann Member of the central European, northern Alpine Helvetic thrust and fold belt, contains the sedimentary record of one of these drowning events which occurred during the Late Hauterivian – Early Barremian. It consists mainly of highly condensed beds, which are rich in glaucony and phosphates. The Altmann Member was hitherto only poorly dated. New ammonite findings and a re-evaluation of existing ammonite fauna allow to precisely date this drowning episode, starting in the Pseudothurmannia seitzi biozone (latest Hauterivian) and lasting until the Coronites darsi biozone (latest Early Barremian). These new age dates, coupled with sequence stratigraphic interpretations allow to better understand the unfolding of the drowning episode, which proceeded in two stages: The first stage consisted in an important phase of marine transgression during the latest Hauterivian, during which carbonate production was highly reduced; the second stage is recorded during the latest Early Barremian by an important sequence boundary, which is associated with a phosphatized hardground, followed by rapid sea-level rise and the deposition of outer ramp sediment associated with the backstepping of the platform. Almost the whole early Barremian is likely to be condensed in this phosphatized hardground, which is associated to a second order sea-level lowstand. The onset of the drowning event is linked to the Faraoni oceanic anoxic event, whereas during the Early Barremian, phosphatization might be the result of important winnowing during a period of highly eutrophic conditions.
Stéphane Bodin - One of the best experts on this subject based on the ideXlab platform.
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mercury anomalies volcanic pulses and drowning episodes along the northern tethyan margin during the latest Hauterivian earliest aptian
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Guillaume Charbonnier, Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract The latest Hauterivian-earliest Aptian time interval includes three episodes of significant environmental change (Faraoni, late early-Barremian, and Taxy Episodes). This time interval appears to partially overlap with large-scale volcanic activity related to the Tristan da Cunha plume along the Rio Grande Rise, High Arctic large igneous province volcanism, and the early phase in the formation of the greater Ontong Java LIP in the Pacific. The establishment of exact temporal relationships between volcanic activity and environmental change remains, however, a major challenge, due to the scarcity of numerical ages for the Early Cretaceous. We report mercury (Hg) contents in uppermost Hauterivian-lowermost Aptian marl/limestone alternations from seven sections along a N S transect in the Western Tethys. The Hg contents in marl samples display rather scattered records, which are generally well correlated with the total organic carbon (TOC) records. In associated limestone beds, five distinct spikes in Hg concentrations occur in three intervals (latest Hauterivian, early Barremian, and latest Barremian). The small amounts of organic matter (
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early cretaceous late berriasian to early aptian palaeoceanographic change along the northwestern tethyan margin vocontian trough southeastern france δ13c δ18o and sr isotope belemnite and whole rock records
Cretaceous Research, 2009Co-Authors: Stéphane Bodin, Nico M.m. Janssen, Alexis Godet, Nicolas Fiet, Virginie Matera, Stephane Westermann, Arnaud Clement, Peter Stille, Karl B. FöllmiAbstract:Stable carbon, oxygen, and strontium isotope records were obtained from uppermost Hauterivian to lowermost Aptian belemnite rostra, which were collected in well-dated sections from the Vocontian Trough (southeastern France). This data set complements previously published belemnite-isotope records from the uppermost Berriasian-Hauterivian interval from the same basin. The belemnite carbon and oxygen isotope record is compared to the carbonate bulk-rock isotope record from the same sections, and from additional Italian sections. With regards to their long-term trends, both belemnite and whole-rock δ18O records are well correlated, except for the uppermost Hauterivian-lower Barremian interval, within which they deviate. This discrepancy is interpreted to be linked to the latest Hauterivian Faraoni oceanic anoxic event and its early Barremian aftermath. The Faraoni level is characterized by enhanced sea-water stratification, probably induced by the onset of a warmer and more humid climate along the northern Tethyan margin. The early Barremian was characterized by stronger vertical sea-water mixing reflected by a decrease in density contrast between sea-surface and deeper waters. The belemnite oxygen isotope record shows a more stable evolution with smaller fluctuations than its bulk-rock counterpart, which indicates that deeper water masses were not as much subjected to density fluctuations as sea-surface water. The comparison of belemnite and bulk-rock carbon isotope records allows observing the impact of regional influence exerted by platform carbonate ooze shedding on the carbon cycle. Discrepancies in the two records are observed during time of photozoan carbonate platform growth. The strontium isotopic record shows a gradual increase from the uppermost Berriasian to the uppermost lower Barremian followed by a rapid decrease until the uppermost Barremian and a renewed small increase within the lowermost Aptian. The major inflection point in the uppermost lower Barremian appears to predate the onset in the formation of the Ontong-Java volcanic plateau.
