Geochronology and fluid inclusion studies of the Lailisigaoer and Lamasu porphyry-skarn Cu-Mo deposits in Northwestern Tianshan, China

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	Geochronology and fluid inclusion studies of the Lailisigaoer and Lamasu porphyry-skarn Cu-Mo deposits in Northwestern Tianshan, China
	Zhu, MT (Zhu, Mingtian); Wu, G (Wu, Guang); Xie, HJ (Xie, Hongjing); Liu, J (Liu, Jun); Mei, M (Mei, Mei)
刊名	JOURNAL OF ASIAN EARTH SCIENCES
	2012
卷号	49 期号:特刊 SI 页码:116-130
关键词	Molybdenite Re-Os dating Zircon SHRIMP U-Pb age Fluid inclusion Porphyry-skarn deposit Northwestern Tianshan
ISSN号	1367-9120
英文摘要	The Lailisigaoer porphyry Mo (Cu) and Lamasu porphyry-skarn Cu deposits are located in the Northwestern Tianshan Orogenic Belt, which is in the northwestern China. According to Re-Os analysis of molybdenite, the time of mineralization of the Lailisigaoer deposit is 377 Ma, and SHRIMP zircon U-Pb analysis dates the ore-hosted intrusion of the Lamasu deposit to 378 Ma. Five types of fluid inclusions (FIs) have been identified in both deposits H2O-rich inclusions, CO2-bearing inclusions, halite-bearing inclusions, methane-rich inclusions and pure CO2 inclusions. In the Lailisigaoer deposit, the early-stage fluid of the quartz phenocryst belongs to a NaCl-H2O system with total homogenization temperatures (T-h) ranging from 300 to 395 degrees C with a mean salinity of 9.0 wt.% NaCl. In the ore-forming stage, the fluid develops into a H2O-NaCl-CO2 system due to boiling and decarbonation. The T-h values and salinities cluster between 220 and 370 degrees C and between 0 and 33.0 wt.% NaCl, respectively. The hydrothermal characteristics of the late quartz-calcite stage are similar to those of the meteoric fluid. In the Lamasu deposit, the early-stage fluid of the quartz phenocryst belongs to a NaCl-H2O system with T-h values ranging from 245 to 459 degrees C and a mean salinity of 6.0 wt.% NaCl. In the ore-forming stage, due to the contact metamorphism between the hydrothermal fluid and wall rock, the fluid evolves to a NaCl-H2O-CH4 system. The T-h values and salinities cluster between 220 and 360 degrees C and between 0 and 17.3 wt.% NaCl, respectively. The fluid of the late quartz-sulfide stage coincides with the meteoric fluid. In the mineralizing fluid of the Lailisigaoer deposit, the captured temperatures and pressures are between 210 and 350 degrees C and between 170 and 600 bars, respectively, which are consistent with fluctuation between hydrostatic and lithostatic pressure corresponding to the estimated paleodepths of 1.7-2.2 km. Boiling is the dominant mineralizing mechanism in the Lailisigaoer deposit, whereas the contact metamorphism between the magmatic hydrothermal fluid and country rocks is the dominant mechanism in the Lamasu deposit. Both deposits are formed in the continental arc setting related to the southward subduction of the North Tianshan Oceanic slab beneath the Yili-Central Tianshan block. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
学科主题	矿床地质
WOS关键词	CARBONIFEROUS VOLCANIC-ROCKS ; PALEOZOIC TECTONIC EVOLUTION ; FREEZING-POINT DEPRESSION ; ASIAN OROGENIC BELT ; U-PB AGES ; WESTERN TIANSHAN ; NW CHINA ; NORTHERN XINJIANG ; GOLD DEPOSITS ; GEOLOGICAL IMPLICATIONS
WOS研究方向	Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000303699200009
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39560]
专题	中国地质调查局
作者单位	Chinese Acad Sci, Guangzhou Inst Geochem, Key Lab Mineral & Metallogeny, Guangzhou 510640, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Zhu, MT ,Wu, G ,Xie, HJ ,et al. Geochronology and fluid inclusion studies of the Lailisigaoer and Lamasu porphyry-skarn Cu-Mo deposits in Northwestern Tianshan, China[J]. JOURNAL OF ASIAN EARTH SCIENCES,2012,49(特刊 SI):116-130.
APA	Zhu, MT ,Wu, G ,Xie, HJ ,Liu, J ,&Mei, M .(2012).Geochronology and fluid inclusion studies of the Lailisigaoer and Lamasu porphyry-skarn Cu-Mo deposits in Northwestern Tianshan, China.JOURNAL OF ASIAN EARTH SCIENCES,49(特刊 SI),116-130.
MLA	Zhu, MT ,et al."Geochronology and fluid inclusion studies of the Lailisigaoer and Lamasu porphyry-skarn Cu-Mo deposits in Northwestern Tianshan, China".JOURNAL OF ASIAN EARTH SCIENCES 49.特刊 SI(2012):116-130.