Journal of Geoscience, Engineering, Environment, and Technology 2020-07-02T00:55:02+00:00 Husnul Kausarian, Ph.D. Open Journal Systems <p style="text-align: justify;"><strong>JGEET (Journal of Geoscience, Engineering, Environment, and Technology) </strong>&nbsp;<strong>(E-ISSN&nbsp;: 2541-5794, P-ISSN&nbsp;: 2503-216X )</strong> is a peer-reviewed and open access journal that publishes significant and important research from area of geological science, related with engineering, environment, and technology. We accept submission from all over the world on English language. Editorial Board&nbsp;members are prominent and active researchers in geological sciences and engineering fields who ensure efficient, fair, and constructive peer-review process. All accepted articles will be published freely and available to all readers with worldwide visibility and coverage. Our Journal already <a href="">indexed </a>in DOAJ, EBSCO, SINTA, GARUDA, Indonesia One Search, Crossref, Index Copernicus, OCLC, BASE, and University Libraries around the world.&nbsp;&nbsp;</p> <p style="text-align: justify;"><strong>ACCREDITED by Ministry of Research, Technology, and Higher Education of the Republic of Indonesia, <a title="Accreditation Certificate" href="" target="_blank" rel="noopener">No.30/E/KPT/2018</a>,&nbsp;October 24, 2018</strong></p> Front Matter JGEET Vol. 05 No. 02 2020 2020-07-02T00:55:02+00:00 JGEET (J. Geoscience Eng. Environ. Technol.) <h1 class="pkp_submission_title">Front Matter JGEET Vol. 05 No. 01 2020</h1> 2020-06-29T04:23:59+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Impacts of Population Density for Landuse Assessment in Cengkareng, West Jakarta 2020-07-01T02:22:36+00:00 Ratih Fitria Putri Aji Wijaya Abadi Naufal Fattah Tastian <p>Economic development in Jakarta has been influencing physical and social characteristics of urban area significantly. For recent years, burgeoning population growth occurs as a result of urban development and contributes to the landuse dynamics in a certain area. Cengkareng, is one of the most developed urban areas in Jakarta and has been experiencing such population and landuse dynamics. Its strategic location has turned this area becomen densely-populated. Increasing population density increase land demand, shapes the settlement pattern, and changes the landuse of the area. A study conducted in Cengkareng District has been done to describe how the population density impacts the landuse features for landuse assessment. The method implemented in this study combines quantitative and qualitative to process statistics and satellite imagery to produce data of population density, landuse change, and settlement pattern of the studied area. The study resulted that Cengkareng has experienced such significant landuse change which is dominantly converted into settlement and offices due to rising of population density. Nucleated settlement pattern has taken more area regarding to increased land need over land supply. It becomes serious problem for Cengkareng such aa slum settlements, flood problems, and land subsidence.</p> <p>&nbsp;</p> <p><strong>Keywords: </strong>Landuse change; Population density; Settlement pattern</p> <p>&nbsp;</p> 2020-06-24T01:26:13+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Rock Physics Formula and RMS Stacking Velocity Calculation to Assist Acoustic Impedance Inversion that Constrain Well Data 2020-07-01T02:22:16+00:00 Handoyo Mochammad Puput Erlangga Paul Young <p>This research ilustrate the generation of acoustic impedance inversion in the absence of well log using stacking velocity input in Salawati Basin, Papua, Indonesia using data obtained from seismic lines and stacking velocity section. Initial acoustic impedance modelswere first before the inversion process and were created by spreading the value of well log data to the all seismic CDP. The calculated acoustic impedance logs from standard sonic and density logs were used to build the initial model of acoustic impedance.First, the stacking velocities was first interpolated on a grid that has the same size as the seismic data using by means of Polynomial algorithm. This was closely followed by the conversion of the stacking velocities to interval velocities using Dix’s equation. The matrix densities were estimated by simple rock physics approach i.e. Gardner’s equation as a velocity function. The initial model of acoustic impedance was calculated by multiplying the densities section and interval velocities section. The resulting initial model of acoustic impedance was inverted to obtain the best of acoustic impedance section based on reflectivity.