Investigators have concluded that melting snow seeping into disintegrating rock caused amassive landslide last week that killed 83 people in a mining area near Lhasa, the
autonomous region.
According to a report released by the rescue headquarters on Friday, steepness of the slope,disintegrating rock and water from snowmelt combined to cause the landslide.
The report was compiled by a team of six experts led by Cen Jiafa, a researcher at a consultingcenter under the Ministry of Land and Resources.
The landslide occurred along a 42 to 45 degree slope in a V-shaped valley.
The report said about 300,000 cubic meters of loose stone and soil triggered the landslide onthe east slope of Zeri Mountain, in Zhaxigang village, Maizhokunggar county.
At about 6 am on March 29, the land gave way and rushed down from an altitude of 5,359meters on the mountainside to 4,535 meters, leaving 2 million cubic meters of debris spreadacross 2 kilometers, according to the report.
Part of the slope was hollowed after the landslide and long cracks in the mountain surface werevisible - the longest was about 600 meters.
The experts said the geological conditions in the area are complicated.
The bare layer of land is made of igneous and sedimentary rocks alternating with each other,and both are disintegrating.
The weather had been extremely dry from November to February. Water from melting snow wasabsorbed into the mountainside and undermined the slope's stability.
The team suggested that monitoring efforts should be improved to prevent further geologicaldisasters.
It also suggested efforts be made to locate and mitigate all similar risks in places includingresidences, construction sites, mining companies and touri spots.
