The structural and environmental history of the Suguta Valley, Northern Kenya Rift

我们建议进行最后一周的考察，以调查肯尼亚北部偏远苏古塔山谷的晚新生代结构库存和湖泊历史。该项目的基本目标是：确定湖泊古气候档案的构造边界条件，利用湖泊沉积物破译古环境史。在完成了山谷全新世湖泊沉积物的构造测绘和调查后，项目最后阶段的目标是：(1)东非中更新世过渡期（MPT）的气候变化特征；(2)轨道强迫对东非湿度的作用是什么？(3)苏加塔河谷和东非其他地区记录的湿期的内部变异性是什么？(4)苏加塔河谷及其邻近盆地的动物对环境变化的响应是什么？(5)这些条件的历史如何与人类物种的进化过程和事件联系起来？对东非中更新世气候和环境变化的研究，以及对当时湖盆构造演化的分析，将极大地受益于我们对干湿循环（如非洲湿润期）的时间、内部变异和原因的扩展知识。

We propose a last one-week expedition to investigate the late Cenozoic structural inventory and lacustrine history of the remote Suguta Valley, northern Kenya. The fundamental objectives of the project are: Defining the structural boundary conditions of lacustrine paleoclimate archives and deciphering the paleo-environmental history using lacustrine sediments. After having completed structural mapping and investigating the Holocene lacustrine sediments in the valley, the objectives for the final phase of the project with special emphasis on the Mid Pleistocene are: (1) What is the character of climate change in East Africa during the Mid-Pleistocene Transition (MPT); (2) What is the role of orbital forcing on East African humidity? (3) What is the internal variability of the wet episode documented in the Suguta Valley and elsewhere in East Africa? (4) What are the faunal responses to the environmental changes in Suguta Valley and the adjacent basins? (5) How can the history of those conditions be related to evolutionary processes and events in hominin species? This investigation of the Mid Pleistocene climate and environmental change in East Africa in concert with the analysis of the tectonic evolution of the lake basins at that time will significantly benefit from our expanded knowledge about the timing, internal variability and causes of dry-wet-dry cycles such as the African Humid Period.