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Tataan Tektonika Batuan Gunung Api di Komplek Adang Kabupaten Mamuju Provinsi Sulawesi Barat Sukadana, I Gde; Harijoko, Agung; Setijadji, Lucas Donny
EKSPLORIUM Vol. 36 No. 1 (2015): MEI 2015
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2015.36.1.2769

Abstract

Adang volcanic complexlocated in Mamuju Region, West Sulawesi can be grouped more detail into seven complexes that are Tapalang, Ampalas, Adang, Malunda, Karampuang, Sumare, and Labuan Rano. Adang complex is one of the main volcanic complexes that still can be identified with good morphological formations. This complex is composed of alkaline volcanic rocks with basic to intermediates composition that have high value of radiation dose rate caused by their radioactive mineral content. Radioactive mineral occurrences on the basaltic-andesitic rocks has never been found in Indonesia, so it becomes very interesting to do research mainly tectonic settings of the volcanic rock complex formation. The purpose of this study is to determine magmatiic typology related with the tectonic setting based on volcanic rock geochemistry using X-Ray Fluorences (XRF) analysis. Adang volcanic rock is the result of a complex process of volcanism having a volcanic center and several lava domes. They are composed of phonolite to dacite rock, with ultrapotassic affinity, interpretation of data concluded that tectonic setting of magmatism formed in active continental margin (ACM). Magmatism source from vulcanic activities influenced by South WestSulawesi micro-continental crust.
Interpretasi Vulkanostratigrafi Daerah Mamuju Berdasarkan Analisis Citra Landsat-8 Indrastomo, Frederikus Dian; Sukadana, I Gde; Saepuloh, Asep; Harsolumakso, Agus Handoyo; Kamajati, Dhatu
EKSPLORIUM Vol. 36 No. 2 (2015): NOVEMBER 2015
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2015.36.2.2772

Abstract

Mamuju and its surrounding area are constructed mainly by volcanic rocks. Volcanoclastic sedimentary rocks and limestones are laid above the volcanic rocks. Volcanic activities create some unique morphologies such as craters, lava domes, and pyroclastic flow paths as their volcanic products. These products are identified from their circular features characters on Landsat-8 imagery. After geometric and atmospheric corrections had been done, a visual interpretation on Landsat-8 imagery was conducted to identify structure, geomorphology, and geological condition of the area. Regional geological structures show trend to southeast – northwest direction which is affects the formation of Adang volcano. Geomorphology of the area are classified into 16 geomorphology units based on their genetic aspects, i.e Sumare fault block ridge, Mamuju cuesta ridge, Adang eruption crater, Labuhan Ranau eruption crater, Sumare eruption crater, Ampalas volcanic cone, Adang lava dome, Labuhan Ranau intrusion hill, Adang pyroclastic flow ridge, Sumare pyroclastic flow ridge, Adang volcanic remnant hills, Malunda volcanic remnant hills, Talaya volcanic remnant hills, Tapalang karst hills, Mamuju alluvium plains, and Karampuang reef terrace plains. Based on the Landsat-8 imagery interpretation result and field confirmation, the geology of Mamuju area is divided into volcanic rocks and sedimentary rocks. There are two groups of volcanic rocks; Talaya complex and Mamuju complex. The Talaya complex consists of Mambi, Malunda, and Kalukku volcanic rocks with andesitic composition, while Mamuju complex consist of Botteng, Ahu, Tapalang, Adang, Ampalas, Sumare, danLabuhanRanau volcanic rocks with andesite to leucitic basalt composition. The volcanostratigraphy of Mamuju area was constructed based on its structure, geomorphology and lithology distribution analysis. Volcanostratigraphy of Mamuju area is classified into Khuluk Talaya and Khuluk Mamuju. The Khuluk Talaya consists of Gumuk Mambi, Gumuk Malunda, and Gumuk Kalukku, while Khuluk Mamuju consists of Gumuk Botteng, Gumuk Ahu, Gumuk Tapalang, Gumuk Adang, Gumuk Ampalas, Gumuk Sumare, and Gumuk Labuhan Ranau.
Evaluasi Sistem Pengendapan Uranium Pada Batuan Sedimen Formasi Sibolga, Tapanuli Tengah Sukadana, I Gde; Syaeful, Heri
EKSPLORIUM Vol. 37 No. 2 (2016): NOVEMBER 2016
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2016.37.2.3112

Abstract

Uranium in nature formed in various deposit type, depends on its sources, process, and depositional environments. Uranium occurrence in Sibolga, hosted in sedimentary rocks of Sibolga Formation, is properly potential to develop; nevertheless, the depositional pattern and uranium mineralization process so far had not been recognized. The research aim is to determine the rock distribution patterns and the existence of uranium grade anomalies based on surface geology and borehole log data. Mineralization occurrences from borehole log data distributed from basalt conglomerate unit (Kgl 1), sandstone 1 unit (Bp 1), conglomerate 2 unit (Kgl 2), and sandstone 2 unit (Bp 2) with their distribution and thickness are thinning to the top. Mineralization distribution in the eastern area, mainly on Kgl 1 unit, dominated by detritus materials from epi-genetic depositional in the form of monazite which is formed along with the formation of granite as its source rock. Meanwhile, mineralization on the upper rocks units formed a channel pattern trending northeast-southwest, which formed in syn-genetic process consist of uraninite, carnotite, and coffinite. Sibolga Formation deposition originated from east to west and uranium deposit formed because of the differences of depositional environment from oxidation in the east to the more reductive in the southwest. The increasing of organic materials in southwest basin caused the reduction condition of depositional environment.
Pola Tahanan Jenis dan Konduktivitas Batuan Mengandung Mineral Radioaktif di Botteng dan Takandeang, Mamuju, Sulawesi Barat Muhammad, Adi Gunawan; Indrastomo, Frederikus Dian; Sukadana, I Gde
EKSPLORIUM Vol. 38 No. 1 (2017): MEI 2017
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2017.38.1.3540

