内蒙古东升庙矿床岩浆热液叠加成矿作用——来自地质与矿物包裹体测温的证据  

Magmatic hydrothermal overprinting in the Mesoproterozoic Dongshengmiao deposit,Inner Mongolia:geological and fluid inclusion evidences

作　　者：彭润民 翟裕生 韩雪峰 王建平 王志刚 秦俊文 

机构地区：[1]State Key laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China [2]Inner Mongolia Geological Prospecting Institute of Chemical Industry,Hohhot 0]0074,China [3]Inner Mongolia Geological Prospecting Institute of Chemical Industry,Hohhot 010074,China

出　　处：《岩石学报》2007年第1期145-152,共8页Acta Petrologica Sinica

摘　　要：The Dongshengmiao Pb-Zn deposit located in the Mesoproterozoic aulacogen in a passive continental margin in the north- west margin of the North-China Craton is widely considered to be a untypical SEDEX deposit.Recently,new types of mineralization such as chalcopyrite veins and re-crystallized sphalerite ores with visible hydrothermal alteration have been found in the deposit at depth.In this paper we report the decrepitation temperatures of fluid inclusions in chalcopyrite,sphalerite and quartz from these new types of ores.The decrepitation temperatures of fluid inclusions in chalcopyrite(4 samples),sphalerite(2 samples)and quartz(5 samples)are 303～456℃,97～497℃,146～350℃and 350～556℃,respectively.The decrepitation temperatures of fluid inclusions in the vein-type chalcopyrite are similar to the decrepitation temperatures of fluid inclusions in chalcopyrite from the Hercynian Oubulage porphyry Cu-Au deposit(313～514℃)and the Chehugou porphyry Cu-Mo deposit(277～485℃),supporting our interpretation that the Dongshengmiao deposit was overprinted by magmatic hydrothermal mineralization.The decrepitation temperatures of fluid inclusions in re-crystallized sphalerite from the Dongshengmiao deposit are characterized by two peaks,97～358℃and 358～497℃.The decrepitation temperatures of fluid inclusions in quartz in ehalcopyrite veins from the Dongshengmiao deposit are also characterized by two peaks,146～350℃and 350～556℃.The lower and higher temperature peaks in both cases are considered to represent two separate mineralization events,original SEDEX mineralization and magmatic hydrothermal overprinting,respectively.The higher decrepitation temperatures of fluid inclusions in quartz and sphalerite from the Dongshengmiao deposit are similar to the decrepitation temperatures(340～526℃)of fluid inclusions in sphalerite from the Baiyinnuoer skarn-type Pb-Zn deposit in the region. Replacement of pyrite by sphalerite and overgrowth of chalcopyrite on pyrite in the Dongshengmiao support our inteThe Dongshengmiao Pb-Zn deposit located in the Mesoproterozoic aulacogen in a passive continental margin in the north-west margin of the North-China Craton is widely considered to be a untypical SEDEX deposit. Recently, new types of mineralization such as chalcopyrite veins and re-crystallized sphalerite ores with visible hydrothermal alteration have been found in the deposit at depth. In this paper we report the decrepitation temperatures of fluid inclusions in chalcopyrite, sphalerite and quartz from these new types of ores. The decrepitation temperatures of fluid inclusions in chalcopyrite （ 4 samples ）, sphalerite （ 2 samples ） and quartz （ 5 samples ） are 303 ～ 456℃, 97 - 497℃, 146 ～ 350℃ and 350 ～ 556℃, respectively. The decrepitation temperatures of fluid inclusions in the vein-type chalcopyrite are similar to the decrepitation temperatures of fluid inclusions in chalcopyrite from the Hercynian Oubulage porphyry Cu-Au deposit （313～ 514℃） and the Chehugou porphyry Cu-Mo deposit （277 ～ 485℃）, supporting our interpretation that the Dongshengmiao deposit was overprinted by magmatic hydrothermal mineralization. The decrepitation temperatures of fluid inclusions in re-crystallized sphalerite from the Dongshengmiao deposit are characterized by two peaks, 97～ 358℃ and 358 ～ 497℃. The decrepitation temperatures of fluid inclusions in quartz in chalcopyrite veins from the Dongshengmiao deposit are also characterized by two peaks, 146～ 350℃ and 350 ～ 556℃. The lower and higher temperature peaks in both cases are considered to represent two separate mineralization events, original SEDEX mineralization and magmatic hydrothermal overprinting, respectively. The higher decrepitation temperatures of fluid inclusions in quartz and sphalerite from the Dongshengmiao deposit are similar to the decrepitation temperatures （340 ～ 526℃ of fluid inclusions in sphalerite from the Baiyinnuoer skarn-type Pb-Zn deposit in the region. Replacement of pyrite by sphalerite a

关 键 词：内蒙古 东升庙矿床 岩浆热液叠加 成矿作用 地质 矿物包裹体 温度测量 

分 类 号：P611.11[天文地球—矿床学]