Parent Material: They occur on land surfaces of Pleistocene or greater age, therefore, they occur on parent material such as crystalline rocks. Aridisols do develop on fluvial and eolian materials, extensively in large deserts such as the Gobi, Namib, or Kalahari desert. Aridisols occur on gypsiferous material formed from marine sedimentary rocks, on unconsolidated sediments, or limestone.