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All Journal IJOG : Indonesian Journal on Geoscience Eksplorium : Buletin Pusat Pengembangan Bahan Galian Nuklir Eksplorium : Buletin Pusat Pengembangan Bahan Galian Nuklir
Rachael, Yoshi
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Chemical Engineering, Chemistry & Bioengineering Earth & Planetary Sciences Energy Engineering Materials Science & Nanotechnology Social Sciences

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Distribution and Characteristics of Rare Earth Elements in Uranium-Ore Deposits from Rirang Area, West Kalimantan Province, Indonesia Adimedha, Tyto Baskara; Farenzo, Rayhan Aldizan; Sukadana, I Gde; Nugraheni, Rosmalia Dita; Pratiwi, Fadiah; Ciputra, Roni Cahya; Indrastomo, Frederikus Dian; Syaeful, Heri; Rachael, Yoshi
EKSPLORIUM Vol 45, No 1 (2024): May 2024
Publisher : Badan Riset dan Inovasi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2024.7058

Abstract

Uranium and rare earth elements (REE) are essential elements for the development of green environmentally friendly, and sustainable energy. To meet the increasing demand for these raw materials, Indonesia has taken steps to explore and map potential deposits, including the Rirang Sector in Melawi Regency, West Kalimantan. However, the available information on the mineralization of these elements in the area is limited. Therefore, this study aimed to provide a detailed characterization on the petrology and geochemical characteristics of uranium ore and to synthesize the mineral genesis of uranium and REE-bearing ore in the Rirang Sector. The analytical methods used included petrography, micro-XRF, and geochemical analysis. The results showed that uranium mineralization was present in brannerites, uranophane, and swamboite associated with tourmaline and monazite ore. Similarly, REE concentrations were hosted by REE-bearing minerals, such as monazite, xenotime, and loparite. Geochemically, the uranium concentration in the monazite ore ranged from 1,110 – 28,440 ppm, while the total REE (TREE) concentration varied between 85,320 to 138,488 ppm. The formation of uranium and REE mineralization were due to the metasomatism process and its association with the Na-rich fluid of felsic intrusion. Notably, the weathering process did not enrich uranium and REE content in the soil but rather decreased it due to the leaching process and the absence of clay minerals capable of absorbing the REE cations on the surface of clay crystal structures.
Radioactive Mineral Distribution on Tin Placer Deposits of Southeast Asia Tin Belt Granite in Bangka Island Ngadenin, Ngadenin; Sukadana, I Gde; Syaeful, Heri; Muhammad, Adi Gunawan; Indrastomo, Frederikus Dian; Rosianna, Ilsa; Ciputra, Roni Cahya; Adimedha, Tyto Baskara; Pratiwi, Fadiah; Rachael, Yoshi
EKSPLORIUM Vol 44, No 2 (2023): November 2023
Publisher : Badan Riset dan Inovasi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2023.6969

Abstract

Bangka Island is an area rich in primary and secondary tin deposits. Tin deposits are formed around the contact between granite and older rocks, while secondary tin deposits are formed in the modern channels and paleochannels. Many previous researchers have researched radioactive minerals in primary tin deposits and modern channel deposits, but research on radioactive minerals in paleo channel deposits has never been carried out. The characterization of radioactive minerals in paleo channel deposits was done in this study to determine the potency of radioactive minerals in secondary tin deposits by comparing the content of radioactive minerals in paleochannels with modern channels and tin mine tailing deposits. The data used were mineralogical data and radioactivity data, along with the uranium and thorium content of the rocks from several previous studies. Data showed significant mineral content differences in paleo channel, modern channel, and tin mine tailings deposits. Mineral (monazite and zircon) content in tin mine tailing deposits was the highest. Source rocks for the radioactive minerals monazite and zircon are predicted to be the granitic rocks or tourmaline quartz veins of primary tin deposits. The radioactivity value of rocks in the paleo channel is relatively the same as the modern channel, ranging from 20 to 150 c/s. Uranium content in paleo channel is the same as modern channel deposits, ranging from 10 to 15 ppm eU. The thorium content of the rocks in the paleo channel ranges from 1 to 60 ppm eTh, while in the modern channel, it ranges from 1 to 45 ppm eTh. The radioactivity value and uranium content of the rocks are less effective for determining potential areas of radioactive minerals in placer tin deposits. In contrast, data on thorium content are quite effective for determining potential areas of radioactive minerals in placer tin deposits.
Magmatic Evolution of Dago Volcano, West Java, Indonesia Adimedha, Tyto Baskara; Harijoko, Agung; Handini, Esti; Sukadana, I Gde; Syaeful, Heri; Ciputra, Roni Cahya; Rosianna, Ilsa; Indrastomo, Frederikus Dian; Pratiwi, Fadiah; Rachael, Yoshi
EKSPLORIUM Vol 44, No 1 (2023): May 2023
Publisher : Badan Riset dan Inovasi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2023.6873

