摘要
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。
Porphyry deposits have been found in Dulan area of the tectonic magmatic belt in eastern section of East KunLun over the past years but the degree of geological work and research for the deposit was quite low due to the limitation of natural conditions. The hosted rocks in the mining area of Eastern Kunlun were dominated by granite. This paper presents zircon U-Pb age data and geochemistry study of hosted rocks using laser ablation ICP-MS technique, which shows that the granite of Dunlan belongs to high-K-calc-alkaline peraluminous granite. The geochemical analysis results of 10 granite samples show that Al2 O3 , Fe2 O, MgO, CaO, P2 O5 , TiO2 with SiO2 have the similar linear correlation trend. The results of the main elements, trace elements and rare elements show that the samples have the same origin. The zircons of granite present mainly euhedral and hypidiomorphic texture, with clear ring developed and high TH/U ratio, which are magmatic zircons. The results show that the intrusion mainly comes from late hercynian indosinian period with ^206Pb/ ^238U average weighted age of （246.0 ±1.1） Ma, （243.4 ±2.8）Ma, （242.1 ±7.9）Ma. East Kunlun region in the indosinian period indeed witnessed large-scale magmatism event.
出处
《电子显微学报》
CAS
CSCD
2015年第3期222-233,共12页
Journal of Chinese Electron Microscopy Society
基金
中国地质调查局地质调查工作项目(No.2011-03-04-06)
国家自然科学基金资助项目(No.4117208840872141)
