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海螺沟冰川地处温暖湿润的海洋环境,冰川运动速度较快,冰川底部接近压融点,存在丰富的冰川融水.冰川底部有丰富的碎屑,为冰川磨蚀提供了有效“研磨工具”.偏光显微镜下观察冰蚀基岩面矿物变形破裂特点,揭示长石、石英、角闪石和黑云母不同程度存在变形、破裂和化学蚀变.受矿物晶格特性制约,黑云母发生弯曲变形较普遍,弯曲方向多与冰川流向一致,少量角闪石也出现弯曲变形;石英和长石多见高角度张性破裂和低角度压剪破裂,个别矿物被完全压碎(糜棱岩化),显示出其刚性特点.冰川底部的磨蚀、拔蚀、冰下流水作用和冰下溶蚀作用在微观尺度上都得到证实.矿物的变形、破碎是冰川底部侵蚀的基本机制,海螺沟冰川单次磨蚀厚度在30～90μm,统计平均50μm,主要产生粉砂粒级碎屑.基岩表面矿物变形破碎程度向下迅速降低.推算本地的冰川侵蚀速率约2.2～11.4mm/a,与其他海洋性山岳冰川侵蚀速率较一致,小于阿拉斯加大规模山麓冰川的侵蚀速率(10～30mm/a),大于大陆性冰川的侵蚀速率(0.1～1.0mm/a).冰川类型、冰川规模是影响侵蚀速率大小的主要因素.
Hailuogou glacier is located in a warm and humid sea environment, glacier movement faster, the bottom of the glacier close to the melting point, there is abundant glacial melt .Black bottom rich debris, glacier abrasion provides an effective “grinding tool” Under the polarized light microscope, the mineral deformation and fracture of glacier basement rock surface were observed to reveal the existence of deformation, rupture and chemical alteration of feldspar, quartz, amphibole and biotite to varying extents.Compared with the characteristics of mineral lattice, the biodegradation of biotite Generally, the bending direction is more consistent with the glacier flow. A small amount of hornblende also appears bending deformation. High-frequency tensile fracture and low-angle pressure-shear fracture occur frequently in quartz and feldspar. Some individual minerals are completely crushed (mylonitization) Showing the rigid characteristics of the glacier.The glacier bottom erosion, ablation, water flow under the ice and the dissolution of ice have been confirmed at the microscopic scale.Metal deformation, crushing is the basic mechanism of glacial bottom erosion, Hailuogou glacier single abrasion The thickness of 30 ~ 90μm, with an average of 50μm, mainly produces silt-level debris.The degree of mineral deformation and crushing of bedrock surface rapidly decreases downward.It is estimated that the local glacier erosion rate is about 2.2 ~ 1 1.4mm / a, which is consistent with the erosion rates of glaciers in other marine mountains, less than the glacier erosion rate of large foothills in Alaska (10 ~ 30mm / a), which is greater than the erosion rate of continental glaciers (0.1 ~ 1.0mm / a) Type, glacier size is the main factor affecting the erosion rate.