新疆金山沟巴塔玛依内山组火山岩及地球化学特征

VOLCANIC ROCKS AND GEOCHEMICAL CHARACTERISTICS OF THE BATAMAYINEISHAN FORMATION IN JINSHANGOU,XINJIANG

早石炭世巴塔玛依内山组为一套陆相火山岩 ,下部以基性熔岩为主 ,上部以中酸性、酸性火山碎屑岩为主。岩石地球化学研究表明 ,区内火山岩呈高铝玄武岩 -安山岩 -英安岩 -流纹岩钙碱性系列的演化趋势。从基性岩到酸性岩稀土模式相似 ,但铕负异常愈加明显。火山活动与金银矿成矿关系密切 ,玄武岩类、火山碎屑岩类Au、Ag、As含量较高 。

The Batamayineishan Formation of early Carboniferous age consists of continental volcanic rocks,which are mainly composed of basic lava in the lower part and intermediate acid,acid volcaniclastic rocks in the upper part.studies of petrogeochemistry suggest that the cale alraline series evolutionary trend of volcanic rocks in Jinshangou is as follows:high Al basalt andesite dacite rhyolite. The chrondrite normalizaed REE distribution patterns are similar to all of the volcanic rocks, but negative Eu anomalies become more obvious from the basic to acid rocks . The relationship between the volcanic activites and the metallogenic process of gold silver deposits is close .Basalt and volcaniclastic rocks have high Au,Ag and As contents,showing that they seem to be ore sources.