Geology and petrography of volcanic rock at KESEDAR Lebir, Gua Musang, Kelantan

This study was about the geology and petrography of volcanic rocks in KESEDAR Lebir of Gua Musang district in south Kelantan with coordinate of latitude ranges from 4° 59' 9.6" N to 5° 1' 52.6" N and longitude from 102° 18' 42.1" E to 102° 23' 1.56" E. The purpose of this research was to produce a geological map of the study area, studying the petrography of volcanic rocks and determine the type of pyroclastic deposits based on the structure present on rock outcrop. Field observation and mapping at the study area were done. Rock samples were collected for laboratory studies. The study area was made up of Upper Carboniferous to Lower Triassic Ming formation as the oldest rock formation with rock of interbedded sandstone, siltstone and mudstone with subordinate carbonaceous mudstone and overlaid by younger Upper Triassic to Jurassic Koh Formation with rhyolitic to dacitic volcanic and pyroclastic rocks. Lithic arenite and mudstone were identified from petrographic studies of sedimentary rocks. Types of volcanic rocks and its formation sequences were found. Rhyolitic to dacitic volcanic lava flow was formed first by pyroclastic surge, followed by dacite and finally overlaid by pyroclastic rocks including coarse ash and pyroclastic breccia. The results from this study can contribute to the knowledge of geology on that area and as reference for future researchers.