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

奥卡万戈裂谷带（ORZ）和三角洲（OD）以及马卡迪卡迪古巨湖（MPL）在非洲南部博茨瓦纳北部形成了一个动力系统，其中构造活动、气候变化、沉积、植被、动物和人类影响在不同的时空尺度上相互作用。该奖项为 ORZ-OD-MPL 复合体中早期大陆裂谷、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支持。目标是开发： (i) ORZ-OD 的结构和构造模型； (ii) MPL OD 和填充阶段演化的年表； (iii) OD-MPL 中复杂气候/植被流域扩张和收缩的历史，以及 ORZ、OD 和 MPL 之间的联系或缺乏。 最重要的科学问题是：构造运动与 ORZ-MPL 系统中的地表过程和气候相互作用的程度如何，以及这种相互作用中涉及哪些反馈回路来控制中新世以来南部非洲中部的环境演变？PI 将结合地震学和沉积物岩心来研究裂谷断层和沉积物填充的几何形状。岩心材料还将用于确定沉积物的来源并建立气候记录。来自岩心的这两个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）对沉积物供应的相对重要性。二维数值模型将整合这些数据，以探索盆地不对称和沉积物载荷的影响，以及这些如何通过载荷和应变定位反馈到盆地发育。

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.