EKSPLORIUM最新文献

{"title":"Ore Mineralization Characteristics in Hydrothermal Alteration at Mangunharjo and Surrounding Areas, Pacitan, Indonesia","authors":"Abdul Faisal Baba, S. Mulyaningsih, R. A. Hidayah","doi":"10.17146/eksplorium.2022.43.1.6194","DOIUrl":"https://doi.org/10.17146/eksplorium.2022.43.1.6194","url":null,"abstract":"The research area is located in Mangunharjo-Grindulu, Pacitan (Indonesia), as part of the Southern Mountain Tertiary Volcanic Arch. Outcrops of quartz veins-riched volcanic rock associated with sulfide minerals are found in this area. The Southern Mountain Oligo-Miocene magmatic arc is known as the potential area that contains precious metal deposits. The study aimed to determine the characteristics of the mineralized zone in this area. The research methods are geological surface mapping, thin-section observation, mineragraphy, and X-Ray Diffraction (XRD). The results show that the constituent lithologies were andesitic lava, breccia, and tuff; co-ignimbrite breccia, dacitic pumice and tuff, and dacitic dike; and pyroxene-rich andesitic volcanic rocks. The geological structure is dominated by oblique normal faults, strike-slip faults, and upward oblique faults associated with shear joints filled with quartz veins. Fieldwork observation, thin-section analyses, and mineragraphic and XRD observations identify three alteration zones in the hydrothermal system: the advanced argillic zone, the intermediate argillic zone, and the chloritized zone. By the mineral’s association, it is interpreted that the advanced argillic zone was formed at a temperature of 220-330oC and pH 3-6 due to dissemination with side rocks located near the hydrothermal flows; the intermediate argillic zone and the chloritized zone were formed at a temperature of 150-300oC and a pH of 5-6 due to chloritized alteration of the hydrothermal fluid carrying the ore. This alteration zone has no economic potential for precious metal minerals so it is better to be developed for education, conservation, and natural laboratories.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77754028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sub-surface Geological Modeling Based on Gravity Residual Data in Adang Volcanic Rock Area, Mamuju, West Sulawesi Province","authors":"Adhika Junara Karunianto, D. Haryanto, Ngadenin Ngadenin","doi":"10.17146/eksplorium.2022.43.1.6089","DOIUrl":"https://doi.org/10.17146/eksplorium.2022.43.1.6089","url":null,"abstract":"The Mamuju area of West Sulawesi Province is composed of Adang volcanic rock that is a product of the process of volcanism in a volcanic complex with an eruption center and several lava domes. The geology of the study area is composed of eleven rock units, namely Adang breccia, Adang lava, lava dome, volcanic conglomerate, Ampalas breccia, Malunda breccia, Boteng lava, Tapalang breccia, limestone, reef limestone, and alluvium. The mineralization of uranium, thorium, and rare earth elements formed in Adang lava thorianite veins. Adang lava is intruded by a dioritoid found in the Mamuju river upstream. The gravity modeling technique has produced two 2-D subsurface models based on gravity data on 2-D cross-sections of the residual gravity map. It is known that the rock density range from 2.10 to 2.85 g/cm3 in the study area. Based on the interpretation of two 2-D subsurface models, a batholith, a giant-sized intrusive rock, is found in the southeastern part of the study area with a rock density of about 2.85 g/cm3 and is interpreted to be dioritoids. Furthermore, deep intrusion rocks also occur in the center part of the study area with a rock density of 2.8 g/cm3. It is estimated to be the same as the rock in the southeastern part of the study area. Dioritoid intrudes a volcanic breccia sedimentary rock with a density of about 2.1 g/cm3.