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地处东昆仑东段重要构造-岩浆带上的都兰地区,近年来发现了一系列斑岩型金属矿床,但由于自然环境条件限制,成矿与地质研究程度尚较低。东昆仑东段都兰地区矿区成矿母岩主要为花岗岩类,本文对主要围岩进行了LA-ICP-MS锆石U-Pb测年和地球化学研究,表明都兰地区花岗岩带岩石类型为高钾钙碱性过铝质;10个花岗岩样品的地球化学分析结果显示,Si O2与Al2O3、Fe2O、Mg O、Ca O、P2O5和Ti O2具有相似的线性递减趋势,样品主量、微量和稀土元素结果反映具有同源性。样品中锆石呈自形-半自形,发育典型的岩浆锆石震荡生长环带,TH/U值较高,为岩浆锆石。测得3个锆石样U-Pb加权平均年龄分别为(246.0±1.1)Ma、(243.4±2.8)Ma和(242.1±7.9)Ma,代表印支期岩体年龄,符合东昆仑地区印支期发生较大规模的岩浆活动事件。
Located in the Dulan area, an important tectonic-magmatic belt in the eastern part of Eastern Kunlun, a series of porphyry metallogenic deposits have been discovered in recent years. Due to the limitation of natural environment, the degree of metallogenetic and geological research is still relatively low. The mineralized host rocks in Dulan area in the eastern part of East Kunlun are mainly granitoids. LA-ICP-MS zircon U-Pb dating and geochemistry of the main surrounding rocks are carried out in this paper. The results show that the granites in Dulan area are High-K calc-alkaline aluminate. The geochemical analysis of 10 granite samples shows that Si O2 has the similar linear decreasing trend with Al2O3, Fe2O, MgO, CaO, P2O5 and Ti O2. The main, minor and REE results reflect homology. The zircons in the samples are self-shaped and semi-self-shaped and developed typical zonogenic zircons. The TH / U values are higher for the magmatic zircons. The zircon-like U-Pb weighted average ages were (246.0 ± 1.1) Ma, (243.4 ± 2.8) Ma and (242.1 ± 7.9) Ma, respectively, representing the age of Indosinian rock mass, Large-scale magmatic events occur.