Discovery of the Peili pegmatitic lithium deposit in Gaoligong area, western Yunnan Province and its implication

Lithium is critical mineral resource in China. Western Yunnan is an important metallogenic area of rare metals in China, but at present, the main reported rare metal resources in the area are Be-Nb-Ta-Sn. In this study, we first report the newly discovered Peili spodumene pegmatitic lithium deposit, Gaoligong area, western Yunnan Province, which is of great significance for the further prospecting of lithium in this area. Whole rock trace element analysis of 6 samples shows that the pegmatites in Peili area are characterized by Li, Be, Rb, Cs, Nb and Nb mineralization. The LA-ICP-MS coltan U-Pb analysis shows that the lithium-pegmatite in Peili area was formed at 18.4 +/- 0.3Ma, which is consistent with the cassiterite U-Pb dating age (17.5 +/- 1.2Ma), indicating Peili pegmatites formed in Cenozoic. Moreover, this age is consistent with the metamorphic age and the forming age of leucogranite in Gaoligongshan area, which suggest pegmatites in Peili might be the product of metamorphic remelting, or the product of further crystallization differentiation of leucogranite. In addition, the ages of pegmatites in this study are consistent with the rare metal metallogenic age in South Tibet, which, combined with the significant regional geochemical anomalies of lithium, suggest the western Yunnan region may be the southern extension of the Himalayan rare metal metallogenic belt with good ore-forming condition for rare metal lithium deposits.