Exploring the links between climate, weathering, and dynamic topography during the upper cretaceous: a geochemical and mineralogical approach within a source-to-sink system

Started in October 2020

Funding: EU program Marie Curie Actions, Université Bourgogne Franche-Comté (UBFC) and université de Bourgogne (uB)

Supervisors: Emmanuelle Pucéat and Pierre Pellenard

Abstract

The major uplift phase encountered by South Africa during the late Cretaceous leaded to a drastic increase in the denudation rates of the south African margin, associated to large sediment accumulation rates offshore. This event provides a unique opportunity to explore the long-term response of chemical weathering and erosion to intense tectonic uplift within a greenhouse climate. To study these processes both ODP/DSDP cores (360, 361) offshore and onshore from the Geological Survey in the Cape Basin/Orange Basin region have been targeted, with sediment accumulation rates already available, that will be used to capture the respective role of weathering and erosion changes in the evolution and distribution of sediments offshore. In this project will be applied a novel geochemical approach, combining clay mineralogical analyses with clay Nd and Hf isotope composition (ΔεHf) to meet three goals. 1) determine the respective evolution of chemical weathering and erosion during the late Cretaceous uplift of South Africa. 2) Find the links between these two processes (weathering and erosion) and the evolution and distribution of detrital fluxes in this tectonic setting. 3) Explore the potential impact of this uplift on late Cretaceous climate evolution, through CO2 by silicate weathering.

Keywords

Nd-Hf, clay analyses, erosion, weathering, greenhouse, tectonic uplift

extrait:

lien_externe:

titre:

Explorer les liens entre le climat, la météorisation et la topographie dynamique au cours de la crétacé supérieur : une approche géochimique et minéralogique dans un système source-puits

date_de_debut_these:

octobre 2020

nom:

Gaitan

date_de_debut_these_numerique:

202010

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kc_raw_content:

Exploring the links between climate, weathering, and dynamic topography during the upper cretaceous: a geochemical and mineralogical approach within a source-to-sink system

Started in October 2020

Funding: EU program Marie Curie Actions, Université Bourgogne Franche-Comté (UBFC) and université de Bourgogne (uB)

Supervisors: Emmanuelle Pucéat and Pierre Pellenard

 

Abstract

The major uplift phase encountered by South Africa during the late Cretaceous leaded to a drastic increase in the denudation rates of the south African margin, associated to large sediment accumulation rates offshore. This event provides a unique opportunity to explore the long-term response of chemical weathering and erosion to intense tectonic uplift within a greenhouse climate. To study these processes both ODP/DSDP cores (360, 361) offshore and onshore from the Geological Survey in the Cape Basin/Orange Basin region have been targeted, with sediment accumulation rates already available, that will be used to capture the respective role of weathering and erosion changes in the evolution and distribution of sediments offshore. In this project will be applied a novel geochemical approach, combining clay mineralogical analyses with clay Nd and Hf isotope composition (ΔεHf) to meet three goals. 1) determine the respective evolution of chemical weathering and erosion during the late Cretaceous uplift of South Africa. 2) Find the links between these two processes (weathering and erosion) and the evolution and distribution of detrital fluxes in this tectonic setting. 3) Explore the potential impact of this uplift on late Cretaceous climate evolution, through CO2 by silicate weathering.

 

Keywords

Nd-Hf, clay analyses, erosion, weathering, greenhouse, tectonic uplift