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88360171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geostatistical Ore Body Modeling on Uranium Mineralization in Remaja Sector, Kalan Area, West Kalimantan","authors":"R. C. Ciputra, M. Heriawan, H. Syaeful, Dhatu Kamajati, Putri Rahmawati","doi":"10.17146/eksplorium.2022.43.1.6622","DOIUrl":"https://doi.org/10.17146/eksplorium.2022.43.1.6622","url":null,"abstract":"Manual ore body modeling on Remaja Sector, Kalan, West Kalimantan generally takes a long time and is subjective. On the other hand, automatic modeling (implicit modeling) is faster, objective, and equipped with uncertainty factors. This study aimed to analyze the comparison between the geostatistical Sequential Indicator Simulation (SIS) ore body model to the manual ore body model. The lithology database was used as input for variogram analysis and SIS simulation. The directional variogram was used to construct an experimental variogram for the lithology with orientation data. The orientation of the lithologies corresponds to the anisotropy of their variogram map. The SIS was carried out in  Block A and Block B with block sizes of 6×6×6 m3 and 5×5×5 m3 respectively. The simulation results were processed to produce a lithology probability model. By using maximum probability as block lithology, simulation results were well validated by the composite database histogram, the lithologies along the tunnel on the geological map of level 450 masl of Eko Remaja Tunnel., and the lithologies along boreholes. The weakness of the geostatistical ore body model was the results depending on the input parameters. Meanwhile, several advantages of the geostatistical ore body model were a faster processing process, equipped with an uncertainty factor, and the block size of the model has taken into account the distance between grade data so that it can be used directly for grade estimation. Quantitatively, the geostatistical ore body model had a higher average percentage of conformity to the lithology of the mineralized zone along the borehole than the manual ore body model.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77050747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review on Granitic Rocks in Sumatra: Intrusion Process, Classification, Mineralization and Potential Uses","authors":"Ronaldo Irzon, H. Syaeful, A. Kusworo, J. Wahyudiono, Ngadenin Ngadenin","doi":"10.17146/eksplorium.2022.43.1.6471","DOIUrl":"https://doi.org/10.17146/eksplorium.2022.43.1.6471","url":null,"abstract":"Granitic rocks are widely distributed in Sumatra and surrounding areas. These granitoids are classified into several granite provinces of Southeast Asia with different intrusion processes and specific characteristics. This paper aims to review the intrusion of granitic rocks in Sumatra and describe the opportunities associated with it. Granite rocks are used to manufacture cultural heritage, works of art, and ornaments because of their weathering resistance, color diversity, and hardness characters. S-type granite intrusion in Sumatra might be associated with tin mineralization while silver-gold with the I-type. Theoretically, granite contains more REE than other igneous rocks. Mining and extraction difficulties complicate the direct REE exploitation from fresh granite. A-type granite relatively contains more REE than the other types, but this type of granite is not correlated with certain provinces. Indonesia has a tropical climate which is prone to weathering. Therefore, it is possible for REE and/or bauxite enrichments in the granite weathering horizon. Granite is assumed to be a potential source of uranium and thorium, especially for the S-type, because it is formed through the compression of sediments that can absorb these radioactive elements from the continental crust.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89424508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectonic Pattern Imaging of Southern Sumatra Region Using Double Difference Seismic Tomography","authors":"Akmal Firmansyah, W. Wandono, M. Ramdhan","doi":"10.17146/eksplorium.2022.43.1.6603","DOIUrl":"https://doi.org/10.17146/eksplorium.2022.43.1.6603","url":null,"abstract":"Southern Sumatra and its surroundings are close to the contact zone of the Indo-Australian plate and Eurasian plate, so the area always relates to the high seismicity zone. The Sumatran subduction zone, the Mentawai fault, and several segments of the Sumatran fault drive seismic activities in the area. Tectonic settings are essential to understanding the area's source and hazard. This understanding can be obtained using the relocated hypocenter distribution and the 3D velocity model in the area. Relocated hypocenters and velocity models are obtained from simultaneous inversion from the BMKG earthquake catalog in January 