Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4727520 | Gondwana Research | 2009 | 22 Pages |
Abstract
The Permian-Jurassic Mahanadi and Pranhita-Godavari Rifts are part of a drainage system that radiated from the Gamburtsev Subglacial Mountains in central Antarctica. From 12 samples we analysed detrital zircons for U-Pb ages, Hf-isotopes, and trace elements to determine the age, rock type and source of the host magma, and TDM model age. Clusters, in decreasing order of abundance, are (1) 820-1000Â Ma, host magmas felsic granitoids with alkaline rock, (2) 1500-1700Â Ma felsic granitoids, (3) 500 to 700Â Ma mafic granitoids with alkaline rock, (4) 2400-2550Â Ma granitoids, and (5) 1000-1200Â Ma felsic and mafic granitoids, mafic rock, and alkaline rock. TDM ranges from 1.5 to 3.5Â Ga. Joint paleoslope measurements and zircon ages indicate that the Eastern Ghats Mobile Belt (EGMB) and lateral belts and conjugate Antarctica are potential provenances. Zircons from the Gondwana Rifts differ from those in other Gondwanaland sandstones in their predominant 820-1000Â Ma and 1500-1700Â Ma ages (from the EGMB and conjugate Rayner-MacRobertson Belt) that dilute the 500-700Â Ma (Pan-Gondwanaland) ages. The 1000-1200Â Ma zircons reflect the assembly of Rodinia, the 500-700Â Ma ones that of Gondwanaland; the other ages reflect collisions in the region.
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Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
J.J. Veevers, A. Saeed,