Sedimentary characteristics and division of Holocene strata in central Inner Mongolia

The Holocene strata of central Inner Mongolia were investigated using sedimentological features and 14C\OSL dating data. The authors present two Holocene profiles that illustrate different sediments from a sand dune in Haoluku, and a lake in Huitengxile. Holocene stratigraphic boundaries are defined by lithological indicators and dating results. The Holocene sequences can be divided into three units. In Huitengxile Lake, the beginning (11.4 ka) of the Holocene was associated with a lake level rise, which led to lithological succession from fluvial clastic sedimentation to lacustrine organic deposition. Sand dune was formed during this period (about 12.5 ka). During the middle Holocene, typical limnological facies (8.2 to 4.5 ka) appeared in Huitengxile Lake, and the climate turned to be warmer and more humid with the occurrence of thick palaeosoil layers (7.0-2.3 ka) in the dune. Evolution of lacustrine environment followed by nearshore environment was evident from 4.5 ka in late Holocene in Huitengxile Lake, and the period (2.3 ka~) of sand dune reactivation during the drought stage was recorded.