Bisnath, Avinash; Frimmel, Hartwig E (2015): Representative analyses of garnet, plagioclase, orthopyroxene, ilmenite, hornblende and biotite for pre-tectonic mafic and metapelitic rocks in Gjelsvikfjella [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.846974, Supplement to: Bisnath, A; Frimmel, HE (2005): Metamorphic evolution of the Maud Belt: P-T-t path for high-grade gneisses in Gjelsvikfjella, Dronning Maud Land, East Antarctica. Journal of African Earth Sciences, 43(5), 505-524, https://doi.org/10.1016/j.jafrearsci.2005.09.007
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Abstract:
A metamorphic petrological study, in conjunction with recent precise geochronometric data, revealed a complex P-T-t path for high-grade gneisses in a hitherto poorly understood sector of the Mesoproterozoic Maud Belt in East Antarctica. The Maud Belt is an extensive high-grade, polydeformed, metamorphic belt, which records two significant tectono-thermal episodes, once towards the end of the Mesoproterozoic and again towards the late Neoproterozoic/Cambrian. In contrast to previous models, most of the metamorphic mineral assemblages are related to a Pan-African tectono-thermal overprint, with only very few relics of late Mesoproterozoic granulite-facies mineral assemblages (M1) left in strain-protected domains. Petrological and mineral chemical evidence indicates a clockwise P-T-t path for the Pan-African orogeny. Peak metamorphic (M2b) conditions recorded by most rocks in the area (T = 709-785 °C and P = 7.0-9.5 kbar) during the Pan-African orogeny were attained subsequent to decompression from probably eclogite-facies metamorphic conditions (M2a).
The new data acquired in this study, together with recent geochronological and geochemical data, permit the development of a geodynamic model for the Maud Belt that involves volcanic arc formation during the late Mesoproterozoic followed by extension at 1100 Ma and subsequent high-grade tectono-thermal reworking once during continent-continent collision at the end of the Mesoproterozoic (M1; 1090-1030 Ma) and again during the Pan-African orogeny (M2a, M2b) between 565 and 530 Ma. Post-peak metamorphic K-metasomatism under amphibolite-facies conditions (M2c) followed and is ascribed to post-orogenic bimodal magmatism between 500 and 480 Ma.
Project(s):
Funding:
German Research Foundation (DFG), grant/award no. 5472008: Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas
Coverage:
Latitude: -71.965000 * Longitude: 3.240000
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License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
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2 datasets
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Datasets listed in this publication series
- Bisnath, A; Frimmel, HE (2005): (Table 4) Representative analyses of garnet, plagioclase, orthopyroxene and ilmenite for pre-tectonic mafic rocks in Gjelsvikfjella. https://doi.org/10.1594/PANGAEA.846972
- Bisnath, A; Frimmel, HE (2005): (Table 5) Representative analyses of hornblende and biotite for pre-tectonic mafic and metapelitic rocks in Gjelsvikfjella. https://doi.org/10.1594/PANGAEA.846973