Response of weathering and erosion to the intense tectonic uplift of the South African Plateau during the Late Cretaceous: Preliminary insights
| Autor: | Cécile Robin, Emmanuelle Pucéat, Germain Bayon, Pierre Pellenard, Esteban Gaitan, François Guillocheau |
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| Přispěvatelé: | Université Bourgogne Franche-Comté [COMUE] (UBFC), Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Goldschmidt 2021 Goldschmidt 2021, Jul 2021, Virtual, France. ⟨10.7185/gold2021.6836⟩ |
| Popis: | International audience; During the Late Cretaceous the South African Plateauexperienced a period of uneven tectonic uplift. It started duringthe Turonian with an early pulse in the eastern margin, whichincreased the sediment accumulation rates in the western side,especially in the Orange and Cape basins. This was followed bya late uplift stage in the western margin during the Campanian,which similarly increased the sediment accumulation rates in theeastern side, particularly in the Transkei and Durban Basins. Thisoccurred within a greenhouse climate and coincided with amarked global climate cooling during the Late Cretaceous.Sediment budget calculations have been performed for thissystem, but quantitative constrains on the long-term response ofthe denudation processes to this tectonic event and climaticvariations remain unsolved. In this study, we combine twogeochemical techniques to determine the intensity of chemicalweathering and physical erosion. We use a new proxy ofchemical weathering intensity, the ΔHf based on coupled Lu-Hfand Sm-Nd isotopic systems in clay fractions [1]. This techniqueis joint with X-ray Diffraction to determine the concomitantevolution of clay mineralogical assemblages thus tracking theprogress of physical erosion. Both methods are applied onsediments from DSDP sites 361 and 249 (Fig. 1). This new dataset will be combined with published sediment budget [2] andclimate records to discuss the links between uplift, margindenudation, chemical weathering and how they impact theaccumulation rates of sediments in the nearby oceanic basins. |
| Databáze: | OpenAIRE |
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