QUANTIFIKASI OF VISIBLE-SHORTWAVE INFRARED SPECTRA OF LANDSAT 9 IMAGE FOR PHOSPHATE MINERAL DETECTION IN MAMUJU AREA, WEST SULAWESI, INDONESIA

• Main Author: Kurniawan, Rajab
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87283
• Institution: Institut Teknologi Bandung

Phosphates are mostly used in the manufacture of fertilizers for plant nutrition and the production of animal feed supplements. Only 10 - 15% of the world's phosphate rock production has other uses, such as pharmaceuticals, ceramics, an important alternative source for rare earth elements (REE), and Lihtium-Iron-Phosphate (LFP) batteries. In Indonesia, various types of rocks are composed of phosphate components, but those with economic value are very limited. Generally, these phosphate resources are found in sedimentary or biogenic phosphate deposits, while phosphate resources derived from igneous rocks are still not found. Therefore, regionally accurate mapping using the spectral-wise method is proposed in this study. The Five spectral references originated from phosphate minerals from the USGS spectral library were used: fluorapatite, chlorapatite, hydroxylapatite, monazite, and xenotime. The spectral-wise method is aimed to identify anomaly of phosphate minerals based on behavior of spectral absorption that shows the same absorption pattern at a wavelength of 2 ?m originated from orthophosphate (PO4). This spectral-wise formulation was then applied to detect the phosphate occurences using Landsat 9 image. The spectral-wise method successfully detected three PO4 at Simboro, Mamuju, and Tapalang prospect zones covering an area of 2,604 ha with P2O5 contents reaching 1.14 - 2.73%. The method has been verified to have an accuracy of about 77% based on comparison with P2O5-containing rock and soil samples in the field study. The high alkaline rock characteristics in the study area are indicative of phosphate mineral anomalies. The potential phosphate mineral zone is more dominant in the rock characteristics in the northern area which is influenced by hydrothermal activities and controlled by geological structures.