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platform induced clay mineral fractionation along a northern tethyan basin platform transect implications for the interpretation of early cretaceous climate change late Hauterivian early aptian
Cretaceous Research, 2008Co-Authors: Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract High-resolution clay-mineral analyses were performed on upper Hauterivian to lower Aptian sediments along a platform-to-basin transect through the northern Tethyan margin from the Neuchâtel area (Switzerland), to the Vocontian Trough (France) in order to investigate links between climate change, carbonate platform evolution, and fractionation patterns in clay minerals during their transport. During the Hauterivian, the northern Tethyan carbonate platform developed in a heterozoan mode, and the associated ramp-like topography facilitated the export of detrital material into the adjacent basin, where clay-mineral assemblages are dominated by smectite and kaolinite is almost absent, thereby suggesting dry-seasonal conditions. During the Late Hauterivian Balearites balearis ammonite zone, a change to a more humid climate is documented by the appearance of kaolinite, which reaches up to 30% of the clay fraction in sediments in the Vocontian Trough. This prominent change just preceded the Faraoni Oceanic Anoxic Event and the onset of the demise of the Helvetic Carbonate Platform, which lasted to the late early Barremian. From the Late Barremian onwards, the renewed growth of the northern Tethyan carbonate platform in a photozoan mode and the associated development of a marginally confined platform topography fractionated the clay-mineral assemblages exported into hemipelagic settings: kaolinite particles were preferentially retained in proximal, platform settings, due to their size and their relatively high specific weight. In the inner platform environment preserved in the Swiss Jura, an average of 32% of kaolinite in the clay fraction is observed during the latest Barremian–earliest Aptian, whereas clay-mineral assemblages of coeval sediments from deeper depositional settings are dominated by smectite and show only minor amounts of kaolinite. This signifies that besides palaeoclimate conditions, the morphology and ecology of the carbonate platform had a significant effect on the distribution and composition of clay assemblages during the Late Hauterivian–Early Aptian along the northern Tethyan margin.
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enrichment of redox sensitive trace metals u v mo as associated with the late Hauterivian faraoni oceanic anoxic event
International Journal of Earth Sciences, 2007Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Silvia Gardin, Thierry Adatte, Rodolfo Coccioni, Virginie Matera, Philipp Steinmann, Karl B. FöllmiAbstract:The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.
