冰蚀三角脊链的发现及其在地貌演化研究中的意义

Discovery of glacial triangle ridge chains and its significance in geomorphologic interpretation

我国东部中低山区是否存在第四纪冰川作用一直存在争论。冰川作用使山体遗留冰蚀遗迹,通过研究冰蚀遗迹可进一步分析山体地貌的演化过程,辨识是否存在冰川作用。利用卫星遥感技术大视域俯视观察山体地貌,可突破地面视野对山体地貌观察的局限性,为冰蚀地貌结构研究提供技术支撑。喜马拉雅山广泛发育现代冰川,冰蚀地貌清晰且典型。通过研究喜马拉雅山脉冰蚀地貌结构,发现了冰蚀三角脊链,揭示了山体冰斗集群发育过程及规律。根据冰斗系统剥蚀推进方向,分辨出对蚀三角脊链、斜蚀三角脊链与追蚀三角脊链3种基本组合形态。冰蚀三角脊链是冰蚀作用的结构性遗迹,我国东部中低山区广泛发育冰蚀三角脊链,进一步佐证我国东部地区曾广泛发育第四纪冰川。

Whether Quaternary glaciation exists in the middle and low mountains of eastern China has been debated for a century.Because glacial landforms are formed by glaciation,further studying on the mountain glacial erosion relics and analyzing on the evolution of geomorphology are significant to identify the existence of glaciation.The satellite remote sensing with a large overlook view breaks the limitation of observation the mountain geomorphology from the ground in the past,and provides the condition to study the structure of glacial erosion geomorphology.Modern glaciers are widespread in the Himalayas with the clear and typical glacial erosion landforms that provide a basis for us to study the ice cirque system.Meanwhile,according to the erosion direction of ice cirque,we distinguish three fundamental combinations such as the symmetrical erosion triangle ridge chains,oblique erosion triangle ridge chains and following erosion triangle ridge chains.Glacial erosion triangle chains are the structural relics of glaciation.Comparative analysis of the mountain landforms in the middle and low mountains of eastern China using the triangle ridge theory,we found glacial erosion triangle ridge chains are widespread in that areas,which proves Quaternary glaciation existing in the eastern China.