Three methods,the trapezoidal rule,the straight lines on log-log plots of area versus thickness and the straight lines on plots of log thickness versus square root of area,of calculating volumes of fallout tephra deposited in Sihai Phase of Jinlongdingzi Volcano of Longgang Volcanic Swarm in Jilin Province are applied in this paper.

The Glacier,the Frozen Soil Landform with Accumulation;

The Analysis of Chemical Compound of Clay Grain in Dabaini Ravine and Chaqing Ravine s Deposits of Dedris Flow;

Based on field investigation and historical data, this article studied characters of deposits in Xibailian Watershed and configuration、 grain composition and changes of relief, act, trying to enrich theories on study of debris flow in Beijing Mountain and provide data to the mitigation of debris flow in Beijing Mountain.

By studying the characteristics of this cave such as the different development subareas, the causes of formation, the karst phenomena, the cave accretion and the environmental variation, it is known that this cave is a full filled reviving karst cave that revives after it had been fully filled by the accretion.

By studying the characteristics of this cave such as the different development subareas, the causes of formation, the karst phenomena, the cave accretion and the environmental variation, it is known that this cave is a full-filled-reviving karst cave that revives after it had been fully filled by the accretion.