Source and evolution of the ore-forming fluid of the Cuonadong Sn-W-Be polymetallic deposit (southern Tibet, China): Constraints from scheelite trace element and Sr isotope geochemistry

• Skarn-type mineralization of the Cuonadong Sn-W-Be polymetallic deposit occurred at ca. 15 Ma. Skarn-hosted scheelite can be divided into an older type 1 and a younger 2 scheelite. The ore-forming fluid was exsolved from Miocene leucogranite. Geochemically isotopically, modified by intense fluid-rock interaction during skarnization greisenization. is first rare-metal with extraordinary metallogenic potential that has been discovered in Tethyan Himalayan belt. shows wide range different types, including greisen-, pegmatite-, skarn-, hydrothermal vein-type mineralization. Of these skarn-type largest inferred resources. In order to constrain source evolution fluid, we conducted detailed study skarn-hosted scheelite, cathodoluminescence imaging, in-situ trace elemental analysis, bulk Sr isotope analysis. addition, analysis fluorite, phlogopite 40 Ar- 39 Ar dating, marble whole-rock geochemical were also conducted. Phlogopite dating indicates skarn formed Ma, which close formation age muscovite granite reported previous studies. Cathodoluminescence images indicate subdivided Type characterized negative Eu anomaly, whereas positive anomaly. Considering temporal spatial relationship between leucogranite ore-bearing skarn, their similar lanthanide tetrad effect as observed REE patterns, propose anomaly inherited leucogranite, while resulted addition 2+ data show fluorite ( 87 Sr/ 86 Sr) i value 0.728885 within values, values (0.709717–0.713480) are those (0.709525–0.712146). Since intergrown responsible for both Water-rock this magma-derived loss magmatic isotopic signature.