CARBON, OXYGEN ISOTOPIC CHARACTERISTIC AND THEIR PALEOENVIRONMENT SIGNIFICANCE FROM QUATERNARY SEDIMENT IN THE TARIM BASIN

Carbon, oxygen isotopic records show that 5 obvious climatic changes gyrateon have taken place in the central Tarim Basin since 3.4MaB.P.. Before 3.16MaB.P., the climate was warm and humid in this area; during 3.16~2.14MaB.P., the climatic environment was relatively warm and humid; during 2.14~1.70MaB.P., the climate changed cold and dry; during 1.7~0.15MaB.P., the climate continued to change cold and dry; during 0.15MaB.P.-today, the climate changed more cold and dry. Since 3.4MaB.P., in around 3.16Ma.B.P., 2.14MaB.P., 1.70MaB.P. and 0.15MaB.P., 4 short warm and humid climatic period ever appeared in this area. On the while, in the central Tarim Basin, paleoclimate change since 3.4MaB.P. has been with the concurrence of the global trend on the scale of million year, on the smaller time scale, however, it has its own obvious regional features.