Neoarchean and Paleoproterozoic Crust Formation in the Ubendian Belt of Tanzania: Insights from Zircon Geochronology and Geochemistry

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dc.creatorKazimoto, Emmanuel O.
dc.creatorSchenk, Volker
dc.creatorBerndt, Jasper
dc.date2016-09-21T12:56:53Z
dc.date2016-09-21T12:56:53Z
dc.date2014
dc.date.accessioned2018-03-27T08:57:30Z
dc.date.available2018-03-27T08:57:30Z
dc.descriptionFull text can be accessed at http://www.sciencedirect.com/science/article/pii/S0301926814002319
dc.descriptionLA-ICP-MS U–Pb zircon geochronological and geochemical data of meta-igneous and metasedimentary rock types of the Katuma Block of the Paleoproterozoic Ubendian Belt in Tanzania are used to unravel the crustal evolution of this metalliferous terrain. The protoliths of the metabasites and orthogneisses previously considered to be Paleoproterozoic are in fact mostly Neoarchean in age (2713 ± 11 Ma to 2638 ± 5 Ma), from which the oldest rocks experienced their first metamorphism during the same Neoarchean orogenic cycle at ca. 2650 Ma. A second event of mafic magmatism (2021 ± 11 Ma) was concomitant with the migmatization of the Neoarchean orthogneisses and was succeeded by granitic intrusions at 1990–1940 Ma. All rocks of the Katuma Block experienced their main metamorphic reworking during several Paleoproterozoic orogenic events, which were recognized by dating of various metamorphic zircon growth zones and the age of magmatic events dated at ca. 2050, 1960 and 1880 Ma. The detritus of the high-grade metasedimentary rocks derived from Neoarchean (Katuma Block or Tanzania Craton?) and Paleoproterozoic provenances and the minimum age for the deposition is constrained by its first metamorphism at ca. 1960 Ma. The Neoarchean and Paleoproterozoic metabasites, gabbronorites and orthogneisses are sub-alkaline in composition displaying a REE and trace element geochemistry akin to those of rocks formed in modern-arc settings. On the basis of the geochemical data, the presence of eclogites, deformation and metamorphic ages, we suggest that in Paleoproterozoic time the Katuma Block was again at an active continental margin, below which a Paleoproterozoic oceanic lithosphere was subducting.
dc.identifierKazimoto, E.O., Schenk, V. and Berndt, J., 2014. Neoarchean and Paleoproterozoic crust formation in the Ubendian Belt of Tanzania: Insights from zircon geochronology and geochemistry. Precambrian Research, 252, pp.119-144.
dc.identifierhttp://hdl.handle.net/20.500.11810/3850
dc.identifier10.1016/j.precamres.2014.06.020
dc.identifier.urihttp://hdl.handle.net/20.500.11810/3850
dc.languageen
dc.publisherElsevier
dc.subjectLA-ICPMS zircon dating
dc.subjectMpanda mineral field
dc.subjectArchean metabasites and orthogneisses
dc.subjectContinental arc
dc.subjectUbendian Belt
dc.titleNeoarchean and Paleoproterozoic Crust Formation in the Ubendian Belt of Tanzania: Insights from Zircon Geochronology and Geochemistry
dc.typeJournal Article, Peer Reviewed

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