ROOT CAUSES OF EXTENSIVE MASS MOVEMENTS IN KUNDASANG SABAH

H.D Tjia

Universiti Kebangsaan Malaysia

Root cause 1 : two active regional fault - Mensaban & crocker zones. Trusmadi Formation in the study area consists of old submarine slump deposits associated with Kinabalu Suture. zones within the formation are phyllonitic with the competent clasts deformed as sigmoids, all clearly resulting from shearing

Root cause 2 : The mass movement of Kundasang involve these chaotic deposits that generated ground movements upon exposure and most probably drainage disturbance through accelerated landuse. 

Root cause 3 : The Kinabalu felsic pluton became emplaced in a span of 9 to 4 million years. Plutonic intrusion can be estimated to have occured at 4km or deeper depth. Now the top of pluton reaches 4095m above sea level. This implies that average annual uplift of the pluton has ranged between 0.9 to 2.03mm. It may be safely assume that the Kinabalu intrusive body is still rising as the summit plateau of glacially sculpted surface is disturbed by normal faults with downthrows of more than 10m.