Geochemistry of Late Triassic weak Peraluminous A-Type Karimun Granite, Karimun Regency, Riau Islands Province

Abstract

-Karimun is an island with various geological deposits: tin, granite, sand, and others. The tin deposit in Karimun is related to the granitoid tin belt which extends from Myanmar to western Indonesia. Late Triassic Karimun Granite is composed of quartz, K-feldspar, plagioclase, biotite, and/or muscovite with small amounts of accessory minerals. The granitoid unit is different with other felsic intrusive rocks in Malay Peninsular because of its A-type affinity although it is classified as part of the Tin Islands. All eight samples can be classified as altered rocks since the occurrence of secondary chlorite was identifed both macroscopically and microscopically. Petrography was used to describe the minerals that form the samples, whereas XRF and ICP-MS were used to study Karimun Granite from the geochemical point of view. Harker diagrams confirm that the granites show similarity to other granite units in Malaysia except for CaO. Whalen diagrams indicate the granite as A-type as well as the SiO 2 , REE, and LILE amounts. REE content in the weak peraluminous granitoid ranges from 183 to 3,296 ppm with Eu and Ce show negative anomalies in the REE spider diagram. Negative anomalies of Eu, Ba, Sr, P, and Ti in normalized spider plot also conclude that the studied granitoid indicates A-type.

Petrography and geochemistry of the Pinkish Lagoi Granite, Bintan Island: Implication to magmatic differentiation, classification, and tectonic history

“…These trends are alike other granitoid units in Eastern Granite Province of Peninsular Malaysia, i.e. Endau Rompin (Ghani et al, 2013), Karimun (Irzon, 2017), both groups of Muncung (Irzon, 2015), and Central Terengganu sector (Ahmad et al, 2002). Among trace elements, V, Ga, Sc, Sr, and Ba depict negative correlation to SiO 2 whilst only Rb with a positive one (Figure 6g-h).…”

“…Among the trace elements, the REE is a particularly useful group of elements to understand the differentiation of any magmatic suite because of the coherent behavior. Total REE for the samples ranging from 173 (LGP 15) to 1015 ppm (LGB 07) with an average of 259 ppm (Irzon et al, 2017). Eu negative anomaly is pronounced in the seven high-K calc-alkaline samples from Lagoi (Figure 8b) in the range of 0.42-0.67 and is attributed to plagioclase and/or feldspar fractionation process (Bagherzadeh et al, 2015;Coloma et al, 2017;Haruna, 2014;Saleh & El-Nisr, 2013).…”

“…The Quaternary alluvium can only be found near Teluk Bintan on the south coast of the island. A total of eight pinkish granites from previous REE study were utilized (Irzon et al, 2017).…”

Geochemistry of Granitoids in Central Sumatra: An Identification of Plate Extension during Triassic

“…AGV-2, GBW 7110 and GBW 7113 were the certified reference materials used in this study in verifying measurement accuracy. The detail of the preparation procedure, the analytical instrument setting, and data verification protocols followed the previous studies of Irzon (2017) and Irzon (2018). Data from previous studies are also incorporated in this paper.…”

A Combined Petrographic-Geochemical Provenance and Tectonic Setting Study of Palaeozoic Rocks, in East Johor Basin, Peninsular Malaysia

“…The geochemical approach in this paper refers to the classification of Roser and Korsch (1986) (Irzon, 2015;2017).…”