Quantifying Late Pleistocene to Holocene Erosion Rates in the Hami Basin, China: Insights Into Pleistocene Dust Dynamics of an East Asian Stony Desert

Abstract

Wind is one of the major processes modifying the land surface in the Hami Basin, as evidenced by wind deflation gravel lags, yardangs, and gravel mantled eolian ripples. We report erosion rates for the Hami Basin using cosmogenic 10Be measurements. Bedrock erosion rates average 0.121 ± 0.0293 mm yr−1, which is similar to those of other wind-eroded arid basins in East Asia, but is anomalously low when modern near-surface wind speeds are considered. We posit that interglacial periods experienced lower erosion rates than glacial periods, and that the Hami Basin was likely once a larger dust producer than at present, with Pleistocene dust emissions driven by the eolian deflation of alluvial terrace deposits as well as bedrock weathering and abrasion. Wind erosion and dust production in the Hami Basin was largely regulated by the synoptically controlled spatial-temporal distribution of precipitation and subsequent landscape evolution since at least the late Pleistocene.