KARAKTERISTIK BATUAN BEKU GUNUNG API KENDIL BERDASARKAN ANALISIS PETROGRAFI, KECAMATAN KEJAJAR, KABUPATEN WONOSOBO, PROVINSI JAWA TENGAH

Abstract

Indonesia is located at the three world's active tectonic plates. These tectonics interact with each other formed a subduction zone that controls the volcanic arc, known as the Ring of Fire. The Quaternary volcanic arc on Java Island has the youngest age, and the volcanic process is still ongoing. Dieng Volcano Complex which consists a complex of stratocones, parasitic vents, and explosion craters are one of the quartenary volcanoes. The research area of Mount Kendil is one of the quaternary volcanic chain trending northwest-southeast in the Dieng Volcano Complex. The purpose of this study is to identify and determine the characteristics of igneous rocks, including texture and mineralogy composition, from the the Kendil volcanism in the past. The research method using primary data with surface geology and petrographic thin section analysis. The results in sample one there are pyroxene, plagioclase, and hornblende embedded in volcanic glass. In sample two minerals such as hornblende, pyroxene, and plagioclase embedded in volcanic glass. The third sample minerals are biotite, plagioclase, and hornblende embedded in volcanic glass. Based on the analyzed data, it can be concluded there
was an evolution of magma from mafic to intermediate. Mafic magma marked by the pyroxene minerals as indicator and intermediate magma marked by hornblende and plagioclase. This research is expected to add information and enrich the literature that discusses the evolution and characteristics of magma in the Mount Kendil area.