GEOCHEMICAL ANALYSIS OF DRILLING SAMPLES TO DETERMINE HYDROTHERMAL ALTERATION ZONES AT GRADIENT THERMAL WELL IN THE PATUHA GEOTHERMAL FIELD, CIWIDEY, BANDUNG REGENCY

• Main Author: Luthfi Luthansyah, Muhamad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67451
• Institution: Institut Teknologi Bandung

The exploration stage through drilling activities and mineral chemical analysis is carried out to determine the distribution of altered mineral and chemical composition of rocks. Drilling activities were carried out from February to March 2022 with a depth of TCH-A of 303 meters and TCH-B of 203.5 meters. Rock core samples were analyzed in the laboratory using the X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) methods to determine the distribution of oxide elements and compounds, as well as the relatively dominant distribution of minerals such as quartz, cristobalite, muscovite, alunite, albite, diopside, labradorite and kaolinite, which are minerals characterizing the presence of alteration zones in TCH-A and TCH-B which both have Argillic and Advanced Argillic alteration zones. Total Alkali Diagram - Silica is used to classify the types of volcanic rocks in the study area so that it can be known that the rocks are dominated by andesite. The Chemical Index Alteration diagram is used to determine the degree of alteration by entering the percentage values of three oxide compounds, namely: Al2O3-K2O-(CaO+Na2O) which shows the level of alteration of poor - moderate - high alteration intensity for TCH-A and moderate - high alteration intensity for TCH-B.