Fig. 1: Schematic illustration of the geomorphologic development of the Hami Basin.

a Map of the Hami-Turpan depression, with major cities labeled. The red dotted line encircles the stony desert described by the schematic. Blue solid line indicates area of dune field. Inset displays physical map of East Asia. Red square represents the region shown on the larger map. Black and yellow lines mark the approximate extent of the Tarim Basin and Hexi Corridor, respectively. b Depositional phase of Neogene sediments. Conglomerate facies were likely derived from alluvial fans, while finer-grained siltstones and mudstones originated from playa deposition. c, d Regional climate system and landscape present during initial aridification of the Hami Basin, likely in the late Miocene or Pliocene. d The lighter-colored finer-grained playa deposits are easily wind-deflated, meaning more dust emissions. c However, northerly winds moving across the depression were likely weaker than present, due to a smaller mountain-basin temperature gradient from higher albedo of the low-lying basin. e, f Present-day version of the Hami landscape and climate. f Vast areas of dark-colored, coarse-grained topographically tiered, eolian-modified gravel surfaces, exposed by wind deflation of finer particles, maintain low albedo. e The lower albedo increases surface temperature of the depression relative to (c, d) and creates a higher temperature gradient, leading to higher surface wind speeds. Modified from ref. ³⁰. Figure 1a made with GeoMapApp (www.geomapapp.org)/CC BY/CC BY⁶⁹ and using Google Earth—US Department of State Geographer, ©2018 Google, Image Landsat/Copernicus.