关键词: 沙粒胶结体, 粒度参数, 形成环境

Abstract: The particles were gained by the dissolution and dispersion of sand cemented bodies (SCB) collected from the Taklimakan desert, and then the Laser Particle Characterization System was conducted to get the characteristic parameters of the particles. In order to analyze the grain-size characteristics of the SCB, the SCB particle characteristic parameters were compared with the sand particles from the local dunes, the inter-dune corridors and the transport sands. The results indicate that: (1) The grain-size distribution curve of the SCB is muti-peaked, both the dunes and the transport sands are single-peaked and the inter-dune corridors is double-peaked; (2) The sorting of the SCB particles is poor, the distribution is positive skewness, and the average particle size (3.17 Φ) is between the size of the dune sands (2.10 Φ) and the inter-dune corridor sands (3.28 Φ) or the transport sands (3.67 Φ); (3) The SCB mainly consists of fine sand and silver sand. Compared with the dune sands, the inter-dune corridors sands and the transport sands, the SCB are enriched in silty sand, clay and medium sand relatively. In conclusion, the SCB is a mixture product of the modern desert on surface. (4) Compared with the dune sands, inter-dune corridor sands and the transport sands, the diameter of SCB creep-saltation and saltation-suspension particles tend to be fine, and the creep moving component proportion is very high. Therefore, from the perspective of the grain-size of the material compositions, the formation of the SCB is affected by the common local sands and the wind power, it is a product formed on the modern land surface influenced by special environment conditions.

Key words: sand cemented bodies, grain-size parameters, formation environment