西准噶尔包古图地区石炭系希贝库拉斯组碎屑锆石LA-ICP-MSU-Pb年代学及其地质意义  

DETRITAL ZIRCON LA-ICP-MS U-Pb DATING OF THE CARBONIFEROUS XIBEIKULASI FORMATION SANDSTONE IN THE BAOGUTU AREA, WEASTERN JUNGGAR,AND ITS GEOLOGICAL SIGNIFICANCE

作　　者：孙羽[1] 赵春环 李永军[1] 佟丽莉[1] 杨高学[1] 严境 焦光磊[1] 易善鑫[1] 

机构地区：[1]长安大学地球科学与资源学院,西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [2]新疆地矿局第一地质大队,新疆鄯善838204

出　　处：《地层学杂志》2014年第1期42-50,共9页Journal of Stratigraphy

基　　金：中国地质调查局地质调查工作项目(基[2010]矿评01-01-05)资助

摘　　要：碎屑岩锆石研究是探讨碎屑岩沉积时代、源区特征和形成环境的一种有效途径。通过对西准噶尔包古图地区希贝库拉斯组砂岩样品进行碎屑锆石LA—ICP—MSU—Pb的年代学研究，获得了34粒锆石U—Pb年龄数据，分布在322～359Ma，4个峰值年龄分别为324．3Ma、334．0Ma、344．oMa和355．oMa；结合前人关于包古图组328．4～345．6Ma以及成吉思汗山组312Ma的年龄，认为本区三组地层的自下而上顺序是包古图组→希贝库拉斯组→成吉思汗山组，这与前人通过野外地质接触关系获得的认识是一致的。西准噶尔地区石炭系包古图组、希贝库拉斯组和成吉思汗山组之间的关系对揭示本区晚古生代地层格架和地质历史具有重要意义。The nature of the contacts between the Baogutu, Xibeikulasi, and Chengjisihanshan formations is important in understanding the regional stratigraphic sequence and Late Paleozoic geologic history in the Baogutu area of the weastern Junggar Basin, and the depositional ages of these stratigraphic units have attracted some attention of geologists. Analysis of detrital zircons is an effective approach to constrain the provenance and deposit ages of these units. LA-ICP-MS U-Pb dating was performed on 34 detrital zircons from the Xibeikulasi Formation sandstone and yielded four peaks at 324.3 Ma, 334.0 Ma, 344.0 Ma, and 355.0 Ma, with a range of 322--359 Ma; Combined with the reported ages of the Baogutu Formation （345.6--328.4 Ma） and Chengjisihanshan Formation （312 Ma）, the new data show that the Xibeikulasi Formation is younger than the Baogutu Formation and older than the Chengjisihanshan Formation, consistent with results from previous field geological study.

关 键 词：年代地层 U—Pb年代学 碎屑锆石.希贝库拉斯组 石炭系 西准噶尔 新疆 

分 类 号：P534.45[天文地球—古生物学与地层学]