STRATIGRAPHY AND PALEOSOLS IN THE SALE TERRACE LOESS SECTION, NORTHWESTERN CHINA

Two paleosols in the Sale terrace loess sequence were investigated to determine if radiocarbon ages for each paleosol could assist in reconstructing the Holocene loess succession as well as the paleoenvironmental record. The upper loess, about 3 m in thickness, carries no surface soil and is still being emplaced. The middle loess was emplaced during the middle Holocene, whereas the lower loess was emplaced prior to 7500 yr BP. Relative weathering in the two buried paleosols is approximately the same with minor differences in clay mineral and elemental composition indicating a slightly wetter paleoclimate in the lower unit becoming drier upwards toward the present. Because there is evidence for considerable chemical homogeneity downwards in the section, with some minor leaching of the mobile elements Ca and Na, there is every reason to believe the 14C dates are uncontaminated and represent true ages. © 1990.