KARAKTERISTIK GRANIT DI GIRIHARJO, LAMPUNG SELATAN

Abstract

This study aims to identify the characteristics of granitoids in Giriharjo, Lampung Selatan, which formed due to crust thickening from the collision between the Woyla volcanic arc and the western Sumatra terrain. The primary focus is on Granodiorite Sulan (Kgdsn), which has received limited research attention. The methodology employed is descriptive-analytical, involving field observations and laboratory analyses using petrographic microscopes. Four granodiorite samples were collected from an area of 9 km². The results indicate two types of granitoid rocks: Tonalite and Granodiorite, with variations in mineral composition and texture. Granodiorite is characterized by a grayish-white color and a massive structure, while Tonalite is predominantly composed of plagioclase. Microscopic analysis reveals suture and intergrowth textures that indicate the influence of plastic deformation. This research contributes significantly to the understanding of Sumatra's geology and the potential for mineral resource exploration in the future. By addressing gaps in knowledge regarding the petrological characteristics and tectonic processes that shaped Granodiorite Sulan, this study hopes to enhance the understanding of magmatic and tectonic processes in this region, providing valuable insights for future geological explorations.