Mega-Yardangs: A Global Analysis

Abstract

Yardangs, analogues of which occur on Mars and possibly on Venus, are wind moulded landforms that develop in the world's drylands. Mega-yardangs (wind-abraded, ridge, and swale features of regional extent) are easily identified on satellite images and these have been employed to map their global distribution. Areas where they are present include Central Asia, the Lut Desert of Iran, northern Saudi Arabia, Bahrain, the Libyan Desert in Egypt, the central Sahara, the Namib Desert, the high Andes and the Peruvian Desert. These features develop in a wide range of rock types, including sandstones, ignimbrites, limestones and basement rocks, occur in hyper-arid areas, form where winds tend to be unimodal in direction, are best developed in areas of sand transport rather than sand accumulation, and occur in plains rather than in mountainous areas.