Sapphirine and corundum bearing granulites from Karur, Madurai Block, Southern India

Tsunogae, T. and Santosh, M. (2003): Gondwana Research, 6, 925-930.


Abstract

We report new occurrences of sapphirine- and corundum-bearing granulites intercalated within orthogneisses at Lachmanapatti and Malappatty in the northern part of Madurai Block. Sapphirine in these localities occurs either as needle-like intergrowth with cordierite and corundum in symplectites and medium to fine grained euhderal to subhedral crystals associated with cordierite and corundum (Lachmanapatti) or in association with plagioclase, corundum, and gedrite (Malappatty). The sapphirine from Lachmanapatti is highly magnesian (XMg = 0.87-0.94) with higher Cr content (up to 0.9 pfu) as compared with those in other localities in the Madurai Block. The sapphirine-corundum association reported in this study has important bearing on the ultrahigh-temperature metamorphism and exhumation history of the northern Madurai Block as well as on the tectonic evolution of the continental deep crust in southern India.