WU Ke-hua¹, LI Po^1,2, HE Wei^1,2, YANG Bo¹, LV Wen-qiang¹, GAO Jian-fei¹

(1. Institute of Mountain Resources, Guizhou Academy of Sciences, Guiyang 550001,China;
2. Guizhou Provincial Association of Caves, Guiyang 550001 ,China)

Abstract：Through sampling alluvium from the Shanwang Cave in the Shuanghe Cave National Geopark，testing the grain size of 40 samples by Mastersizer 2000 and counting Mz, σI, SKI , KG , etc, we found that: (1)silt and clay are the dominant grain fractions of sediments in the Shanwang Cave ancient underground channel, whose content level is over 70%. The alluvium section is composed of two series of  sand whose size varies from big to small (samples from 9th to 1th and 40th to 31th )and one series whose size is small and the grain size level is uniform (samples from 30th to 10th); (2)the size classification level is low, whose characteristics are similar to river deposition and the progress of deposition possibly has two stages of strong rainfall and one stage of weak rainfall; (3)the grain size is smaller and the concentrated distribution is compared with the grain size of river deposition, and the suspension component level of deposition is high, which makes it clear that the water level of cave river is steady or shows a weakly hydrodynamic force, the ground vegetation is better and soil erosion is weak in the watershed range as well.

Key words： cave alluvium; grain size; Shuanghe Cave; Guizhou Province

EARTH AND ENVIRONMENT Vol. 42, No.2, Tot No.298, 2014, Page 138-144