Dwa Desa Warnana, Siti Zulaikah, Amien Widodo, Wien Lestari, Juan Pandu Gya Nur Rochman, Sigit Tri Wicaksono, Fadhilah, Hanif Izzudin Zakly, Aditya Pratama, Nordiana Mohd Muztaza, Rodeano Roslee
Geochemical characterization has been widely carried out to classify the types of rocks and volcanic materials. Volcanic rocks are a major component of the Earth's crust and have their own unique characteristics. Classification and mapping are particularly beneficial for the exploration of specific minerals. This research focuses on studying and analyzing the geochemistry of volcanic materials in the Bromo-Tengger-Semeru (BTS) area, East Java, Indonesia. Whole-material geochemistry from 55 volcanic product samples from the BTS area was determined by X-ray fluorescence (XRF). The XRF results showed that the dominant compounds were CaO (12.5 Wt%), Fe2O3 (27.5 Wt%), and SiO2 (41.3 Wt%). Results also reveal that mostly the BTS volcanic material was classified in the ultramafic lamprophyre Aillikites series. Meanwhile, the analysis based on the comparison of % K2O vs. % SiO2 values shows that BTS volcanic material is included in the alkaline series absarokite and belongs mainly to the post-caldera stage. These features potentially host rare earth elements (REEs)-bearing minerals. ©2025 The authors.
Department of Geophysical Engineering, Faculty of Civil Planning and Geo-Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia; Department of Physics, Faculty of Mathematics and Natural Science, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Materials and Metallurgical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia; Mining Department, Faculty of Engineering, Universitas Negeri Padang, Padang, 25173, Indonesia; Research Center for Geological Disaster, National Research and Innovation Agency (BRIN), Bandung, 40135, Indonesia; School of Physics, Universiti Sains Malaysia, Penang, 11800, Malaysia; Faculty of Science and Technology, Universiti Malaysia Sabah, Kota Kinabalu, 88400, Malaysia