Rare-Metal Granites from Various Zones of the Early Mesozoic Magmatic Areal (Mongolia): Geochemical and Petrogenetic Features

Resumo

This study is aimed at comparative analysis of the chemical evolution, age, and petrogenetic features of the Li–F granites from various zones of the Early Mesozoic magmatic areal. The newly obtained geochemical data preclude the formation of rare-metal Li–F granites by processes of magmatic differentiation of a palingenic granitic magma, parental to the Baga–Khentei Pluton. The rare-metal granites of the peripheral zone of the Early Mesozoic magmatic areal, compared to their counterparts from the central part (the Baga–Khentei Pluton), are more enriched in some elements that accumulated intensively during fluid–magmatic differentiation (Li, Rb, Sn, Ta, and F), often forming a concentrated mineralization. This corroborates the potential of rifted fringes of batholiths in the context of the connection of rare-metal mineralization and magmatism. The geochemical specifics of the Khentei intrusion granite from the central part of the Early Mesozoic magmatic areal may imply a deeper source related to the mantle plume.