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Biostratigraphy, sedimentology and sequence stratigraphy of the latest Hauterivian - Early Barremian drowning episode of the Northern Tethyan margin (Altmann Member, Helvetic nappes, Switzerland)
Eclogae Geologicae Helvetiae, 2006Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Pascal Linder, Karl B. FöllmiAbstract:During the Early Cretaceous, major palaeoceanographic changes are mirrored on the northern Tethyan carbonate platform by changes in the carbonate factory and by platform drowning. The Altmann Member of the central European, northern Alpine Helvetic thrust and fold belt, contains the sedimentary record of one of these drowning events which occurred during the Late Hauterivian – Early Barremian. It consists mainly of highly condensed beds, which are rich in glaucony and phosphates. The Altmann Member was hitherto only poorly dated. New ammonite findings and a re-evaluation of existing ammonite fauna allow to precisely date this drowning episode, starting in the Pseudothurmannia seitzi biozone (latest Hauterivian) and lasting until the Coronites darsi biozone (latest Early Barremian). These new age dates, coupled with sequence stratigraphic interpretations allow to better understand the unfolding of the drowning episode, which proceeded in two stages: The first stage consisted in an important phase of marine transgression during the latest Hauterivian, during which carbonate production was highly reduced; the second stage is recorded during the latest Early Barremian by an important sequence boundary, which is associated with a phosphatized hardground, followed by rapid sea-level rise and the deposition of outer ramp sediment associated with the backstepping of the platform. Almost the whole early Barremian is likely to be condensed in this phosphatized hardground, which is associated to a second order sea-level lowstand. The onset of the drowning event is linked to the Faraoni oceanic anoxic event, whereas during the Early Barremian, phosphatization might be the result of important winnowing during a period of highly eutrophic conditions.
Thierry Adatte - One of the best experts on this subject based on the ideXlab platform.
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mercury anomalies volcanic pulses and drowning episodes along the northern tethyan margin during the latest Hauterivian earliest aptian
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Guillaume Charbonnier, Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract The latest Hauterivian-earliest Aptian time interval includes three episodes of significant environmental change (Faraoni, late early-Barremian, and Taxy Episodes). This time interval appears to partially overlap with large-scale volcanic activity related to the Tristan da Cunha plume along the Rio Grande Rise, High Arctic large igneous province volcanism, and the early phase in the formation of the greater Ontong Java LIP in the Pacific. The establishment of exact temporal relationships between volcanic activity and environmental change remains, however, a major challenge, due to the scarcity of numerical ages for the Early Cretaceous. We report mercury (Hg) contents in uppermost Hauterivian-lowermost Aptian marl/limestone alternations from seven sections along a N S transect in the Western Tethys. The Hg contents in marl samples display rather scattered records, which are generally well correlated with the total organic carbon (TOC) records. In associated limestone beds, five distinct spikes in Hg concentrations occur in three intervals (latest Hauterivian, early Barremian, and latest Barremian). The small amounts of organic matter (
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platform induced clay mineral fractionation along a northern tethyan basin platform transect implications for the interpretation of early cretaceous climate change late Hauterivian early aptian
Cretaceous Research, 2008Co-Authors: Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract High-resolution clay-mineral analyses were performed on upper Hauterivian to lower Aptian sediments along a platform-to-basin transect through the northern Tethyan margin from the Neuchâtel area (Switzerland), to the Vocontian Trough (France) in order to investigate links between climate change, carbonate platform evolution, and fractionation patterns in clay minerals during their transport. During the Hauterivian, the northern Tethyan carbonate platform developed in a heterozoan mode, and the associated ramp-like topography facilitated the export of detrital material into the adjacent basin, where clay-mineral assemblages are dominated by smectite and kaolinite is almost absent, thereby suggesting dry-seasonal conditions. During the Late Hauterivian Balearites balearis ammonite zone, a change to a more humid climate is documented by the appearance of kaolinite, which reaches up to 30% of the clay fraction in sediments in the Vocontian Trough. This prominent change just preceded the Faraoni Oceanic Anoxic Event and the onset of the demise of the Helvetic Carbonate Platform, which lasted to the late early Barremian. From the Late Barremian onwards, the renewed growth of the northern Tethyan carbonate platform in a photozoan mode and the associated development of a marginally confined platform topography fractionated the clay-mineral assemblages exported into hemipelagic settings: kaolinite particles were preferentially retained in proximal, platform settings, due to their size and their relatively high specific weight. In the inner platform environment preserved in the Swiss Jura, an average of 32% of kaolinite in the clay fraction is observed during the latest Barremian–earliest Aptian, whereas clay-mineral assemblages of coeval sediments from deeper depositional settings are dominated by smectite and show only minor amounts of kaolinite. This signifies that besides palaeoclimate conditions, the morphology and ecology of the carbonate platform had a significant effect on the distribution and composition of clay assemblages during the Late Hauterivian–Early Aptian along the northern Tethyan margin.
