Correlation of Neoproterozoic diamictites in southern Namibia
Publikation: Beitrag in Fachzeitschrift › Übersichtsartikel (Review) › Beigetragen › Begutachtung
Beitragende
Abstract
In order to present a conclusive new correlation model for Neoproterozoic glacial units of southern Namibia, ten different sections and a variety of samples thereof were studied and analysed with respect to field relationships, whole rock geochemistry, zircon U-Pb dating as well as Th-U ratios, Hf isotopic measurements and zircon grain size analyses, combined with the new method of LA-ICP-MS U-Pb dating of cap carbonates. This multi-method approach allowed for the construction of a correlation model for the Cryogenian and Ediacaran units of southern Namibia. Furthermore it revealed, that (1) sediments deposited during four glacial Neoproterozoic events in Southern Namibia did all show very similar detrital zircon features, allowing the interpretation of continuous recycling of the same material over the most part of the Neoproterozoic, which is also supported by the geochemical whole rock analyses, (2) cap carbonates are worth analysing concerning their U-Pb isotope ratios and can result in valuable age determinations, if reset and overprinted areas are recognised and avoided for laser ablation, (3) proving the Sturtian and the Marinoan age for the Numees Fm and the Namaskluft Mbr by U-Pb dating their overlying carbonate sequences was finally possible, (4) the Witvlei Grp sedimentation ends at 579 ± 52 Ma, which is the age for the stromatolites of the Okambara Mbr, representing the uppermost deposits of the Witvlei Grp, and this leading to (5) the start of Nama Grp sedimentation for southern Namibia was not earlier than 579 ± 52 Ma.
Details
Originalsprache | Englisch |
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Aufsatznummer | 104159 |
Fachzeitschrift | Earth-science reviews |
Jahrgang | 233 |
Publikationsstatus | Veröffentlicht - Okt. 2022 |
Peer-Review-Status | Ja |
Extern publiziert | Ja |
Schlagworte
ASJC Scopus Sachgebiete
Schlagwörter
- Correlation, Glaciation, Namibia, Neoproterozoic