REKONSTRUKSI SIKLUS PENGEMDAPAN BATUGAMPING TERUMBU DANBATUGAMPING FRAGMENTAL DI DAERAH CIKAMUNING, PADALARANG,JAWA BARAT BERDASARKAN DATA SINGKAPAN DAN DATA SUMUR DANGKAL

• Main Author: Amanda Utami, Dwi
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/73651
• Institution: Institut Teknologi Bandung

Carbonate sedimentary cycle reconstruction in Cikamuning, Padalarang, Jawa Barat have been done by integrating outcrop data and shallow well data from well ITB-1 (150,9m), well ITB-2 (45m), and well ITB-3 (65m). Carbonate sedimentary cycle reconstruction in this study area is different than previous because supported by shallow well data. Four (4) facies association can be identified based on outcrop observation and supported by core data. They are respectively from the older to the younger are: Coral BindstoneRudstone facies association, Prograding Rudstone-Packstone facies association, Well Bedded Turbiditic Packstone-Grainstone facies association, and Thick Bedded to Massive Rudstone-Grainstone facies association. The Coral Bindstone to Rudstone facies association is dominated by Platy Coral Bindstone facies and Coral Rudstone to Floatstone facies. The interpreted depositional environment for this facies association is reef margin platform carbonate. Prograding Rudstone to Packstone facies association is dominated by Coral Floatstone to Rudstone facies and Foraminifera Packstone to Grainstone facies. The interpreted depositional environment for this facies association is reef slope. Field observation indicated that Prograding Rudstone to Packstone facies association have prograding patterns that is use to named for this facies association. Well Bedded Turbiditic Packstone to Grainstone facies association is dominated by Foraminifera Wackestone to Packstone facies, Foraminifera Packstone to Grainstone facies, and marl. Field observasion indicated that this facies association have gradded bedding, parallel lamination, and convolute sediment structures indicated of turbiditic deposit incomplete Bouma classic turbidite sequence that is use to named this facies association. The interpreted depositional environment for Well Bedded Turbiditic Packstone to Grainstone facies association is basin environment with turbiditic mechanism. Thick Bedded to Massive Rudstone to Grainstone facies association is dominated by Coral Floatstone to Rudstone facies and Foraminifera Packstone to Grainstone facies, characterized by thick, massive bedded rudstone, with erosional truncation at the base and marl-calcareous clay intercalations. The interpreted depositional environment for this facies association is basin environment with debris flow mechanism. Two major reef sedimentation cycle can be identified from the study area, they are carbonate reef cycle and carbonate fragmental cycle. The carbonate reef cycle started by the growth of reef which is manifested by Coral Bindstone Facies, while keep up phase is manifested by progradation symptoms from the reef margin carbonate platform facies. Keep up phase and progradation is interpreted occure in Highstand System Tract (HST) condition as the turbiditic deposition shown up. Carbonate reef cycle then replaced by carbonate fragmental cycle, characterized by thick bedded to massive carbonate rudstone with erosional base. Physical characterization for the thick bedded to massive carbonate rudstone give indication that this depositional energy system is bigger than turbiditic below it, but paleotology data indicated that bathymetry condition from Thick Bedded to Massive Rudstone facies is deeper compare to facies group below it. Depositional environment interpretation and modelling depositional facies reconstruction indicate that the reef body located on the south-west area prograding to north-east and deepening to the north east-east.