Geological Characterization of Rare Earth Elements in Aceh's Igneous Rocks: A Step Toward Sustainable Mining

This study investigates and characterizes the presence of rare earth elements (REEs) in igneous rock samples from the Lokop geological complex in East Aceh, Indonesia. The Lokop geological area is strategically significant due to its underexplored potential for REE resources, since Indonesia aims to enhance its contribution to the global low-carbon transition through sustainable mineral development. Twenty rock and soil samples were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS) for mineralogical and petrographic characterization, revealing albite-rich plagioclase feldspars hosted in quartzite. REE trace analysis via inductively coupled plasma optical emission spectrometry (ICP-OES) showed Total Rare Earth Elements and Yttrium (TREE+Y) concentrations ranging from 111.20 to 1727.30 ppm. The content of Light Rare Earth Elements (LREEs), ranging from 75.30 to 1225.40 ppm, was significantly higher than that of Heavy Rare Earth Elements (HREEs), which ranged from 35.90 to 501.90 ppm. The highest TREE+Y concentration (1727.30 ppm) was observed in an andesitic rock sample from the Kolon riverbank outcrop, predominantly composed of LREEs, including Cerium (944.90 ppm) and Neodymium (195.50 ppm). The LREE concentration, primarily Lanthanum (498.70 ppm), was also present in this sample. This research provides an important foundation for the sustainable development of Indonesian REE resources, contributing to the global low-carbon economy. ©: © 2025 The author(s).