Abstract

Dago Volcano is a product of Miocene Sunda Arc volcanism located southeast of the capital city of Jakarta. The morphological change from flat lava flow to steeper lava morphology implies a process of magma evolution under Dago Volcano. This research provides an overview of the magma evolution that occurs on this volcano. The methods used include volcanostratigraphic analysis, petrographic analysis, mineral chemistry, and whole-rock geochemistry. The volcanostratigraphy of Dago Volcano is composed of two eruption centers and a flank eruption forming lava and cinder cones products. The mineralogical associations of Dago Volcano products include plagioclase, olivine, and clinopyroxene. The mineral textures of Dago edifices show zoning, sieve, and reaction rims textures. Geochemically, the Dago Volcano product has a magma affinity of med-K calc-alkaline with quite high levels of MgO, Ni, and Cr approaching the characteristics of primitive magma. The magma evolution process of Dago Volcano includes fractional crystallization and magma mixing which originates from the same magma source.
Characterization of Radioactive and Rare Earth Elements in Heavy Minerals from River Sediments in Marau Region, Ketapang, West Kalimantan Pratiwi, Fadiah; Rachael, Yoshi; Widodo, Widodo; Fauzi, Rachman; Madyaningarum, Nunik; Adimedha, Tyto Baskara; Indrastomo, Frederikus Dian; Sukadana, I Gde
EKSPLORIUM Vol 45, No 1 (2024): May 2024
Publisher : Badan Riset dan Inovasi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2024.6971

Abstract

Alluvium deposits from the Kendawangan River located in Marau, Ketapang, West Kalimantan have been known for their radioactive and rare earth mineral potential. In this paper, heavy minerals taken from alluvium deposits will be characterized to determine the elemental distribution of uranium, thorium, and rare earth elements in each mineral and their mineralogical composition. The samples are taken by panning and prepared using the flotation method to obtain heavy mineral concentrates. Geochemical analysis was carried out using a Bruker M4 Tornado plus Micro-XRF and continued with mineralogical analysis using AMICS (Advanced Mineral Identification and Characterization System) software. It was found that the distribution of heavy minerals from the sand samples was dominated by manganoan ilmenite, ilmenite, rutile, zircon, magnetite, and monazite, as well as thorite, cassiterite, xenotime, allanite, and other minerals in small quantities. Uranium, thorium, and rare earth elements are found in monazite, thorite, xenotime, zircon, and allanite.
Makassar Strait Thrust - Mamuju Segment (MSTM) Perspective on Radioactive Mineral Exploration: A Case Study in Rantedoda, Mamuju Ciputra, Roni Cahya; Pratiwi, Fadiah; Putra, Aldo Febriansyah; Syaeful, Heri; Indrastomo, Frederikus Dian; Adimedha, Tyto Baskara; Rachael, Yoshi; Sukadana, I Gde
Indonesian Journal on Geoscience Vol. 12 No. 3 (2025)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.12.3.319-341

Abstract

The Makassar Strait Thrust – Mamuju Segment (MSTM) is a key structural feature influencing uranium (U), thorium (Th), and rare earth element (REE) mineralization in Mamuju, West Sulawesi. This study explores the relationship between tectonic deformation, weathering processes, and mineralization, focusing on the Rantedoda sector. Integrated geomorphic, geological, radiometric, petrographic, and geochemical analyses reveal that MSTM faults act as conduits for hydrothermal fluids, promoting mineral mobilization, alteration, and enrichment in fault zones. MSTM produced curved NW ̶ SE to N ̶ S thrusts torn by NE ̶ SW right-lateral strike-slip faults in the studied area. Radiometric data highlight anisotropic distributions of U, Th, and dose rates aligned with NE ̶ SW and NW ̶ SE fault trends. Geochemical indices demonstrate that weathering is critical for REE and Th enrichment, as high eTh and low K values indicate. Moreover, fault-facilitated hydrothermal clay alteration supports U adsorption, as noted by high values of all radiometric parameters in the area near a fault. These findings establish the critical role of fault systems in controlling mineralization processes, providing a framework for targeted exploration strategies in tectonically complex terrains of the Mamuju area.
Analisis Geologi Teknik Longsor di Desa Kuatae, Kecamatan Kota Soe, Nusa Tenggara Timur Syaeful, Heri; Kamajati, Dhatu; Rachael, Yoshi; Damaledo, Ebenheser
EKSPLORIUM Vol. 42 No. 1 (2021): MEI 2021
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2021.42.1.6081

