Cavernous Weathering in Aeolian Sandstones: An Example from the Yongningshan Hill of the Loess Plateau, Northwest China

Abstract

Cavernous weathering is commonly found on sandstone slopes in different environments. Either a single dominant process or polygenetic agents require to be invoked in order to interpret the development. The Yongningshan hill of the central Loess Plateau is representative of cliff dwellings in Northwest China, which is characterized by welldeveloped cavernous weathering features and provides a good opportunity for the better understanding of sandstone weathering in the Loess Plateau. Multiple methods, including field survey, in-situ rock strength measurement, along with experiments on samples for microscopic observation, element composition and salt chemistry, were employed to investigate the controlling factors of cavernous weathering. The results show that cavern development is different on the four slopes with the western slope hosting massive honeycombs, tafoni and hardened surfaces. The porous and permeable aeolian sandstones are fundamental, because they provide space and pathways for the transportation of water and salt, honeycombs dominantly aligning within the lamination of cross-beds. The environmental factors such as the seasonal wetting and drying cycle, aeolian salt, moisture and water vapor are key factors for the development of cavernous weathering forms. The northern and northwestern wind-blown dust storms have brought abundant salts, the lengthier dry periods of the wetting and drying cycle being beneficial for salt accumulation within caverns, favoring salt weathering.

Leachate Lithium Characteristics of Loess‐paleosol Sequences on the Chinese Loess Plateau and their Paleoclimatic Significance

“…Chinese loess deposits are an important source of paleoclimatic information for global change researchcomparable to that provided by marine sediments and ice cores-because of their wide distribution, continuous deposition, and rich archive of environmental information (Liu et al, 1986;Kukla and An, 1989;Kemp, 2001). Numerous studies have been conducted on the paleoclimatic and paleoenvironmental record of the loess deposits of the Chinese Loess Plateau (CLP) since ~2.6 Ma, using physical, chemical, and biological proxies (An et al, 1991;Ding et al, 1993;Gallet et al, 1996;Qiang et al, 2011;Chen et al, 2022;Chevalier et al, 2022).…”