Palomagnetism of Mesoproterozoic Lavas in the Barby Formation of the Sinclair Region, Southern Namibia

Xinxin Xu, David A. D. Evans, Joseph E. Panzik, Ulf Linnemann, Mandy Hofmann, Jenna Hessert, R. Hanson

Research output: Contribution to conferencePoster

Abstract

Southern Namibia is part of the Kalahari Craton, which is speculated to have occupied a central location the Rodinia supercontinent. The Sinclair region, along the western margin of the Kalahari Craton, comprises several low-grade volcano-sedimentary sequences that are amenable to paleomagnetic study. With a stratigraphic thickness of between 3000m and 5000m, low metamorphic grade, and gentle deformation, the Barby lavas provide ample opportunity for generating a robust paleomagnetic pole. The goal of this project is to combine newly collected field data of the Barby formation with previously published paleomagnetic results from the Sinclair region, to obtain a fuller understanding of the motion of the Kalahari craton as global paleogeography transitioned between the Nuna and Rodinia supercontinents. Paleomagnetic results from previous sampling campaigns demonstrate a North to Northeast shallow characteristic remanent magnetization, bolstered by positive inverse baked-contact tests on ca. 1100-Ma dikes that intrude the Barby lavas. Here we present initial results from the latest field season, sampling five different structural panels of different bedding attitudes (younging directions as follows): Vergenoeg (NE), Klein Haremub (SE), Naus (N), Aruab (SW), and Osis (W; the Osis panel is isolated and is only tenuously correlated with the other Barby sections). Our sampling includes regional fold tests, more inverse baked-contact tests, and intraformational conglomerate tests on the age of magnetization. New zircon U-Pb geochronology via laser-ablation ICP-MS dates the nonconformably underlying Haremub granite at ca. 1335 Ma, providing a maximum age for the Barby succession. The combination of geochronologic and paleomagnetic results will help to constrain the location of the Kalahari Craton in mid-Mesoproterozoic time.

Original languageAmerican English
StatePublished - Nov 2 2015
Externally publishedYes
EventGeological Society of America Abstracts with Programs -
Duration: Oct 23 2017 → …

Conference

ConferenceGeological Society of America Abstracts with Programs
Period10/23/17 → …

Disciplines

  • Earth Sciences

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