Riset Geologi dan Pertambangan最新文献

{"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}

{"title":"FASIES DAN LINGKUNGAN PENGENDAPAN FORMASI KANIKEH, CEKUNGAN BULA, MALUKU","authors":"Akhmad Khahlil Gibran, A. Kusworo","doi":"10.14203/RISETGEOTAM2020.V30.1108","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1108","url":null,"abstract":"Batuan silisiklastik berumur Trias yaitu Formasi Kanikeh, tersebar di Pulau Seram hingga Pulau Kesui dan Teor dari Maluku hingga Maluku Tenggara. Formasi Kanikeh telah lama dikenal memiliki karakteristik batuan induk yang baik. Pemahaman tentang Formasi Kanikeh masih minim, interpretasi lingkungan pengendapan dan korelasi stratigrafi masih ada perbedaan. Tujuan penelitian ini adalah mendapatkan hasil interpretasi lingkungan pengendapan berdasarkan data terbaru. Metode yang digunakan dalam penelitian ini adalah pengukuran penampang stratigrafi pada empat lintasan pengamatan di daerah Seram Bagian Timur dengan menggunakan pendekatan analisis litofasies dan asosiasi fasies. Hasil dari penelitian ini menunjukkan adanya 9 litofasies, yaitu: Litofasies Batupasir Konglomeratan (Sg); Litofasies Batupasir Lapisan Silangsiur Mangkok (Sp); Litofasies Batupasir Bioturbasi (Sb); Litofasies Batupasir Karbonan (Sc); Litofasies Batupasir Bergelombang (Sw); Litofasies Batupasir Flasser (Sf); Litofasies Batupasir Laminasi Sejajar (Sh); Litofasies Batulumpur Lenticular (Fl); Litofasies Batulumpur Berlapis (Fsc). Deskripsi litofasies tersebut termasuk ke dalam suatu sistem pengendapan pasang-surut (intertidal) yaitu tidal channel, tidal sand flat, tidal sand-mud mixed flat, dan tidal mudflat. Formasi Kanikeh terendapkan dengan sistem pengendapan batuan silisiklastik yang dipengaruhi oleh arus pasang-surut pada lingkungan pengendapan transisi. ABSTRACT - Facies and depositional environment of Kanikeh Formation, Bula Basin, Maluku. The Triassic siliciclastic rocks, Kanikeh Formation are spread across Seram, Kesui, and Teor Island from Molucca to Southeast Molucca. The Kanikeh formation has been known as an excellent source rock. However, its interpretation of the depositional environment and stratigraphic correlation are still poorly understood. This study aims to give a better understanding of the depositional environment. This study consists of Lithofacies descriptions and facies associations of four stratigraphy measuring sections in Eastern Seram Island. The results of this study indicate that there are 9 lithofacies, including conglomeratic sandstone (Sc); Through cross bed sandstone (Sp); Bioturbated sandstone (Sb); Carboniferous sandstone (Sc); Wavy Sandstone (Sw); Flasser Sandstone (Sf); parallel laminated sandstone (Sh); lenticular mudstone (Fl); dan laminated mudstone (Fsc). The lithofacies description is included in four facies associations which are included in a tidal deposition system (intertidal) there are tidal channels, tidal sand flat, tidal sand-mud mixed flat, dan tidal mudflat. Based on the results Kanikeh Formation is deposited with a siliciclastic deposition system influenced by tidal currents within transition deposition environments.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82269420","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":"ANALISIS SPASI LUBANG BOR UNTUK MENGEVALUASI SUMBERDAYA TIMAH ALUVIAL DAN MINERAL IKUTANNYA DI PULAU BANGKA DENGAN GLOBAL ESTIMATION VARIANCE","authors":"Raymond Kosher Sianturi, M. N. Heriawan, Syafrizal Syafrizal","doi":"10.14203/RISETGEOTAM2020.V30.1115","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1115","url":null,"abstract":"Pulau Bangka merupakan daerah yang kaya akan mineralisasi timah yang dibawa oleh batuan granit. Selain kaya akan mineralisasi timah, ilmenite, rutile, anatase, zircon, monazite, dan xenotime juga hadir dalam batuan granit sebagai mineral aksesoris. Mineral-mineral ini juga terdapat dalam endapan sekunder timah aluvial dan disebut mineral ikutan timah (MIT). Optimasi spasi bor antara timah dan mineral ikutan timah dibutuhkan agar spasi tersebut dapat mewakili timah dan mineral ikutan timah. Metode yang digunakan pada penelitian ini adalah pendekatan geostatistik melalui metode Global Estimation Variance (GEV) untuk menghitung nilai relative error . Dari hasil penelitian didapatkan bahwa timah lebih homogen daripada mineral ikutan timah. Spasi optimum yang mewakili Sn (timah) dan mineral ikutan timah berdasarkan pada 8 (delapan) daerah di Pulau Bangka adalah 20 - 25 m untuk measured , 30 - 40 m untuk indicated , dan 40 - 50 m untuk inferred . ABSTRACT – Drill Hole Spacing Analysis for Evaluation of Tin