PROVENANCE OF PAMALUAN FORMATION IN MUARA TAE, EAST KALIMANTAN

• Main Author: SUKO WIRATMOKO , EKO
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/26893
• Institution: Institut Teknologi Bandung

<p align="justify">Pamaluan Formation is siliciclastic sedimentary rock on Kutai Basin which aged identified Late Oligocene-Early Miocene. This formation was deposited on the post rift phase of Kutai Basin, influenced by the thermal sagging mechanism. This study aimed to recognize the provenance of Pamaluan Formation in Muara Tae, East Kalimantan by using geochemical and petrography analysis. Geochemical approachment held by spectrometer analysis X-Ray Fluorescence (XRF), combine with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) to understand the paleoenvironment condition based on the main elements and trace elements. Petrography analysis is used to find out percentage composition of the grain. <br /> <br /> Pamaluan Formation was deposited on lagoon environment at Early Miocene. Geochemical analysis delivered by bivariate plot diagram of the major elements indicate that chemical provenance of Pamaluan Formation originated from mafic igneous provenance, intermediate igneous provenance, and quartzose sedimentary provenance. Bivariate plot diagram major elements discriminant, K2O/Na2O against SiO2, and La-Th-Sc indicate the tectonic setting in the active continental margin. Petrographic analysis perform on 14 sandstones samples by area counting method, it used as control for geochemical analysis result. Based on the analysis, the sandstone identified as of lithic arenite, subarkosic, feldspathic greywacke, and sublithic arenite. Comparison of quartz, feldspar, and lithic (QFL) shows the provenance is recycled orogenic, meanwhile comparison of composition monocrystalline quartz, feldspar, lithic (QmFL) shows that the provenance are quartzose recycled, craton interior, and mixed. Sedimentary rock fragmen and metasediment rock originated from Rajang Group as provenance of Pamaluan Formation.<p align="justify">