Collaborative Research: Interactions Between Incipient Continental Rifting, Fluvial Systems, and Regional Climate in Southern Africa: The Okavango-Makgadikgadi Complex, Botswana

非洲南部博茨瓦纳北方的奥卡万戈裂谷带（ORZ）、三角洲（OD）和马卡迪卡迪古巨湖（MPL）构成了一个由构造活动、气候变化、沉积作用、植被、动物群和人类活动等多种因素在不同时空尺度上相互作用的内陆体系。该奖项为ORZ-OD-MPL复合体中初期大陆裂谷，排水模式和新近纪/第四纪区域气候之间的相互作用和反馈的多学科研究提供了支持。目标是：（i）ORZ-OD的结构和构造模型;（ii）OD和MPL填充阶段的演化年表;（iii）OD-MPL中复杂气候/植被的流域扩张和收缩历史，以及ORZ、OD和MPL之间的联系或缺乏联系。 首要的科学问题是：在多大程度上构造与地表过程和气候的ORZ-MPL系统，以及参与这种相互作用的反馈回路，以控制自中新世以来的环境演变中南部非洲？PI将使用地震学和沉积物岩心相结合的方法来观察裂谷断层和沉积物填充的几何形状。此外，来自岩心的材料将用于确定沉积物的来源和建立气候记录。这两个岩心数据集将用于评估气候（通过可变侵蚀）与构造控制（河流迁移/捕获等）的相对重要性。沉积物供应。二维数值模型将整合这些数据，以探索盆地不对称性和沉积物负荷的影响，以及这些影响如何通过负荷和应变局部化反馈到盆地发展中。

The Okavango Rift Zone (ORZ) and Delta (OD), and the Makgadikgadi Paleo-Megalake (MPL) form adynamic system in northern Botswana, southern Africa, where tectonic activity, climate change,sedimentation, vegetation, fauna, and human influences interact with each other at various spatial andtemporal scales. This award provides support for a multidisciplinary study of the interactions and feedbacks between incipient continental rifting, drainage patterns, and Neogene/Quaternary regional climate in the ORZ-OD-MPL complex. The objectives are to develop: (i) a structural and tectonic model of the ORZ-OD; (ii) chronologies for the evolution of the OD and infilling phases of the MPL; and (iii) histories of drainage basin expansions and contractions of the complex climate/vegetation in the OD-MPL, and the links, or lack thereof, between the ORZ, OD, and MPL. The overarching scientific question is: to what degree tectonics interacted with surface processes and climate in the ORZ-MPL system, and what feedback loops were involved in this interaction to control the environmental evolution of central southern Africa since the Miocene?The PIs will use a combination of seismology and sediment cores to look at the geometry of the rift faults and sediment fill. The material from the cores will additionally be used to establish provenance of the sediment and build climate records. These two datasets from the cores will be used to assess the relative importance of climate (via variable erosion) versus tectonic control (river migration/capture, etc.) on sediment supply. A 2D numerical model will integrate these data to explore the effect of basin asymmetry and sediment loading and how these feedback into basin development via loading and strain localization.