Abstract:
The early Paleozoic Halong-Qinghe arc is an important rare metallogenic belt in Altay, Xinjiang. Many large- and medium-scale rare metal (lithium, beryllium, tantalum and niobium) deposits distributed within this belt, and ore-hosted pegmatite were mainly formed in Triassic (250-205 Ma) and Jurassic (200-180 Ma). In Halong-Azubai pegmatite ore field, ore-bearing pegmatite is mainly composed of microcline type pegmatite, microcline-albite type pegmatite and albite-spodumene type pegmatite. The pegmatite type and associated mineralization occurs four horizontal zoning in sequence, characterized by II zone beryllium mineralization and III zone lithium mineralization. Combined with field geological characteristics, petrogenetic and metallogenetic epoch, and geochemical characteristics, we suggest that rare metal mineralization in Halong -Azubai pegmatite ore field was the product of their own pegmatite magmatic-hydrothermal evolution; the initial pegmatite magma may related to the partial melting of mantle material in ancient crust.