西准噶尔萨吾尔地区早古生代火山岩的发现及其意义  

The discovery on the Early Paleozoic magmatism in the Sawuer area,West Jungaar

作　　者：张达玉[1,2] 周涛发[1] 袁峰[1] 邓宇峰[1] 许超[1] 张若飞[1] 李鹏 王金林[2] 

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009 [2]中国科学院新疆生态与地理研究所新疆矿产资源研究中心,乌鲁木齐830011 [3]新疆有色706地质大队,阿尔泰836600

出　　处：《岩石学报》2015年第2期415-425,共11页Acta Petrologica Sinica

基　　金："十二五"国家科技支撑计划(2011BAB06B01);国家自然科学基金项目(41302050;40772057;41040025);国家重点基础研究发展规划项目(2007CB411304;2001CB409800);新世纪优秀人才支持计划项目(NCET-10-0324);矿床地球化学国家重点实验室开放基金(201102)联合资助

摘　　要：萨吾尔地区位于西准噶尔北部,是以出露泥盆-石炭系火山碎屑-沉积岩为特征的构造单元。本次工作测得萨吾尔西南部铁普克玄武安山岩的锆石LA-ICPMS U-Pb年龄为427.6±4.2Ma,形成于中志留世;同时测得侵入该玄武安山岩内的花岗斑岩的锆石LA-ICPMS U-Pb年龄为387.2±2.9Ma,是中泥盆世的中酸性岩浆作用。本文首次报道了萨吾尔地区存在早古生代岩浆活动的年龄证据。与邻近的塔尔巴哈台和谢米斯台地区代岩浆作用的时空分布对比显示,塔尔巴哈台-萨吾尔和谢米斯台两个地质单元在早古生代可能具有一致的成岩背景。The Sawuer area is located in the north part of the West Junggar region, which is characterized by the outcrops of the Devonian-Carboniferous pyroclastic sedimentary strata. In this study, the authors focused on the basaltic andesite from Tiepuke district, Southwest Sawuer area. The basaltic andesite strata are E-W trending, and there are some post-volcanism granite porphyry intruding into the basaltic andesite strata. After detailed geological mapping, the basaltic andesite was dated as 427.6 ±4. 2Ma with the LA- ICPMS U-Pb dating method, and the granite porphyry inserting in the Tiepuke basaltic andesite strata intruded at 387. 2 ± 2. 9Ma. The dating results suggest that basaltic andesite from Tiepuke district was erupted is Early Paleozoic magmatism. This is the first time to report the discovery of the Early Paleozoic magmatism in the Sawuer area, which change the traditional understanding that there is no Early Paleozoic magmatism in Sawuer area. The basaltic andesite from Tiepuke district, comparing with the spatial and temporal distribution characters of the magmatism from the adjacent Tarbaghatai and Xiemisitai area, indicate that the Early Paleozoic magmatism in Sawuer may formed in the consistent background within Tarbaghatai-Sawuer-Xiemisitai setting, Northewest Junggar area.

关 键 词：早古生代 火山岩 LA-ICPMS U-PB定年 萨吾尔 西准噶尔 

分 类 号：P588.121[天文地球—岩石学] P588.144[天文地球—地质学]