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enrichment of redox sensitive trace metals u v mo as associated with the late Hauterivian faraoni oceanic anoxic event
International Journal of Earth Sciences, 2007Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Silvia Gardin, Thierry Adatte, Rodolfo Coccioni, Virginie Matera, Philipp Steinmann, Karl B. FöllmiAbstract:The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.
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the late Hauterivian faraoni oceanic anoxic event in the western tethys evidence from phosphorus burial rates
Palaeogeography Palaeoclimatology Palaeoecology, 2006Co-Authors: Stéphane Bodin, Alexis Godet, Karl B. Föllmi, Jean Vermeulen, Nicolas Fiet, Hubert Arnaud, Andre Strasser, Thierry AdatteAbstract:In the uppermost Hauterivian sediments of the western Tethys, a short-lived anoxic event (Faraoni event) is documented both in the form of an interval enriched in organic matter (pelagic realm) and in a condensed interval enriched in glauconite and phosphate (shelf realm). This latter interval represents the onset of a drowning episode on the Helvetic carbonate platform along the northern tethyan margin that lasted throughout the early Barremian. This drowning episode marks a turning point in the way the platform carbonate factory functioned: during the Hauterivian carbonate production was dominated by heterozoans, whereas during the late Barremian a photozoan assemblage developed that is preserved in the so-called Urgonian limestone. The late Hauterivian Faraoni oceanic anoxic event is of particular interest because it is not accompanied by a major positive shift in y 13 C unlike other oceanic anoxic events during the Cretaceous (Valanginian, early Aptian, Cenomanian–Turonian boundary). We have analyzed four (hemi-)pelagic sections with regards to their phosphorus content to better understand the palaeoceanographic conditions related to this anoxic event and the associated changes in the shallow-water carbonate factory. The sections are
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Evolution of the marine stable carbon-isotope record during the early Cretaceous : A focus on the late Hauterivian and Barremian in the Tethyan realm
Earth and Planetary Science Letters, 2006Co-Authors: Alexis Godet, Stéphane Bodin, Karl B. Föllmi, Jean Vermeulen, Silvia Gardin, Nicolas Fiet, Thierry Adatte, Zsolt Berner, Doris Stüben, Bas Van De SchootbruggeAbstract:Abstract In order to improve our understanding of the relationships between the late Hauterivian oceanic anoxic Faraoni event, contemporaneous platform drowning along the northern Tethyan margin and global environmental change in general, we established high-resolution δ 13 C and δ 18 O curves for the late Hauterivian and the entire Barremian stage. These data were obtained from whole-rock carbonate samples from the Veveyse de Châtel-Saint-Denis section (Switzerland), the Fiume-Bosso section and the nearby Gorgo a Cerbara section (central Italy), and the Angles section (Barremian stratotype, France). We observe an increase of 0.3‰ in mean δ 13 C values within sediments from the middle Hauterivian Subsaynella sayni ammonite zone to the Hauterivian–Barremian boundary; δ 13 C values remain essentially stable during the early Barremian. During the latest early Barremian and most of the late Barremian, δ 13 C values increase slowly (until the Imerites giraudi zone) and the latest Barremian is characterized by a negative trend in δ 13 C values, with minimal values at the Barremian–Aptian boundary. During the earliest Aptian, δ 13 C mean values start to rise again and attain + 2.25‰. We interpret the evolution of the δ 13 C record as resulting from the interaction between changes in the carbon cycle in the Tethyan basin and the adjacent platforms and continents. In particular, changes towards warmer and more humid conditions on the continent and coeval phases of platform drowning along the northern Tethyan margin may have contributed to enhance the oceanic dissolved inorganic carbon (DIC) reservoir which may have pushed the δ 13 C record towards more negative values and exerted a general attenuation on the δ 13 C record. From this may have come the general change from a heterozoan to a photozoan carbonate platform community, which influenced the evolution in δ 13 C values by increasing the export of aragonite and diminishing export of dissolved organic carbon into the basins.
