| 东天山土屋–延东铜矿带石英钠长斑岩与辉钼矿形成年龄及其重要意义 |
| |
| 引用本文： | 肖兵,陈华勇,王云峰,杨俊弢.东天山土屋–延东铜矿带石英钠长斑岩与辉钼矿形成年龄及其重要意义[J].大地构造与成矿学,2017,41(1):145-156. |
| |
| 作者姓名： | 肖兵 陈华勇 王云峰 杨俊弢 |
| |
| 作者单位： | 1. 中国科学院 广州地球化学研究所,中国科学院矿物学与成矿学重点实验室,广东广州510640;中国科学院大学,北京100049;2. 中国科学院 广州地球化学研究所,中国科学院矿物学与成矿学重点实验室,广东广州510640;3. 新疆地质矿产开发局第一地质大队,新疆昌吉,831100 |
| |
| 基金项目： | 国家重点基础研究计划“973”项目“新疆北部古弧盆体系成矿机理”，中国科学院“百人计划”项目 |
| |
| 摘 要： | 土屋–延东铜矿带位于东天山大南湖–头苏泉岛弧带上,是目前新疆最大的铜矿带。铜矿体主要赋存于石炭纪斜长花岗斑岩和晚古生代企鹅山群中,但是前人研究表明斜长花岗斑岩的成岩年龄(339~332 Ma),明显老于成矿年龄(约322Ma),因此,土屋–延东铜矿带的致矿岩体至今还存有争议。本次研究首次对该铜矿带晚石炭世石英钠长斑岩进行了详细的岩相学和LA-ICP-MS锆石U-Pb年代学分析,并结合辉钼矿Re-Os同位素年龄测定,探讨土屋–延东铜矿带矿床成因。对延东铜矿4件辉钼矿样品进行Re-Os同位素分析,得到322.0±2.7 Ma的加权平均模式年龄和319.1±9.1 Ma等时线年龄,明显要晚于斜长花岗斑岩年龄。两个石英钠长斑岩样品LA-ICP-MS锆石U-Pb年龄分别为324.9±2.4 Ma和324.5±2.1 Ma,表明石英钠长斑岩为晚石炭世岩浆活动的产物。岩相学研究表明,石英钠长斑岩中发育黄铜矿+绿泥石+硬石膏+方解石矿物组合,这与延东铜矿主成矿阶段的矿物组合基本一致,并且石英钠长斑岩成岩年龄与辉钼矿年龄在误差范围内一致,表明石英钠长斑岩可能与土屋-延东铜矿带铜矿形成有着密切关系,这一发现可能为大南湖–头苏泉岛弧带晚石炭世铜矿的勘查提供新的思路。
|
| 关 键 词： | 东天山 大南湖-头苏泉 土屋-延东铜矿带 石英钠长斑岩 辉钼矿 年代学 |
Zircon U-Pb and Molybdenite Re-Os Dating of the Tuwu-Yandong Cu Deposit Belt of the Eastern Tianshan Mountains and its Geological Significance |
| |
| XIAO Bing,CHEN Huayong,WANG Yunfeng,YANG Juntao.Zircon U-Pb and Molybdenite Re-Os Dating of the Tuwu-Yandong Cu Deposit Belt of the Eastern Tianshan Mountains and its Geological Significance[J].Geotectonica et Metallogenia,2017,41(1):145-156. |
| |
| Authors: | XIAO Bing CHEN Huayong WANG Yunfeng YANG Juntao |
| |
| Abstract: | The Tuwu-Yandong Cu deposit belt,located in the Da'nanhu-Tousuquan island arc belt of the eastern Tianshan mountains,is the largest Cu deposit belt in Xinjiang.The deposits are hosted in the Carboniferous plagiogranite porphyry and the Late Paleozoic Qi'eshan Group.However,previous studies show that the age of the plagiogranite porphyry (339-332 Ma) is obviously older than the mineralization age (about 322 Ma).Therefore,the mineralization-causative intrusion of the Tuwu-Yandong Cu deposit belt is still controversial.In this study,petrography and in situ zircon U-Pb LA-ICP-MS analyses for the quartz albite porphyry are combined with Re-Os isotope analysis of molybdenite to provide constraints on the genesis of the Tuwu-Yandong Cu deposit belt.Re-Os isotope analysis of molybdenite from the Yandong Cu deposit yields a weighted mean model age of 322.0±2.7 Ma and an isochron age of 319.1±9.1 Ma,which are obviously younger than that of the plagiogranite porphyry.LA-ICP-MS zircon U-Pb ages of 324.9±2.4 Ma and 324.5±2.1 Ma have been attained from two quartz albite porphyry samples.Petrographic studies show that the mineral assemblages of chalcopyrite + chlorite + anhydrite + calcite are developed in the quartz albite porphyry,which is same with the mineral assemblage identified in the main mineralization stage.Moreover,the age of the quartz albite porphyry is identical to the mineralization age,suggesting that the quartz albite porphyry may have some genetic relationships to Cu mineralization in the Tuwu-Yandong Cu deposit belt.This find will provide new insights on the Late Carboniferous Cu exploration in the Dananhu-Tousuquan island arc belt. |
| |
| Keywords: | eastern Tianshan Mountains Dananhu-Tousuquan Tuwu-Yandong Cu deposit belt quartz albite porphyry molybdenite geochronology |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