2012-December 2020 using the double difference seismic tomography method. Seismic velocity inversion of P- and S- wave tomograms image the thermal zone beneath Dempo and Patah volcanoes at a depth of 30-50 km. Slab dehydration is also observed in several forearc high zone. Both phenomena are associated with negative anomalies. The Sumatran and Mentawai fault zones are marked between negative and positive anomalies on the contact zone. The subducted slab of the Indo-Australian plate is observed until a depth of 150 km, which is the maximum depth of nodes used in this study. The granitic basement beneath Anak Krakatau volcano is detected until 10 km. Two of those geological features are related to positive anomalies.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90189583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peningkatan Perolehan Uranium, Torium, dan Logam Tanah Jarang dalam Residu Pelarutan Parsial pada Pengolahan Monasit","authors":"Novita Sari Fatihah, Mutia Anggraini, Afiq Azfar Pratama, K. Widana","doi":"10.17146/eksplorium.2021.42.2.6044","DOIUrl":"https://doi.org/10.17146/eksplorium.2021.42.2.6044","url":null,"abstract":"ABSTRAK. Monasit merupakan mineral hasil samping pengolahan timah yang mengandung fosfat, logam tanah jarang, dan unsur radioaktif berupa uranium dan torium. Unsur-unsur tersebut dapat dimanfaatkan secara optimal jika terpisah satu dengan yang lainnya melalui proses pengolahan. Pengolahan monasit meliputi proses dekomposisi, pelarutan parsial, dan pengendapan. Pemisahan unsur logam tanah jarang dari unsur radioaktif dalam monasit dilakukan melalui proses pelarutan parsial, akan tetapi pemisahan tersebut belum optimal sehingga diperlukan proses lebih lanjut untuk meningkatkan perolehan unsur-unsur tersebut. Pada penelitian ini, proses tersebut dilakukan melalui dua metode yaitu pelarutan total dengan asam klorida (HCl) yang bertujuan untuk melarutkan semua unsur dalam endapan dan pengendapan dengan ammonium hidroksida (NH4OH) yang bertujuan untuk memisahkan unsur radioaktif dan unsur logam tanah jarang. Kedua metode tersebut dilakukan pada kondisi optimum proses dengan berbagai variasi pH, suhu, dan waktu. Berdasarkan hasil pengamatan diperoleh bahwa kelarutan optimum masing-masing unsur sebesar 67,6% uranium, 15,3% torium, dan 50,8% LTJ pada kondisi proses pelarutan pH 1, pada suhu 80°C selama 2 jam. Sedangkan pada proses pengendapan diperoleh recovery pengendapan masing-masing unsur sebesar 57% uranium, 75,7% torium, 4,8% logam tanah jarang pada kondisi pH 6. Berdasarkan data tersebut disimpulkan bahwa uranium, torium, dan logam tanah jarang dapat larut pada kondisi proses pelarutan pH 1, suhu 80°C selama 2 jam, dan dapat dipisahkan pada kondisi pH pengendapan 6.ABSTRACT. Monazite is a by-product of tin processing containing phosphate, rare earth elements, and radioactive elements such as uranium and thorium. These elements can be utilized optimally if separated from one another through processing. Monazite processing includes decomposition, partial dissolution, and precipitation processes. The separation of rare earth elements from radioactive elements in monazite is carried out through a partial dissolution process, but the separation is not optimal so that further processes are needed to increase the recovery of these elements. In this study, the process was carried out using two methods, namely total dissolution with hydrochloric acid (HCl) which aims to dissolve all elements in the precipitate and precipitation with ammonium hydroxide (NH4OH) which aims to separate radioactive elements and rare earth elements. Both methods were carried out under optimum process conditions with various variations in pH, temperature, and time. Based on observations, it was found that the optimum solubility of each element was 67.6% uranium, 15.3% thorium and 50.8% LTJ under the dissolving process conditions of pH 1, at 80°C for 2 hours. While in the deposition process, the precipitation recovery of each element is 57% uranium, 75.7% thorium, 4.8% rare earth metals at pH 6 conditions. Based on these data, it can be concluded that uranium, thorium, and rare ear","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79912604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Sedimentary Process of Sand Deposits in Bogowonto River, Purworejo, Central