PETROGENESIS OF TECTONIC-CONTROLLED VOLCANIC PRODUCTS IN SUOH VOLCANO AND ITS VICINITY, WEST LAMPUNG REGENCY

• Main Author: Purnama Agung, Alkautsar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/83401
• Institution: Institut Teknologi Bandung

Suoh Volcanic Zone is an active volcanic complex within Lembah Suoh, a pull-apart basin that formed due to the Great Sumatran Fault’s presence in the western part of Lampung Province, Indonesia. In 1933, a highly explosive eruption killed numerous inhabitants, albeit a phreatic eruption. Mapping and rock sampling show a strong explosive nature is found in most volcanic products within Lembah Suoh’s vicinity. Thus, a study of eruption characteristics and magma processes is needed. Tectonic, microtextural petrographic, and geochemical approaches prove the weak zones along the fault lines within the Lembah Suoh area control the magmatic processes, which are proven by the low degree of magma assimilation and strong decompression traces in the crystals despite the generally unabundant magmatic supply and the highly viscous magma character. The analysis from the Suoh Volcanic Zone products is then compared to other products in the area that mainly show a lesser degree of tectonic control. This study, hopefully, can become the basic model of the magmatic process for the future Suoh Volcanic Zone’s eruption hazard mitigation. On the other hand, products that have been classified will contribute to updating the geological map on a local scale.