Macroscopic interwoven textures and their origin of yardangs in the Qaidam Basin, Northern Qinghai-Tibet Plateau

Abstract

The macroscopic texture characteristics of yardangs can be used for distinguishing the origin of landforms on the Earth’s surface and even on other planetary surfaces. However, few studies have been conducted on them. Generally, yardangs in a region develop one type of texture macroscopically. In this study, we found two textures interwoven on a macro scale in the yardang distribution area in the Qaidam Basin (QB): rectilinear (RL) and arc-shaped (AS). The reason for the development of yardangs into two textures in an area is unclear, and the relationship between them also needs to be elucidated further. Analysis of the regional environment, stratigraphic lithology, and geological structure suggests that the RL texture of yardangs in the study area was also shaped by wind erosion, which is similar to that of the normal yardang texture eroded by a single prevailing wind. However, the folding structures exist widely in the study area, and this causes the outcrops of the wind-eroded strata to be always arc-shaped. The wind-eroded yardangs developed on the AS strata, and are thus arranged along AS outcrops of strata and eventually exhibited an AS texture. The development of the two textures was controlled by different decisive factors, and they developed independently. Conclusively, yardangs tend to be wind-eroded into an RL texture macroscopically under the action of a single prevailing wind, and the anticlinal (synclinal) structures causes the yardangs to be arranged in arc-shaped patterns.