Characteristics of the Subglacially-formed Debris-rich Chemical Deposits and Subglacial Processes of Qiangyong Glacier
西藏枪勇冰川冰下富碎屑化学沉淀特征与冰下过程

Subglacially-formed debris-rich chemical deposits were found both on bedrock surface and in bedrock crevice at the edge of Qiangyong Glacier, one of the continental glaciers in Tibet. Grain size distribution, internal structures and chemical components of the chemical deposits were analyzed. It can be inferred that the temperature of some parts of the ice-bedrock interface is close to melting point and there exists pressure melting water under Qiangyong Glacier. Debris, especially those from continental aerosols, can release Ca++ in the water. At the lee-side of obstacles on glacier bed the CO2 in the melted water might escape from the water and the melted water might refreeze due to the dramatically reduced pressure, making the enrichment and precipitation of CaCO3. The existence of subglacial melting water and the process of regelation under Qiangyong Glacier indicates that sliding could contribute some proportion to the total movement of Qiangyong glacier and it belongs to multiplex cold-temperate glaciers.