Nabkha (coppice dune) fields of south-central New Mexico, USA

A nabkha (coppice dune) plain covers 4500 km(2) of southern New Mexico, U.S.A. The nabkhas occur in arcuate fields extending 1-6.5 km downwind of source areas that are commonly prominent topographic depressions. Down-wind, the nabkha fields merge into vegetated sand sheets. Mean grain size and dune height decrease downwind across a studied nabkha field indicating sediment deposition within 1-2 km of the sources. Mesquite nabkhas are important because they replace grasses during desertification in North America. Because the nabkha fields include sediment deposition as well as erosion, these nabkha fields may exist for longer than previously studied examples in Africa. (C) 2000 Academic Press.