In discussions on loess, two types are often demarcated: glacial loess and desert loess. The origin of the idea of desert loess appears to lie with V.A. Obruchev who observed wind-carried silt on the Potanin expedition to Central Asia in 1895. It might be considered that desert loess would be defined as loess associated with deserts but it came to be thought of as loess produced in deserts. This led to some controversy as no mechanism for producing silt particles in deserts was readily available. Bruce Butler in Australia in particular cast doubt on the existence of desert-made loess.
