FUSI CITRA LANDSAT 7 ETM+ DAN CITRA ASTER G-DEM UNTUK IDENTIFIKASI ZONA ALTERASI HYDROTHERMAL TERKAIT MINERAL DI SEBAGIAN KALIMANTAN BARAT - Ananda, Irvan Nurrahman; Danoedoro, Projo (GEOMATIKA, 2014)
Indonesia sebagai negara kepulauan dengan potensi sumber daya mineral yang melimpah. Salah satunya adalah mengindikasikan terdapat batuan teralterasi hydrothermal. Batuan teralterasi hydrothermal dapat digunakan sebagai indikator berbagai macam mineral. Data penginderaan jauh dengan teknik pengolahan citra banyak digunakan untuk melihat potensi mineral melalui pendekatan fisik medan. Pada penelitian ini, aspek fisik medan diperoleh melalui interpretasi visual LANDSAT 7 ETM+ dan ASTER G-DEM yang telah diolah menggunakan tiga metode fusi yaitu Principal Component (PC), Intensity Hue and Saturation (IHS), dan fusi hasil Band Ratioing. Selain itu, dilakukan juga proses pemfilteran spasial. Analisis yang digunakan adalah petrografi untuk mengetahui kandungan mineral pada batuan terkait zona alterasi hydrothermal. Hasil penelitian ini menunjukkan bahwa Principal Component memiliki akurasi bentuklahan tertinggi sebesar 71,15%. Akurasi tertinggi untuk parameter batuan (litologi) sebesar 70,98% yang diperoleh dari Intensity, Hue, and Saturation. Pemetaan zona alterasi hydrothermal Â ini menghasilkan empat zona yaitu Argilik 1399,42 km2, Potasik 2913,46 km2, Propilitik 1160,54 km2, dan Serisitik 946,38 km2.Kata Kunci: mineral, fusi, pemfilteran spasial, alterasi hydrothermal, interpretasi visual, petrografiABSTRACTIndonesia as an archipelagic country has huge potentials of mineral resources. One of them is an indication of hydrothermal alteration rocks. Hydrothermal alteration rocks can be used for indicating various type of minerals. Remote sensing data with image processing techniques have been frequently used to determine the mineral potentials through terrain analysis approach. In this study, physical aspects of terrain parameters were obtained using visual interpretation of LANDSAT 7 ETM+ and ASTER G-DEM imagery, which have been processed using three fusion methods, i.e. Principal Component (PC), Intensity, Hue, and Saturation (IHS), and image fusion from Band Ratioing techniques. In addition spatial filtering was also applied. Laboratory analysis of rock petrographic analysis was conducted to identity the mineral content of the rocks in order to determine the hydrothermal alteration zones. Results of this study showed that Principal Component (PC) fusion techniques have the highest accuracy for landform identification with 71.15%. Highest accuracy for rocks (lithology) is 70.98%, which was obtained from Intensity, Hue, and Saturation fusion techniques. Mapping of hydrothermal alteration zones showed four hydrothermal alterated zones, i.e. Argilic alteration zone with an area of 1399,42 km2, 2913,46 km2 zone of potassic alteration, Propilitic alteration zone 1160,54 km2, and 946,38 km2 zone of Serisitic alteration.Keyword: mineral, image fusion, spatial filtering, hydrothermal alteration, visual interpretation, petrographic