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Contact Name
Andri Agus Rahman
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jurnal@rmpi.brin.go.id
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+6282120080815
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eksplorium@brin.go.id
Editorial Address
Gd. 720, KST BJ Habibie, Kawasan Puspiptek Serpong, Tangerang Selatan 15314
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Kota bogor,
Jawa barat
INDONESIA
Eksplorium : Buletin Pusat Pengembangan Bahan Galian Nuklir
ISSN : 08541418     EISSN : 2503426X     DOI : https://doi.org/10.55981/eksplorium
EKSPLORIUM is published to deliver the results of studies, research and development in the field of nuclear geology. The manuscripts are the result of study, research and development of nuclear geology with scope: geology, exploration, mining, nuclear minerals processing, safety and environment, and development of nuclear technology for the welfare.
Articles 176 Documents
Eksplorasi Geokimia untuk Menentukan Daerah Prospek Mineralisasi Emas Tipe Urat Epitermal: Studi Kasus di Daerah Tompaso, Kabupaten Minahasa Selatan, Sulawesi Utara Idrus, Arifudin; Fadlin; Hartono, Hill Gendoet
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.2021.42.1.6230

Abstract

North Sulawesi, including the Tompaso region, South Minahasa district, is a part of the magmatic belts hosting potential hydrothermal ore deposits. This study is aimed to determine the prospect area for epithermal vein-type gold mineralization, based on geochemical exploration including rock and BLEG (Bulk Leach Extractable Gold) stream sediment geochemistry. Mapping of geology, alteration and vein direction, sampling (ore/rock and stream sediment), and geochemical analysis were performed. Gold in rock samples was analyzed by FA/AAS, and other elements were detected by AAS, while BLEG samples were analyzed using the cyanide leach and AAS methods. The study area is occupied by andesitic lava and diorite, which are suffered by silica-clay, argillic and propylitic alteration. An integration of geological mapping, alteration zones and vein direction with lithogeochemical survey enables to determine the prospect areas, which consist of Asam and Polangkok prospects. At the Asam prospect, the ore sample contains gold up to 0.03 ppm, where the gold anomaly in BLEG samples show a threshold of 13.52 ppb Au. At the Polangkok prospect, two NW-SE trending veins (P1 and P2 Veins) were discovered with a width of up to 5 m. Vein P1 and P2 contains of up to 0.31 and 0.16 ppm Au, respectively. Mineralization at the Polangkok prospect coincides with Ag anomaly of BLEG samples with a threshold of 67.18 ppb. The two prospect areas are recommended for follow-up exploration.
Identifikasi Deformasi Tektonik Aktif Berdasarkan Ekstraksi Kelurusan Morfologi dan Seismisitas di Sukabumi, Jawa Barat Mahbub, Rizqi Muhammad; Ragil, Candra
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.2021.42.1.6139

Abstract

The epicenter of the earthquake in Sukabumi has formed subsurface deformation which is now also recorded on the surface area. This is manifested through the geomorphology of the scarp and river lineaments. Extraction of lineaments produced by geological deformation can be used to identify its active tectonic deformation. The research objective is to determine the relationship between the active fault structure and the dominant direction of lineaments in the study area. The Edge Enhancing Filtering method is used to interpret lineaments manually and semi-automatically. The lineament geospatial data was extracted using the Sastratenaya formula to determine the chronology of the lineaments formed. The Sastratenaya formula results showed the lineaments recorded by DEM images data processing, the first segment direction is N315°E and the second is N10°E, both are interpreted as the result of fault reactivation. It can be interpreted that the Cimandiri Fault, which is an active fault that has an N88°E/85° rake 33° sinistral oblique-slip fault movement, affects the lineaments direction of two segments in the research area of Sukabumi, West Java.
Mikrozonasi di Daerah Plampang, Nusa Tenggara Barat Iswanto, Eko Rudi; Riyanto, Theo Alvin; Suntoko, Hadi
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.2021.42.1.6243

Abstract

Nusa Tenggara Barat (NTB) Province is an area with intense seismic activity. This phenomenon is caused by tectonic activity as the result of the convergency of the Eurasia-Australia Plates (subduction zone) in the south and the Flores Fault in the north as well as the presence of local faults. Regarding the plan to develop the Samota area in Sumbawa Island, NTB, a study concerning earthquakes should be done. The purpose of this study is to map the seismic vulnerability index (Kg) through microtremor measurement by using the Horizontal to Vertical Spectral Ratio (HVSR) analysis method. The result of the study is a seismic vulnerability map of the Plampang area which its northern part has a low seismic vulnerability index indicated by the amplification factor value of less than three compared to other areas. The geology of the northern part of the Plampang area consists of volcanic rocks which has hard rock characteristic, very thin sediment thickness, and composed of Tertiary or older rocks. Seismic vulnerability maps can be useful as a reference for earthquake mitigation to reduce its risks.
Interpretasi Struktur Geologi Berdasarkan Fault Fracture Density (FFD) dan Implikasinya Terhadap Potensi Likuefaksi di Daerah Kalibening, Kabupaten Banjarnegara, Jawa Tengah Sunan, Huzaely Latief; Gibran, Akhmad Khahlil; Aditama, Maulana Rizki; Iswahyudi, Sachrul; Widiatmoko, Fajar Rizki; Widagdo, Asmoro; Laksono, FX Anjar Tri
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.2021.42.1.6129

