Dolerite intrusions within iron ore of the maremane dome as possible time markers and stratigraphic control units
Loading...
Date
2024
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Western Cape
Abstract
The Maremane Dome (MD) lies in the Griqualand West basin of the Northern Cape and hosts iron (Fe) ore deposits, which are among the richest in South Africa. High-grade iron ores in South Africa belong to the Neoarchaean to early Paleoproterozoic Transvaal Supergroup. The largest iron deposits are attributed to the Asbestos Hills Subgroup of the Ghaap Group, Griqualand West basin. These iron deposits are developed along the 2.2-2.0 Ga erosional unconformity zone (so-called pre-Gamagara unconformity), where it crosscuts the Banded Iron Formations (BIFs). The current model of the Fe ore formation is a supergene origin, attributed to the leaching of the silica component from the BIFs as a result of alteration at the surface, with the largest deposits developed within karst environments. Multiple ferruginized dolerite sills and dykes intersect the BIFs and the ore at various stratigraphic levels. The geochemistry, age, and deformation history of these magmatic intrusions are not well understood. A detailed study of the dolerite intrusions, including their petrography, geochemistry and U/Pb age dating, can potentially provide robust markers for the iron mining industry and improve the understanding of the geological history of the region. Present research focuses on these magmatic intrusions, their textural, mineralogical, and geochemical characteristics, and aims to address a need for the mining industry to have reliable stratigraphic markers and control when correlating drill cores with each other and with the regional stratigraphy.
Description
Keywords
Ferruginization, Maremane Dome, Wolhaarkop Dome, Transvaal Supergroup, Iron Mineralization