#TITLE_ALTERNATIVE#

• Main Author: SIDNEY ERRIYANTORO (NIM 12006010), EROS
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13440
• Institution: Institut Teknologi Bandung

This study is conducted through petrography and modal composition analysis, using point-counting-method following Gazzi-Dickinson. The calculated modal composition is then plotted in Q-F-L, Qm-F-Lt, and Qp-Lv-Ls diagrams. The Kantu Fm. Sandstones is divided into Sandstone Unit (lower Late Eocene), and Sandtone – Claystone Unit (upper Late Eocene) based on its lithology characteristic. The Kantu Fm. sandstones are very fine to medium sand grain (0,0625 – 0,4 mm), consisting of quartz (35 - 50%), feldspar (3 – 6%), mica (4 – 8%), lithic fragments (18 – 28%), opaque material (1 – 3%), with matrix (7 – 17%), and cement (4 – 7%) present between grains. Zircon, epidot, and tourmaline (up to 1% in total) and carbon (5 – 8%) are occasionally present. Kantu Fm. sandstones are classified as sublitharenite, lithic greywacke, dan litharenite. Based on petrographic analysis and modal composition plotting in the diagrams, the main source of the Kantu Fm. sandstones is most likely the Kapuas Complex / Lubok Antu Melange (Late Jurassic – Early Cretaceous) and Rajang Group (Early Cretaceous – Middle Eocene) which located north – northeast of Ketungau Basin. The Kapuas Complex and Rajang Group was deformed and uplifted on Middle Eocene – Late Eocene during Sarawak Orogeny.