Exploration and research progresses of rare metals in Himalayan belt, Tibet

For a long time, it is believed that the Himalayan belt of Tibet is characterized by abundant polymetallic Au, Au-Sb and Pb-Zn deposits, while rare metalsare not included in the main prospecting targets. The Himalayanbelt has attracted extensive attentions due to new discoveries of rare metals such as beryllium and lithium in recent years.Based on the geological prospecting achievements and scientific research progresses, this paper summarizes the exploration and research progresses of newly discovered rare metal deposits in the Himalayan belt. It is proposed that six types of rare metal mineralization occurred in the Himalayan belt, including pegmatite type lithium-beryllium deposit, cassiterite-sulfide type tin-beryllium deposit, skarn type beryllium-tin-tungsten deposit, skarn type beryllium-niobium-tantalite deposit, albialite granite type beryllium-niobium-tantalite deposit, and hydrothermal vein type fluorite-beryllium deposit. Among them, the pegmatite type lithium-beryllium ore and cassiterite-sulfide type tin-beryllium deposits have the most economic prospecting values. These rare metal deposits are closely related to the Miocene leucogranites, and are the products of the high degree of crystallization differentiation of magmatism. They are new members of the Indo-Asian continental collisional orogenic mineralization, and constitute the rare metal metallogenic series related to the leucogranites in the Himalayan belt. It is suggested that the future geological research works in the region should be focused on: (1)Zonings of the highly differentiated leucogranites lithofacies and their corresponding rare metals; (2) The symbiotic and separate mechanisms of lithium, beryllium, niobium, tantalum, tungsten, and tin; (3) Metallogenic model and exploration model for Himalayan type rare metal deposits; (4) Relationship between rare metals and Pb-Zn-Au-Sb mineralization. Most of the newly discovered rare metal deposits in the Himalayan belt are close to the border areas of China. Through further exploration and evaluation, it is expected to be a new strategic rare metal metallogenic belt in Tibet.