Felsic crust development in the Kaapvaal Craton, South Africa: A reference sample collection to investigate a billion years of geological history
Moyen, J.F., McCoy-West, A.J., Bruand, E., Millet, M.A., Nebel, O., Cawood, P.A., Saji, N., Ladwig, A., Klaver, Martijn, and Elburg, M. (2024) Felsic crust development in the Kaapvaal Craton, South Africa: A reference sample collection to investigate a billion years of geological history. Earth-Science Reviews, 250. 104680.
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Abstract
The crust of the Kaapvaal craton accreted throughout the Archaean over nearly 1 billion years. It provides a unique example of the various geological processes that shape Earth's continental crust, and is illustrated by a reference collection of granitoids and mafic rocks (SWASA collection). This sample collection is fully characterised in term of age, major and trace elements, and documents the following multistage history of the craton. In the Barberton area, the initial stages of accretion (stage B.I, > 3.33 Ga and B.II, 3.28—3.21 Ga) correspond to the formation of a sodic (TTG) crust extracted from a near-chondritic reservoir. Stage B.III (ca. 3.1 Ga) corresponds to reworking of this crust, either through intracrustal melting, or via recycling of some material into the mantle and melting of this enriched mantle. Stage B.IV (2.85—2.7 Ga) corresponds to the emplacement of small, discrete plutons involving limited intracrustal reworking. The Northern Kaapvaal craton corresponds to a mobile belt flanking the Barberton cratonic core to the North. Stage NK.I (> 3.1 Ga) resembles stages B.I and B.II: formation of a TTG crust from a chondritic reservoir. In contrast, stage NK.II. (2.97–2.88 Ga) witnesses probable rifting of a cratonic fragment and formation of greenstone basins as well as a new generation of TTGs with both the mafic and felsic magmatism extracted from an isotopically depleted mantle (super-chondritic) reservoir. Intra-crustal reworking dominates stage NK.III (2.88–2.71 Ga), whereas sanukitoids and related granites, involving a mantle contaminated by recycled crustal material, are common during stage NK.IV (ca. 2.67 Ga). The SWASA collection are available as a reference collection to investigate the behavior of other systems of interest during a variety of crust evolution modes.
Item ID: | 81997 |
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Item Type: | Article (Research - C1) |
ISSN: | 1872-6828 |
Keywords: | Archaean, Continental crust, Kaapvaal craton, SWASA, Tonalite-trondhjemite-granodiorite, TTG |
Copyright Information: | © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) |
Funders: | Australian Research Council (ARC) |
Projects and Grants: | ARC FL160100168 |
Date Deposited: | 21 Mar 2024 01:40 |
FoR Codes: | 37 EARTH SCIENCES > 3705 Geology > 370511 Structural geology and tectonics @ 10% 37 EARTH SCIENCES > 3705 Geology > 370503 Igneous and metamorphic petrology @ 60% 37 EARTH SCIENCES > 3703 Geochemistry > 370302 Inorganic geochemistry @ 30% |
SEO Codes: | 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280107 Expanding knowledge in the earth sciences @ 100% |
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