Collaborative Research: Evolution of the Deep South Atlantic Since the Last Interglacial Period Inferred from a Depth Transect of Cape Basin Sediment Cores

有相当多的证据表明，深海在控制更新世冰期和间冰期的演变方面发挥了一定的作用。 然而，经过几十年的研究，对于沉积物示踪剂在多大程度上可以区分冰河时代海洋和现代海洋之间的深海环流差异，仍然存在争议。 这一合作项目将利用沿着纳米比亚边缘和开普盆地的一个深度断面的岩心，在最后一次冰期-间冰期循环的八个时间段内，为几种常见的古海洋学示踪剂（包括海底d18 O和d13 C、放射性碳、Cd/Ca、Zn/Ca和B/Ca）生成多代用指标记录，调查过去的海洋环流变化。 这些时间片代表了从间冰期到整个冰期循环的演变过程。 该研究将围绕一系列问题，涉及大西洋水团演变、环流和碳循环之间的联系、保守和非保守代理之间的差异，以及与海洋混合效应不同的主要边界条件变化的可能性。更广泛的影响：该项目将提供世界海洋两个主要深水团在整个冰周期中混合的详细情况，这将广泛用于海洋学家和气候科学家。 资金将支持两个博士学位。学生和提供代理数据收集和解释的重要经验。 该项目还将作为夏季REU研究员的平台，并为几名本科生学习研究和实验室技术提供支持。 此外，资金将有助于通过德克萨斯州A M大学的深地学院开发一门关于深地环流的课程。

There is considerable evidence that the deep ocean plays some role in governing the evolution of Pleistocene ice ages and interglacial periods. Yet after several decades of research, there is still debate over the degree to which sedimentary tracers can distinguish differences in deep ocean circulation between ice age oceans and the modern ocean. This collaborative project will investigate past ocean circulation changes by generating multi-proxy records for several common paleoceanographic tracers (including benthic d18O and d13C, radiocarbon, Cd/Ca, Zn/Ca and B/Ca) for eight time slices over the last glacial-interglacial cycle using cores along a depth transect from the Namibian margin and Cape Basin. These time slices would represent the step in evolution from interglacial state through a full glacial cycle. The research will focus around a series of questions concerning water mass evolution in the Atlantic Ocean, the connection between circulation and carbon cycling, differences between conservative and non-conservative proxies, and the possibility for major boundary condition changes distinct from ocean mixing effects. Broader impacts:This project will provide a detailed picture of the mixing between the two principal deep water masses of the world's ocean across a full ice cycle, which will be of widespread use to oceanographers and climate scientists. Funding will support two Ph.D. students and provide significant experience in proxy data collection and interpretation. The project will also serve as a platform for a summer REU fellow and provide support for several undergraduate students to learn research and laboratory techniques. Additionally, funding will help develop a lesson on deep earth circulation through the Deep Earth Academy at Texas A&M University.