and Associated Minerals Resources in Bangka Island Using Global Estimation Variance. Bangka Island is an area rich in granite rocks bearing tin mineralization. Besides that, ilmenite, rutile, anatase, zircon, monazite, and xenotime are also present in granite as mineral accessories. These minerals are also present in alluvial tin deposits and called as tin associated minerals. Optimization of drill hole spacing between tin and its associated minerals is indispensable so that these spacing can represent the spatial distribution of tin and its associated minerals. Global Estimation Variance (GEV) is used to calculate the relative error. This study showed that tin is more homogeneous than its associated minerals. The optimum spacings representing Sn (tin) and its associated minerals based on the case studies of eight sites at Bangka Islandare20–25m,30–40m,and40–50mfor obtaining the measured, indicated, and inferred resources, respectively.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90679644","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":"PEMETAAN PERMEABILITAS MAGNETIK PERMUKAAN BERBASIS CITRA SAR POLARIMETRIK DENGAN PENGUKURAN IN SITU DI LAPANGAN GUNUNG API","authors":"Asep Saepuloh, Edo Kharisma Army, Zaki Hilman","doi":"10.14203/RISETGEOTAM2020.V30.1080","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1080","url":null,"abstract":"Pemetaan parameter fisis berupa permeabilitas magnetik permukaan pada zona lemah yang terkait dengan aktivitas tektonik maupun vulkanik perlu dilakukan seiring dengan meningkatnya aktivitas kegempaan maupun kegunungapian dalam beberapa tahun terakhir. Pendeteksian keberadaan zona lemah umumnya dilakukan berdasarkan parameter kelurusan struktur geologi, reflektansi spektra, dan temperatur permukaan dengan memanfaatkan citra satelit optis. Makalah ini mengolah parameter yang berbeda berupa permeabilitas magnetik permukaan ( μ r ), yaitu parameter fisis yang diturunkan dari citra satelit Polarimetric Synthetic Aperture Radar (PolSAR) dengan polarisasi penuh ( quad-polarization ) dan diverifikasi dengan pengukuran in situ . Parameter μ r permukaan merupakan salah satu parameter yang digunakan untuk mengidentifikasi keberadaan zona lemah jalur fluida termal dari bawah sampai ke permukaan gunung api aktif. Aktivitas hidrotermal mengakibatkan degradasi nilai magnetik batuan di sekitarnya, sehingga ekstraksi nilai permeabilitas magnetik permukaan μ r dianggap sangat efektif untuk mengidentifikasi jalur fluida termal di permukaan. Modifikasi pada metode dielectric from Polarimetric Synthetic Aperture Radar (dPSAR) menggunakan citra PolSAR dilakukan untuk mendapatkan parameter permeabilitas magnetik permukaan μ r , yaitu kemampuan permukaan tanah dalam menerima respon medan magnet, disamping permitivitas dielektrik e r . Pengukuran μ r in situ di lapangan menggunakan alat ukur Ferromaster Magnetic Permeability Meter dilakukan untuk menganalisis tingkat akurasi μ r dari hasil inversi dPSAR. Berdasarkan uji validasi, nilai koefisien determinasi R 2 yang diperoleh cukup tinggi, yaitu sekitar 0,73 antara μ r hasil dPSAR dan pengukuran lapangan. Selain itu, hasil uji normalitas menunjukkan nilai residual antara keduanya terdistribusi normal. Hal ini mengindikasikan bahwa pendeteksian μ r dengan metode dPSAR memiliki potensi untuk dikembangkan dan diaplikasikan lebih lanjut dalam pemetaan fisis geologi di permukaan. ABSTRACT - Surface Magnetic Permeability Mapping Using Sar Polarimetric and In Situ Measurement at Volcanic Field. Physical parameters mapping of surface magnetic permeability in weak zones associated with tectonic and volcanic activity is necessary due to the increasing seismic and volcanic activity in recent years. Typically, weak zones are detected from lineament related geological structures, reflectance spectra, and surface temperature visually on optical satellite images. This paper processed a different physical parameter of surface magnetic permeability (μ r ) derived from the Polarimetric Synthetic Aperture Radar (PolSAR) quad-polarization satellite image that was verified by field measurement. The μ r was used to identify the weak zones connected to the fluid path of the subsurface hydrothermal system of an active volcano. The activity of hydrothermal fluids through the weak zones is responsible for the degradation of the magnetic permeabil","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81609361","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":"EVALUASI POTENSI LIKUIFAKSI DI WILAYAH CEKUNGAN BANDUNG BERDASARKAN METODE ANALISIS MULTI-SENSOR GELOMBANG