Abstract

The existence of geological structures is often associated with landslides and earthquakes. The Kalibening area is an interesting location for research on that purpose. This area is composed of Pleistocene and Recent rocks units. Based on its stratigraphy, the rocks in the area are truncated by fault structure. It means that the fault in the area is categorized as an active fault. The high morphology and a basin existence on its center indicate that the area formation was controlled by faults. The research is carried out to determine the trend of the geological structures that control the study area. To determine the trend of the geological structure, a structural mapping method of Fault Fracture Density (FFD) map combined with the Bouguer anomaly residual map and hillshade lineaments map is used. In general, the most important thing in the study of structural geology is the geometry of the structural elements. The conceptual model of geological structures is subsequently used to analyze the liquefaction potential of the study area. The interpretation of the structures shows the existence of dextral strike-slip fault followed by companion faults and pull-apart basin that is inferred as the result of normal faulting in the strike-slip mechanism. The dextral strike-slip fault produces a basin filled with loose sediment that is prone to liquefaction in the event of an earthquake and ground motion. This study concludes that the Kalibening area is prone to liquefaction due to the existence of the movement of dextral strike-slip fault, loose sediments that dominate the study area, and shallow groundwater table.
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.
Pemisahan Unsur-unsur pada Monasit Bangka dengan Pengendapan Bertingkat Novriyanisti, Anggi; Prassanti, Riesna; Widana, Kurnia Setiawan
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.2021.42.1.6093

Abstract

Monazite is a mineral side product of tin processing, which mainly contains uranium (U), thorium (Th), rare earth elements (REE), and phosphate compounds (PO4). Besides these main elements, monazite also contains other metals such as aluminum (Al), iron (Fe), bismuth (Bi), gallium (Ga), and thallium (Tl). The elements in monazite must be separated to be used. This study aims to determine the effect of pH variations in the separation of components in monazite with multilevel precipitation and determine elements produced from each pH variation. The variation pH starts from pH 0,5 to 10 with a different pH of zero points five. The elements in monazite are separated gradually, beginning from the decomposition process using sodium hydroxide (NaOH), dissolving with hydrochloric acid (HCl), and graded deposition with ammonium hydroxide (NH4OH). The elements were analyzed using the instrument Inductively Coupled Plasma Optical Spectroscopy (ICP-OES) and UV-Visible Spectrophotometer. The effect of pH variations produced precipitated pH 3, pH 6, pH 6.5, and pH 7. The elements produced at each pH variation are uranium, thorium, rare earth elements, aluminum, iron, bismuth, gallium, and thallium. Uranium and thorium were mostly at pH 3 with the recovery of U 72.3% and Th 46.33% and rare earth elements at pH 6.5 with 41.87% recovery. The elements Fe and Bi mostly settle at pH 3 with levels of 37.9 ppm and 100.9 ppm. The elements Al, Ga, and Tl, precipitate most at pH 6.5 with grades of 30.2 ppm, 69.8 ppm, and 8 ppm respectively.
Potensi Thorium dan Uranium di Kabupaten Bangka Barat Ngadenin, Ngadenin; Syaeful, Heri; Widana, Kurnia Setiawan; Nurdin, Muhammad
EKSPLORIUM Vol. 35 No. 2 (2014): NOVEMBER 2014
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2014.35.2.2754

Abstract

Thorium and uranium in Bangka Island are mainly found in monazite mineral. In the geological point of view the monazite formed in S type granite, sandstones and alluvial deposits. In Bangka Baratwhere several S types granite and also alluvial deposites and this area considered as a potential area for monazite placer. S type granites are predicted as a source of monazite while alluvial deposits are considered as a dispersion place for deposition of monazite. The purpose of this study is to determine the geological information and to know the hypothetical potency of thorium and uranium resources in alluvial deposits. The methodsusedin this study are geological mapping, measurement of thorium and uranium contents in the rock, sampling of granite for petrographic analysis, sampling of heavy mineral in alluvial deposits for grain size analysis. Results of the research show that the lithology of West Bangka region composed of schist unit, meta-sandstone unit, granite intrusion, diabase intrusion, sandstone unit and alluvial deposits. Monazite is found in granite intrusion, sandstone unit and alluvial deposits. Evolving fault strend to northwest-southeast, northeast-southwest and west-east.The results of the grain size analysis of heavy mineral shows the average percentage of monazite in the heavy mineral is 6.34%. Other potential minerals contained in placer deposits are zircon 36.65%, ilmenite 19.67% and cassiterite 14.75%.
Facies Analysis, Sedimentology and Paleocurrent of The Quaternary Nenering Formation, Pengkalan Hulu, Malaysia Ulfa, Yuniarti; Yu, Evonne Hooi Rong; Kit, Ooi Cheng
EKSPLORIUM Vol. 35 No. 2 (2014): NOVEMBER 2014
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Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2014.35.2.2755

