VANCOUVER, April 7, 2013 /PRNewswire/ - China Gold International Resources Corp. Ltd. (TSX: CGG; HKEx: 2099) (the "Company" or "China Gold International Resources") reports that on April 5, 2013, Beijing time, the commanding center for the rescue team for the landslide occurred in Ze Ri Mountain, Pu Lang Valley, Si Bu Village, Zha Xi Gang Town, Mozhugongka County, Lhasa City, Tibet Autonomous Region of the People's Republic of China (the "Site") released conclusions on the causes of March 29, 2013 landslide in Tibet. The commanding center for the rescue team is led by the Government of the Tibet Autonomous Region of the People's Republic of China. The conclusions are based on an investigation led by research fellow, Prof. Cen Jiafa from the Consulting and Research Center of The Ministry of Land and Resources of China.
According to the conclusions, the super-large landslide and debris avalanche was a geological disaster caused by a combination of driving factors, which are: steep surface, broken rock, and meltwater.
Four reasons were named in the conclusions to explain the causes of the landslide:
- First, the landslide originated from the knick point of V-shaped Pu Lang Valley, where the slope, angled at 42-45°, is quite precipitous and the flow channel is long and narrow. The crown of the landslide is positioned at 5,359 meters and the toe is at 4,535 meters above sea level, forming a drop of 824 meters.
- Second, complicated geological structures such as thrusting and sliding structures were developed in the region, featuring a very active Quaternary tectonism. Rock exposures in the region include several stages of igneous rocks as well as sedimentary rocks. Surface sediment on the mountain is mainly debris and cobbles, and thus, the mountain was named "Ze Ri", which means "the mountain of broken rocks" in local language.
- Third, the region experienced a fairly dry season from November 2012 to February 2013; whereas since March 2013, it has seen repeated snowing. Meltwater seepage into ground has weakened the geotechnical competence of the mountain side.
- Fourth, loss of competence in the clastic eluvial sediments at the crown triggered the landslide, wherein the loose sediments at the foot were pushed to slip, thus causing the whole disaster.