Paleo-uplift forced regional sedimentary evolution:A case study of the Late Triassic in the southeastern Sichuan Basin,South China  

作　　者：Fangyu He Qingsong Cheng Dongtao Zhang Yubing Ji Ziying Wang Tenghui Lu 

机构地区：[1]PetroChina Zhejiang Oilfield Company,Hangzhou 310023,China [2]School of Geoscience and Technology,Southwest Petroleum University,Chengdu,610500,China [3]Sichuan Natural Gas Geology Key Laboratory,Southwest Petroleum University,Chengdu,610500,China

出　　处：《Petroleum》2024年第3期462-473,共12页油气（英文）

基　　金：supported by science and technology project of PetroChina Zhejiang Oilfield Company(grant numbers:zjyt-2021-kj-008).

摘　　要：The sedimentary environment of the Upper Triassic in the southeastern Sichuan Basin is obviously controlled by Luzhou paleo-uplift(LPU).However,the influence of paleo-uplift on the sedimentary patterns of the initial stages of this period in the southeastern Sichuan Basin has not yet been clear,which has plagued oil and gas exploration and development.This study shows that there is a marine sedimentary sequence,which is considered to be the first member of Xujiahe Formation(T_(3)X^(1))in the southeastern Sichuan Basin.The development of LPU resulted in the sedimentary differences between the eastern and western Sichuan Basin recording T_(3)X^(1)and controlled the regional sedimentary pattern.The western part is dominated by marine sediments,but the eastern paleo-uplift area is dominated by continental sedimentation in the early stage of T_(3)X^(1),and it begins to transform into a marine sedimentary environment consistent with the whole basin in the late stage of the period recorded by the Xujiahe Formation.The evidences are as follows:(1)time series:based on the cyclostratigraphy analysis of Xindianzi section and Well D2,in the southeastern Sichuan Basin,the period of sedimentation of the Xujiahe Formation is about 5.9 Ma,which is basically consistent with the Qilixia section,eastern Sichuan basin,where the Xujiahe Formation is widely considered to be relatively complete;(2)distribution and evolution of palaeobiology:based on analysis of abundance evolution of major spore-pollen,many land plant fossils are preserved in the lower part of T_(3)X^(1),indicates the sedimentary environment of continental facies.In the upper part of T_(3)X^(1),the fossil of terrestrial plants decreased,while the fossil of marine and tidal environment appeared,this means that it was affected by the sea water in the late stages of T_(3)X^(1);(3)geochemistry:calculate the salinity of water from element indicates that the uplift area is continental sedimentary environment in the early stage of T_(3)X^(1),while the central and western area

关 键 词：Luzhou paleo-uplift Late Triassic CYCLOSTRATIGRAPHY PALYNOLOGY Sedimentary environment 

分 类 号：P5[天文地球—地质学]