Ocean-continent interactions in the mid Cretaceous Equatorial Atlantic realm

该项目旨在通过对海洋沉积物的XRF扫描，分析植物蜡质的矿物组成、碳、氢同位素组成和无机地球化学参数，破解中白垩纪超级温室世界的陆地环境动力学和古海洋变化。我们的建议将试图回答这些项目产生的古环境关键问题。我们期望陆地和海洋领域的数据直接相关，从而有机会获得在所调查的时间片内全球变化的全面视图。不同分辨率的分析将在上阿拉伯河至下图拉尼亚区间进行，以评估各种古海洋事件形成期间的环境和海洋变化。这些事件分别是最新的阿尔及利亚海洋缺氧事件Id （OAE Id）、中期Cenomanian事件（MCE）和晚期Cenomanian事件（OAE 2），它们都代表了全球碳循环的重大扰动。将沿着OOP Leg 207 （Demerara Rise）的两个地点（地点1258和1260）的地层拼接进行调查。为了更好地估计南美洲北部和西北非洲过去大规模的水文-陆地变化及其对热带大西洋黑色页岩沉积的影响，将对DSDP站点367（佛德角盆地-晚阿尔比安至晚塞诺曼尼亚）和370（摩洛哥海域，晚阿尔比安至中塞诺曼尼亚）从东大西洋选定的区间进行补充分析。该项目旨在实现以下主要目标：•确定径流变化，从而确定一般在阿尔比世晚期至Turonian早期以及特别在特殊的古海洋学事件（OAE Id， MCE和OAE 2）期间的陆地气候变化。•提供了在阿尔比世晚期至Turonian早期Demerara隆起的陆地输入海洋领域的估计。•测试在塞诺曼尼亚晚期热带大西洋干旱气候和含盐底水形成的概念模型。•提供海洋古温度变化与陆地气候之间的联系。•估算大尺度水文变化及其对富有机质沉积物积累的影响。•验证与OAE形成相关的显著/pCO2下降的假设。

The project aims at deciphering terrestrial environmental dynamics and palaeoceanographic changes during the mid-Cretaceous super-greenhouse world based on the analysis of macerals, carbon and hydrogen isotope composition of plant-wax lipids and inorganic geochemical parameters via XRF scans in marine sediments. Our proposal shall try to answer paleoenvironmental key questions arising from these projects. We expect a straightforward correlation of data from the terrestrial and marine realms, thus yielding the opportunity to obtain a comprehensive view of global change during the investigated time slice. Analyses in varying resolution will be carried out across the upper Albian to lower Turanian interval to assess environmental and oceanographic change during the formation of various palaeoceanographic events. These events are the latest Albian Oceanic Anoxic Event Id (OAE Id), the Mid Cenomanian Event (MCE) and the Late Cenomanian OAE 2 all of which are representing major perturbations of the global carbon cycle. Investigations will be made along a stratigraphic splice of two sites from OOP Leg 207 (Demerara Rise) (Sites 1258 and 1260). Complementary analyses will be performed on selected intervals of DSDP Site 367 (Cape Verde Basin - Late Albian to Late Cenomanian) and 370 (off Morocco, Late Albian to (?) middle Cenomanian) from the eastern Atlantic in order to better estimate past large-scale hydrological-terrestrial changes in northern South America and NW Africa and their influence on the deposition of black shales in the tropical Atlantic. The project has been designed to achieve the following main goals: • Identification of runoff variations and thus terrestrial climate change during the Late Albian to early Turonian in general and during exceptional palaeoceanographic events (OAE Id, MCE and OAE 2) in particular. • Providing an estimate of terrestrial input into the marine realm at Demerara Rise during the latest Albian to early Turonian. • Testing the conceptual model of arid climates and saline bottom water formations in the tropical Atlantic during the late Cenomanian. • Providing linkages between marine palaeotemperature variations and terrestrial climate. • Estimation of changes in large-scale hydrology and its consequence for the accumulation of organic-rich sediments. • Testing the hypothesis of a significant /pCO2 drop connected to OAE formation.