摘要
云南会泽和毛坪铅锌矿床位于扬子地块西南缘川-滇-黔铅锌多金属矿集区的中南部,小江断裂带、昭通-曲靖隐伏断裂带和垭都-紫云断裂带的构造复合部位,是我国著名的MVT型铅锌矿床。本文以会泽和毛坪铅锌矿为例,系统研究了矿床中矿石硫化物、矿区相关碳酸盐岩地层中微量硫酸盐(CAS)以及外围不同时代膏盐层中石膏的硫同位素组成,探讨了膏盐层在云南会泽和毛坪铅锌矿成矿中的作用。会泽矿床矿石硫化物的δ^(34)S_(V-CDT)值为11.0‰~20.0‰,多数集中在13.0‰~17.0‰之间,平均14.7‰,大致代表总硫的同位素组成。石炭系碳酸盐岩地层中微量硫酸盐的δ^(34)S_(V-CDT)值为10.4‰~18.6‰,平均13.1‰,较矿石硫化物的值稍低。矿区外围石炭系膏盐层中石膏的δ^(34)S_(V-CDT)值为12.9‰~17.1‰,平均13.6‰,与石炭系碳酸盐岩中微量硫酸盐的δ^(34) S_(V-CDT)值几乎完全一致。毛坪矿床矿石硫化物的δ^(34)S_(V-CDT)值与其赋存层位密切相关,赋存于摆佐组(C1b)的矿石硫化物的δ^(34)S_(V-CDT)值为7.1‰~17.5‰,平均12.8‰,较会泽矿石硫化物的值稍低,与石炭系碳酸盐岩地层中微量硫酸盐和石膏的值一致;赋存于宰格组(D3zg)的矿石硫化物的δ^(34)S_(V-CDT)值为18.3‰~22.7‰,平均21.1‰,与赋存于摆佐组(C1b)的矿石硫化物的值和会泽矿床矿石硫化物的值明显不同。矿区外围宰格组(D3zg)膏盐层中石膏的δ^(34)S_(V-CDT)值为21.9‰~25.9‰,平均23.6‰,与毛坪矿床宰格组(D3zg)矿石硫化物的值相似。通过对比会泽、毛坪矿床中不同赋矿层位矿石硫化物、石炭系不同层位碳酸盐岩中微量硫酸盐和矿区外围不同时代膏盐层中石膏的硫同位素组成及变化规律,提出会泽、毛坪铅锌矿床矿石硫化物中的硫主要来源于赋矿层位膏盐层中石膏硫酸盐的热还原。其中会泽铅锌矿的硫绝大部分来自石炭系膏盐层,只有10%的硫来自下伏的�
The Huize and Maoping deposits,the famous high-grade Mississippi Valley-type lead-zinc deposits in China,are located in the central south of the Sichuan-Yunnan-Guizhou lead-zinc polymetallic ore cluster area in the southwestern margin of the Yangtze block and tectonically in structural composite area of Xiaojiang fault zone,Zhaotong-Qujing hidden fault zone,and Yadu-Ziyun fault zone.This study discussed effect of sulfate evaporate salt layer on lead-zinc mineralization of the Huize and Maoping deposits using sulfur isotope compositions of sulfides and gypsum from the two deposits.δ34SV-CDTvalue of the Huize ore sulfides ranges from 11.0‰ to 20.0‰（averaging 14.7‰）,with most concentrated in 13.0‰～17.0‰,roughly representing total sulfur isotopic composition.δ34SV-CDT value of the carbonate-associated sulfate ranges from 10.4‰to 18.6‰（averaging 13.1‰）,slightly lower than the ore sulfides.δ34SV-CDTvalue of the gypsum in the Carboniferous gypsum salt layer ranges from 12.9‰ to 17.1‰（averaging 13.6‰）,which is consistent with that of the carbonate-associated sulfate.δ34SV-CDTvalue of the ore sulfides in the Maoping deposit is closely related to its occurrence layers.Theδ34SV-CDT value of the ore sulfides in the Baizuo Formation（C1 b）ranges from 7.1‰to 17.5‰,with an average of 12.8‰,which is slightly lower than carbonate-associated sulfate and gypsum in Carboniferous carbonate strata.Theδ34SV-CDTvalue of ore sulfides in the Zaige Formation（D3 zg）ranges from 18.3‰ to 22.7‰,with an average of 21.1‰.The results are unlikely with the ore sulfides in the Baizuo Formation（C1 b）or the Huize deposit.Theδ34SV-CDT value of the gypsum in the Zaige Formation（D3 zg）ranges from 21.9‰ to 25.9‰,with an average of23.6‰,which is slightly higher than sulfides in the Zaige Formation（D3 zg）.By comparing the sulfur isotopic compositions of the sulfides,sulfate and gypsum,we propose that the sulfur in the ore sulfides of Huize and Maoping lead-zinc deposits mainly
作者
任顺利
李延河
曾普胜
邱文龙
范昌福
胡古月
REN Shunli1 , LI Yanhe2 , ZENG Pusheng3 , QIU Wenlong4 , FAN Changfu2 , HU Guyue2(1 China University of Geosciences （Beijing）, Beijing, 100083 2 MRL Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing, 100037 ; 3 National Research Center for Geoanal ysis , Beij ing , 100037; 4 Kunming University of Science and Technology, Kunming, 65009)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2018年第5期1041-1055,共15页
Acta Geologica Sinica
基金
国家自然科学基金项目(编号41473014)资助成果
关键词
会泽超大型铅锌矿床
毛坪铅锌矿床
硫同位素
膏盐层
Huize lead-zinc deposit
Maoping lead-zinc deposit
sulfur isotope
sulfate evaporate salt layer
