Response of terrestrial environments to short-term climate perturbations: Low-latitude signals during the mid-Cretaceous super greenhouse world (ODP Leg 207, Demerara Rise)

该项目旨在通过对海洋沉积物中的花粉和孢子的分析，破译白垩纪中期超级温室世界的陆地环境动力学。这种方法可以将陆地和海洋领域的数据直接联系起来，从而有机会获得对全球变化的全面看法。高分辨率孢粉学分析将在Cenomanian/Turonian边界区间（CTBI）进行，以评估海洋缺氧事件2 （OAE 2）黑色页岩形成期间的陆地环境变化，这代表了全球碳循环的主要扰动。为了评估热带地区的陆地环境变化，将对OOP Leg 207 （Demerara Rise）的两个CTBI部分进行孢粉学分析。将对DSDP站点551（英格兰西南部）或Wunstorf（德国北部）的中纬度CTBI记录进行补充分析，以获得陆地环境变化的区域差异图像。该项目旨在实现以下主要目标：(1)确定与热带和中纬度地区OAE 2形成有关的陆地气候扰动（如降水和温度变化）。(2)验证了pC02显著下降与OAE 2形成有关的假设。(3)提供了在OAE 2形成期间Demerara隆起海洋领域的陆地输入估计。(4)识别OAE 2形成过程中来自陆地和海洋领域的环境信号之间的领先和滞后。

The project aims at deciphering terrestrial environmental dynamics during the mid-Cretaceous supergreenhouse world based on the analysis of pollen and spores in marine sediments. This approach allows a straightforward correlation of data from the terrestrial and marine realms, thus yielding the opportunity to obtain a comprehensive view of global change. High-resolution palynological analyses will be carried out across the Cenomanian/Turonian boundary interval (CTBI) to assess terrestrial environmental change during formation of the Oceanic Anoxic Event 2 (OAE 2) black shale representing a major perturbation of the global carbon cycle. To assess terrestrial environmental change in the tropics, palynological analyses will be carried out on two CTBI sections from OOP Leg 207 (Demerara Rise). Complementary analyses will be performed on mid-latitude CTBI records from DSDP Site 551 (off SW England) or Wunstorf (N Germany) to obtain a regionally differentiated picture of terrestrial environmental change. The project has been designed to achieve the following main goals: (1) Identification of terrestrial climatic perturbations (such as precipitation and temperature change) connected to OAE 2 formation in the tropics and mid-latitudes. (2) Testing the hypothesis of a significant pC02 drop connected to OAE 2 formation. (3) Providing an estimate of terrestrial input into the marine realm at Demerara Rise during OAE 2 formation. (4) Identification of leads and lags between environmental signals from the terrestrial and marine realms during OAE 2 formation.