Java, and Progo River, Kulonprogo, Yogyakarta Using Granulometric Analysis","authors":"Muchamad Ocky Bayu Nugroho, Y. Rizkianto, Riyan Ranggas Yuditama, Akbar Ryan, A. Maulana","doi":"10.17146/eksplorium.2021.42.2.6436","DOIUrl":"https://doi.org/10.17146/eksplorium.2021.42.2.6436","url":null,"abstract":"Sedimentation is the most traditional separation technique and it is relying on efficient coagulation and flocculation to produce flocs with good settling properties. Bogowonto River and Progo River belong to South Serayu Area. There are similar geological processes that affected the river forming process i.e., erosional process, provenance, and fault systems. The sand sedimentation process for each river could be different due to geometry and river morphology. This research aims to reveal the possible parameters that affected the sedimentary process and sediment material along the stream river. Granulometric analysis was done in this research. Samples were taken from 3 points (upstream, middle, and downstream) of Bogowonto river and Progo river. Statistically, the upstream and middle stream of Bogowonto River shows more dunes and beach environment characters than Progo River. It could be interpreted if Bogowonto has more deposit plain like point bar than Progo River. The downstream area has been interpreted as the upper part of estuarine due to river and beach environment. The volcanic arc (Tertiary & Quarternary) is the main sediment source for these rivers. The sediment supply of the Progo River is strongly influenced by Merapi’s eruption whereas Bogowonto river is dominated by reworked Old Andesite Formation (OAF) & Sumbing’s material. Morphologically, Bogowonto has more meandering features than Progo that indicates the development of river stage in a long time and wide distributed sediment materials.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78280432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Penentuan Komposisi Bahan Bakar Nabati Dalam Bahan Bakar Minyak Campuran Menggunakan Metode Direct Counting C-14","authors":"Neneng Laksminingpuri Sanusi, Moch Faizal Ramadhani, Nurfadhlini Nurfadhlini, Lisa Aisyah","doi":"10.17146/eksplorium.2021.42.2.6363","DOIUrl":"https://doi.org/10.17146/eksplorium.2021.42.2.6363","url":null,"abstract":"ABSTRAK. Telah dilakukan penentuan komposisi bahan bakar nabati (BBN) dalam bahan bakar minyak campuran (BBMC) dengan metode direct counting C-14. Penentuan komposisi BBN dalam BBMC dilakukan dengan cara memipet 10 mL BBMC ke dalam vial gelas kemudian ditambahkan 10 mL larutan sintilator Ultima Gold F (UGF) ke dalamnya. Vial tersebut dikocok agar campuran menjadi homogen kemudian dicacah menggunakan LSC (Liquid Scintillation Counter) Elmer Perkin 2900TR selama 20 menit sebanyak 30 siklus. Hasil pencacahan ditampilkan dalam bentuk tSIE (transformed external standard spectrum) dan cpm (cacahan permenit). Hasil analisis memperlihatkan nilai cpm yang meningkat seiring kenaikan persentase BBN dalam BBMC. Nilai cpm terendah dan tertinggi untuk sampel bensin, avtur, dan solar berturut-turut adalah 14,2363 dan 62,0343, 10,664 dan 44,535, serta 9,410 dan 61,789. Terdapat korelasi kuat antara nilai tSIE dan nilai cpm pada bensin dan solar tapi tidak pada avtur. Hasil analisis terhadap sampel uji menunjukkan bahwa sampel tersebut berada di luar grafik deret sampel. Metode direct counting ini diharapkan dapat menjadi referensi dalam uji mutu BBMC.ABSTRACT. The composition of biofuel (BF) in mixed oil fuel (MOF) has been determined using the C-14 direct counting method. Determination of the composition of BF in MOF was carried out by pipetting 10 mL of BBMC into a glass vial and then adding 10 mL of Ultima Gold F (UGF) scintillator solution into it. The vial was shaken so that the mixture became homogeneous and then counted using the Elmer Perkin 2900TR LSC (Liquid Scintillation Counter) for 20 minutes for 30 cycles. The results of the counting are displayed in the form of tSIE (transformed external standard spectrum) and cpm (counts per minute). The results of the analysis show that the value of cpm increases with the increase in the percentage of BF in MOF. The lowest and highest cpm values for gasoline, avtur, and diesel samples were 14.2363 and 62.0343, 10.664 and 44.535, and 9.410 and 61.789, respectively. There is a strong