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mercury anomalies volcanic pulses and drowning episodes along the northern tethyan margin during the latest Hauterivian earliest aptian
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Guillaume Charbonnier, Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract The latest Hauterivian-earliest Aptian time interval includes three episodes of significant environmental change (Faraoni, late early-Barremian, and Taxy Episodes). This time interval appears to partially overlap with large-scale volcanic activity related to the Tristan da Cunha plume along the Rio Grande Rise, High Arctic large igneous province volcanism, and the early phase in the formation of the greater Ontong Java LIP in the Pacific. The establishment of exact temporal relationships between volcanic activity and environmental change remains, however, a major challenge, due to the scarcity of numerical ages for the Early Cretaceous. We report mercury (Hg) contents in uppermost Hauterivian-lowermost Aptian marl/limestone alternations from seven sections along a N S transect in the Western Tethys. The Hg contents in marl samples display rather scattered records, which are generally well correlated with the total organic carbon (TOC) records. In associated limestone beds, five distinct spikes in Hg concentrations occur in three intervals (latest Hauterivian, early Barremian, and latest Barremian). The small amounts of organic matter (
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early cretaceous late berriasian to early aptian palaeoceanographic change along the northwestern tethyan margin vocontian trough southeastern france δ13c δ18o and sr isotope belemnite and whole rock records
Cretaceous Research, 2009Co-Authors: Stéphane Bodin, Nico M.m. Janssen, Alexis Godet, Nicolas Fiet, Virginie Matera, Stephane Westermann, Arnaud Clement, Peter Stille, Karl B. FöllmiAbstract:Stable carbon, oxygen, and strontium isotope records were obtained from uppermost Hauterivian to lowermost Aptian belemnite rostra, which were collected in well-dated sections from the Vocontian Trough (southeastern France). This data set complements previously published belemnite-isotope records from the uppermost Berriasian-Hauterivian interval from the same basin. The belemnite carbon and oxygen isotope record is compared to the carbonate bulk-rock isotope record from the same sections, and from additional Italian sections. With regards to their long-term trends, both belemnite and whole-rock δ18O records are well correlated, except for the uppermost Hauterivian-lower Barremian interval, within which they deviate. This discrepancy is interpreted to be linked to the latest Hauterivian Faraoni oceanic anoxic event and its early Barremian aftermath. The Faraoni level is characterized by enhanced sea-water stratification, probably induced by the onset of a warmer and more humid climate along the northern Tethyan margin. The early Barremian was characterized by stronger vertical sea-water mixing reflected by a decrease in density contrast between sea-surface and deeper waters. The belemnite oxygen isotope record shows a more stable evolution with smaller fluctuations than its bulk-rock counterpart, which indicates that deeper water masses were not as much subjected to density fluctuations as sea-surface water. The comparison of belemnite and bulk-rock carbon isotope records allows observing the impact of regional influence exerted by platform carbonate ooze shedding on the carbon cycle. Discrepancies in the two records are observed during time of photozoan carbonate platform growth. The strontium isotopic record shows a gradual increase from the uppermost Berriasian to the uppermost lower Barremian followed by a rapid decrease until the uppermost Barremian and a renewed small increase within the lowermost Aptian. The major inflection point in the uppermost lower Barremian appears to predate the onset in the formation of the Ontong-Java volcanic plateau.
