【摘要】 马衔山南麓混杂堆积物的石英砂扫描电镜观察揭示,颗粒表面有密集分布的贝壳状断口、“V”形坑、断块等,且有不规则的棱角状外形,部分颗粒出现擦痕和水下磨光面,表面化学溶蚀和沉淀析出现象不发育,属泥石流成因,反映温暖干凉的沉积环境。更多还原

【Abstract】 The examination of grain surfaces of quartz from the Maxian Mountain by a scanning electronic microscope reveal distinct and different groups of surface features. These quartz sand grains are characterized primarily by conchoidal fractures which are densely distributed and interposed with each other, mechanical V shaped pits, blocky fractures and irregular appearance with sharp edges. The Diaphragm like impact pit is a rather representative surfact feature in the debris flow environment. In addition, large striae and subaqueous polished surfaces were also observed on the part quartz grains. However, chemical solution precipitation features were seldom on the sand grain surface. These coincide with the warm cool paleoenvironment in this area.The classification of the quartz sand grain surface features proposed by D.H. Krinsley was applied to the analysis and statistics of surface features of each sand grain. And after comparing the statistical data with D.H.Krisley’s, the suthors arrive at the same conclusion as those of the former analysis, i.e. this group of mixed accumulation is virtually the result of debrisflows not that of glaciation.更多还原