地质学报2011，Vol.85Issue(5)：744-756,13.DOI:CNKI:11-1951/P.20110511.1659.002
长江中下游成矿带铜多金属矿床中灰泥丘的发现及其意义——以武山和冬瓜山铜矿为例
Discovery and Significance of Carbonate Mud Mounds from Cu-polymetallic Deposits in the Middle and Lower Yangtze Metallogenic Belt:Examples from the Wushan and Dongguashan Deposits
摘要
Abstract
Bedded sulfide orebodies occur in the Wushan and Dongguashan Cu deposits in the Middle and Lower Yangtze mineralization belt. In this study, we found a typical circular or laminated texture in the bedded sulfide ores. Based on microscopic observation of thin sections of the ore samples, carbon and oxygen isotopic analysis, and scanning electron microscope (SEM) observation, we suggested that this type of sulfide ores belongs to a mineralized kind of carbonate mud mound. The macroscopic structures of these sulfide ores are quite similar to those of cavities system of typical carbonate mud mounds, and there are also bacteria structures found in some of the ore samples with SEM analysis. Previous studies show that the carbonate mud mound generally develops in a slope setting with water depth deeper than platform. It is also shown that the occurrence of carbonate mud mound has a close relationship with sea-floor hydrothermal exhalative ore-forming processes. The conservation conditions of the carbonate mud mounds in the two copper deposits are different, in the Dongguashan Cu deposit a lot of primary exhalative sedimentary textures are preserved, bacteria structures are found, and the carbon-oxygen isotopic compositions show primary sedimentary characteristics, while those in the Wushan Cu deposit show hydrothermal altered/overprinted textures, and no bacteria structures have been found so far, the carbon-oxygen isotopic compositions also indicate a hydrothermal reworking. In summary, the discoveries of carbonate mud mounds structure sulfide ores in the Wushan and Dongguashan Cu deposits provide new evidence for the Hercynian sedimentary hydrothermal-exhalative mineralization in the Middle and Lower Yangtze metallogenic belt.关键词
长江中下游/武山铜矿/冬瓜山铜矿/灰泥丘/热水喷流沉积成矿Key words
Middle and Lower Yangtze metallogenic belt/ Wushan Cu deposit/ Dongguashan Cu deposit/ Carbonate mud mounds/ Sedimentary hydrothermal-exhalative/ mineralization引用本文复制引用
蒋少涌,丁清峰,杨水源,朱志勇,孙明志,孙岩,边立曾..长江中下游成矿带铜多金属矿床中灰泥丘的发现及其意义——以武山和冬瓜山铜矿为例[J].地质学报,2011,85(5):744-756,13.基金项目
本文为十一五国家科技支撑计划重点课题(编号2009BAB43B03),江苏省基金创新学者攀登项目(编号BK2008026)和安徽省公益性地质工作项目(编号2007-7)资助的成果. （编号2009BAB43B03）
