African A-Type granites: A geochemical review on metallogenic potential Leonidas C. Vonopartis a, ⁎, Judith A. Kinnaird a,c,d , Paul A.M. Nex a , Laurence J. Robb a,b,c a School of Geosciences, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa b Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, United Kingdom c DST-NRF CIMERA, University of Johannesburg, PO Box, 524, Johannesburg 2006, South Africa d Camborne School of Mines, University of Exeter, Penryn Campus, Penryn TR10 9FE, United Kingdom abstract article info Article history: Received 27 November 2020 Received in revised form 11 May 2021 Accepted 11 May 2021 Available online 15 May 2021 Keywords: A-Type Anorogenic African granites Tin granites Trace element geochemistry Metallogenic potential Tin and other high-field-strength (HFS) elements are becoming increasingly significant, driven by technological advancements and a global effort to develop alternative energy solutions. A-type granites are associated with the mineralisation of these critical metals and therefore, investigating the influences on their metallogenic potential is essential for future exploration. The geochemical comparison between selected mineralised and unmineralised African A-Type granites, highlights the importance and implications of fractionation, crustal contamination, crustal emplacement and the composition and evolution of the magmatic-hydrothermal fluid in the develop- ment of endogranitic Sn mineralisation. Trace elemental ratios such as Zr/Hf, Nb/Ta and Y/Ho demonstrate the relationship between the degree of fractionation and interaction with acidic, F- and Cl-rich magmatic- hydrothermal fluids in these mineralised and barren African examples. Circumstantial differences in magmatic origin, not only directly influence the metallogenic budget of a granite but also influence the F and B content of the later stages of felsic magmatism. These volatiles prolong fractionation, consequently facilitating the likelihood of HFS element saturation and the development of an economic deposit. Moreover, the combination of continen- tal setting and the enrichment of HFS and volatile elements by the assimilation of fortuitous crustal lithologies can upgrade an originally unfavourable magma composition, to one with a potential for mineralisation. It is therefore shown that mineralisation is ultimately achieved through a series of sequential, incompatible and HFS element enrichment stages, which culminate in the accumulation of sufficient metals to produce economi- cally significant mineralisation. © 2021 Elsevier B.V. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Regional geology and granite petrography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1. Botswana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1.1. The Thamaga granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.2. The Kgale granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Namibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.1. The Erongo granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.2. The Gross and Klein Spitzkoppe granites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3. Nigeria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3.1. The Kudaru Ring Complex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3.2. The Ririwai Ring Complex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4. South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4.1. The Nebo granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4.2. The Bobbejaankop granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.4.3. The Lease granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.5. Sudan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.5.1. The El Dair Complex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Lithos 396–397 (2021) 106229 ⁎ Corresponding author. E-mail address: leonidas.vonopartis@students.wits.ac.za (L.C. Vonopartis). https://doi.org/10.1016/j.lithos.2021.106229 0024-4937/© 2021 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Lithos journal homepage: www.elsevier.com/locate/lithos