Geochemical characteristics of global leucogranite and their mineralized relationship with rare metals
This paper is the result of mineral exploration engineering.[Objective]Recently,leucogranites have become a hot spot in the study of petrogenesis and rare metal metallogeny.However,the spatiotemporal distribution characteristics of global leucogranite are still unclear.For further prospecting of rare metals in China,it is essentially to clarify the spatiotemporal distribution of leucogranite and the metallogenic specialization between leucogranite and rare metal deposits.[Methods]We collect 1155 geochemical data from 115 leucogranites worldwide,and combine with our recently achievements from the Nanling Region,Western Sichuan,Southern Tibet,and Altai.[Results]In reference to the composition,this study reveals that the content of SiO2 in leucogranite is exceed 1％ higher than the global average value of granite,while the REE content of the rocks with rare metal mineralization is extremely low.Spatially,the content of SiO2 and ALK(Na2O+K2O)of leucogranites in the Hercynian orogenic belt in Central and Western Europe are lower than those of the Himalayan leucogranites,as well as those of Western China.Meanwhile,the SiO2 and ALK content of leucogranite in Western China are lower than Eastern China.Both leucogranites in Central and Western Europe and North America are rich in P2O5.The highest values of Li,Be,Nb,Ta,Ga,Rb and Sn in the samples appear in Central and Western Europe,while the highest values of W present in eastern China.Cenozoic SiO2 and ALK content of leucogranite were higher than Paleozoic but lower than Mesozoic.Notablely,Paleozoic leucogranite are enriched in P2O5.Besides,tourmaline is a vital indicator of Neoproterozoic leucogranite.[Conclusions]The mineralized leucogranite are generally lack of magmatic garnet.Those leucogranite with feature of A/CNK>1.2.Rb/Sr>1,ΣREE>10×10-6 are mostly related to Sn-W-Nb-Ta mineralization,while Rb/Sr>1,ΣREE<10×10-6 of leucogranite more akin to Li-Sn-Nb-Ta-Be mineralization.All the data indicate that the Mesozoic leucogranites in Eastern China are the most evolved leucogranites worldwide and the best mineralization potential.
leucogranitegeochemistryrare metalsmineral exploration engineeringHimalayasHercynian orogenic beltEastern ChinaWestern China
万方数据
维普
