Tectonics and climate in a low-latitude rift: rift-shoulder denudation and sedimentation processes in northern Lake Malawi

低纬裂谷的构造和气候：马拉维湖北部裂谷肩剥蚀和沉积过程

• 批准号: 5423602
• 负责人: Professor Dr. Manfred Strecker, Ph.D.
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5423602?language=en
• 关键词: Tectonics; climate; low; latitude; rift

Lake Malawi is an integral part of the East African Rift and contains an important low-latitude paleoclimate record reflecting the influence of climatic changes on erosion and rift sedimentation. An available network of high resolution seismic reflection profiles (3000 km length) provides an outstanding opportunity to characterize and quantify mass flux and sediment volumes in the northern Malawi Rift. Previous work has identified 100 kyr sedimentary cycles in the imaged seismic packages. A basin-wide analysis of this dataset with correlated seismic packages, and comparison with long-term denudation rates derived from thermochronology (U-Th/He; apatite fission track) will help assess the influence of multiple climate changes on erosion and sedimentation processes. In conjunction with geochronologic work on existing drill cores, and information to be obtained from future ICDP drilling in northern Lake Malawi the proposed analysis of seismic stratigraphic packages and low temperature thermochronology of rift-shoulder rocks will result in an improved model of sedimentation in an active rift. In addition, the expected results will determine the importance of climate vs. tectonic processes in rift sedimentation.

马拉维湖是东非裂谷的一个组成部分，包含了一个重要的低纬度古气候记录，反映了气候变化对侵蚀和裂谷沉积的影响。现有的高分辨率地震反射剖面网络（3000公里长）为描述和量化马拉维裂谷北部的质量通量和沉积物体积提供了绝佳的机会。以前的工作已经在成像的地震包中确定了100 kyr的沉积旋回。利用相关地震包对该数据集进行全盆地范围的分析，并与热年代学（U-Th/He；磷灰石裂变径迹）得出的长期剥蚀率进行比较，将有助于评估多种气候变化对侵蚀和沉积过程的影响。结合对现有钻孔岩心的地质年代学工作，以及今后在马拉维湖北部进行的ICDP钻探将获得的资料，拟议的地震地层包和裂谷肩部岩石的低温热年代学分析，将改进活动裂谷的沉积模型。此外，预期结果将确定气候与构造过程在裂谷沉积中的重要性。