correlation between tSIE and cpm values for gasoline and diesel but not for avtur. The results of the analysis of the test sample indicate that the sample is outside the sample series graph. This direct counting method is expected to be a reference in the BBMC quality test.","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83122038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Karakterisasi Hidrogeologi Daerah Sekitar Tapak PLTN di Bengkayang, Kalimantan Barat","authors":"Adiman Muhammad, Rachman Fauzi, Adhika Junara Karunianto, Wira Cakrabuana, Widodo Widodo","doi":"10.17146/eksplorium.2021.42.2.6479","DOIUrl":"https://doi.org/10.17146/eksplorium.2021.42.2.6479","url":null,"abstract":"ABSTRAK. Evaluasi tapak merupakan tahap penting dalam penentuan lokasi calon tapak PLTN skala komersial di Indonesia. Aspek–aspek yang dikaji dalam evaluasi tapak berdasarkan peraturan yang berlaku antara lain aspek geoteknik dan aspek dispersi zat radioaktif. Untuk mendukung kajian aspek tersebut maka perlu adanya kajian karakterisasi hidrogeologi daerah sekitar tapak. Tujuan penelitian ini adalah menentukan karakteristik hidrogeologi daerah sekitar tapak PLTN di Kabupaten Bengkayang, Provinsi Kalimantan Barat berdasarkan aspek geologi dan geofisika. Metode yang dilakukan adalah pemetaan geomorfologi, pemetaan geologi, pemetaan hidrogeologi, pengukuran geolistrik, serta analisis terpadu. Secara morfologi, daerah penyelidikan dibagi menjadi tiga satuan, yaitu dataran aluvial, bukit terisolasi, dan dataran pantai. Secara stratigrafi, satuan batuan yang ditemukan berurutan dari tua ke muda adalah andesit, granodiorit, diorit, endapan pasir kuarsa, endapan pantai, dan endapan aluvial. Pengukuran geofisika menggunakan metode geolistrik dilakukan pada 12 lintasan dengan masing-masing panjang lintasan 470 m dan spasi elektroda 10 m. Pada penampang geolistrik ditemukan beberapa anomali pada kompleks batuan beku yang mengalami frakturasi atau tubuh diorit yang menerobos satuan andesit. Nilai anomali ini berkisar antara 300 Ωm dan >8000 Ωm. Nilai resistivitas yang sangat rendah (<30 Ωm) diinterpretasikan sebagai endapan aluvial yang jenuh air dengan ketebalan mencapai ±100 m. Daerah penelitian dapat dibagi menjadi tiga satuan hidrogeologi; akuifer dengan aliran melalui ruang antarbutir kelulusan tinggi, akuifer dengan aliran melalui ruang antarbutir kelulusan sedang, dan akuifug setempat berarti. Secara umum pola aliran tanah bebas mengalir relatif dari SSW ke NNE.ABSTRACT. Site evaluation is an important phase of site selection for commercial-scale nuclear power plants (NPP) in Indonesia. Geotechnical and radioactive material dispersion aspects are some of the aspects which are assessed in site evaluation under provisions of laws and regulations. To support those aspect evaluations, it is necessary to conduct hydrogeological characterization in the vicinity of the NPP site. The purpose of this study is to determine the hydrogeological characteristic of the vicinity of the NPP site in Bengkayang Regency, West Kalimantan Province based on geological and geophysical aspects. The methods of this study consist of geomorphological mapping, geological mapping, hydrogeological mapping, geoelectric measurement, and integrated analysis. The study area consists of three morphological units: alluvial plain, isolated hills, and coastal plain. Stratigraphically, the lithology units of the study area, from the oldest to the youngest, consist of andesite, granodiorite, diorite, quartz sand deposits, coastal deposits, and alluvial deposits. The geophysical measurement used is the geoelectric method which is conducted at 12 electrode arrays with 470 m length and spacing o","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83418611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution and Mineralogical Characteristic of Raya Volcanics, West Kalimantan","authors":"W. A. Draniswari, F. Pratiwi, Ngadenin Ngadenin, I. Sukadana, T. B. Adimedha, R. C. Ciputra, Ekky Novia Stasia Argianto, Erwina Aminarthi, V. Supraba","doi":"10.17146/eksplorium.2021.42.2.6511","DOIUrl":"https://doi.org/10.17146/eksplorium.2021.42.2.6511","url":null,"abstract":"","PeriodicalId":11616,"journal":{"name":"EKSPLORIUM","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86557064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}