Study On Granulometric Characteristics Of The Sand Material On Typical Haloxylon Ammodendron Nebkha In The Ebinur Lake Region, Xinjiang

Nebkha is a common kind of biological wind deposition geomorphy in arid and semi-humid desert, and sandy coast. The dunes are extensively distributed in China, but little attention is put to it. This paper chooses Ebinur lake valley as research area,according to the analysis to the sediment grain-size samples collected from the surface of typical Haloxylon ammodendron Nebkha and the field investigate,mainly elaborates the granulometric characteristics of the sediment grain-size samples and their environmental information. The main conclusions can be summarized as follows:(1)The main mechanical sediments components of Haloxylon ammodendron Nebkha is sand with the average content over 90.34% in Ebinur lake region, while little 8.59% silt approximately, and very little in clay (1.06%) content. The particle size distributes in 0.45μm~1124.68μm,is mainly consists of fine sand (34.50%) , medium sand (29.23%) and very fine sand (17.32%).(2)The medium grain sizes of sandy materials are distributed in the range of 1.42φ-3.19φ, the average is 2.27φ. The values are all single value, distributed in the range of 0.91φ-2.90φ, the average is 1.90φ. The average particle sizes are distributed in 1.56Φ-3.42Φ, the average is 2.35Φ.The sorted coefficients are within the scope of 0.76Φ-1.42Φ, the average is 1.20Φ.The sorting of sandy materials are very poorly. The distribution range of Skewness is 0.70Φ-10.49Φ, the average is 6.53Φ.It is of very fine skewed. The distribution range of Kurtosis is 1.06Φ-3.65Φ,the average is 2.44Φ.It is of very Leptokurtic.(3)The mechanical sediment component of Haloxylon ammodendron Nebkha change regularly on different parts. The coarse sand composition components (sand) increase from the windward base of slope,became the maximum on the middle slope, then decrease constantly ,became the minimum on the middle leeward slope through the slope tip, finally,increase slightly to the leeward base of slope. But, the change regularity of the fine sand composition components (silt and clay) and the grain size parameters is the opposite.(4)They are of positive correlationship arbitrary between each of average particle sizes, sorted coefficient,skewness and kurtosis. The total degree of correlation are higher. It is higher positive correlationship that sorted coefficient and kurtosis(R=0.9638), sorted coefficient and skewness(R=0.9291), skewness and kurtosis(R=0.8216). It is obvious positive correlationship that average particle sizes and skewness(R=0.6088), average particle sizes and sorted coefficient(R=0.5049). It is lower positive correlationship that average particle sizes and kurtosis(R=0.3391).The average particle sizes are bigger(finer), while the sortings are more poorly,the skewnesses are more fine skewed, the kurtosises are more leptokurtic.(5)According to the stuty on granulometric characteristics of the sediment grain-size samples, it is found that the grain-size composition, grain-size parameter, grain-size frequency distribution curve, accumulated probability curve and the scatter plots of grain size parameters include many environmental information. The discriminant analysis results (Y) have more clear environmental indication significance about discrimination and confirmation of the sedimentary environment in some region.