东天山博格达地层小区石炭纪地层研究进展  

Research Progress on Carboniferous Strata in Bogda Area,Eastern Tianshan

作　　者：初建朋[1,2] 李勇[1] 郭俊锋[1] 肖良[1] 张永明[2] 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]山东理工大学资源与环境工程学院,山东淄博255000

出　　处：《西北地质》2016年第2期229-236,共8页Northwestern Geology

基　　金：中国地质调查局项目"新疆1:25万三道岭幅(K46C001002)区调(修测)"(1212011120470)

摘　　要：1∶25万三道岭幅区调项目重新划分和厘定了博格达小区的地层系统,特别是对石炭纪地层的研究,有了一些新的进展,包括:在原塔克尔巴斯陶组内发现不整合界面,从而将该组解体,其下部层位岩性、岩相和古生物特征可以和托斯巴斯陶组对比,从而将它们重新厘定为黑山头组,时代为早石炭世中晚期,并发现该组在下涝坝与下伏上泥盆统康古尔塔格组为整合接触;将塔克尔巴斯陶组上部层位厘定为姜巴斯套组,依据发现的Choristites等腕足化石,笔者认为该组上部应该已经存在晚石炭世地层;依据地层接触关系、古生物化石以及锆石U-Pb年龄,将七角井组的地质时代厘定为晚石炭世早期,它和柳树沟组为同时异相沉积;在祁家沟组顶部灰岩中发现了有孔虫等丰富的微体化石,认为它的时代是晚石炭世中期,和阿什喀腊组为同时异相沉积。The project of geological survey in 1∶250000Sandaoling Sheet made some research progresses on carboniferous stratigraphic redivision,including the unconformity interface found in Tuckerbasstao Formation.According to the fossils of lower strata in Jiangbasstao Formation,it＇s thought that the geological age of this lower strata is the middle and late period of Early Carboniferous.Some brachiopod fossil elements of late carboniferous have been found in the higher strata of Jiangbasstao Formation,such as Brachythyria,Cancrinella,Choristite,Ella,Paramuirwoodiaand Wellerella,the further analysis showes that these brachiopod fossils can be grouped into Choristites-Paramuirwoodia fossil assemblage zones in North Xinjiang region and the geological age of the higher strata is early period of Late Carboniferous.Based on contact relationship between these strata,fossils and zircon U-Pb age,the geological age of Qijiaojing Formation has been revised as early period of Late Carboniferous.The results suggest that the Liushugou Formation,Qijiaojing Formation,Qijiagou Formation and Ashenkala Formation belong to different sedimentary facies with same geological age.

关 键 词：石炭纪 地层 研究进展 博格达 东天山 

分 类 号：P534.45[天文地球—古生物学与地层学]