新疆七角井德哲塔勒德上石炭统奥尔吐组沉积相特征及意义  

The Sedimentary Facies Characteristics and Significance of Aoertu Formation,Dezhetalede,Qijiaojing Town,Xinjiang

作　　者：郭丽娜[1] 李勇[1] 苏春乾[1] 肖良[1] 周建仁[1] 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054

出　　处：《新疆地质》2014年第1期48-52,共5页Xinjiang Geology

基　　金：新疆1:25万三道岭幅(K46C001002)区域修测项目成果;教育部博士点基金(20100205110003)联合资助

摘　　要：新疆巴里坤县七角井镇德哲塔勒德地区上石炭统奥尔吐组沉积相类型为扇三角洲相和滨海碎屑岩相。扇三角洲平原泥炭沼泽沉积和平原分流河道粗碎屑沉积组成扇三角洲平原亚相;水下分流河道和水下分流河道间沉积组成扇三角洲前缘亚相。主体是由碎屑岩组成不同规模的韵律层,发育平行层理、交错层理、较大型的楔状交错层理、水平层理。其中水平层理一般发育在静水地带,平行层理、交错层理则分别主要出现在以高流态、高水动力为特征的条件下,二者交互出现,反映地层沉积于海水进退较频繁的滨浅海地带。本组地层基本层序内部为由下至上粒度变细的特征,显示为海进过程。同时发现了大量化石,包括头足化石:尖形卡拉温菊石(Cravenoceras acutum Liang);腕足化石:网格长身贝(Dictyoclostus sp.),在含碳细砂岩中发现了桶箍芦木化石(Calamites cf.schützeiformis Kidst.et Jongm)碎片,结合该组沉积岩成分成熟度和结构成熟度均较低的特征,岩石为近岸源区快速剥蚀、搬运、堆积形成的,所含植物化石碎片是沿途生长的植物异地埋藏形成的,说明本组沉积岩是在滨海区沉积形成的。Fan delta and littoral clastic rock facies have been recognized from the upper carboniferous Aoertu Forma-tion, QiJiaoJing Zhelandesayi of Qijiaojing town,Xinjiang ,Fan delta plain subfacies can be further divided into peat swamps deposition of Fan delta plain and coarse clastic fan delta plain distributary channel deposits;underwater distribu-tary channel and underwater distributary inter-channel deposits form fan delta front subfacies;parallel bedding, cross-bed-ding, larger wedge cross bedding and horizontal bedding exist in the clastic rock rhythm of different scale layer.Horizon-tal bedding generally develop in the static water area,parallel bedding and cross-bedding respectively appear in the high flow and high characteristics of hydrodynamic conditions,both for the interactive,this phenomenon reflect edimentary stratum the offshore area of seawater in a more frequently. The size of sediments become thinner from the bottom in ba-sic sequence within the group formation.This feature displays transgression process.At the same time,founding a lot of fossils,including:Cephalopod: Cravenoceras acutumLiang;brachiopod:Dictyoclostus sp. etc, the aloe vera plant fossil fragments was found in carbon fine sandstone with Structure of sedimentary rocks and lower maturity.The rock is formed offshore source area rapid erosion,handling,stacking.plant fossils(Calamites cf. schützeiformis Kidst. et Jongm) fragments formed for long-distance buried along the growth of plants.At the same time, it shows that this group of sedi-mentary rocks deposits in offshore area.

关 键 词：上石炭统 奥尔吐组 沉积相 扇三角洲 滨海相 

分 类 号：P618.13[天文地球—矿床学]