The geochemical characteristics of rare earth elements of A type and Ⅰ type granites were studied in the Sawuer region, Xinjiang. The characteristics of two types granites are different obviously,because the A type a...The geochemical characteristics of rare earth elements of A type and Ⅰ type granites were studied in the Sawuer region, Xinjiang. The characteristics of two types granites are different obviously,because the A type and Ⅰ type granites formed at different stage of the post-collisional period. The Sentasi intrusion and Wokensala intrusion are the Ⅰ type granites formed at the late of post-collisional period, and there is extrusion translating to extension stress. The characteristics of rare earth elements show that the fractional crystallization of the Ⅰ type granites is indistinct, and the sources of the Ⅰ type granites come from the mantle. The Kuoyitasi intrusion and Qiaqihai intrusion are the A type granites formed at the end of post-collisional period, and there is extension stress. The characteristics of rare earth elements show that the fractional crystallization of the A type granites is distinct. The sources of the A type granites come from the mantle but interfused by the crust.展开更多
LA-ICP MS zircon U-Pb dating results of granites from Sawuer Mountains in North Xinjiang, NW China, are reported based on 1：50 000 regional geologic surveys. Zircon U-Pb dating shows that the granitoids have magmatic...LA-ICP MS zircon U-Pb dating results of granites from Sawuer Mountains in North Xinjiang, NW China, are reported based on 1：50 000 regional geologic surveys. Zircon U-Pb dating shows that the granitoids have magmatic crystallization age of 320 ± 2 Ma. In addition, zircons with ages of 341 -358 Ma could be subdivided into two groups, i. e. , Group 1 with a weighted mean age of 342 ± 3 Ma and Group 2 with a weighted mean age of 354 ± 2 Ma. The petrology and geochemistry of granitoids from Sawuer Mountains suggest their mixed origin. The granite from Sawuer Mountains occurred in an extensional setting, most probably related to post-orogenic processes during the closure of the Peo-Asian Ocean ; namely, represent the tectonic setting shifted from compress to post-collisional setting.展开更多
The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidin...The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidinclusion ^3He/^4He ratios are 0.64 Ra-4.25 Ra and 1.16 Ra-9.48 Ra, ^40Ar/^36Ar ratios are 282-359 and 312-525 for Kuoerzhenkuola and Buerkesidai gold deposits respectively.The ore-forming fluids of two deposits possessed the same source and derived mainly from mantle beneath the island arc (including oceanic crust and oceanic sediments by subduction of oceanic plate). They were diluted by incorporating meteoric water to form a mixture of mantle- and partial meteoric water-derived fluid. The ore-forming fluids of twodeposits are of the same evolutionary histories. From the early to the late mineralization stages, the ratios of meteoric water/mantle- derived fluid in ore-forming fluid increasedgrad ually. Based on these results and detailed geological and geochemical studies on the two deposits, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits occurring in the same volcanic apparatus.展开更多
文摘The geochemical characteristics of rare earth elements of A type and Ⅰ type granites were studied in the Sawuer region, Xinjiang. The characteristics of two types granites are different obviously,because the A type and Ⅰ type granites formed at different stage of the post-collisional period. The Sentasi intrusion and Wokensala intrusion are the Ⅰ type granites formed at the late of post-collisional period, and there is extrusion translating to extension stress. The characteristics of rare earth elements show that the fractional crystallization of the Ⅰ type granites is indistinct, and the sources of the Ⅰ type granites come from the mantle. The Kuoyitasi intrusion and Qiaqihai intrusion are the A type granites formed at the end of post-collisional period, and there is extension stress. The characteristics of rare earth elements show that the fractional crystallization of the A type granites is distinct. The sources of the A type granites come from the mantle but interfused by the crust.
文摘LA-ICP MS zircon U-Pb dating results of granites from Sawuer Mountains in North Xinjiang, NW China, are reported based on 1：50 000 regional geologic surveys. Zircon U-Pb dating shows that the granitoids have magmatic crystallization age of 320 ± 2 Ma. In addition, zircons with ages of 341 -358 Ma could be subdivided into two groups, i. e. , Group 1 with a weighted mean age of 342 ± 3 Ma and Group 2 with a weighted mean age of 354 ± 2 Ma. The petrology and geochemistry of granitoids from Sawuer Mountains suggest their mixed origin. The granite from Sawuer Mountains occurred in an extensional setting, most probably related to post-orogenic processes during the closure of the Peo-Asian Ocean ; namely, represent the tectonic setting shifted from compress to post-collisional setting.
文摘The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidinclusion ^3He/^4He ratios are 0.64 Ra-4.25 Ra and 1.16 Ra-9.48 Ra, ^40Ar/^36Ar ratios are 282-359 and 312-525 for Kuoerzhenkuola and Buerkesidai gold deposits respectively.The ore-forming fluids of two deposits possessed the same source and derived mainly from mantle beneath the island arc (including oceanic crust and oceanic sediments by subduction of oceanic plate). They were diluted by incorporating meteoric water to form a mixture of mantle- and partial meteoric water-derived fluid. The ore-forming fluids of twodeposits are of the same evolutionary histories. From the early to the late mineralization stages, the ratios of meteoric water/mantle- derived fluid in ore-forming fluid increasedgrad ually. Based on these results and detailed geological and geochemical studies on the two deposits, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits occurring in the same volcanic apparatus.
