Abstract
When Supercontinent Rodinia began to break up at ~800 Ma, wide rifts formed evolving into a passive margin of the Mozambique Ocean. At one stage, organic-rich pelites with gypsum (the later host rock of tsavorites) were interbedded with siliciclastics, carbonates, and bimodal volcanic rocks. Ocean closure, subduction, collision and welding of various microcontinents and volcanic arcs formed the Mozambique Belt and at ~550 Ma, ended with the assembly of Supercontinent Gondwana. In East Africa, deformation and metamorphism climaxed at 615–600 Ma Fritz et al. (J. Afr. Earth Sci. 86:65–106, 2013 [1]). At peak metamorphic conditions, anatexis of siliciclastic metasediments produced abundant metamorphic mobilizates such as pegmatites and quartz veins. In the black schist hosting tsavorites, however, partial melting only produced small fractions of a supercritical hydrous liquid. Most of this liquid remained within the host but migrated over short distances into structural traps of different origin; turbid green grossular crystallized from the melt and transparent tsavorite from exsolved fluids.
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References
Fritz, H., Abdelsalam, M., Ali, K.A., et al.: Orogen styles in the East African Orogen: a review of the Neoproterozoic to Cambrian tectonic evolution. J. Afr. Earth Sci. 86, 65–106 (2013)
Hagemann, S.G., Lisitsin, V.A., Huston, D.L.: Mineral system analysis: quo Vadis. Ore Geol. Rev. 76, 504–522 (2016)
Pohl, W.L., Nauta, W.J., Niedermayr, G.: Geology of the Mwatate Quadrangle and the Vanadium Grossularite Deposits of the Area (with a Geological Map 1:50,000). Kenya Geol Survey Report No. 101, 1–55, Nairobi (1979)
Feneyrol, J., Giuliani, G., Demaiffe, D., et al.: Age and origin of the tsavorite and tanzanite mineralizing fluids in the Neoproterozoic Mozambique Metamorphic Belt. Can. Mineral. 55, 763–786 (2017)
Feneyrol, J., Giuliani, G., Ohnenstetter, D., et al.: Worldwide tsavorite deposits: new aspects and perspectives. Ore Geol. Rev. 53, 1–25 (2013)
Pohl, W.L., Horkel, A.: Notes on the geology and mineral resources of the Mtito Andei-Taita area (Southern Kenya). Mitt. Oesterr. Geol. Ges. 73, 135–152 (1980)
Warren, J.K.: Sabkhas, saline mudflats and pans. In: Warren, J.K. (ed) Evaporites: sediments, resources and hydrocarbons, chapter 3, pp. 139–220. Springer, Berlin–Heidelberg (2006)
Giuliani, G., Dubessy, J., Ohnenstetter, D., et al.: The role of evaporites in the formation of gems during metamorphism of carbonate platforms: a review. Miner. Deposita. 53, 1–20 (2018)
Jacob, J.-B., Martelat, J.-E., Goncalves, P., Giuliani, G., et al.: New P-T-X conditions for the formation of gem tsavorite garnet in the Voi area (southwestern Kenya). Lithos. 320–321, 250–264 (2018)
Thomas, R., Rericha A., Pohl, W.L., Davidson, P.: Genetic significance of the 867 cm−1 out-of-plane Raman mode in graphite associated with V-bearing green grossular. Mineralogy and Petrology (online) https://doi.org/10.1007/s00710-018-0563-1 (2018)
Gorbaty, Y.E., Bondarenko, G.V.: The physical state of supercritical fluids. J. Supercrit Fluid 14, 1–8 (1998)
Martelat, J.-E., Paquette, J.-L., Bosse, V., et al.: Chronological constraints on tsavorite mineralizations and related metamorphic episodes in Southeast Kenya. Can. Mineral. 55, 845–865 (2017)
Pohl, W.L.: Economic Geology, Principles and Practice: Metals, Minerals, Coal and Hydrocarbons—An Introduction to Formation and Sustainable Exploitation of Mineral Deposits. Wiley, Oxford (2011)
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Pohl, W.L. (2019). The Tsavorite (Gem Quality Vanadium Grossularite) Minerogenetic System in East Africa. In: Rossetti, F., et al. The Structural Geology Contribution to the Africa-Eurasia Geology: Basement and Reservoir Structure, Ore Mineralisation and Tectonic Modelling. CAJG 2018. Advances in Science, Technology & Innovation. Springer, Cham. https://doi.org/10.1007/978-3-030-01455-1_18
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