DIAGENESIS ANALYSIST AND POROSITY DEVELOPMENT OF RAJAMANDALA CARBONATE THROUGHOUT THIN SECTION AND STABLE ISOTOPE APPROACHES: A CASE STUDY FROM CIKAMUNING AREA, WEST JAVA-INDONESIA

• Main Author: ALAM PERDANA, LISNANDA
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/16293
• Institution: Institut Teknologi Bandung

Rajamandala carbonate rock (Oligocene-Miocene) cropped out in West Java with northeast-southwest trend. Petrography detail analysis have been conducted using <br /> <br /> <br /> polarization and cathodoluminescence microscope, integration with isotope data is the main control for synthesizing diagenesis evolution. <br /> <br /> <br /> This research using three shallow well which are ITB_URC-1, ITB_URC-2, ITB_URC-3 (90-151m) combine with surface data. Carbonate cement analysis showed us domination of blocky, isopach cement with aggrading characteristic. Main composition of cement is Fe-calcite with dolomitization in several places. Cathodoluminescence analysis reveal that dolomitization occur three times with saddle, planar and polimodal texture with inequally distribution. Stable isotope <br /> <br /> <br /> value of ?18 range from -2o/000 until -8o/000 and ?13C range from 2 o/000 until -2o/000 indicate that carbonate rock diagenesis have been through burial phase with <br /> <br /> <br /> highly develop in cementation process connected with water formation and meteoric water. <br /> <br /> <br /> This research confirmed that porosity modification in Cikamuning area controlled by five diagenesis zone which are marine, meteoric phreatic, mixing, burial with <br /> <br /> <br /> meteoric phreatic zone as main factor controlling porosity. Porosity value in the well have a small percentation (<10%) and dominated with dissolution. <br /> <br /> <br /> Dolomitization just localized and not significant for enhancing porosity. The result of the whole analysis reveal that diagenesis in subsurface can be modelled by surface data with erasing surfacial process.