Sedimentology, Facies Analysis and Geoheritage Sites of the Kudat Formation (Oligocene - Early Miocene) in Kudat Peninsula, Sabah, NW Borneo.

This paper reports the detailed facies analysis carried out on the Kudat Formation (Oligocene – Early Miocene), NW Borneo exposed around the Kudat Peninsula, Sabah, comprising of the basement rock (Chert-Spilite Formation), sedimentary and igneous rocks. The Kudat Peninsula, situated at the northern part of Sabah, has undergone several episodes of uplift and deformation, during Late Cretaceous to Early Eocene. For the sedimentary formation, ten simplified lithofacies are identified; parallel laminated sandstone, trough cross laminated sst, parallel laminated sandstone and rippled top, coarse pebbly sandstone, massive sandstone, amalgamated sandstone, thin rippled sandstone interbedded with mudstone, parallel and wavy laminated sandstone, parallel laminated sandstone with carbonaceous laminae and parallel laminated mudstone; with the contact of the bedding is either sharp, gradational, irregular or erosive base. Three facies assemblages are recognized, there are tide-influenced facies successions, wave-influenced facies successions and deep marine-influenced facies successions. Tide-influence facies successions show coarsening upward with a low abundance and low diversity trace fossil assemblages. Wave-influenced facies successions signify a prograding wave-influenced shoreline with coarsening upward trends. Deep marine-influenced facies successions display thick sequence of sandstone, predominantly massive to amalgamated sandstone. The distribution of facies assemblages and analysis suggests a shallowing phase due to the sequences of the deep marine, shallow marine and marginal marine environments during late Early Miocene/early Middle Miocene uplift and deformation. One of the localities, Tanjung Simpang Mengayau, has the main fascinated place to visit in Kudat Peninsula with its coastal landforms like tafoni and caves. These landscapes which show a good geological features will cultivate visitors to appreciate our nature even more thus to preserve our valuable treasures for future generations.

Keywords—Sedimentology, facies, Kudat Formation, Sabah.