PERMUKAAN","authors":"N. Dewi, Adrin Tohari, Imam Muttaqien","doi":"10.14203/RISETGEOTAM2020.V30.1131","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1131","url":null,"abstract":"Secara geologi, wilayah Cekungan Bandung tersusun oleh endapan danau Bandung purba yang terdiri atas lapisan lempung dengan sisipan lapisan pasir sehingga rentan terhadap likuifaksi akibat gempa bumi. Metode analisis multi-sensor gelombang permukaan ( MASW ) adalah salah satu metode geofisika yang menghasilkan model satu dimensi kecepatan gelombang geser ( Vs ) terhadap kedalaman. Makalah ini menyajikan hasil analisis potensi likuifaksi menggunakan data profil Vs di 5 lokasi yang tersebar di wilayah Cekungan Bandung. Data Vs diperoleh dengan menggunakan 24 geophone yang tersebar dengan spasi 4 meter di setiap lokasi penelitian. Hasil analisis data menggunakan metode MASW menghasilkan profil Vs dan Vs30 di setiap lokasi yang menunjukkan bahwa lapisan tanah di wilayah Cekungan Bandung dapat diklasifikasi dalam kelas situs E dan D. Sedangkan berdasarkan hasil analisis potensi likuifaksi menggunakan profil Vs , dengan mempertimbangkan percepatan tanah puncak yang dihasilkan oleh Sesar Lembang ( M w 6,5), mengindikasikan bahwa lapisan pasir di dalam endapan danau purba mempunyai potensi likuifaksi pada kedalaman dan ketebalan yang bervariasi. Lapisan pasir dengan nilai Vs < 175 m/detik yang menyebabkan potensi likuifaksi di daerah Bojongemas lebih tinggi dibandingkan dengan daerah lainnya. Hasil penelitian ini menunjukkan kesesuaian dengan hasil analisis likuifaksi berdasarkan metode uji penetrasi standar dari hasil penelitian terdahulu. ABSTRACT - The Evaluation of Liquefaction Potential in Bandung Basin Area Based on Multi-sensor Analysis of Surface Wave. The Bandung Basin region is composed of ancient Bandung lake sediment deposits consisting of thick clay layers intercalated with sand layers, which is vulnerable to liquefaction due to earthquakes. The multi-sensor surface wave (MASW) analysis method is a geophysical method that produces a one-dimensional model of shear wave velocity (Vs) against depth . . This paper presents the results of an analysis of the potential for liquefaction using Vs profile data at 5 locations spread across the Bandung Basin. using 24 geophones with 4-m spacing. The results of data analysis using the MASW method produce Vs and Vs30 profiles at each location which indicate that the soil layers in the Bandung Basin area can be classified into E and D site classes. Meanwhile, based on the results of the analysis of potential liquefaction using the Vs profile, taking into account the peak soil acceleration produced by the Lembang Fault (Mw 6.5), indicates that the sand layer in ancient lake sediment deposits has the potential for liquefaction at varying depths and thicknesses. Sand layer with a value of Vs <175 m / sec which causes the potential for liquefaction in the Bojongemas area is higher than in the other areas. The results of this study confirm liquefaction analysis based on the standard penetration test method from the previous study","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73073327","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":"PELINDIAN BIJIH NIKEL LATERIT KADAR RENDAH MENGGUNAKAN METODE ATMOSPHERIC ACID LEACHING DALAM MEDIA ASAM KLORIDA (HCL)","authors":"D. Permana, Rizky Kumalasari, Wahab Wahab, M. Musnajam","doi":"10.14203/RISETGEOTAM2020.V30.1097","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1097","url":null,"abstract":"Ekstraksi nikel laterit menggunakan metode hidrometalurgi lebih efisien dari segi konsumsi energi dengan lebih sedikit gas buang dibandingkan dengan metode pirometalurgi. Hal ini menyebabkan nikel laterit berkadar rendah dapat diekstraksi lebih banyak menggunakan metode hidrometalurgi. Salah satu metode hidrometalurgi dalam mengekstraksi nikel dari bijih nikel laterit adalah Atmospheric Acid Leaching . Penelitian ini bertujuan untuk memperoleh data persentase perolehan nikel, menentukan variabel yang paling berpengaruh dan menentukan kondisi optimum dalam proses pelindian. Pada penelitian ini dilakukan variasi pada faktor-faktor yang berpengaruh dalam proses leaching yakni temperatur, konsentrasi asam dan waktu pelindian. Analisis kandungan nikel hasil pelindian dilakukan menggunakan Atomic Adsorbtion Spectroscopy (AAS). Hasil penelitian menunjukkan bahwa persentase perolehan nikel terendah adalah 9,40% Ni dan tertinggi 75,76% Ni. Perhitungan ANOVA digunakan untuk menentukan faktor paling berpengaruh pada proses pelindian nikel laterit. Faktor yang paling berpengaruh