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New evidence for the early onset of supergene alteration along the Kalahari unconformity

Citation

Vafeas, NA and Blignaut, LC and Viljoen, KS and Meffre, S, New evidence for the early onset of supergene alteration along the Kalahari unconformity, South African Journal of Geology, 121, (2) pp. 157-170. ISSN 1012-0750 (2018) [Refereed Article]


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Copyright Statement

Copyright 2018 Geological Society of South Africa

DOI: doi:10.25131/sajg.121.0012

Abstract

The manganese ore of the Hotazel Formation in the Kalahari Manganese Field, which has been thrust along the Blackridge thrust fault, has been subjected to various degrees of pre-thrusting hydrothermal and post-thrusting supergene alteration. Coarse-grained apatite, which appears to be formed under supergene conditions on textural grounds, is present in the thrusted manganese ore in previously unrecorded abundances. U-Pb dating of this apatite within the thrusted manganese ore has placed the onset of chemical weathering of the succession at a 77 7.5 Ma, approximately 35 million years earlier than previously thought for the area. This implies that erosion along the Post-African I land surface, as well as the effects of supergene alteration in the Kalahari Manganese Field must have commenced within the late Cretaceous Period, subsequent to earlier erosion along the African land surface.

Item Details

Item Type:Refereed Article
Keywords:manganese, metal ores, Upper Cretaceous, Cretaceous, Africa, manganese ores, metasomatism, South Africa, Southern Africa, U/Pb, absolute age, Mesozoic mineral deposits, genesis, Northern Cape Province, South Africa
Research Division:Earth Sciences
Research Group:Geology
Research Field:Geochronology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
UTAS Author:Meffre, S (Dr Sebastien Meffre)
ID Code:129976
Year Published:2018
Funding Support:Australian Research Council (CE0561595)
Web of Science® Times Cited:2
Deposited By:CODES ARC
Deposited On:2019-01-02
Last Modified:2019-03-08
Downloads:0

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