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Western Tropical Atlantic

Dynamics of Coniacian-Santonian black shale formation (OAE3) in the western tropical Atlantic (ODP Leg 207, Demerara Rise): understanding South-American and cross-equatorial relationships in climate variability at millennial time scales

In this project we elaborate an integrated, millennial time scale data base of the Coniacian-lower Campanian Oceanic Anoxic Event 3 (OAE 3) for the western tropical Atlantic (ODP Leg 207, Demerara Rise) that allows

to address the development, controls and phase relationships of black-shale formation along the Suriname continental margin in response to South-American climate variability and

to understand the causes for and effects of changes in productivity and/or water-column anoxia/euxinia on massive organic carbon burial in the north-western exit of the Equatorial Gateway.

The data compared with existing synchronous proxy records from the Deep Ivorian Basin (equatorial West-Africa, ODP 959) at the south-eastern exit of the Gateway to assess east-west relationships in tropical climate development and black shale formation.

The project provides unique opportunity to study the continuous development of upper Cretaceous black shale cyclicity at high time resolution in a holistic view. We expect to define boundary conditions for marine sedimentation off Suriname in relation to South-American climate and ocean circulation, similar to mechanisms detected for the conjugate African margin. The detailed assessment of these scenarios is considered essential to understand and distinguish local and remote controls, to identify lead/lag relations of climate evolution and marine sedimentation, and finally to better address the role of the tropics on climate change during greenhouse/hothouse conditions.