青海虎头崖—肯德可克矿区地球化学特征及其喷流成矿作用

Geochemistry and sedimentary exhalative mineralization in Hutouya—Kendekeke field,Qinghai Province,China

虎头崖—肯德可克矿区地处柴达木南缘东昆仑祁漫塔格成矿带中,矿床产出的大地构造背景为晚古生代的弧后扩张盆地,矿床类型为Sedex型。对虎头崖—肯德可克矿区中的虎头崖铅锌矿、肯德可克多金属矿、北沟铁矿和景仁铜矿进行现场调查,并对具有代表性的火山岩及矿石进行岩矿鉴定、化学全分析、稀土、微量元素分析及全岩硫同位素分析。结果表明:矿区火山岩基本属于含钾高的亚碱性系列,总体表现为亲弧裂谷特征,火山喷发喷流成矿作用具有多旋回的特点;矿石稀土元素、微量元素分析说明热水喷流成矿作用的存在,与Sedex型喷流成矿特征和弧后伸展盆地大地构造环境相符合。虎头崖—肯德可克矿区具有如下成矿特点:以层控矿床为主,主要为海西期弧后盆地成矿;具有多个层位成矿、以多元素成矿为主、具有由深源到浅源的成岩成矿作用的演化特征。

Abstract： Hutouya--Kendekeke field is located in the southern margin of the Qaidam, Qimantage ore belt of East Kunlun. The tectonic background of this field is the arc spreading basin in Carboniferous, Late Paleozoic. The Hutouya, Kendekeke and its nearby deposits （such as Jinren and Beigou） were used as the research objects. Based on a large number of references, systematic field investigation and laboratory analysis of rock and mineral geochemistry, the regional geological setting and mineralization conditions of the deposit were focused on, the mineralization law was summed up, and the genesis type was discussed. Through the rock and mineral identification, chemical analysis, REE, trace element analysis and whole-rock sulfur isotope analysis of the representative volcanic rocks and minerals in Hutouya, Kendekeke and its peripheral mine areas, it is found that the volcanic rocks are basically sub-alkaline series with high potassium, with the overall performance of pro-arc rift characteristics; the role of volcanic exhalative mineralization has the characteristics of multi-cycle. The results of REE and trace element analysis of minerals also show that the exhalative mineralization exists, which is consistent with the metallogenic characteristics of Sedex deposit and tectonic environment of back-arc extensional basin. Furthermore, the mineralization characteristics of Hutouya, Kendekeke and its peripheral mine areas are summarized as follows： mainly stratabound deposits, mainly back-arc basinmineralization in Hercynian, with multiple layers forming, multi-element mineralization in the main component and with deep to shallow digenetic mineralization evolution and other features.