VOLCANOSTRATIGRAPHY IN THE LOKON VOLCANO AREA AND ITS SURROUNDINGS, NORTH SULAWESI

Abstract

Lokon Volcano is an active Quaternary volcano located in the Celebes - Sangihe Volcanic Arc. This study was conducted to explain the stratigraphy of volcanic rocks based on geomorphological analysis and petrological characteristics. Based on the geomorphological analysis, the Lokon Volcano area is divided into 9 geomorphological domains (Kayawu, Woloan, Kamasi, Irang, Lokon, Tatawiran, Galean, Kinilow, and Empung) separation is carried out based on topographic straightness patterns, reliefs, and topographic distribution patterns. Based on the field description, the rock unit is divided into 18 geological units in the form of lava flows, pyroclastic flows, pyroclastic falls, and mudflows. Volcanology units of Lokon Volcano and its surroundings according to ISC (Indonesian Stratigraphic Code) are classified into Crown Tatawiran, Crown Kinilow, Crown Empung, and Crown Tou Lokon. Crown Kinilow is dominated by pyroclastic deposits with a scorious textured basalt composition, while Crown Empung is dominated by basalt lava flows. Crown Tou Lokon consists of 3 hummocks, namely Lokon which is dominated by pyroclastic flows, Irang which is dominated by lava flows with holohyalin textures, and Tompuluan which is dominated by pyroclastic falls. Lokon Mountain volcanic facies are divided into Tatawiran Proximal Facies, Kinilow Central Facies, Kinilow Proximal Facies, Kinilow Medial Facies, Empung Central Facies, Empung Proximal Facies, Lokon Central Facies, Lokon Proximal Facies, Lokon Medial Facies, Irang Central Facies, Irang Proximal Facies, Tompuluan Central Facies, and Tompuluan Proximal Facies.