SHRIMP U-Pb Dating of Jingtou Composite Pluton in Liulong Gold Orefield of Xingguo County, Southern Jiangxi Province, and Its Geological Significance
///In this paper, SHRIMP U-Pb technique was employed to date the ages of the main body and the altered patched body. The result is (162.6±2.6) Ma (MSWD=0.75), whereas the age of the chloritized patched body is (156.6±1.7) Ma(MSWD=0.46). These data imply that the main body and the patched body might have resulted from the same magma reservoir. From regional geological information and researches on geochemical characteristics of Jingtou composite pluton, some conclusions have been reached: 1) the intrusion of Jingtou composite pluton took place in Middle Jurassic, and the minor body characterized by further differentiation should be the extensional product of the lithosphere; 2) during the intrusion of the middle-plutonic granite to the hypabyssal diortite-trachydolerite, the magmatic activities lasted for 6 Ma, suggesting that there existed a concentrated period of Au and W/Sn mineralization; 3) in southern Jiangxi Province, the metallogenic age of Au are basically concordant with that of W/Sn, and the ore-forming processes are mainly concentrated in the period of 150~165 Ma.