Sedimentary facies and palaeogeography of the Songliao Basin and its peripheral areas during Carboniferous-Permian time

The tremendous oil reserves reside in the deeper parts of the Songliao Basin. The basin, judged from the sedimentary facies and palaeogeography during the Carboniferous to Permian in integration with the well logs and other geophysical data, was located in the littoral and shallow-marine environments during the Carboniferous with the sea water gradually deepening from north to south; neritic-deeper neritic environments during the Early Permian with the sea water gradually deepening from east to west, and continental and/or alternative marine-continental environments during the Late Permian with the sea water gradually deepening from north to south again.