Hydrothermal fluid evolution in the Cuonadong Sn–W–Be polymetallic deposit, southern Tibet: indicated by the in–situ element and boron isotope compositions of tourmaline

The Cuonadong Sn–W–Be polymetallic deposit in the Himalayan leucogranite belt is a representative hydrothermal deposit. role of fluid exsolution directly from magma and reaction with surrounding rocks for ore-forming element enrichment still controversial. Tourmaline significant B-bearing mineral deposit, its geochemical B isotopic signatures can record source evolution fluid. Two types tourmaline quartz vein (Tur-1) skarn (Tur-2) were used this study. Both Tur-1 Tur-2 have low X-site occupancy mainly belong to alkali group. plots schorl field, whereas largely Mg-rich dravite. isotope analyses δ 11 values −13.7 −13.2‰, has higher −11.1 −9.3‰. distinct contact relationship compositions suggest that was formed magmatic-hydrothermal little influence had genetic leucogranite, involved more high strong metasomatic texture. contents than those indicate between magmatic rock essential precipitation elements.