Clay mineral assemblages in Shihezi Formation of Huaibei coal-bearing strata are determined by X-ray diffraction and Differential Thermal Analyzer, that is restated to the sediment faces and climatic changes in the so...Clay mineral assemblages in Shihezi Formation of Huaibei coal-bearing strata are determined by X-ray diffraction and Differential Thermal Analyzer, that is restated to the sediment faces and climatic changes in the source area, and to a lesser extent, alterations during burial diagenesis. In the Upper Shihezi Formation, the clay fraction is dominated by kaolinite in northern part of the coal field, which was formed in alluvial sediment environment. But in the South of Huaibei coal field, the clay mineral assemblage consists of mainly illite that reflects the influence of sea water. The predominately kaolinite and sederite composition of the clay fraction in the lower Shihezi Formation sediments documents less relief and gentle erosion of kaolinite rich soils developing under warm source area. In the lower part of Shihezi Formation, some chlorite is detected, which suggests transformation of illite or kaolinite to chlorite under conditions of burial diagenesis.展开更多
文摘Clay mineral assemblages in Shihezi Formation of Huaibei coal-bearing strata are determined by X-ray diffraction and Differential Thermal Analyzer, that is restated to the sediment faces and climatic changes in the source area, and to a lesser extent, alterations during burial diagenesis. In the Upper Shihezi Formation, the clay fraction is dominated by kaolinite in northern part of the coal field, which was formed in alluvial sediment environment. But in the South of Huaibei coal field, the clay mineral assemblage consists of mainly illite that reflects the influence of sea water. The predominately kaolinite and sederite composition of the clay fraction in the lower Shihezi Formation sediments documents less relief and gentle erosion of kaolinite rich soils developing under warm source area. In the lower part of Shihezi Formation, some chlorite is detected, which suggests transformation of illite or kaolinite to chlorite under conditions of burial diagenesis.