Bulletin of the Geological Society of Malaysia, Volume 51, June 2005, pp. 7 – 12
School of Science and Technology, Universiti Malaysia Sabah, Locked bag No. 2073, 88999 Kota Kinabalu, Sabah, Malaysia
Abstract: Lake Linumunsut in central Sabah is a drowned river valley caused by landslide debris damming one of Namatoi River tributaries. The lake sits on mudstone layers of Kapilit Formation deposited about 12-15 million years ago. The morphology of the lake has changed slightly over the last 30 years due to siltation. The lake is filled with mud and very fine grained sands up to 3 meters thick eroded from the mudstone and thin sandstone in the catchments area. The lake will not be completely filled up with sediments in the near future as the unsettled mud is easily flushed out from the lake during heavy rain. However the morphology of the lake will change drastically once stream down cutting along Linumunsut River reach the bottom of the lake.
Keywords: Lake Linumunsut, drowned valley, landslide, siltation and stream erosion