Abstract

Landslides in Kuatae Village, Kota Soe District often occur during the rainy season. The slope failures cause damage to houses and other infrastructures. The research of slope failure has been carried out by using engineering geological mapping, engineering geological drilling, laboratory test, slope stability analysis, and identification of countermeasure options. Based on the mapping results, slope failures occur in two models, the first one was coral limestone blocks translation failure over marl and claystone, and the second one was rotation failure on marl that controlled by the base layer which contact with claystone. The result of the standard penetration test on claystone and marl showed a very high consistency value. The slope stability analysis had shown the slope is in a stable state, but slope failure occurred in several places on the marl and claystone area. Those indicated that the material had encounter shear strength degradation under several circumstances. Further investigation on the degradation of the rock material, such as slake durability and swelling clay are very important to determine the most appropriate countermeasure option to be applied in the landslide case of Kuatae Village.
Karakterisasi Geoteknik Fondasi Kandidat Tapak PLTN dengan Metode Seismik Refraksi Haryanto, Dwi; Rachael, Yoshi; Kamajati, Dhatu; Prasetyo, Gagah Hari; Syaeful, Heri; Indrastomo, Frederikus Dian
EKSPLORIUM Vol. 42 No. 2 (2021): NOVEMBER 2021
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2021.42.2.6538

Abstract

Presidential Regulation (Perpres) number 38 of 2018 concerning the National Research Master Plan for 2017–2045, the Government of Indonesia establishes several main areas that will become national research priorities, one of which is the energy sector. In the research theme of electricity technology based on new and renewable low/zero carbon energy, there is the topic of research on commercial-scale Nuclear Power Plant (NPP) technology. On the research topic, it was determined that within the research period of 2020–2024, a prototype nuclear power plant would be produced. Research related to the geotechnical characterization of the nuclear power plant site using the seismic refraction method was carried out to complement the previous research data. The purpose of this study was to determine the subsurface rock layer profile for estimation of work related to nuclear power plant foundations. Geological mapping and geophysical data acquisition, processing, as well as soil/rock interpretation based on the compression wave velocity (Vp) parameter are carried out to achieve this goal. The results of geological mapping show that there are 2 igneous rock units, namely quartz diorite and andesite. The results of processing and interpreting seismic refraction data produced a cross-sectional model of Vp in the subsurface rock layers. There are 3 rock layers in the research location, namely soil layer (Vp = 361–715 m/s), weathered igneous rock layer (Vp = 1.386–2,396 m/s), and fresh igneous layer (Vp = 3.789–6.133 m/s). The estimated density of fresh igneous rock based on calculations is 2.43–2.74 g/cm3. The modeling results can show the depth and structure of the subsurface layer of fresh igneous rock that can be the foundation of nuclear power plants.
Distribution and Characteristics of Rare Earth Elements in Uranium-Ore Deposits from Rirang Area, West Kalimantan Province, Indonesia Adimedha, Tyto Baskara; Farenzo, Rayhan Aldizan; Sukadana, I Gde; Nugraheni, Rosmalia Dita; Pratiwi, Fadiah; Ciputra, Roni Cahya; Indrastomo, Frederikus Dian; Syaeful, Heri; Rachael, Yoshi
EKSPLORIUM Vol. 45 No. 1 (2024): MAY 2024
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2024.7058

