Middle Holocene low deposition rate caused by dune stabilization at Duolun nur in Otindag Dune Field

Abstract

Dune fields in the semi-arid area are highly sensitive to the environment and climate change. When the climate is humid, enhanced vegetation cover limits aeolian activity. When the climate is dry and vegetation cover is reduced, the dunes migrate and produce dust. This will significantly affect the dust deposition flux in nearby lakes, which in turn can provide evidence of dune activity. We present the record of Duolun nur (nur means lake) in the northern Otindag dune field since 14 cal ka BP. A striking feature of the record is the very low deposition rate between 1.1 and 7.8 cal ka BP. We attribute it to the decreased dune activity and reduced dust flux. Similar periods of low deposition rates in the mid-Holocene have been also found in other lakes in the Otindag dune field. Although spatial heterogeneity exists in the low deposition rates periods of lake records and the paleosol development periods of dune records, the lake records match well with the dune records in the same location. Our finding provides new evidence of dune activity from the perspective of lacustrine deposition, and this is generally applicable to any dune field with a lake.