Evolution of the western Namibian drainage systems since Eocene times - a multi-methodical approach

始新世以来纳米比亚西部排水系统的演变——多方法研究

• 批准号: 261205704
• 负责人: Professor Dr. Ulf-Gerhard Linnemann
• 金额: --
• 依托单位: Museum für Mineralogie und Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/261205704?language=en
• 关键词: Evolution; western; Namibian; drainage; systems

The planned project aims to the reconstruction of drainage basin evolution over a long period of time and large areal distribution using sediments of the recent rivers and their precursors. With respect to the constantly very low erosion rates since Eocene times, exceptionally well-preserved remnants of Eocene to recent fluvial strata and a lack of precise age determinations, the western Namibian drainage system was chosen as working area. In order to obtain precise ages of the single terrace levels and to detect changes in the provenance of the sediments, this is the first study coupling the routinely used terrestrial cosmogenic nuclides (TCN) 10Be, 21Ne and 26Al from quartz and detrital zircon geochronology using U-Th-Pb and Lu-Hf isotopics complemented by single grain morphometrics. In addition to these methods, we plan a feasability study of entirely new and advanced dating techniques including cross-calibration of 26Al and 36Cl in calcite, as well as 36Cl, 41Ca, and 53Mn in magnetite. Succeeding or not, the scientific outcome of this rather chancy objective will not put the above mentioned primary objective at risk. Based on precise age determinations from routinely used TCN and uniquely high-resolution provenance analyses obtained from zircon we will be able to establish the timing of terrace forming events, and, therefore draw further conclusions like aspects of geology and palaeogeography (tectonic uplift, incision events, variability of catchment areas). The sediments will also provide data that will facilitate the reconstruction of potential changes in the sediment fluxes, source to sink dynamics, fluvial palaeoenvironment and some palaeoclimatic conditions, like water supply and discharge. Hence, this proposal is in contrast to the vast majority of all earlier studies, which are generally limited to small areas and/or short periods of time and aim either at palaeogeographic and/or geologic reconstructions or at the understanding of palaeoclimatic conditions. Finally, the cooperation of two institutions with fully-equipped state-of-the-art laboratories accompanied with advanced experience makes this project quite unique and economical.

计划中的项目旨在利用现代河流及其前体的沉积物重建流域在很长一段时间内的演变和大范围的区域分布。鉴于始新世以来的侵蚀率一直很低，始新世遗迹保存极为完好，以及缺乏准确的年龄测定，纳米比亚西部排水系统被选为工作区。为了获得单一阶地水平的准确年龄和探测沉积物来源的变化，这是第一次结合常规使用的陆地宇宙成因核素(TCN)10Be、21Ne和26Al的石英和碎屑锆石年代学的U-Th-Pb和Lu-Hf同位素结合单颗粒形态计量学的研究。除了这些方法外，我们还计划对全新和先进的测年技术进行可行性研究，包括方解石中26Al和36Cl以及磁铁矿中36Cl、41Ca和53Mn的交叉校准。无论成功与否，这一相当冒险的目标的科学结果都不会危及上述首要目标。根据常规使用的TCN的精确年龄测定和从锆石获得的独特的高分辨率物源分析，我们将能够确定阶地形成事件的时间，从而得出进一步的结论，如地质和古地理方面(构造抬升、切割事件、集水区的变异性)。沉积物还将提供有助于重建沉积物通量、源汇动力学、河流古环境和一些古气候条件(如供水和排放)的潜在变化的数据。因此，这一建议与绝大多数以前的研究形成对比，这些研究一般局限于小范围和/或短时间段，目标要么是古地理和/或地质重建，要么是对古气候条件的了解。最后，两个机构的合作，拥有设备齐全的最先进的实验室，并辅之以先进的经验，使这个项目相当独特和经济。

项目成果

Attempts to understand potential deficiencies in chemical procedures for AMS: Cleaning and dissolving quartz for 10Be and 26Al analysis

尝试了解 AMS 化学程序中的潜在缺陷：清洁和溶解石英以进行 10Be 和 26Al 分析

• DOI: 10.1016/j.nimb.2019.02.007
• 发表时间: 2019
• 期刊: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 作者: Merchel S;Gärtner A;Bookhagen B;Chabilan A;Gurlit S
• 通讯作者: Gurlit S