Riset Geologi dan Pertambangan最新文献

{"title":"Characterization of Thorium-bearing Minerals Using Micro-XRF in Metamorphic Rocks of Harau, West Sumatera","authors":"T. B. Adimedha, H. Syaeful, F. D. Indrastomo, Ngadenin Ngadenin, W. A. Draniswari","doi":"10.14203/risetgeotam2022.v32.1162","DOIUrl":"https://doi.org/10.14203/risetgeotam2022.v32.1162","url":null,"abstract":"In 1974, BATAN conducted a survey to review the potential of radioactive minerals in Harau, West Sumatra. The survey shows that there are radiometric anomalies in several locations in the area. However, the survey has not been able to show the radioactive elements and minerals found in Harau. This study aims to identify and characterize radioactive elements and minerals in Harau. To prove that detailed geological mapping, radiometric mapping with Gamma Spectrometer RS-125, and analysis using Micro-XRF \"M4 Tornado Plus®\". The results of geological and radiometric mapping show that there are high thorium contents in the metamorphic rocks of the Kuantan Formation reaching 2300 ppm eTh. Identification of thorium-bearing minerals using a micro-XRF instrument resulted in thorium-bearing minerals found in the Harau area are thorite (ThSiO4), yttrialite (YThSi2O7), and monazite ((Ce,Nd,Th)PO4) with thorium levels within 2.75 - 42.75% ThO2 but experiencing a significant increase in Fe. In principle, micro-XRF analysis can identify minerals well, but this analysis can be supported by other analyzes so that it can provide much more precise results. This research is expected to provide information about the occurrences of thorium-bearing minerals in Harau, West Sumatera.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"18 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90378510","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":"Kinetics Study of Leaching Ore Nickel Laterite Using Hydrochloric Acid in Atmosphere Pressure","authors":"Wahab Wahab, Deniyatno Deniyatno, Marthines Saranga, Y. Supriyatna","doi":"10.14203/risetgeotam2022.v32.1163","DOIUrl":"https://doi.org/10.14203/risetgeotam2022.v32.1163","url":null,"abstract":"Leaching of nickel laterite ore at atmospheric pressure is a leaching method that can be operated at >100⁰C temperatures in an atmospheric pressure, which is applicable to a low-grade laterite ore. This research aimed to study the effect of temperature, acid concentration, and leaching time on nickel extraction percentage and the leaching kinetics. Hydrochloric acid (HCl) was used as a leaching agent and several variables were applied, i.e., temperature (80⁰C, 90⁰C, 100⁰C), HCL concentration (5 M, 6 M, 7 M), and leaching duration (120 minutes, 150 minutes, 180 minutes) to investigate their effect on nickel extraction percentage. In addition, the kinetics of the leaching process was studied using a Shrinking Core Model. The results showed that the percentage of nickel extraction increased with increasing temperature, HCl concentration, and leaching time. The lowest percentage of nickel extraction of 51.29% was obtained when 80⁰C, five molar HCl, and 120 minutes leaching duration were applied. In contrast, The highest percentage of nickel extraction of 97.22% was obtained at 100⁰C, seven molar HCl, and 180 minutes of leaching time. The kinetics study results show that diffusion through the unreacted solid product layer controls the nickel leaching rate.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"36 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87296062","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":"Cover dan Preface Volume 32 Nomor 1 Tahun 2022","authors":"Andri Agus Rahman","doi":"10.14203/risetgeotam2022.v32.1217","DOIUrl":"https://doi.org/10.14203/risetgeotam2022.v32.1217","url":null,"abstract":"","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"51 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79133793","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":"Coseismic and postseismic deformation from the 2007 Bengkulu earthquake based on GPS Data","authors":"I. Meilano, S. Susilo, E. Gunawan, S. Rahmadani","doi":"10.14203/risetgeotam2021.v31.1182","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1182","url":null,"abstract":"On September 12, 2007, a M8.5 megathrust earthquake occurred along the Sunda trench near Bengkulu, West Sumatra. GPS data in Sumatra have indicated the coseismic and postseismic deformations resulting from this earthquake. Our estimate of coseismic displacements suggests that the earthquake displaced up to ~1.8m at GPS stations located north of the epicenter. Moreover, our principal strain estimation in the region suggests that the maximum coseismic extensional strain is ~40 ppm. Our analysis of GPS data in the region suggests that the postseismic decay of the 2007 Bengkulu earthquake was 46 days, estimated using a logarithmic function.