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通过采集双河洞国家地质公园的山王洞洞穴冲积物,利用Mastersizer 2000对40个沉积物样品的粒度进行测试分析并计算平均粒径(Mz)、标准偏差(σI)、偏度(SK I)和峰度(K G)等相关参数。结果表明:(1)山王洞地下古河道沉积物优势粒级以粉砂、黏土为主,其含量占总体水平的70%以上,整个冲积剖面表现为2套(9-1号与40~31号样品)由粗到细变化的砂体相互叠置和1套(30-10号样品)粒级含量相对稳定且粒级较小的砂体构成;(2)山王洞冲积物分选性差,具有河成沉积物的特点,冲积物粒径大小表明可能存在两个降雨量较大阶段和一个降雨量较小阶段;(3)沉积物颗粒较地表河沉积粒度细且分布集中,悬浮总体的累积百分含量高,反映洞穴古河道河流总体水位稳定或水动力较弱,可能与洞穴流域范围内地表植被好,地表侵蚀不严重有关。
By collecting the alluvial deposits of Shanwang Cave in Shuanghe Cave National Geological Park, the particle size of 40 sediment samples was tested by Mastersizer 2000 and the average particle size (Mz), standard deviation (σI), skewness (SKI) And kurtosis (KG) and other related parameters. The results show that: (1) The dominant grain size of sediments in Shawangwang underground channel is dominated by silt and clay, accounting for more than 70% of the overall level. The whole alluvial profile shows 2 sets (9-1 and 40-31 ) Samples were composed of coarse to fine sand bodies superimposed on each other and 1 set of sandstones (grain size 30-10) with relatively stable grain size and smaller grain size. (2) Shanwang cave alluviality was poorly sorted, With the characteristics of river sediments. The size of alluvial sediments indicates that there may be two periods of heavy rainfall and a small rainfall. (3) Sediment particles are thinner and more concentrated than surface river sediments, The accumulative percentage is high, reflecting that the overall water level of ancient river courses in caves is stable or the hydrodynamic force is weak, which may be related to the good vegetation on the surface of the caves and the non-serious surface erosion.