Abstract

Uranium and rare earth elements (REE) are essential elements for the development of green environmentally friendly, and sustainable energy. To meet the increasing demand for these raw materials, Indonesia has taken steps to explore and map potential deposits, including the Rirang Sector in Melawi Regency, West Kalimantan. However, the available information on the mineralization of these elements in the area is limited. Therefore, this study aimed to provide a detailed characterization on the petrology and geochemical characteristics of uranium ore and to synthesize the mineral genesis of uranium and REE-bearing ore in the Rirang Sector. The analytical methods used included petrography, micro-XRF, and geochemical analysis. The results showed that uranium mineralization was present in brannerites, uranophane, and swamboite associated with tourmaline and monazite ore. Similarly, REE concentrations were hosted by REE-bearing minerals, such as monazite, xenotime, and loparite. Geochemically, the uranium concentration in the monazite ore ranged from 1,110 – 28,440 ppm, while the total REE (TREE) concentration varied between 85,320 to 138,488 ppm. The formation of uranium and REE mineralization were due to the metasomatism process and its association with the Na-rich fluid of felsic intrusion. Notably, the weathering process did not enrich uranium and REE content in the soil but rather decreased it due to the leaching process and the absence of clay minerals capable of absorbing the REE cations on the surface of clay crystal structures.
Characterization of Radioactive and Rare Earth Elements in Heavy Minerals from River Sediments in Marau Region, Ketapang, West Kalimantan Pratiwi, Fadiah; Rachael, Yoshi; Widodo; Fauzi, Rachman; Madyaningarum, Nunik; Adimedha, Tyto Baskara; Indrastomo, Frederikus Dian; Sukadana, I Gde
EKSPLORIUM Vol. 45 No. 1 (2024): MAY 2024
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2024.6971

Abstract

Alluvium deposits from the Kendawangan River located in Marau, Ketapang, West Kalimantan have been known for their radioactive and rare earth mineral potential. In this paper, heavy minerals taken from alluvium deposits will be characterized to determine the elemental distribution of uranium, thorium, and rare earth elements in each mineral and their mineralogical composition. The samples are taken by panning and prepared using the flotation method to obtain heavy mineral concentrates. Geochemical analysis was carried out using a Bruker M4 Tornado plus Micro-XRF and continued with mineralogical analysis using AMICS (Advanced Mineral Identification and Characterization System) software. It was found that the distribution of heavy minerals from the sand samples was dominated by manganoan ilmenite, ilmenite, rutile, zircon, magnetite, and monazite, as well as thorite, cassiterite, xenotime, allanite, and other minerals in small quantities. Uranium, thorium, and rare earth elements are found in monazite, thorite, xenotime, zircon, and allanite.
Magmatic Evolution of Dago Volcano, West Java, Indonesia Adimedha, Tyto Baskara; Harijoko, Agung; Handini, Esti; Sukadana, I Gde; Syaeful, Heri; Ciputra, Roni Cahya; Rosianna, Ilsa; Indrastomo, Frederikus Dian; Pratiwi, Fadiah; Rachael, Yoshi
EKSPLORIUM Vol. 44 No. 1 (2023): MAY 2023
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2023.6873

Abstract

Dago Volcano is a product of Miocene Sunda Arc volcanism located southeast of the capital city of Jakarta. The morphological change from flat lava flow to steeper lava morphology implies a process of magma evolution under Dago Volcano. This research provides an overview of the magma evolution that occurs on this volcano. The methods used include volcanostratigraphic analysis, petrographic analysis, mineral chemistry, and whole-rock geochemistry. The volcanostratigraphy of Dago Volcano is composed of two eruption centers and a flank eruption forming lava and cinder cones products. The mineralogical associations of Dago Volcano products include plagioclase, olivine, and clinopyroxene. The mineral textures of Dago edifices show zoning, sieve, and reaction rims textures. Geochemically, the Dago Volcano product has a magma affinity of med-K calc-alkaline with quite high levels of MgO, Ni, and Cr approaching the characteristics of primitive magma. The magma evolution process of Dago Volcano includes fractional crystallization and magma mixing which originates from the same magma source.
Co-Authors . Iskandarsyah Adi Gunawan Muhammad Adimedha, Tyto Baskara Agung Harijoko Ciputra, Roni Cahya Damaledo, Ebenheser Dhatu Kamajati, Dhatu Dwi Haryanto Esti Handini Farenzo, Rayhan Aldizan Fauzi, Rachman Frederikus Dian Indrastomo, Frederikus Dian Heri Syaeful I Gde Sukadana Mardania, Faneza Nur Maulana, Muhammad Wira Mirna Berliana Garwan, Mirna Berliana Ngadenin Ngadenin Nugraheni, Rosmalia Dita Nunik Madyaningarum, Nunik Prasetyo, Gagah Hari Pratiwi, Fadiah Putra, Aldo Febriansyah Putri Rahmawati Rosianna, Ilsa Sukmawan, I Gusti Made Widodo Widodo Widodo