青海天重峡金矿地球化学特征及矿床成因

Geochemical characteristics and genesis of the Tianchongxia gold deposit,Qinghai

在详细分析拉脊山地区天重峡金矿床成矿背景、矿床地质特征的基础上,对赋矿玄武岩进行了研究。岩石地球化学特征表明为低钾钙碱性岩石,稀土元素Eu具弱负异常特征,微量元素中Ba、Sr、Th、Ta、Ti相对贫化,Rb、K、Ce、Hf则相对富集。硫化物δ34S变化范围为4.49‰~5.8‰,均值为5.14‰,显示深源硫的特征。综合研究认为,天重峡金矿床为与岩浆期后热液作用有关的构造蚀变岩型金矿床。

On the basis of detailed analysis of metallogenic setting and ore deposit features in the Tianchongxia gold deposit located in Laji mountain, the ore-bearing basalt was studied. The lithogeochemieal characteristics show that the basalt is low potassic calcic alkali rock ; The REE has characteristics of weak negative Eu anomaly. The trace elements of Ba, Sr, Th, Ta and Ti in the basalt are depleted but Rb, K, Ce and Hf are relatively enriched. The 834S value of sulfide ranges from 4.49‰ to 5.8‰ with a mean of 5.14‰, which indicated that there is a typical deep source sulfur. Comprehensive study result shows that Tianchongxia gold deposit is a tectonic altered rock type gold deposit related to post-magmatic hydrothermal.