Mapping Volcanic Features and Structures Using Remotely Sensed and Digital Terrain Models (DTM) in South Central Mindanao, Philippines

Abstract

A preliminary regional image map showing the generat geotogy of south-central Mindanao was produced from digitatty enhanced images captured by the Landsat 4 Thematic Mapper (TM) satellite, lmage interpretation was also effectively undertaken using 3D views of the area generated by draping color composite images over the digital terrain model (DTM) on obtained from Shuffle Radar Topographic (SRTM) data sets of 90m resolution- Broad tithotogic units, strutcturat features and various lava flow uhits were further discriminated using false color compos,'fesb, and ratioing and principal component analysis to make a relativetyd etailedg eologicm ap of the Apo volcanic complex. Maior faults and lineaments were extracted by using edge enhancemenfti tters.They exhibit N-S and NW trends which are consistent with the prominent Philippine Fault and Cotabato-Sindangan Fault Zone in the east and southwest part of Mindanao, respectively. Alteration zones west-southwest of Mount Apo were also delineated but need further investigation as these may imply close relationship with the geothermal field that is presently being operated by PNOC-EDC northwest of the Mt. Apo Peak.