The Chew Bahir Drilling Project - Deconvolving climatic versus tectonic forcing in the source-to-sink sediment system of extensional provinces: New insights from the Chew Bahir Basin, South Ethiopia

Chew Bahir 钻探项目 - 对伸展省源-汇沉积系统中的气候与构造强迫进行反卷积：来自埃塞俄比亚南部 Chew Bahir 盆地的新见解

• 批准号: 252193660
• 负责人: Professor Dr. Daniel Melnick
• 金额: --
• 依托单位: Instituto de Ciencias de la Tierra
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/252193660?language=en
• 关键词: Chew; Bahir; Drilling; Project; Deconvolving

The complex kinematic evolution of continental rifts and the conspiring effects of climate and tectonics on the surface-process system requires a holistic approach in deciphering paleoenvironmental changes reflected in drill cores. Such an approach must entail the reconstruction of the tectono-geomorphic characteristics of the sediment source-routing-sink system, because erosion and sediment transport are mainly a function of topography, climate, and lithology. Here, we propose such a study of the Chew Bahir catchment in southern Ethiopia, aimed at linking the tectonogeomorphic evolution of the basin with the sediment-routing system, and ultimately the depositional record of the Chew Bahir drilling site, to be obtained under the auspices of the International Continental Drilling Program (ICDP). The recovered drill core is expected to corresponding to an interval spanning at least the ultimate 800-1,200 kyr, targeted to provide data on environmental change to better assess hominin evolution and migration. By integrating our catchment-wide study with the drilling record we aim at deconvolving climatic and tectonic forcing impacting sediment routing and deposition in the Chew Bahir basin. Our results will improve the understanding of three important aspects of the sedimentary records of extensional systems and their relationship with major hominin migration corridors. These include: 1) the forcing mechanisms impacting landscape development; 2) sediment production and deposition; and 3) the paleo-environmental significance of sedimentary deposits in a crucial sector of the East African Rift. In order to achieve these goals, we will follow a four-tiered approach: I) determine the spatiotemporal variations in sediment sources and routing by provenance analysis and dating of fluvial terraces; II) quantify modern and past erosion rates using cosmogenic nuclides and sediment volumes estimated from seismic reflection profiles; III) establish the timing of fluvial captures and drainage reversals in the catchment; and IV) link the tectono-geomorphic evolution with the sedimentary record of the ICDP drillhole. We will use sedimentological techniques in provenance analysis and constrain the age of terrace deposits using cosmogenic nuclides and 14C, to cover a broad age spectrum. Our geomorphic analysis will be aided by 12-m digital elevation models obtained from TanDEM-X data. Together, the tectono-geomorphic analysis, the provenance study, and new geochronology of sedimentary deposits will provide an unprecedented data set that will be ultimately linked to the depositional record of the drillhole in the basin center, thus contributing to our understanding of the link between environmental change and hominin evolution in light of active tectonics and repeated climate change.

大陆裂谷的复杂运动学演变以及气候和构造对表面处理系统的阴谋作用需要一种整体方法来解密钻芯中反映的古环境变化。这样的方法必须需要重建沉积物源源线链接系统的构造地球形状特征，因为侵蚀和沉积物的运输主要是地形，气候和岩性的函数。在这里，我们提出了一项对埃塞俄比亚南部的Chew Bahir集水区的研究，旨在将盆地的构造地质形态演变与沉积物穿孔系统以及Chew Bahir钻井现场的沉积记录联系起来，并根据国际大陆钻探计划（ICDP）获得。预期回收的钻头将与至少跨越最终800-1,200 KYR的间隔相对应，该间隔旨在提供有关环境变化的数据，以更好地评估人类的演化和迁移。通过将我们的集水区研究与钻井记录相结合，我们旨在解除volt vol的气候和构造迫使造影在Chew Bahir盆地中的沉积物路由和沉积。我们的结果将提高人们对扩展系统沉积记录的三个重要方面的理解及其与主要的人类迁移走廊的关系。其中包括：1）影响景观发展的强迫机制； 2）沉积物的产生和沉积； 3）沉积物在东非裂谷至关重要的部门中的古环境意义。为了实现这些目标，我们将遵循一种四层方法：i）确定沉积物来源的时空变化以及通过出处分析和河流露台约会的路由； ii）使用从地震反射曲线估计的宇宙核素和沉积物量来量化现代和过去的侵蚀速率； iii）在集水区中建立河流捕获和排水逆转的时机； iv）将构造地球形态演变与ICDP钻孔的沉积记录联系起来。我们将在出处分析中使用沉积学技术，并使用宇宙核素和14C来限制露台沉积的年龄，以覆盖广泛的年龄频谱。我们的地貌分析将通过从串联X数据获得的12米数字高程模型来帮助。构成晶状体地球化分析，出处研究和新的沉积沉积物学教量学将提供一个前所未有的数据集，最终将与盆地中心中的钻孔的沉积记录联系起来，从而有助于我们对环境变化和本性变化之间的联系和重复的clectimate climate climate climate climpatiate Chripts的理解。

项目成果

Continental rifting at magmatic centres: structural implications from the Late Quaternary Menengai Caldera, central Kenya Rift

岩浆中心的大陆裂谷：肯尼亚中部裂谷晚期第四纪 Menengai 火山口的结构影响

• DOI: 10.1144/jgs2019-021
• 发表时间: 2019
• 期刊: Journal of the Geological Society
• 影响因子: 2.7
• 作者: Melnick;Strecker
• 通讯作者: Strecker