Authors
RK Shaw, M Arima, H Kagami, CM Fanning, K Shiraishi, Y Motoyoshi
Publication date
1997/9
Journal
The Journal of Geology
Volume
105
Issue
5
Pages
645-656
Publisher
The University of Chicago Press
Description
Metamorphic and protolith ages of five rock types (mafic granulite, orthopyroxene granulite, leptynite, sillimanite granite, and metapelite) from Rayagada, in the north‐central part of the Eastern Ghats Granulite Belt (EGGB), India, were determined from Rb‐Sr and Sm‐Nd whole rock and mineral isochrons in combination with SHRIMP U‐Pb zircon data. Most of the whole rock isochron ages in both Sm‐Nd and Rb‐Sr systems point to either ∼1450 or ∼1000, Ma, and the mineral isochron ages are ∼1000, ∼800, and ∼550 Ma. SHRIMP U‐Pb zircon ages of ∼940 Ma were obtained from metapelite, which are in close agreement with the Sm‐Nd and Rb‐Sr isochron ages. From all these data, four age clusters (∼1450, ∼1000, ∼800, and ∼550 Ma) have been noted. The 1450 Ma ages are interpreted to represent igneous protolith formation of mafic granulite and leptynite. The 1000 Ma age cluster is regarded as the …
Total citations
19981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020202120222023276158141053987787881159466144