Yardangs and Dome Dunes of Mongolia's Gobi

Kate Ritley

Whitman College, Walla Walla, Washington

    Northeast of Tavan Har is a five square kilometer area characterized by yardangs, dome dunes, and other eolian features. The yardangs are eroded from Upper Cretaceous, cross-bedded muddy sands, and nearly all are oriented along a northwest-southeast axis, with a tall, steep northwest side and a gently sloping southeast side. Adjacent dome dunes contain beds dipping in all directions. In this sand sea the dome dunes are transitional to other types of dunes: longitudinal dune characteristics include a long axis in a northwest-southeast direction, and slip faces have characteristics of both transverse and barchan dunes in different places. Other wind-related landforms include: vegetated sand mounds, which appear to be positive-feedback features; vegetation-anchored sand pedestals; and inactive, semi-consolidated dunes currently being eroded. In total the eolian landforms indicate prevailing winds from the northwest and variable winds from all directions.