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

摘要

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.