Bouldery mud flow deposit at Ranau, Sabah, East Malaysia

Author : T. K. Leong
Publication : Bulletin of the Geological Society of Malaysia
Page : 139-146
Volume Number : 3
Year : 1970

Bulletin of the Geological Society of Malaysia, Volume 3, March 1970, pp. 139 – 146

Bouldery Mudflow Deposit at Ranau, Sabah, East Malaysia


University of Malaya


Abstract: A Quaternary diamicton covering an area of at least 4 sq km occurs around and northwest of Ranau, Sabah. The deposit consists of large round boulders of adamellite and cobbles and fragments of sedimentary rock in a muddy matrix. The largest boulder in the deposit measures approximately 20x10x10 meters and is estimated to weigh not less than 4,700,000 kg.

Absence of sorting, lack of lateral gradation in size of clasts, the great size of the boulders, and field relationships indicate that this is a mudflow deposit. The mudflow probably originated in the Pinosuk Plateau where rock debris of a similar composition is present. The deposit in Ranau represents the most easterly extension of the mudflow.