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"151 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79722136","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":"Wireline logs vs drilling events: Which one to believe in implying subsurface pressure?","authors":"A. Ramdhan, Arifin Arifin, Rusmawan Suwarman","doi":"10.14203/risetgeotam2021.v31.1176","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1176","url":null,"abstract":"As generally known, subsurface pressure can be implied using both wireline logs and drilling events. However, there may be a case where wireline logs and drilling events do not indicate the same subsurface pressure. Data from four vertical wells located in the South Sumatra Basin, Indonesia, were analyzed as a case study. Two wells, Wells A and D, encountered high overpressured zones, confirmed by drilling events and wireline logs data. The two others, Wells B and C, only encountered low overpressured zones, inferred by the relatively low mudweight used during the drilling. However, the wireline logs of Wells B and C show a reversal as Wells A and D. There are two hypotheses to explain the condition in Wells B and C. First, the wireline logs reversal is due to shallow carbonate cementation. Second, Wells B and C were drilled in an unintentional underbalanced condition. The method used includes XRD, SEM, and titration analysis. The results show that the first hypothesis is false, while the second is true. It may be due to some missing information related to drilling events in the final well report of Wells B and C.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"62 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83921409","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":"Geothermal Reservoir Identification based on Gravity Data Analysis in Rajabasa Area- Lampung","authors":"M. Sarkowi, R. C. Wibowo","doi":"10.14203/risetgeotam2021.v31.1164","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1164","url":null,"abstract":"Gravity research in the Rajabasa geothermal prospect area was conducted to determine geothermalreservoirs and faults as reservoir boundaries. The research includes spectrum analysis and separation of the Bouguer anomaly to obtain a residual Bouguer anomaly, gradient analysis using the second vertical derivative (SVD) technique to identify fault structures or lithological contact, and 3D inversion modeling of the residual Bouguer anomaly to obtain a 3D density distribution subsurface model. Analysis was performed based on all results with supplementary data from geology, geochemistry, micro-earthquake (MEQ) epicenter distribution map, and magnetotelluric (MT) inversion profiles. The study found 3 (three) geothermal reservoirs in Mount Balirang, west of Mount Rajabasa, and south of Pangkul Hot Spring, with a depth of around 1,000-1,500 m from the ground level. Fault structures and lithologies separate the three reservoirs. The location of the reservoir in the Balirang mountain area corresponds to the model data from MEQ, temperature, and magnetotelluric resistivity data. The heat source of the geothermal system is under Mount Rajabasa, which is indicated by the presence of high-density values (might be frozen residual magma), high-temperature values, and the high number of micro-earthquakes epicenters below the peak of Mount Rajabasa.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"31 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82839538","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":"Time Defendability of Ground Resistance Properties and Its Application of Vitric Tuff on the Development of Ground Enhancement Material","authors":"Jakah Jakah, D. Muslim, A. T. Mursito, Z. Zakaria, H. Nurohman","doi":"10.14203/risetgeotam2021.v31.1149","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1149","url":null,"abstract":"Ground repair material is an essential part of the grounding system as a lightning rod to reduce the risk of lightning activity. Grounding repair materials consist of conductive and superconductive materials, commonly known