It is previously believed that Kaijiang-Liangping area was an ocean trough during Changxing age of Late Permian-Early Indo-Chinese epoch in Early Triassic

and was called "Kaijiang-Liangping ocean trough".The understanding and definition of the sedimentary framework in this area are directly related with exploration deployment in the northeastern part of Sichuan basin.Based on sedimentological study and the new understan-(dings) obtained from drilling and seismic data

it is demonstrated

in respects of tectonic setting and the concept and sedimentation of ocean trough

that Kaijiang-Liangping area was not an ocean trough during Changxing age of Late Permian-early Early Triassic

but a platform-shelf with relatively deep water within a carbonate platform

and the sediment was dominated by micrite with some high energy shoal deposits.