Rare Earth Elements on the A-type Unggan Granite and Its Comparison to the A-type Section of Sibolga Granite

Abstract

Rare earth elements are often correlated to A-type granite. Unggan Granite is A-type granite which is located in Sijunjung Regency, West Sumatra. This study discusses the rare earth elements composition on A-type Unggan Granite and compares the element abundance to the nearest A-type granite from Sibolga. Total REE of the studied location in the part of Solok Quadrangle is averagely 860 ppm. XRF and ICP-MS at Center for Geology Survey were applied to measure the composition of major oxides, trace elements, and rare earth elements in the selected granite. Megascopically, the samples are dark red and coarse grain granites with quartz and feldspar as major minerals. Major oxides content of the samples affirms the samples as granite based on geochemistry composition. Ga, Nb, and Y amounts in the granites reveal the A-type affinity. The average REE abundance of Unggan Granite is higher than the A-type section of Sibolga Granite. The selected rock are classified in shoshonitic series with lanthanum and neodymium as the major REE. Negative Ce and negative Eu anomalies in normalized spider plot are detected in the samples. The granite characters are worth to be explored more for national income from rare earth elements resource.