as Ground Enhancement Materials (GEM). GEM has a low resistivity, very effectively supporting lightning shock energy to earth. Vitric tuff, a pyroclastic rock, is composed of an aluminosilicate (phyllosilicate) mineral group developed as a grounding improvement material. The primary purpose of this study was to determine the decrease in resistivity of vitric tuff in its development as a GEM. The research method consisted of field observations and laboratory experiments (treatment with chemical-physical activation and formulation with additives). The results showed that moisture content, SiO2/Al2O3 ratio (quartz and feldspar mineral/albite), clay mineral, crystal quality (impurities), carbon, and salt were influenced by vitric tuff resistivity. With the vitric tuff formulation and additives, the resistivity reduction is above 99%. Based on experiments, the best formulation of GEM made from tuff is 65% activated vitric tuff, 27% activated charcoal, 6% NaCl, and 2% Cement Material Cellulose. The formula produces a resistivity value of 0.0124 Ω-m, which is stable with time and meets GEM requirements (ρ ≤ 0.20 Ω-m). Riset Geologi dan Pertambangan Indonesian Journal of Geology and Mining Vol.31, No 2, pages 63–76 doi: 10.14203/risetgeotam2021.v31.1149","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"57 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76901786","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":"TWO-DIMENSIONAL INVERSION MODELING OF MAGNETOTELLURIC (MT) SYNTHETIC DATA OF A GRABEN STRUCTURE USING SimPEG","authors":"I. Muttaqien, J. Nurjaman","doi":"10.14203/risetgeotam2021.v31.1121","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1121","url":null,"abstract":"The magnetotelluric (MT) method is a passive exploration method in geophysics that utilizes natural electromagnetic waves as a signal source. MT operates in the frequency range of 10 -5 - 10 6 Hz , designed to study the structure of the conductivity below the earth's surface with a depth range from several tens of meters to the upper mantle. In this paper, 2-dimensional inversion modeling is performed on MT synthetic data using the SimPEG software. First, forward modeling is done by making a 2-dimensional conductivity model in the form of a valley (graben), which aims to produce MT synthetic data in TE (transverse electric) mode, TM (transverse magnetic) mode, and a combination of TE mode and TM mode. Next, an inversion modeling is performed on the MT synthetic data by adding a 5% Gaussian noise and a  10 -5 floor as data uncertainty to obtain a 2-dimensional conductivity inversion model. The final result can be validated by comparing the true model and the inversion model and between observational data (synthetic) and predictive predicted data. The results of this study provide a significant fit of the model and suitability of the data. The inversion quality is validated with an RMS Error for TE mode of 0.349%, TM mode of 0.348%, and a combination of TE and TM mode of 0.249%.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"33 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91146551","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":"CHARACTERIZATION OF ROCK LAYERS BASED ON REFRACTION SEISMIC METHOD: A CASE STUDY OF MENTARANG’S HYDRO-POWER PLANT, MALINAU REGENCY, NORTH KALIMANTAN","authors":"W. Priyanto, Jauhari Arifin","doi":"10.14203/risetgeotam2021.v31.1160","DOIUrl":"https://doi.org/10.14203/risetgeotam2021.v31.1160","url":null,"abstract":"North Kalimantan Province is a new province that is dynamic in development in order to prosper the inhabitants. The research and exploration to make a plan to develop new renewable energy are one of their main programs. The hydro-power plant of Mentarang, Malinau Regency, Kalimantan Utara is a plan program in 2020. The research study of hydro-power plants is essential as a reference in the development plan and avoids the hazard, miss calculation due to human error, etc. Seismic refraction is used in the feasibility study and detailed engineering study (FS DED) of Mentarang's Hydro-power plant. Analysis from the Seismic refraction method can be used as an input parameter for deciding the feasibility of Mentarang's hydro-power plant. This study aims to characterize the sub-surface layers, structure, and sub-surface layer thickness within this area. The seismic refraction method uses the intercept time or travel-time versus distance and processed using the reciprocal method, then it is modelled using inversion and resulted in a 2D profile. This research study was used the seismic refraction method with geometry acquisition of 14 sources with two spread and 5 meters of geophone interval.  