山东省海阳市郭城镇BIF型铁矿地球化学特征与矿床成因探讨  

Geochemical Characteristics and Genesis of BIF Iron Deposit in Guocheng Town,Haiyang City,Shandong Province

作　　者：王浩然 刘建朝[1] 张燕娜 陈俊生 张高鑫 张海瑞 WANG Haoran;LIU Jianchao;ZHANG Yanna;CHEN Junsheng;ZHANG Gaoxin;ZHANG Hairui(Chang＇an University,Xi＇an 710054,Shaanxi,China;Shanclong Provincial NO.4 Institute of Geological and Mineral Survey,Weifang 261021,Shanclong,China)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]山东省第四地质矿产勘查院,山东潍坊261021

出　　处：《西北地质》2018年第4期156-165,共10页Northwestern Geology

基　　金：2016年度省直地质勘查项目专项资金"山东省鲁东地区前震旦纪地层含矿性研究"(SDZS-2016-GTT01);2016年度省直地质勘查项目专项资金"山东省三稀矿产资源潜力及找矿方向研究"(SDZS-2016-GTT01);长安大学研究生科研创新实践项目"山东省微山稀土矿成矿熔体-流体演化过程:来自方解石;萤石的制约"(2018019)

摘　　要：郭城镇条带状铁矿(BIF)位于胶莱盆地东北缘,赋存于古元古代荆山群变质岩中。通过与冀东迁安和山西五台地区的铁矿对比,可以看出郭城铁矿地球化学特征主要为化学沉积,但有一定量的碎屑参与。在后澳大利亚太古宙页岩(PAAS)稀土配分图中,轻稀土元素亏损、高的Y/Ho值以及La和Y正异常的特征表明铁矿沉淀于海相环境,而高的Sr/Ba、Ti/V值以及Eu的强烈正异常表明火山热液的参与,成矿物质来源于火山活动。无明显的Ce负异常,表明当时可能存在一个缺氧的大气环境。根据矿石及围岩的氢氧同位素值特征,可以看出其成矿作用流体的类型为混合岩化型热液。The banded iron formation （BIF） of Guocheng town is located in the northeastern mar gin of Jiaolai Basin, which was occurred in metamorphic rocks of Proterozoic Jingshan group. Af ter comparing with the iron deposits in Qian＇an area of East Hebei and Wutai area of Shanxi, it＇s found that Guocheng iron deposit was formed by chemical sedimentary, with certain amount of involved debris. In the REE distribution diagram of Post Australian Archean Shale （PAAS）, this deposit has depleted LREE, with high Y/Ho ratio and positive La Y anomalies, indicating that this deposit was precipitated in the marine environment. The high Ti/V ratio and strong Eu posi tive anomaly stand for the participation of volcanic hydrothermal fluid. Thus, it＇s believed that the metallogenic material was derived from the volcanic activity. There was no obvious negative Ce anomaly, indicating that there might be an anoxic atmosphere at that time. The hydrogen and oxygen isotopes of ore and surrounding rock indicate that the ore forming fluids not only sourced from volcanic hydrothermal solution, but also from other fluids.

关 键 词：古元古代 条带状硅铁建造 氢氧同位素 成矿特征 海阳市 

分 类 号：P595[天文地球—地球化学]