Study On The Structural Characteristics And Sedimentary Environment Of Thick Loose Layer In Huainan Mining Area

This paper take some geologic disasters caused by coal mining under the thickloose bed such as water inrush, mud, sand inrush, ground subsidence as theengineering background, take the the thick quaternary sediments of Huainan minearea as the research objiect, systematic analysis the quaternary sedimentcomposition, particle size distribution, particles arrangement of sample, evolutionrule of the sedimentary environment. The research has important theoreticalsignificance and practical value for the safey mining under thick loose bed.Grain-size analysis is the material method in the research of Quaternaryenvironmental research, it has great significance for finding the material of sediment,hydrodynamic condition and sedimentary environment. Grain-size distribution isone of the most important features of sediment, Because of the different transportmedium and intensity, different sedimentary has different grain composition, we canjudge the sedimentary environment through the grain-size analysis. According to thegrain-size analysis, we can know the main of the sample is silt, and include a littlefine sand, the average grain-size concentration between4-5.6, the sorting of most ofthe sample is medium, small part of the sample is good, individual of the sample isbad, we can judge the determine hydrodynamic conditions is changing between theintermediate and high energy, sometimes, the low energy is appeared.X-ray diffraction technology is an important means of the material compositionanalysis, according to the analysis, we can infer the Quaternary paleoclimatecharacteristics. The mainly composition of the clay mineral is illite, small part of thesample’s mainly is kaolinite, so the climate of most of the area is warm or cold littlerain, but in part of the area, in different times, the hot and humid climate is appeared.We could observe microstructure of matter by environmental scanning electronmicroscopy, we can infer the sedimentary environment and evolution historyaccording to the mineral characteristics and residual structure. We can see the shapeof different clay minerals by ESEM, most of the clay minerals has been out of shape,so the clay minerals of this area should be come from transported deposit, and somemineral grains grinding is good, may be because of the water.By the comprehensive analysis of the loose bed structure characteristics and itssedimentary environment, we can know that it is similar of the loose bed structure, but the difference appeared in individual areas. The main sedimentary environmentin this area is beach sedimentary and river sedimentary, the climate in this area isdifferent, most of the climate is warm or cold little rain.