Characteristics and Modeling of Saline Lake Gravity Flow Deposition in the Qianjiang Formation,Northern Qianjiang Depression,Jianghan Basin
Large-scale gravity flow deposits were first doscovered in the saline lake deposits of the Qianjiang Formation within the Qianjiang Depression.Their depositional characteristics,diagenetic mechanisms,main controlling factors,and favorable lithofacies require further investigation.Through petrographic observations of 20 core wells,combined with logging data,thin sections,mineralogical composition,and grain size analysis,ten gravity flow-related lithofacies were identified.The gravity flow deposits can be classified into four genetic facies:storm gravity flow,sliding-slumping,debris flow,and turbidity flow deposits.Based on lithofacies asso-ciations,the gravity flow deposits can be further subdivided into proximal,middle,and distal deposits.During the sedimentation of Mbr40,the climate was dry,and the secondary fracture zone in the Tankou area was ac-tive,leading to sliding and slumping.During the sedimentation of Mbr40M,the climate was relatively humid,and flooding triggered the long-distance transport of hyperconcentrated flows.Pure massive siltstones and fine sandstones from clastic flows,as well as parallel laminated sandstones from turbidity flows,are favorable reser-voir rocks.The combination of parallel laminated siltstone,massive siltstone,and mudstone is the dominant lithofacies associations formed during fluid transformation.
saline lake gravity flowsedimentary characteristicsdepositional modelQianjiang DepressionQianjiang Formation
万方数据
维普
