Abstract:

The total content of REE(ΣREE)from mudstones of the Eogene Shahejie Forma-tion in Dongpu Depression is relatively high,the average value is 215.34 ppm.Ce is thehighest of the REE group,ΣCe is richer than ΣY and ΣCe/ΣY is also high(2.73 on aver-age).These mudstones yield right declined W-shapped curves with negative Ce and Euanomalies,therefore,their REE distribution patterns are parallel to each other.In addi-tion,the REE parameters(Ce/Ce^①,Eu/Eu^①,Sm/Nd,ΣCe/ΣY,La_N/Sm_N and Ce_N/Yb_N) only vary with in a narrow range with small deviations.This indicates that theywere deposited in a lake basin environment.