GEOCHEMICAL CHARACTERS OF LEPTYNITES FROM THE VISAKHAPATNAM AREA IN THE EASTERN GHATS GRANULITE TERRANE, INDIA

Leptynites occur with minor bands of basic granulites, charnockites, c alc-silicate rocks, quartzites and khondalites in the Visakhapatnam ar ea in the Eastern Ghats granulite terrane (EGGT), India. Interbedded g rey and cream leptynite types are distinguished based on field relatio ns and geochemistry. The mineralogical and geochemical evidences favou r a metasedimentary origin for leptynites. The total REE, LREE/HREE an d Eu-Eu data indicate their derivation from the post-Archaean granodi oritic upper crust comprising large proportions of impure greywackes w ith K-rich granitic components. Copyright (C) 1996 Elsevier Science Lt d