摘要
胶东乳山金矿是我国单脉金储量最大的矿床,金的成矿具有多期多阶段的特点。为了研究早期矿化的时代,利用绢云母40Ar/39Ar法测定了乳山金矿含矿脉体旁围岩蚀变带中的绢英岩年龄。结果表明,围岩花岗岩的强烈绢英岩化蚀变年龄为129 Ma,比金发生大规模沉淀的成矿时间早约10 Ma,表明乳山金矿是多期热液成矿事件的产物,但这一事件也发生于120±10 Ma,从而证明乳山金矿与胶东其他地区金矿一样都是在中生代构造机制转折、岩石圈强烈减薄的构造背景下集中成矿的,这为进一步认识乳山金矿的成因机制和成矿动力学背景提供了新的证据。
The Rushan gold deposit, which is located tn the Jiaodong Peninsula, is Currently the largest lode type gold deposit in china in terms of gold resources in single lode. It is characterized with multi-stage mineralization. In order to study the time of early alteration/mineralization, the ^40Ar/^39Ar Ar dating method is employed to analyze sericite from quartz-sericite-pyrite alteration zone beside the auriferous quartz lodes of the Rushan gold deposit. The result shows that the quartz-sericite-pyrite alteration occurred at ca. 129 Ma, 10 Ma earlier than that of the main gold mineralization. This means that the Rushan gold deposit was formed through multi-stage hydrothermal events. As the age of quartz-sericite-pyrite alteration （129 Ma） is within the age range （120 ±10 Ma） of a large hydrothermal metallogenic event, it is suggested that the hydrothermal alteration and mineralization of the Rushan gold deposit are still related to that single large metallogenic event. It is proved that the Rushan deposit and other gold deposits in the Jiaodong Peninsula were formed in Mesozoic under the condition of tectonic regime transaction, strong thinning of lithosphere, and large-scale metallogeny. This new data helped us to understand much moor of the gold metallogeny and geodynamic settings in the Jiaodong Peninsula.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2006年第2期109-114,共6页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家自然科学基金资助项目(40273024)
