Abstract:

The material composition and geochemical characteristics of surface sediments in arid areas are important for revealing the source， formation process and sedimentary environment. The multi-index parameters of particle size and full particle size parameters reveal the differentiation characteristics of the origin， origin and action process of the Hobq Desert sediment in three regions， which were shown as follows： The sediment in the eastern part of the Hobq Desert was thin， with a mean particle size of 0.17 mm， the largest full particle size distribution parameter C （755.66）， the smallest μ and Dc values （-0.36 and 0.010）； The sediment in north branch of the west was middle， the average particle size was 0.30 mm， and the full particle size distribution parameters was 537.91， -0.32 and 0.12， respectively； These two areas have strong sand activity， and sediments are mainly wind sand sediments formed by long-distance transfer of particle suspension and transition， mainly medium-high disturbance and recursive suspension deposition， and sediment components are highly mixed with homology. The sediment component of the south branch of the west was coarse， with an average particle size of 0.29 mm， the smallest full-grain diameter distribution parameter C （289.94）， and the largest μ and Dc values （-0.15 and 0.25）， including some river sediments.

Key words: sediment, grain size, depositional environment, Hobq Desert