| 东昆仑马尼特金矿床赋矿花岗闪长岩锆石U-Pb年龄及岩石地球化学特征 |
| |
| 引用本文： | 李积清,王涛,陈静,白宗海,林艳海.东昆仑马尼特金矿床赋矿花岗闪长岩锆石U-Pb年龄及岩石地球化学特征[J].矿物岩石,2019,39(3):69-77. |
| |
| 作者姓名： | 李积清 王涛 陈静 白宗海 林艳海 |
| |
| 作者单位： | 青海省地质调查院,青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012;青海省地质调查院,青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012;青海省地质调查院,青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012;青海省地质调查院,青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012;青海省地质调查院,青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012 |
| |
| 基金项目： | 青海省应用基础研究项目 |
| |
| 摘 要： | 马尼特金矿床位于东昆仑木孜塔格-布青山蛇绿混杂岩带,是近年来在东昆仑发现的与马尔争组地层有关的构造蚀变岩型小型金矿床,矿体主要赋存于晚三叠世花岗闪长岩与围岩的接触部位。本次研究通过对赋矿花岗闪长岩体的LA-ICP-MS锆石U-Pb定年,全岩主量元素、微量元素的研究,探讨了该岩体的形成时代,成因类型及其形成构造环境。结果显示:该花岗闪长岩的锆石U-Pb年龄为213.25 Ma±0.62 Ma(MSWD=0.99),代表其侵入时代为晚三叠世。岩石w(SiO2)在66.96%~68.3%之间,K2O/Na2O=0.54~0.63,相对富钠,贫w(MnO)(平均0.03%),w(P2O5)(0.14%~0.16%)和w(TiO2)(0.4%~0.46%),A/CNK值为1.05~1.16,平均1.106,w(Al2O3)介于15.37%~15.72%之间,里特曼指数δ值为1.43%~1.89%,TFeO/MgO为1.72~1.84,DI为74.19~79.94,表明其为过铝质、钙碱性系列的I型花岗岩。岩石稀土总量较低(ΣREE=110.67×10^-6~121.36×10^-6),表现出轻稀土富集而重稀土亏损的右倾曲线,LREE/HREE=13.54~15.12,(La/Yb)N=20.42~20.7],轻重稀土分馏明显,负Eu异常中等(δEu介于0.94~0.99之间),大离子亲石元素Rb,Ba,Sr以及U,Th相对富集,高场强元素Nb,Ta及K,P,Ti相对亏损,具有火山弧花岗岩特征。结合其形成时代及区域构造背景,认为其形成于早-中生代巴颜喀拉地块和东昆仑地块后碰撞构造环境。
|
| 关 键 词： | 锆石U-PB年龄 晚三叠世 花岗闪长岩 马尼特金矿床 东昆仑 岩石地球化学 |
ZIRCON U-Pb AGE AND PETROGEOCHEMICAL CHARACTERISTICS OF ORE-HOSTING GRANODIORITE IN MANITE GOLD DEPOSIT,EAST KUNLUN |
| |
| Li Jiqing,Wang Tao,Chen Jing,Bai Zonghai,Lin Yanhai.ZIRCON U-Pb AGE AND PETROGEOCHEMICAL CHARACTERISTICS OF ORE-HOSTING GRANODIORITE IN MANITE GOLD DEPOSIT,EAST KUNLUN[J].Journal of Mineralogy and Petrology,2019,39(3):69-77. |
| |
| Authors: | Li Jiqing Wang Tao Chen Jing Bai Zonghai Lin Yanhai |
| |
| Institution: | (Qinghai Institue of Geological Survey,Northern Qinghai-Tibet Plateau GeologicalProcesses and Mineral Resources Laboratory,Xining 810012,China) |
| |
| Abstract: | The Manite gold deposit is a small scale structural altered rock type gold deposit related to the Marzheng Formation in the Muztag-Buqingshan ophiolitic melange zone in east Kunlun. Gold ore bodies mainly occur in the contact area between the granodiorite and the late Triassic wall rock.Based on the LA-ICP-MS zircon U-Pb dating of ore-hosted granodiorite and the study of major elements and trace elements in the whole rock,the formation age,genetic type and tectonic setting of the granodiorite are discussed.LA-ICP-MS zircon U-Pb dating yields an age of 213.25Ma+0.62Ma(MSWD=0.99)(late Triassic period).Geochemical analysis of the granodiorite shows w(SiO2)is between 66.96%~68.3%,K2O/Na2O is 0.54~0.63.The rock is relatively rich in sodium,poor in w(MnO)(average 0.03%),w(MnO)(average 0.03%),w(P2O5)(0.14%~0.16%)and w(TiO2)(0.4%~0.46%).A/CNK value is in the range of 1.05~1.16 (average 1.106),w(Al2O3)is between 15.37%~15.17.72%.DI is 74.19~79.94,characteristic of I-type granite of aluminous and calc-alkaline series.The total REE of rocks is relatively low (REE=110.67×10^-6~121.36×10^-6)and shows a right-inclined curve of light rare earth enrichment and heavy rare earth depletion.LREE/HREE=13.54~15.12,(La/Yb)N=20.42~ 20.7].Light and heavy rare earth fractionation is obvious with medium negative Eu anomaly(Eu =0.94~0.99).Large ion lithophiphilic elements Rb,Ba,Sr,U and Th are relatively enriched, high field strength elements Nb,Ta and K,P,Ti are also relatively enriched,characteristic of volcanic arc granite.Based on its formation age and regional tectonic background,it is proposed that the granodiorite was formed in the post-collision tectonic environment of the Bayan Hara Block and the East Kunlun Block in the early Mesozoic. |
| |
| Keywords: | zircon U-Pb age late Triassic granodiorite Manite gold deposit east Kunlun rock geochemistry |
| 本文献已被 维普 万方数据 等数据库收录！ |
|
