蒙古国查干苏布尔加和苏廷铜矿容矿斑岩体SHRIMP锆石U-Pb年龄--对南戈壁斑岩型铜矿成矿时代及成矿背景的约束

SHRIMP zircon U-Pb dating of Tsagaan Suvarga and Shuteen porphyry copper deposits: Constraints on metallogenic time and tectonic setting of porphyry-type mineralization in South Gobi, Mongolia

对蒙古国南戈壁地区查干苏布尔加和苏廷斑岩型矿床的容矿花岗岩进行SHRIMP锆石U-Th-Pb同位素测定,结果表明查干苏布尔加斑岩型铜钼矿床矿化花岗闪长岩的侵位年龄为368±4Ma,苏廷铜矿花岗岩的侵位年龄为333±4Ma,表明它们形成于不同的时代。结合已有资料提出,蒙古南戈壁地区发育2条时代不同的斑岩型铜矿带:一条为晚泥盆世,以欧玉陶勒盖和查干苏布尔加矿床为代表;另一条为中晚石炭世,以苏廷及曼达赫斑岩型矿床为代表。同时,结合区域资料,初步探讨了2条斑岩成矿带的成矿地质背景。

Granitic porphyries hosting the Tsagaan Suvarga and Shuteen porphyry-type copper deposits in the South Gobi, Mongolia, were dated by using SHRIMP zircon U-Th-Pb technique. The dating results show that the Tsagaan Suvarga granodiorite and Shuteen granite were emplaced at 368±4Ma and 333±4Ma, respectively, suggesting that they formed in two different geological epochs. In combination with data available, the authors hold that there are two metallogenic zones of porphyry-type copper deposits with different ages in the South Gobi area of Mongolia： one is Late Devonian in age, which is represented by Oyu Tolgoi and Tsagaan Suvarga copper deposits, and the other is Late Carboniferous in age, with the Shuteen and Mandah deposits being typical ones. The geological settings of the two porphyry-type metallogenic zones are preliminarily discussed in the context of regional tectonic evolution.