论文部分内容阅读
云南大理点苍山是大理冰期的命名地,保存有确切的末次冰期冰川作用遗迹.对点苍山冰碛物石英砂进行了扫描电镜形态特征分析,获得了其石英砂形态特征及其频率,并在冰川成因的典型特征的频率上取得了新的认识.扫描电镜分析表明,点苍山冰碛物石英砂形态特征主要为:石英砂形状主要为次棱角状、尖棱角状和多棱角状,边缘多可见次棱脊和棱脊磨损,表面起伏度高;机械特征主要有贝壳状断口、平行解理面、裂隙、粘附碎片、擦痕、机械V形坑;化学特征主要有蚀坑和蚀缝、蜂窝状溶蚀表面、无定形硅沉淀和硅质薄膜.在石英砂表面与冰川作用密切相关的擦痕的频率为8%~32%;粘附碎片的频率为16%~40%;裂隙的频率为12%~32%.通过对点苍山冰碛物的石英砂扫描电镜分析,得出该第四纪海洋性冰斗冰川和悬冰川的石英砂形态特征及其频率.该冰碛物石英砂原始形态特征明显,机械特征频率不高,是近源堆积的冰碛物石英砂的典型形态特征.
Dian Cangshan, Dali, Yunnan, is named after the Dali ice period, and has preserved the exact glacial relics during the last glacial period. The morphological characteristics of the quartz sand of the Cangshan moraine were analyzed by scanning electron microscopy, and its morphology and frequency of quartz sand were obtained. The frequency of the typical features of glacial origin has gained a new understanding.The scanning electron microscopy analysis shows that the morphology of the quartz sand in Dian Cangshan moraine is mainly composed of subgranular, sharp angular and polygonal angular, It can be seen that the secondary ridges and ridges are worn and the surface undulation is high. The mechanical characteristics include shell-like fractures, parallel cleavage planes, fissures, adherent debris, scratches and mechanical V-shaped pits. The main chemical features are pits and etched , Honeycomb dissolution surface, amorphous silicon precipitation and siliceous film.The frequency of scratches closely related to glacier action on quartz sand surface is 8% -32%, the frequency of adhesion fragments is 16% -40% The frequency is 12% ~ 32% .Through the scanning electron microscope analysis of the quartz sand in the Dian Cangshan glacier, the quartz sand morphological characteristics and frequency of the Quaternary glacial ice bucket glacier and suspended glacier are obtained. The moraine quartz Sand original morphological characteristics Significantly, the mechanical characteristic frequency is not high, the typical morphological characteristics proximal tills deposited quartz sand.