安徽铜陵天马山金硫矿床地质地球化学特征

Geological and Geochemical Characteristics of the Tianmashan Au-S Deposit in Tongling,Anhui Province

安徽铜陵天马山金硫矿床发育上部层状矿体和下部网脉状矿体,地球化学特征呈现出明显的垂向变化和二元结构性。从下部网脉状矿化岩石到上部层状矿石,Pb、Zn、Au、Ag、As、Hg等含量和δ18O值总体逐渐增高,Cu、Mo、Cr、Co、Ni、REE等含量和成矿温度499℃→65℃及δ34S值总体呈逐渐降低趋势。黄铁矿的δ34S值为+4.0‰～+9.6‰,上部层状块状矿石中方解石和石英的δ18O平均值为+13.7‰,下部网脉状矿化岩矿石中脉石英或全岩δ18O平均值为+12.3‰。地质地球化学特征反映天马山金硫矿床为海底热水喷流沉积成因。

The Tianmashan Au-S deposit is geochemically characterized by a vertical variation and a ＂two-member texture＂ as well as the development of the upper stratiform ore bodies and the lower disseminated-veinlet mineralized rocks（ores）.Pb,Zn,Au,Ag,As,Hg content and average δ18O values increase progressively whereas Cu,Mo,Cr,Co,Ni,REE content,measured temperatures（from 499℃ to 65℃） of fluid inclusions and δ34S decrease gradually from the lower disseminated-veinlet mineralized rocks（ores） to the upper stratiform ore bodies.δ34S values of pyrite range from ＋4.0‰ to ＋9.6‰.The average δ18O value of calcite and quartz in the upper stratiform ore body is ＋13.7‰,while that of quartz and whole rock in the lower disseminated-veinlet mineralized rocks（ores） is ＋12.3‰.These geological-geochemical characteristics suggest that the Tianmashan Au-S deposit is of the submarine sedimentary exhalative origin.