Skripsi
PETROGENESIS AND AFFINITY MAGMA OF GRANITOID GRANIT GARBA, IN BIABIA AREA AND SURROUNDING, MUARADUA DISTRICT, SOUTH SUMATRA
Research on the geochemistry and petrogenesis of granitoid rocks that make up Granite Garba (Kgr) was conducted in Biabia, Muaradua District, South OKU, South Sumatra. Granit Garba is one of the basements that make up the Garba Mountains which was exposed due to uplift in the Paleogene. The research was conducted using two approaches, namely petrographic analysis and rock geochemistry. Petrographic and geochemical analyzes were carried out to determine the genesis and tectonic environment of Granit Garba rock formation. The petrographic analysis of the granitoid rocks shows that Granit Garba is composed of quartz monzonite and granodiorite wherein the thin section of rock samples there are special textures, namely perthite, graphic and myrmekitic which are the characteristic textures of acid igneous rocks. Observations of the thin section also show that the two rocks have the main composition of oligoclase type plagioclase minerals, alkali feldspar and quartz. Based on the geochemical analysis, the main oxide elements of the granitoid rocks are I-type granite with an affinity magma calc-alkaline series and saturation levels of alumina which are classified as metaluminous to peraluminous. The Harker diagram of the main oxide of the sample shows a negative trend for the elements MgO, CaO, P2O5, FeO, and MnO or a decrease in the elements as SiO2 increases. In addition, the plotting of the Harker diagram also shows a trend positive on the elements Al2O3 and K2O which is interpreted as evidence of crystal fractionation and mixing of two different magmas. The trend spread also shown on Na2O. Analysis of trace elements in rock samples in the study area showed that the I-type granite experienced a weak level of crystal fractionation so the mineralization in the area was also low. The tectonic environment of this rock formation is an active continental margin, volcanic arc granite which is formed as a result of the subduction process of two plates.
Inventory Code | Barcode | Call Number | Location | Status |
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2207002382 | T74516 | T745162022 | Central Library (Referens) | Available |
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