Geology of Pelagat, Besut, Terengganu and petrology of plutonic rock in Kg. Sungai Rual, Jeli, Kelantan

Pelagat is one of the sub-district in Besut District. Besut District is located in the North of Terengganu and Pelagat is the northest part of Besut which bordered Terengganu and Kelantan. The study area is covered 25km2 with the dimension area of 5km x 5km from latitudes of 5° 44' 0.4” N to 5° 41' 17.5” N and longitudes of 102° 25' 27.7” E to 102° 28' 10.3” E. There are three main types of rock in this area; igneous, sedimentary and metamorphic rocks. The igneous rock consists of granite, sedimentary rock consists of sandstone while metamorphic rock consists of slate. A geological mapping fieldwork was carried out inside the study area to determine the lithology and structures according to their geological characteristics. A geological map with cross section was produced by using ArcMap. This study also presented stratigraphy, geomorphology, structural geology and historical geology of Pelagat area. Based on geomorphological analysis, from elevation aspect Pelagat area consisted of lowland (below 180m) and highland (above 180m). The highest elevation is 580m (Bukit Yong) and the lowest elevation is 0m from sea level. There are two types of drainage pattern which are dendritic and parallel. Most part of the lowland area are highly weathered due to human activity (quarry and plantation). Based on structural analysis, the lineament is trending N-S (Positive lineament) and NW-SE (Negative Lineament). There one major faults with direct from Northeast to Southwest. Based on historical geology, the deposition of shale and sandstone in Pelagat occur during Late Carboniferous. Then granite intruded the sedimentary layer during Triassic. The contact area between granite and sedimentary layer (shale and sandstone) metamorphosed into slate. And finally, the continental deposition of cross-bedded sandstone occurs during Jurassic-Cretaceous. For specification, petrology analysis of plutonic rock is done in Kg. Sungai Rual. Petrology analysis is divided into two section which is petrographic analysis and geochemistry analysis. In petrographic analysis point counting and QAP classification is done to thin section of rock sample. While in geochemistry analysis, four graph was plotted which are TAS classification, AFM diagram, ACNK and R1-R2 geotectonic discrimination.