Mesoproterozoic high-grade metamorphism in pelitic rocks of the northwestern Ubendian Belt: Implication for the extension of the Kibaran intra-continental basins to Tanzania

摘要: Paleoproterozoic basement rocks are thought to form the northwestern end of Ubendian Belt in Tanzania that disappears towards north below a Mesoproterozoic sedimentary cover. The is known constitute three litho-tectonic terranes Katuma, Wakole and Ubende. Through dating zircon (SHRIMP U-Pb) monazite (U-Th-total Pb electron microprobe ages) high-grade metasedimentary Terrane we have detected solely ages, showing no sign reworking older basement. These findings signify hosts younger sediments times metamorphosed P-T conditions (peaked at 670-680 degrees C/8.5-8.9 kbar). Two distinct phases metamorphic events separated by 160 Ma been dated 1166 +/- 14 1007 6 U-Pb zircon). Zircon ages supported in-situ with 1170 10 Ma, 1022 5-1016 Ma. first age closely related period S-type granitoid emplacement about 1200 Karagwe-Ankolean Kibaran Belts. second cluster overlaps global orogenic cycle, also recorded neighboring Irumide This group associated assembly hypothetical Rodinia Supercontinent. recent model for evolution suitably explains spatial temporal settings overlying Belt. Due its proximity being bound Terranes Ubende it can be interpreted metasediments initially were deposited an intra-continental basin was later squeezed between these old regional ca. 1000 compressional event Irumide, (C) 2014 Elsevier B.V. All rights reserved.