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platform induced clay mineral fractionation along a northern tethyan basin platform transect implications for the interpretation of early cretaceous climate change late Hauterivian early aptian
Cretaceous Research, 2008Co-Authors: Alexis Godet, Stéphane Bodin, Thierry Adatte, Karl B. FöllmiAbstract:Abstract High-resolution clay-mineral analyses were performed on upper Hauterivian to lower Aptian sediments along a platform-to-basin transect through the northern Tethyan margin from the Neuchâtel area (Switzerland), to the Vocontian Trough (France) in order to investigate links between climate change, carbonate platform evolution, and fractionation patterns in clay minerals during their transport. During the Hauterivian, the northern Tethyan carbonate platform developed in a heterozoan mode, and the associated ramp-like topography facilitated the export of detrital material into the adjacent basin, where clay-mineral assemblages are dominated by smectite and kaolinite is almost absent, thereby suggesting dry-seasonal conditions. During the Late Hauterivian Balearites balearis ammonite zone, a change to a more humid climate is documented by the appearance of kaolinite, which reaches up to 30% of the clay fraction in sediments in the Vocontian Trough. This prominent change just preceded the Faraoni Oceanic Anoxic Event and the onset of the demise of the Helvetic Carbonate Platform, which lasted to the late early Barremian. From the Late Barremian onwards, the renewed growth of the northern Tethyan carbonate platform in a photozoan mode and the associated development of a marginally confined platform topography fractionated the clay-mineral assemblages exported into hemipelagic settings: kaolinite particles were preferentially retained in proximal, platform settings, due to their size and their relatively high specific weight. In the inner platform environment preserved in the Swiss Jura, an average of 32% of kaolinite in the clay fraction is observed during the latest Barremian–earliest Aptian, whereas clay-mineral assemblages of coeval sediments from deeper depositional settings are dominated by smectite and show only minor amounts of kaolinite. This signifies that besides palaeoclimate conditions, the morphology and ecology of the carbonate platform had a significant effect on the distribution and composition of clay assemblages during the Late Hauterivian–Early Aptian along the northern Tethyan margin.
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enrichment of redox sensitive trace metals u v mo as associated with the late Hauterivian faraoni oceanic anoxic event
International Journal of Earth Sciences, 2007Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Silvia Gardin, Thierry Adatte, Rodolfo Coccioni, Virginie Matera, Philipp Steinmann, Karl B. FöllmiAbstract:The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.
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Biostratigraphy, sedimentology and sequence stratigraphy of the latest Hauterivian - Early Barremian drowning episode of the Northern Tethyan margin (Altmann Member, Helvetic nappes, Switzerland)
Eclogae Geologicae Helvetiae, 2006Co-Authors: Stéphane Bodin, Alexis Godet, Jean Vermeulen, Pascal Linder, Karl B. FöllmiAbstract:During the Early Cretaceous, major palaeoceanographic changes are mirrored on the northern Tethyan carbonate platform by changes in the carbonate factory and by platform drowning. The Altmann Member of the central European, northern Alpine Helvetic thrust and fold belt, contains the sedimentary record of one of these drowning events which occurred during the Late Hauterivian – Early Barremian. It consists mainly of highly condensed beds, which are rich in glaucony and phosphates. The Altmann Member was hitherto only poorly dated. New ammonite findings and a re-evaluation of existing ammonite fauna allow to precisely date this drowning episode, starting in the Pseudothurmannia seitzi biozone (latest Hauterivian) and lasting until the Coronites darsi biozone (latest Early Barremian). These new age dates, coupled with sequence stratigraphic interpretations allow to better understand the unfolding of the drowning episode, which proceeded in two stages: The first stage consisted in an important phase of marine transgression during the latest Hauterivian, during which carbonate production was highly reduced; the second stage is recorded during the latest Early Barremian by an important sequence boundary, which is associated with a phosphatized hardground, followed by rapid sea-level rise and the deposition of outer ramp sediment associated with the backstepping of the platform. Almost the whole early Barremian is likely to be condensed in this phosphatized hardground, which is associated to a second order sea-level lowstand. The onset of the drowning event is linked to the Faraoni oceanic anoxic event, whereas during the Early Barremian, phosphatization might be the result of important winnowing during a period of highly eutrophic conditions.
