Evolution of the Terminal Ediacaran–earliest Cambrian ecosystems in the southern Nama Basin (GRIND-ECT drilling project): When, why, and how? – A multidisciplinary approach

纳马盆地的演替为研究地球上第一批多细胞生命形式的生活条件、快速灭绝和被形态上不同的动物取代提供了独特的可能性。该项目提案涉及重建这些后生动物的兴衰过程中不断变化的环境，伴随着阿达马斯托海洋的关闭和沉积条件的变化。了解地球生命进化中这些关键事件的机制和时间对于确定生命本身发展的驱动因素至关重要。据我们所知，目前的项目代表了第一个综合的方法，描述了在新元古代晚期到寒武纪早期的纳玛盆地动力学的细节，它将提供一个全面的图片有关盆地演化使用一种新的方法相结合的成熟的方法在盆地分析。我们试图回答以下工作假设：（1）那玛盆地层序包含大量的小型和大型沉积事件。(2)库比斯亚群沉积物以被动边缘沉积为特征。(3)Schwarzrand亚群沉积物显示出高火山弧的影响所引起的关闭阿达马斯托海洋和不断变化的构造制度。(4)纳马盆地埃迪卡拉后生动物的殖民历史是由盆地构造环境决定的。(5)第一后生动物宿主生态系统的演变受到海平面变化的影响。(6)前寒武纪-寒武纪过渡期动物群交换的可能驱动因素是由构造环境引起的。验证这些假设将导致前寒武纪Nama盆地的全面，高时间风化方案，并可能提供一个独特的机会，了解地质构造对海水的影响，并破译埃迪卡拉纪晚期第一个多细胞生命出现的驱动力。我们将借助现代和创新方法（碳酸盐U-Pb测年、灰烬U-Pb高精度锆石测年、碎屑锆石最大沉积年龄、基于疑源类的生物地层学）进行更好的年龄控制。这决定了影响这些生态系统的因素和事件何时发生，它们为什么被破坏，以及它们如何导致生物群的更替。

The Nama Basin successions offer a unique possibility for studying the living conditions, rapid extinction and replacement by morphologically distinct animals of the first multi-cellular lifeforms on earth. This project proposal deals with reconstructing changing environments during the rise and fall of these metazoans which was accompanied by the closure of the Adamastor Ocean and changing sedimentary conditions. Understanding the mechanism and timing of these key events in evolution of life on earth is crucial for determining drivers of development of life itself. To the best of our knowledge the present project represents the first integrated approach describing the Nama Basin dynamics in such a detail during the Late Neoproterozoic to the earliest Cambrian that it will provide a comprehensive picture concerning the basin evolution using a novel approach of a combination of well-established methods in basin analysis. We try to answer the following work hypotheses: (1) The Nama Basin successions incorporate a great number of small and big scale sedimentary events. (2) The Kuibis Subgroup sediments are characterized by passive margin sedimentation. (3) The Schwarzrand Subgroup sediments show high volcanic arc influence induced by the closure of the Adamastor Ocean and a changing tectonic regime. (4) The colonisation history of the Nama Basin by the Ediacaran metazoans was determined by the basinal tectonic setting. (5) The evolution of first metazoan hosting ecosystems is influenced by sea level changes. (6) Possible driving factors of faunal exchange during the Precambrian-Cambrian transition are induced by tectonic environments.Answering these hypotheses will result in a comprehensive, high temporal weathering scheme of the Precambrian Nama Basin and may offer a unique opportunity understanding the geotectonic impact in seawater and to decipher driving forces for the late Ediacaran of-a-kind appearances of the first multicellular life. We will do so with the help of a much more improved age control by modern and innovative methods (U-Pb dating of carbonates, U-Pb high precision zircon dating of ashes, maximum deposition ages derived from detrital zircon, biostratigraphy based on acritarchs). This determines WHEN factors and events influencing these ecosystems happened, WHY they were trigged, and HOW they led to a biota replacement.