Abstract

Nenering Formation is essentially made up of semi-consolidated sediments, which are divided into basal conglomerate beds, conglomeratic sandstone, cross-bedded sandstone, and siltstone to muddy layers facies. It is overlie unconformable to the Berapit Formation, but conformable to the Kroh and Grik Formations. The stratigraphy of Nenering Formation is a fining upwards sequence where the thickness of conglomerate beds become thinner upwards and become thicker for conglomeratic sandstone. The thickness varies from 0.5 m to tenths of meters. The more sandy in the upper portion (cross-bedded sandstone) overlie with thin siltstone and mudstone facies. The clast and grain composition suggested that the material making up the sedimentary sequence were derived predominantly from the erosion of granitoid rocks and sedimentary and metamorphic rocks constitute a minor provenance. Imbrications and the trend sizes of clasts indicate that the palaeo-current flow toward northeast. Cross bedding that was found in conglomerate and sandstone indicates the main channel depositional environment. The sequence stratigraphy of this area match with the Saskatchewan fluvial braided channel model.
Identifikasi dan Estimasi Kadar Mineralisasi Uranium Secara Kuantitatif Berdasarkan Log Gross-Count Gamma Ray di Sektor Lemajung, Kalimantan Barat Muhammad, Adi Gunawan
EKSPLORIUM Vol. 35 No. 2 (2014): NOVEMBER 2014
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2014.35.2.2756

Abstract

Lemajung sector, is one of uranium potential sector in Kalan Area, West Kalimantan. Uranium mineralization is found in metasiltstone and schistose metapelite rock with general direction of mineralization east-west tilted ± 70⁰ to the north parallel with schistocity pattern (S1). Drilling evaluation has been implemented in 2013 in Lemajung sector at R-05 (LEML-40) with total depth of 300 meters and has been completly with well-logging by gross-count gamma ray. The purpose of this activity is to determine uranium mineralization grade with quantitatively methode in the rocks and also determine the geological conditions in sorounding of drilling area. The methodology involves determining the value of k-factor, geological mapping for the sorounding of drill hole, determination of the thickness and grade estimation of uranium mineralization with gross-count gamma ray. Quantitatively from grade estimation of uranium using gross-count gamma ray log can be known that the highest % eU3O8 in the hole R-05 (LEML-40) reaches 0.7493≈6354 ppm eU found at depth interval from 30.1 to 34.96 m. Uranium mineralization is present as fracture filling (vein) or tectonic breccia matrix filling in metasiltstone with thickness from 0.10 to 2.40 m associated with sulphide (pyrite) and characterized by high ratio of U/Th.
Studi Keberadaan Mineralisasi Uranium Di Daerah Biak Numfor, Provinsi Papua Barat Suharji, Suharji; Subiantoro, Lilik; Syaeful, Heri; Widana, Kurnia Setiawan; Prabowo, Hery
EKSPLORIUM Vol. 35 No. 2 (2014): NOVEMBER 2014
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2014.35.2.2757

Abstract

This study was conducted based on the findings of radioactive minerals in the form of indication of relatively high radiation dose rate anomalies. The hypothesis underlying the existence of a high radiation dose rate is the deposition of uranium derived from basalt rock Auwea Formation, uranium enrichment derived from limestone to the soil surface, and the deposition of uranium resulted from the use of fertilizers in agriculture. Therefore the research aimed to obtain the conclusion of its hypotheses. Research methodology applied is geological mapping, radiometric measurement of uranium (U), thorium (Th), and potassium(K) in the field using RS 125 to determine in-situ grade of elements, radiometric measurements of plant fertilizer, sampling, and laboratory analysis of the element grade. Based on the analysis and evaluation of survey data it is known that in the area around Maryendi, Darmapis and Denafi, indicate the presence of anomalous zones which is characterized by the presence of uranium (U) dark brown soil – reddish brown, with the value of the radiation dose of 1.9 to 4,032.3 nSv/h and grade of uranium (U)has 20.27 to 325 ppm eU. Based on the analysis of source rock of uranium, it is concluded that limestone is the source rock of uranium in research area. The results of field observations of the fertilizer and basalt rock of Auwea Formation, it is found that no anomalies may indicate material/rock that acts as the source of uranium.

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