[Gerdes] Evolution of the Terminal Ediacaran–earliest Cambrian ecosystems in the southern Nama Basin (GRIND-ECT drilling project): When, why, and how? – A multidisciplinary approach
German Title: Die Entwicklung der spätediakarisch–frühkambrischen Ökosysteme im südlichen Nama-Becken (GRIND-ECT Bohrprojekt): Wann, warum und wie? – Ein multidisziplinärer Ansatz
Current Status: approved
Main Applicant:Dr. Axel Gerdes
Prof. Dr. Simone Kasemann
Prof. Dr. Ulf Linnemann
Conveyor Duration: 36
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.