#TITLE_ALTERNATIVE#

• Main Author: IBNU KOESHIDAYATULLAH (NIM 12007040), ARDIANSYAH
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13281
• Institution: Institut Teknologi Bandung

Antu Mountain area and surroundings, has interesting limestone characteristic and representative for limestone facies study. Geographically, it is located in 50 N 705000 – 709000 and E 108000 - 115000, in Tanjung Mangkalihat Village, Kutai Timur Regency, East Kalimantan, 28 km2 (4 km x 7 km) wide. Geomorphology in research area has certain characteristic patterns; mountain, stream, valley and ridge. These patterns are controlled by structure and lithology. The rivers pattern in research area are controlled by fractures in limestone and by the karstification process. There are six geomorphological units in research area : Folded Ridge, Karst Ridge, Antu Mountain Karst Reef Hills, Karst Plain, Monoclinal Valley and Sinkhole Valley units. Stratigraphy in research area is divided into three informal units, there are from the oldest: Early - Middle Miocene Reefal Limestone Unit which is comparable to Tendehantu Formation and dominated by bioclastic limestone. Middle Miocene Calcarenite Limestone Unit which is comparable to Golok Formation with dominated by calcarenite limestone and interbeded calcarenite with marl. Middle-Late Miocene Marl Unit which is comparable Golok Formation consist of marl and interbeded marl with calcarenite. That three units deposited conformably. Limestone facies distribution can be analyzed representatively in Gunung Antu area. Limestone facies consist of 3 major facies: Reef Front Framestone, Fore Reef Coralline – Talus Rudstone – Grainstone, Fore Reef Packstone – Floatstone. Geological structure in research area has northwest – southeast and west - east trends. The structures in research area were formed in Plio – Pleistocene age with main stress northwest – southeast.Firstly was formed thrust fault of Gunung Antu and followed by normal fault of Gunung Antu.