dalam penelitian ini adalah temperatur (B), diikuti konsentrasi asam (A), waktu pelindian (C), interaksi konsentrasi-temperatur (AB), interaksi temperatur-waktu (BC), interaksi konsentrasi-waktu (AC) dan interaksi konsentrasi-temperatur-waktu (ABC). Kondisi optimum pelindian diperoleh pada kondisi temperatur 75°C, konsentrasi asam 2,9-3 Molar dalam waktu 69-70 menit dengan perolehan nikel >70%. ABSTRACT -  Leaching o f Low-Grade Nickel Laterite Ore Using Atmospheric Acid Leaching Method i n Hydrochloric Acid . Nickel laterite extraction using the hydrometallurgical method is more efficient in energy consumption with less exhaust gas than the pyrometallurgical method. This method causes the extraction of low-grade nickel laterite ore using hydrometallurgy could be more effective. One of the hydrometallurgical methods to extract nickel from its ore is atmospheric acid leaching. This research aims to determine the percentage of nickel recovery through the leaching process, determine the most influenced leaching factor, and determine the optimum leaching condition. The main factors that influence the leaching process are temperature, acid concentration, and leaching time. Atomic adsorption spectroscopy was chosen to analyze the leaching solution. This research showed that the lowest recovery of nickel leaching was 9,40% of Ni, and the highest was 75,76% of Ni. Analysis of variance (ANOVA) was used to determine the most influenced factor of leaching. The most influenced factor was the temperature (B), followed by acid concentration (A), duration (C), the interaction of acid concentration-temperature (AB), the interaction of temperature-duration (BC), the interaction of acid concentration-duration (AC), and interaction of acid concentration-temperature-duration (ABC). The optimum leaching condition is at 75°C of temperature, 2,9-3 molar of acid concentration, in 69-70 minutes of duration, ","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73953894","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":"KARAKTERISTIK ISOTOP 18O DAN 2H DARI BEBERAPA MATAAIR PANAS DI JAWA BARAT","authors":"Satrio Satrio, Rasi Prasetio, Paston Sidauruk","doi":"10.14203/RISETGEOTAM2020.V30.1090","DOIUrl":"https://doi.org/10.14203/RISETGEOTAM2020.V30.1090","url":null,"abstract":"Mataair panas di Jawa Barat tersebar hampir merata dari selatan hingga utara dan umumnya berada di daerah gunung api, baik yang masih aktif maupun yang sudah tidak aktif. Pada tahap eksplorasi panas bumi, keberadaan mataair panas ini sangat menarik untuk diteliti, khususnya terkait komposisi isotopnya. Penelitian ini bertujuan untuk mengetahui karakteristik sumber air panas di Jawa Barat dengan menggunakan pendekatan isotop stabil 2 H dan 18 O dari sejumlah sampel air panas yang diambil dari beberapa lokasi, yang meliputi Gunung Pancar dan Ciseeng, Bogor; Gunung Gede, Cianjur; Santa, Sukabumi; serta Palimanan, Cirebon. Hasil analisis isotop 18 O dan 2 H sampel air dari beberapa mataair panas di Jawa Barat menunjukkan bahwa karakteristik mataair panas Gunung Pancar dan Sukabumi lebih dominan berasal dari air meteorik. Sementara mataair panas daerah Ciseeng dan Palimanan merupakan hasil interaksi dengan batuan karbonat (CaCO 3 ). Sedangkan mataair panas area Gunung Gede berasal dari hasil interaksi dengan batuan andesitik dengan fraksi air andesitik antara 0,03 hingga 0,21. ABSTRACT – Stable Isotopes ( 18 O and 2 H) Characteristics of Several Hot Springs in West Java. Hot springs locations in West Java are distributed from south to north and are generally associated with active or inactive volcanoes. During the exploration stage, hot springs become a point of interest for geothermal investigation, especially regarding the water isotope compositions. This study aimed to obtain the hot springs' characteristics in West Java based on the 18 O and 2 H isotope compositions. Water samples were collected from several hot springs in West Java, i.e., Gunung Pancar and Ciseeng, Bogor; Gunung Gede, Cianjur; Santa, Sukabumi; and Palimanan, Cirebon. The result shows that the characteristics of Gunung Pancar and Sukabumi hot springs are dominated by meteoric water. Meanwhile, interactions with carbonate rocks occur in Ciseeng and Palimaman hot springs. While, hot springs in Gunung Gede are the product of water interaction with andesitic rocks, with the fraction of andesitic waters between 0.003 to 0.21.","PeriodicalId":41045,"journal":{"name":"Riset Geologi dan Pertambangan","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86955017","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}