Based on the abundant core

logging curves

seismic data

sequence stratigraphy

mineralogy

sedimentology and other research methods

the systematic dissection of shales in the upper and lower member of The Fourth and third member of the Shahejie formation in Dongying Sag was carried out by combining macro and micro analysis. The research results show that: ① The mineral composition of shale in saline lacustrine basin is characterized by rich carbonate

and there are mainly high content carbonate shale facies and calcareous shale facies. ② The deep-water shale sequence of the lacustrine rift basin is characterized by inundation unintegrated sequence. The shale section of the Upper E

s

4

- Lower E

s

3

sub-member in Dongyin

g Sag can be divided into two third-order sequences

four fourth-order sequences （system tracts） and eight fifth-order sequences （parasequence groups）. ③ There is an obvious coupling relationship between shale lithofacies and sequence. The late lacustrine extensional system tract and early high system tract are the favorable stages of high content carbonate shale facies. The research and understanding have certain guiding significance for the division of shale sequence and the prediction of lithofacies distribution in saline lacustrine rift basins.