The analysis result of the 2D inversion profile model, in general, is classified as four strata layers. These strata are categorized as weathered layers with 5-15 meters of thickness, clay, and Sandstone about 5-20 meter of layer thickness, Sandstone with the layer thickness of about 20-50 meters, and lastly, granite, lava rocks, or limestone with depth more than 70 meters below the subsurface. There is a possibility of a structure at an offset of 70 meters, but this method's limitation will overestimate the conclusion. Therefore, it is necessary to bring another method that more sensitive to work further in research study evaluation of hydro-power plant Mentarang, Malinau Regency, North Kalimantan.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"69 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90453241","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":"MIKROZONASI SEISMIK WILAYAH PADALARANG, KABUPATEN BANDUNG BARAT MENGGUNAKAN METODE HORIZONTAL TO VERTICAL SPECTRAL RATIO (HVSR)","authors":"Gabrio Hikma Januarta, Tedi Yudistira, Adrin Tohari, Erlangga Ibrahim Fattah","doi":"10.14203/RISETGEOTAM2020.V30.1087","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1087","url":null,"abstract":"Dalam kurun waktu lima tahun terakhir terjadi peningkatan aktivitas tektonik di wilayah selatan Pulau Jawa. Salah satu sesar aktif di wilayah Jawa Barat yaitu Sesar Cimandiri dan Sesar Lembang. Sesar Cimandiri berarah barat daya-timur laut, sedangkan Sesar Lembang berarah timur-barat. Melalui citra satelit DEM ( Digital Elevation Model ) pertemuan kedua sesar diduga berada di wilayah Padalarang, Kabupaten Bandung Barat. Keberadaan infrastruktur penghubung kota seperti jalan tol, rel kereta api serta permukiman penduduk yang padat menjadikan daerah tersebut merupakan daerah yang berpotensi mengalami kerusakaan saat terjadi gempa bumi. Dalam upaya mitigasi diperlukan studi mikrozonasi untuk mengetahui karakteristik  tanah. Metode Horizontal to Vertical Spectral Ratio (HViSR) digunakan untuk mengestimasi nilai frekuensi dominan ( f 0 ) dan faktor amplifikasi ( A 0 ) daerah setempat dari data pengukuran mikrotremor. Dari 42 titik pengukuran didapatkan nilai frekuensi dominan ( f 0 ) yang terbagi kedalam dua zona yaitu 1,4–3,5 Hz dan 3,5–6 Hz. Sedangkan nilai faktor amplifikasi ( A 0 ) berkisar antara 2–8. Nilai indeks kerentanan seismik ( K g ) berkisar antara 1–30, daerah dengan indeks kerentanan seismik ( K g ) sedang hingga tinggi berada di Kecamatan Ngamprah dan Kecamatan Cisarua, sedangkan indeks kerentanan seismik ( K g ) pada daerah Kecamatan Padalarang relatif rendah hingga sedang. ABSTRACT – Seismic Microzonation of Padalarang District, West Bandung Regency Using Horizontal to Vertical Spectral Ratio (HVSR) Method .  In the last five years, tectonic activity has increased in the southern region of Java Island. One of the active faults i n the West Java region is Cimandiri Fault and Lembang Fault. The Cimandiri Fault is southwest-northeast, while the Lembang Fault is east-west. Through DEM (Digital Elevation Model) satellite imagery, the intersection of the faults is probably located in Padalarang, West Bandung Regency. The existence of urban infrastructures such as toll roads, railways, and dense settlements makes this area have the potential to experience damage during an earthquake. Therefore, in mitigation efforts, microzonation studies are needed to determine the dynamic characteristics of soils in the area. Horizontal to Vertical Spectral Ratio (HVSR) method is used to estimate the value of dominant frequency (f 0 ) and the amplification factor (A 0 ) from microtremor measurement data. From 42 measurement points, the dominant frequency value (f 0 ) is divided into two zones, 1.4–3.5 Hz and 3.5–6 Hz. The amplification factor (A 0 ) ranges from 2–8 . The value of the seismic vulnerability index ( K g ) ranges from 1–30; areas with moderate to high seismic vulnerability indexes are in Ngamprah and Cisarua Districts, while the seismic vulnerability index in the Padalarang District is relatively low to moderate.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":"11 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88257425","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}