BIUSTRE

Carbonate-silicate inclusions in garnet as evidence for a carbonate-bearing source for fluids in leucocratic granitoids associated with granulites of the Southern Marginal Zone, Limpopo Complex, South Africa

Show simple item record

dc.contributor.author Safonov, O.G.
dc.contributor.author Mityaev, A.S.
dc.contributor.author Yapaskurt, V.O.
dc.contributor.author Belyanin, G.A.
dc.contributor.author Elburg, M.
dc.contributor.author Rajesh, H.M.
dc.contributor.author Golunova, M.A.
dc.contributor.author Shcherbakov, V.D.
dc.contributor.author Butvina, V.G.
dc.contributor.author van Reenen, D.D.
dc.contributor.author Smit, C.A.
dc.date.accessioned 2022-09-06T09:01:43Z
dc.date.available 2022-09-06T09:01:43Z
dc.date.issued 2020-01
dc.identifier.citation Safonov, O.G. et al. (2020)Carbonate-silicate inclusions in garnet as evidence for a carbonate-bearing source for fluids in leucocratic granitoids associated with granulites of the Southern Marginal Zone, Limpopo Complex, South Africa. Gondwana Research, 77, 147–167. https://doi.org/10.1016/j.gr.2019.07.012 en_US
dc.identifier.issn 1342-937X
dc.identifier.uri http://repository.biust.ac.bw/handle/123456789/483
dc.description.abstract We present a study of carbonate-bearing polyphase inclusions in garnets from leucocratic granitoids intruding metapelitic granulites of the Southern Marginal Zone (SMZ) of the Neoarchean Limpopo high-grade complex, South Africa, during the post-peak stage (2710–2650 Ma; U-Pb ages for zircons and monazites). Ternary feldspar thermometry suggests that the granitoid magma cooled from temperatures 800–900 °C at a pressure of ca. 6.5 kbar. Abundant CO2 fluid inclusions in quartz and T-XCO2 phase equilibria modeling via PERPLE_X imply ac- tion of an essentially carbonic fluid in the granitoids. Cores of almandine-rich garnet grains from the granitoids contain polyphase carbonate-bearing inclusions with a distinct negative crystal shape. The major carbonate in the inclusions is a strongly zoned magnesite-siderite variety, whereas pyrophyllite is the predominant silicate phase. Raman spectra of unexposed inclusions revealed a presence of CO2, as well as CH4 and H2O. The carbonate-bearing inclusions coexist with larger polyphase inclusions composed of biotite, quartz, K-feldspar, plagioclase, sillimanite, which are interpreted as relics of granitic melts. Modeling the mineral assemblage preserved within the carbonate-bearing inclusions shows that their present mineral and chemical compositions are a product of interaction of the trapped aqueous‑carbonic fluid with host garnet during cooling below 400 °C. Despite strong modifications, the inclusions bear evidence for initial saturation of the fluid with Mg‑carbonate. This is taken as an evidence for an origin of the fluids by devolatilization of the Mg-rich carbonate-bearing ultra- basic greenstone rocks of the Kaapvaal Craton that were buried under the SMZ. Being generated at temperatures between 650 and 700 °C, the fluid subsequently participated in anatexis and coexisted with the granite magma during exhumation and interaction of the SMZ granulites with cratonic rocks. en_US
dc.language.iso en en_US
dc.publisher Elsevier B.V. en_US
dc.subject Carbonate-silicate inclusions en_US
dc.subject Garnet en_US
dc.subject Carbonate-bearing source of a fluid en_US
dc.subject Devolatilization en_US
dc.subject Leucocratic granitoids en_US
dc.subject Southern Marginal Zone of the Limpopo Complex en_US
dc.title Carbonate-silicate inclusions in garnet as evidence for a carbonate-bearing source for fluids in leucocratic granitoids associated with granulites of the Southern Marginal Zone, Limpopo Complex, South Africa en_US
dc.description.level phd en_US
dc.description.accessibility unrestricted en_US
dc.description.department ees en_US


Files in this item

This item appears in the following Collection(s)

  • Faculty of Sciences
    This collection is made up of pre and post research articles created by both staff and students from Faculty of Sciences

Show simple item record

Search BIUSTRE


Browse

My Account