Abstract

The general investigation activities of radioactive minerals in Mamuju Area, West Sulawesi is a respon of the environmental radioactivity measurement result, which shows the existence of high radioactivity value. High radioactive mineral content found in Botteng and Takandeang Villages. From the outcrops, they composed of leucite-basalt rocks; meanwhile the subsurface characteristics of this area are unknown. To characterize the subsurface geology, related to uranium and thorium mineralization in Botteng and Takandeang area, geophysical measurement conducted using resistivity and Induced Polarization (IP) methods. The measurements carried out using Wenner and dipole-dipole configurations. The measurements started with the creation of six measurement paths where three lines: GF/BTGY-01, GF/BTGK-02, and GF/BTGK-04 are in Botteng and three other lines: GF/TKDK-01, GF/TKDK-07 and, GF/TKDY-06 are in Takandeang. Measurements conducted by crossing the surface radiometric anomaly distribution. The result showed anomaly occurences on autobreccia distribution in GF/TKDY-6, GF/TKDK-07, and GF/BTGK-04 locations. Several mineralization indication on surface identified in GF/BTGK-0, and GF/TKDK-01 sections, charaterized by chargeability anomalies more than 25.14 ms and 81.4 ms respectively. All significant anomalies are recomended as drilling location.
Geological Structure Control on the Formation of Metal Mineralization at Quartz Veins in Jendi Village, Wonogiri Regency, Central Java Widagdo, Asmoro; Sukadana, I Gde; Indrastomo, Frederikus Dian
EKSPLORIUM Vol. 43 No. 2 (2022): NOVEMBER 2022
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/eksplorium.2022.43.2.6623

Abstract

Quartz veins in the Jendi area and its surroundings are formed by geological structures with distributions and patterns that need to be known. This study uses data on striation, quartz vein orientation, and metal content in quartz veins. The use of this data aims to determine the relationship between the vein direction pattern and its metal mineral content with the main structure that forms it. The results of this study can be useful in determining the structural model and distribution of veins in the study area. The research method was carried out through a series of field and laboratory work. Fieldwork includes measuring striation data, measuring the orientation of quartz veins, and taking quartz vein samples. Studio work includes stereographic analysis of striation data, rosette diagram analysis of vein measurement data, and analysis of metallic element content of quartz veins. The quartz vein mineralization zone in the study area is controlled by a right slip fault with a northwest-southeast trend that forms a transtension zone with a north-south trend. The north-south trending veins are generally thick, long/continuous, and have a high metal content.
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.
Radioactive Mineral Distribution on Tin Placer Deposits of Southeast Asia Tin Belt Granite in Bangka Island Ngadenin, Ngadenin; Sukadana, I Gde; 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 : BRIN Publishing

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.
Characteristics and Genesis of Mount Pengki: A Scoria Cone of Dago Volcano, West Java, Indonesia Adimedha, Tyto Baskara; Ciputra, Roni Cahya; Rosianna, Ilsa; Sukadana, I Gde; Harijoko, Agung; Handini, Esti; Pratiwi, Fadiah; Indrastomo, Frederikus Dian; Syaeful, Heri; Rachael, Yoshi; Sukmawan, I Gusti Made
EKSPLORIUM Vol. 45 No. 2 (2024): NOVEMBER 2024
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2024.7131

Abstract

Scoria cones are a typical product of volcanic activity constructed by the bomb and lapilli-sized pyroclasts formed by Strombolian eruption. Mount Pengki is a scoria cone found in Miocene Dago Volcano, West Java. Mount Pengki was a remnant of a Miocene volcano that was exceptionally well preserved and exposed. This scoria cone contains layers of scoria beds and a lava flow unit. The study aims to characterize the exposed scoria bed deposits and investigate the eruptive history and degradation process of Mount Pengki. Field observation, including measured sections and detailed characterizations of the Mount Pengki quarry, allows us to observe its volcanic sequence from its internal structure toward the surface. Morphometric analysis of Mount Pengki can describe the degradation process undergone by the scoria cone. The early phase deposits were characterized by massive to weakly bedded, poorly sorted, clast-supported beds mainly composed of coarse lapilli to bombs/blocks scoria grain. The middle phase deposit typically shows well-stratified, well-sorted, clast-supported scoria beds with coarse ash to coarse lapilli grain size. The late phase deposit is similar to the middle phase deposit, with additional features of coarser-grain, reverse grading, and clast-supported lenticular beds. Eruptive mechanisms involved in the formation of Mount Pengki include ballistic transport of clasts, fallout deposition, and grain avalanching process. The degradation process was likely influenced by prolonged exposure to weathering, cone rim collapse, and regional deformation processes.