Research On The Lithofacies Paleogeography Of The Upper Carboniferous Lousuan Stage-Lower Permian Zisongian Stage In Yin’gen-Eji’na Banner Basin

Under the guidance of the theories on stratigraphy geology, sedimentary petrology,petrography and historical geology, the author, by collecting and analyzing previous datapublished, field geological investigation and testing and analysis, analyzes the lithofaciespaleogeography of the Upper Carboniferous Lousuan Stage-Lower Permian Zisongian Stagein Yin’gen-Eji’na Banner Basin through the analysis of the sedimentary facies and sedimentprovenance on the basis of the study of the strata, sedimentary and paleontological featuresfrom the late Carboniferous epoch to the early stage of Early Permian.The strata of the research area consists of Shibanshan Formation, Jijitaizi Formation,Ganquan Formation and Amushan Formation, the first three of which developed in thewestern part of the Basin, mainly distributed in regions such as Hazhu-Xiaohulishan-Hunaiba-sike, Meiyaoxishan-Jijitaizi and Nuergai and the last one only deposited to the east of Eji’naBanner. Among the rocks, clastic rocks occupy the first, volcanic rocks come second and theamount of carbonate rocks is much smaller. The research area is abundant in shallow seaanimal fossils like Brachiopoda, Anthozoa and Fusulinids while land plant fossils are few innumber.Sedimentary facies of the Basin can be classified into six types: the well-developedlittoral facies in the clastic rock of Shibanshan Formation, Ganquan Formation and AmushanFormation, neritic shelf fades in the Amushan Formation, carbonate platform facies which arewidely distributed in Jijitaizi Formation and the middle part of Amushan Formation, deltafacies distributed merely in Ganquan Formation and Amushan Formation in Ulaan Ovoo, fandelta facies which develops only in Ganquan Formation in Nuergai and Xiaohulishan, andtidal-flat facies which are less developed.The overall analysis of the sediment provenance of the research area shows that thesource area of the depression Hongshishan-Heiyingshan is the low uplift belt of Mazongshan-Saihantaolai-Qiedao or Mongolia, and the source area of the depression Hongliudaquan is theuplift belt of Dunhuang-Alashan-Langshan. To the north of the Enggerwusu fault in thedepression Badain Jaran-Yin’gen, the provenance originates from the uplift of Qiedao andDunhuang-Alashan-Langshan uplift belt to the north. On the whole, Upper CarboniferousLousuan Stage-Lower Permian Zisongian Stage mainly originates from Dunhuang-Alashan-Langshan uplift belt and Qiedao uplift.Based on the above analysis, the author draws the lithofacies paleogeographic maps ofUpper Carboniferous Lousuan Stage-Dalan Stage and Upper Carboniferous Xiaodushan Stage-Lower Permian Zisongian Stage of the Yingen Ejina Banner Basin and analyzes theirpaleogeographic characteristics, depositional filling and evolution features. LateCarboniferous-Early Permian Zisong period, the research area is Intracontinental rift basinsunder Stretch background, basically inherited the Early Carboniferous sedimentary basinspattern. Late Carboniferous Lousuan-Dalan period in which, the west of the basin in thestretch under tension forming a shape of Hongshishan-Baiheshan-Pengboshan centers ofsubsidence, and Shibanshan Formation, Jijitaizi Formation were deposited in the westernbasin. During this period, the deposition pattern of the basin are northernHongshishan-Heiyingshan depression, central Mazongshan-Saihantaolai-Qiedao lowamplitude uplift and southern Hongliudaquan depression consisting of two depressions abulge. Late Carboniferous Xiaodushan period-Early Permian Zisong period, under the actionof volcanic activity,etc. Eastern basin formed Engeerwusu-Suhongtu-Yinggete rift center.With the scope of the process of deposition of transgressive from west to east and graduallyexpand and cover the whole area,This phase deposition in the western basin of GanquanFormation, Eastern deposited only Amushan Formation, Although the deposition pattern ofinherited the Lousuan-Dalan period characteristic of two depressions a bulge. But extended tothe southern basin depression range eastward boundary with FormingHliudaquan-Badanjilin-Yingen Depression.