HYDROTERMAL ALTERED MINERAL MAPPING OF MOUNT PAPANDAYAN CRATER, WEST JAVA, BASED ON HYPERION HYPERSPECTRAL IMAGERY AND FIELD OBSERVATION

• Main Author: Nanda Paringgusti Wijan, Nadira
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/45280
• Institution: Institut Teknologi Bandung

Mapping of hydrothermal alteration minerals is carried out to support exploration activities, including in the field of geothermal and mineral deposits. Remote sensing using satellite is an time- and cost-effective method field observation, and can be used to help map large areas and / or difficult to reach. Hyperion satellite imagery is a hyperspectral image that has good spectral resolution for mapping hydrothermal alteration minerals, can be obtained openly, but its application is realtivly scarce. This study aims to apply hyperspectral satellite imagery analysis in mapping hydrothermal alteration mineral distribution zones, which are also validated by field observations. The study was conducted in the crater of Mount Papandayan, Garut Regency, West Java. Hyperspectral Hyperion image for this region are processed through a series of stages, namely pre-processing which includes radiometric correction and FLAASH atmospheric correction, Minimum Noise Factor (MNF) transformation, spatial selection based on Pixel Purity Index (PPI), selecting endmember based on USGS library and field data, and making maps of abundance of alteration mineral endmember using Linear Spectral Unmixing (LSU). The results of Hyperion image analysis were validated by field data in the form of field descriptions and analysis of field samples with Portable Infrared Mineral Analyzer (PIMA) and ASD Spectroradiometer. The entire results of the processing and analysis of this laboratory are integrated to compile alteration mineral zoning in the study area. Image analysis shows the presence of selected endmember minerals, namely alunite, kaolinite-montmorillonite, and halloysite as well as sulfur in the study area. Image analysis showed valid results using field sample spectra as a library compared to USGS. The alteration mineral assemblage zones that can be found in the study area are the Halloysite Zone, Kaolinite Zone, and Pyrophyllite Zone along with two zones which are ex-situ alterations. There is a correlation between the distribution of alteration mineral zones and field conditions. The Halloysite zone tends to correlate with the Kawah Baru pyroclastic deposit. The Pyrophillite Zone was found to be correlated with Papandayan products which formed the Welomorang Punggungan geomorphological unit. The Kaolinite Zone was found to correlate with crater regions that have active manifestations.