Prof Dirk van Reenen

Overview

Research interests Dirk is a metamorphic petrologist with special interest in studying deep crustal geological processes that guided the formation and exhumation of ancient granulite facies terranes. His research focuses on the Neoarchean Limpopo Complex of southern Africa, its relationship with >3.0 Ga granite-greenstone belts of the juxtaposed Kaapvaal Craton, and the link with hypozonal orogenic gold mineralization. This ongoing research strongly relies on vital geological input that is continuously provided by collaborating earth scientists from local and international universities and research institutions. Regional and detailed structural-geological mapping of much of the Limpopo Complex in South Africa including the granite-greenstone terrane of the juxtaposed KVC formed the basis for an integrative approach that also comprised geophysical, petrological, geochronological, fluid inclusion and stable isotopic data and numerical modelling of complex geological processes. This integrated approach underpins the concept of an intra-crustal gravity-driven Limpopo orogeny at 2.72-2.62 Ga that was directed by mantle heat flow (mantle plume) that triggered a buoyant crustal-scale granulite diapir which penetrated the pre-Limpopo crust at ~2.72 Ga underneath the present CZ. This research established the Limpopo granulite facies terrane and the distinctive contact relationship with the juxtaposed ZC and KVC granite-greenstone belts at 2.72-2.62 Ga. Dirk’s research also suggests that a superimposed regional high-grade thermal event that affected the entire Limpopo Complex and juxtaposed Kaapvaal Craton at ~2.02 Ga was not associated with major deformation or growth of new metamorphic mineral assemblages. Thermo-tectonic activity associated with this regional thermal event is restricted to discreet high-grade shear zones that reflect reactivation of early (Neoarchean in age) sheared structures. Dirk van Reenen joined the Department of Geology at UJ (previously RAU) in 1971. He is an NRF B-rated scientist who permitted his NRF registration to lapse at the end of 2022. His more than 140 peer-reviewed publications in national and international journals resulted in an h-index of 42. Dirk successfully (co)supervised fifteen MSc, and eight PhD students and organized nine international field workshops in the Limpopo Complex and juxtaposed greenstone belts of the Kaapvaal craton. He acted as the Head of the Department of Geology (1995-1997) and as Dean of the Faculty of Science (1998-2003). Selected recent publications Van Reenen, D.D., Smit, C.A., Huizenga, J.M., 2024. The Neoarchean Limpopo Complex 1952-2024 . Official Field Guide to the 22-26 July 2024 Limpopo Field Workshop. Van Reenen, D.D., Clark, M.D., Smit, C.A., Tsunogae, T., Safonov, O. 2023. Review of the thermo-tectonic evolution of the Central Zone of the Limpopo Complex with implications for conflicting published geodynamic models. South African Journal of Geology , 126, 339–372. https://doi.org/10.25131/sajg.126.0010 Van Reenen, D.D., Smit, C.A., Huizenga, J.M., Tsunogae, T., Safonov, O. 2023. Thermo-tectonic evolution of the Neoarchaean Southern Marginal Zone of the Limpopo granulite Complex (South Africa). South African Journal of Geology , 126, 373-406. https://doi.org/10.25131/sajg.126.0027 Koizumi, T., Tsunogae, T., van Reenen, D.D., Smit, C.A., Belyanin, G.A., 2023. Fluid migration along deep crustal shear zone: A case study of the Rhenosterkoppies Greenstone Belt in the northern Kaapvaal Craton, South Africa. Geological Journal 58(10), 3928-3947. https://doi.org/10.1002/gj.4818 Safonov O. G., Yapaskurt V. O., Elburg M. A., van Reenen D. D., Rajesh H. M., Smit C. A., Perchuk A.L., Butvina, V. G. (2021) Melt-to shear-controlled exhumation of granulites in granite–gneiss domes: petrological perspectives from metapelite of the Neoarchean Ha-Tshanzi structure, Central Zone, Limpopo Complex, South Africa. Journal of Petrology 62, 1-26. https://doi.org/10.1093/petrology/egab097 Mityaev, A.S., Safonov, O.G., Reutsky, V.N., Izokh, O.P., Varlamov, D.A., Kozlovskii, V.M., Van Reenen, D.D. 2020. Isotope characteristics of carbonate rocks of greenstone belts as an indicator of a possible source of fluids in Precambrian granulite complexes: An example from the Giyani greenstone belt and the Limpopo granulite complex, South Africa. Doklady Earth Sciences , 492(1), 66-70. https://doi.org/10.1134/S1028334X20050153 Van Reenen D.D., Smit C.A., Perchuk A.L., Huizenga J.M., Safonov O.G., Gerya T.V. 2019. The Neoarchaean Limpopo orogeny: exhumation and regional-scale gravitational crustal overturn driven by a granulite diapir. In: The Archaean Geology of the Kaapvaal Craton, Southern Africa (Eds. A. Kröner, A. Hofmann), Ch. 8, Springer, Cham, pp. 185-224. Smit, C.A, van Reenen, D.D., McCourt, S., Huizenga, J.M., Belyanin, G., and Vafeas, N.A. 2019. Hypozonal gold mineralization in the Giyani Goldfield, Northern Kaapvaal Craton/Limpopo Complex. South African Journal of Geology 122.4, doi: 10.25131, sajg. 122.0037. Perchuk, A.L., Safonov, O.G., Smit, C.A., van Reenen, D.D., Zakharov, V.S., Gerya, T.V. 2018. Precambrian ultra-hot orogenic factory: Making and reworking of continental crust. Tectonophysics 746 (2018) 572–586 Safonov, O.G., Yapaskurt, V.O., Elburg, M., van Reenen, D. D., Tatarinova, D.S., Varlamov, D.A., Golunova, M. A., Smit, C.A. 2018. P–T Conditions, Mechanism and Timing of the Localized Melting of Metapelites from the Petronella Shear Zone and Relationships with Granite Intrusions in the Southern Marginal Zone of the Limpopo Belt, South Africa. Journal of Petrology , 59, 695–734, doi: 10.1093/petrology/egy052 Rajesh, H.M., Belyanin, G.A., Safonov, O.G., Vorster, C., van Reenen, D.D. 2018. Garnet-bearing low-Sr and high-Sr Singelele leucogranite: A record of Neoarchean episodic melting in collisional setting and Paleoproterozoic overprint in the Beit Bridge complex, southern Africa. Lithos 322, 67–86