摘要
夏甸金矿是胶东地区典型的蚀变岩型金矿床,该矿床沿走向NNE、倾向SE的招平断裂带展布,控矿断裂上盘主要为胶东群变质岩,下盘为中粗粒二长花岗岩,矿体主要产于断裂带下盘的黄铁绢英岩中。对取自夏甸金矿井下的岩和矿石进行了主、微量元素地球化学特征分析,夏甸金矿床岩石具有LREE及LILE富集、HREE及HFSE亏损、壳幔混合的特征,且黄铁绢英岩Eu负异常明显。从岩石构造环境判别图解可以看出,断裂带下盘岩体是在古元古代挤压造山环境下或由挤压向伸展转化时期形成。结合文献综合对比分析可知,夏甸金矿床可能是早白垩世华北克拉通伸展背景下形成的产物,作为郯庐断裂带的次级断裂——招平断裂在该时期发生伸展活动,不仅为含矿热液的上升提供通道,而且为金矿床的形成提供有利条件。
Xiandian gold deposit in Eastern Shandong Province is a characteristic alteration-rock type gold deposit along the Zhaoping fault zone which strike in NNE and dip in SE. The hanging wall of the ore-controlling fault is Jiaodong rock group and the footwall is medium- and coarse-grained monzogranite. Ore bodies formed mainly in the fault’s footwall containing pyrite-beresite. The major and trace elements of the rocks were investigated. The results show that they are characterized by enrichment of LREE and LILE, depletion of HREE and HFSE, curst-mantle mixing, and obvious Eu negative anomaly. The tectonic discrimination diagrams show that the batholiths in the footwall formed in the compressive orogenic background or in the stage when the compressive orogenic environment transformed into extensional environment. Based on the research data of forefathers, the Xiadian gold deposit maybe formed in the extensional environment of the North China craton in early Cretaceous. Zhaoping fault which is the secondary fault of Tan-lu fault belts was in the stretch-faulted environment during this period. It provided not only the passage of ore-bearing hydrothermal solution but also the favorable conditions of the gold deposit formation.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2014年第10期2621-2633,共13页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(41172187)
中国地质调查局项目(1212011121096)
关键词
夏甸金矿
微量元素
招平断裂
华北克拉通
壳幔混合
Xiadian gold deposit
trace element
Zhaoping fault
North China craton
curst-mantle mixing