Volcanostratigraphy for supporting geothermal exploration

Volcanostratigraphy is stratigraphy related to volcanism and its products. This includes stratigraphy for a general scoping of a regional area and detailed analysis in a local area. On the basis of Indonesian Stratigraphic Code 1996, from low to high rank, volcanostratigraphic units are Hummock (Gumuk), Crown (Khuluk), Brigade (Bregada), Super Brigade (Manggala), and Arc (Busur). For more detailed stratigraphic study these ranked units can be classified into genetic rock units based on source location, processes and absolute age. Genetic processes include transportation and cooling or deposition mechanisms. These lead to physical- and chemical- properties of the volcanic rocks and provide the history of volcanism and potentially geothermal processes in an area. For many areas in Indonesia the understanding of the volcanostratigraphy is an important dataset for geothermal exploration.