Skripsi
STUDI KARAKTERISTIK BATUAN GRANITOID DAN EVOLUSI MAGMA DAERAH NYUKANG HARJO DAN SEKITARNYA, KABUPATEN LAMPUNG TENGAH, LAMPUNG
The Nyukang Harjo area, Central Lampung Regency, Lampung province is exposed to granitoid rocks in the morphology of low hills to high hills. Igneous rocks in the study area are widely distributed and have interesting characteristics both megascopically, petrographically, and in terms of chemical composition. This study aims to determine the characteristics of granitoid rocks both petrographically and geochemically as well as the evolution of magma that occurs and the tectonic environment that forms granitoid rocks in the study area. The method used in this research includes field observation and laboratory analysis. Laboratory analysis consists of petrographic analysis to determine the petrographic characteristics of granitoid, and XRF (X-Ray Fluorescence) geochemical analysis to determine the chemical elements in granitoid rocks. Based on petrographic analysis, the rock names are quartz syenite and quartz monzonite, both of which are a group of plutonic igneous rocks that are acidic to intermediate. The constituent minerals are dominated by alkaline feldspar minerals and there are plagioclase minerals (An30-An38), and a little quartz, biotite, hornblende, muscovite, titanite, and secondary minerals chlorite, sericite, and opaque with special textures in the form of perhite, graphic, and myrmekite. Geochemical analysis shows that the granitoid rocks in the study area have a magma affinity in the form of tholeiitic to calc-alkaline. The magma differentiation process is depicted in the Harker diagram which shows the evolution of alkaline magma that has high Mg and Fe content then crystal fractionation occurs so that the magma initially is bases become acidic because the content of MgO and Fe2O3 decreases as SiO2 increases. The granitoid in the study area are assumed to have formed in a VAG (Volcanic Arc Granitoid) tectonic environment and a syn collision granitoid
Inventory Code | Barcode | Call Number | Location | Status |
---|---|---|---|---|
2207002301 | T74218 | T742182022 | Central Library (Referens) | Available |
No other version available