SEDIMENTOLOGY AND GEOCHEMISTRY OF THE SINGA FORMATION SUCCESSION AT TELUK CHEK DENDANG, LANGKAWI

The Upper Devonian – Lower Permian Singa Formation of the Langkawi Island consists of black and dark-grey carbonaceous mudstone and siltstone and interbedded lighter quartzite. A detailed sedimentological study and facies analysis of the Singa Formation at Teluk Chek Dendang, Langkawi was conducted to determine the possible palaeo-depositional environment. Two stratigraphic sections of the Singa Formation were logged at Teluk Chek Dendang and one at Tanjung Malai. The sections were divided into facies based on lithology and sedimentary structures. Five different types of facies are identified: 1) Massive siltstone facies-F1; 2) Finely laminated siltstone facies-F2; 3) Thick laminated mudstone facies-F3; 4) Finely laminated mudstone facies-F4; and 5) Black mudstone facies-F5. The succession encountered in the Singa Formation at Teluk Chek Dendang have been divided into two coarsening upward facies association. The facies association grades upward from an offshore facies association (FA 1) composed of black mudstone and finely laminates mudstone facies, into a lower shoreface facies association (FA 2) composed of finely lamination siltstone and massive siltstone facies. Mineral and micro-sedimentary structures are identified through petrographic analysis. The main constituents of the Singa Formation at Teluk Chek Dendang are clay minerals and silt-grade quartz grains. Micro-sedimentary structures of Singa Formation under polarizing microscope possesses fine lamination between mud and siltstone. Erosional features – scours are seen under thin section with slightly coarser sediment occurs within the scours. The geochemistry analysis also proved the rocks of Singa Formation consists of mainly Quartz (SiO2) and clay minerals. The facies succession is interpreted as coastal depositional environment, specifically the prodelta depositional environment.