</p> 2020-06-24T02:05:47+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Analysis of Ultramafic Rocks Weathering Level in Konawe Regency, Southeast Sulawesi, Indonesia Using the Magnetic Susceptibility Parameter 2020-07-01T02:23:51+00:00 Jahidin LO. Ngkoimani LM. Iradat Salihin Hasria Erzam S. Hasan Irfan Ido Suryawan Asfar <p>The Konawe region is part of the Sulawesi Southeast Arm ophiolite belt where ultramafic rocks are exposed in the form of dunite and peridotite. The formation of nickel deposits is closely related to the weathering process of ultramafic rocks as a source rock. Ultramafic rocks exposed to the surface will experience weathering which is influenced by many factors, including in the form of climate change, topography, and existing geological structures.</p> <p>The weathering process in the source rock can influence variations in chemical elements and magnetic properties in laterite soil profiles. For example, the chemical weathering might affect magnetic mineralogy and the physical weathering could affect granulometry as well as the quantity of magnetic minerals in the soil. Condition of weathering of ultramafic rocks (initial, moderate and advanced) can affect nickel content in laterite sediments. The weathering profile study of serpentine mineral is an indication of the lateralization process that occurs in ultramafic rocks and is carried out through petrographic analysis of thin cuts and polish cuts. Determination of weathering level like this is based on the level of weathering of the mineral serpentine.</p> <p>In this study, the determination of the weathering level of ultramafic rocks (initial, moderate, and continued) uses magnetic susceptibility parameter. A total of 232 ultramafic rock core samples obtained from 34 hand samples were taken from different places and weathered levels were analyzed. The results of the research have shown that the magnetic susceptibility of ultramafic rocks in the study area varies, from 580 x 10-6 SI to 4.724 x 10-6 SI. Based on the value of magnetic susceptibility, magnetic minerals contained in ultramafic rock samples are hematite and geotite minerals. This means that the weathering level of ultramafic rock samples is the continued weathering level. The level of continued weathering that occurs in ultramafic rocks in the study area produces nickel laterite deposits with a nickel content of 1.65 - 2.40% in the saprolite zone, 0.42% in the saprock zone, and 0.20 - 0.51% in the basic rock zone (bedrock).</p> 2020-06-24T03:00:06+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Simultaneous Equation Model for Economic Calculation of Households of Independent Rubber Farmers in Mineral Land in Kampar Regency, Riau Province 2020-07-01T02:24:37+00:00 Heriyanto Heriyanto Asrol <p>Rubber is a plantation crop which is mostly a source of community income in Kampar District. As a source of household income, rubber farming is managed by households independently. This study generally aims to design models and government policy strategies in the development of smallholder rubber plantations on land typology mineral land conditions on the economic decision making of rubber farmer households. Specifically, this study was conducted with the aim of analyzing the characteristics of independent smallholders and internal and external dominant factors that influence the allocation of working time, income and household expenses of rubber farmers. This research was conducted using a survey method located in Kampar District. The data used in this study consisted of primary data obtained using the interview method. Samples were taken by simple random sampling method with 60 rubber farmers. Descriptive analysis and Economic Decision Model of Rubber Farmer Households using the simultaneous equation model approach with the Two Stages Least Square (2SLS) analysis method were performed to answer the research objectives. The results showed that only internal factors of farm households are responsive to household economic decisions. There are no external factors included in the model that are responsive to the economic decisions of rubber farming households in Kuantan Singingi Regency regarding the aspects of production, working time allocation, income and expenditure of rubber farming households. From the aspect of production, no responsive internal or external factors were found, but the biggest effect was the number of productive rubber stems. From the aspect of work time allocation, internal factors that are responsive to influence are the total outpouring of farmer work, outpouring of farm family work in businesses and the workforce of farmer households. Furthermore, from the aspect of farmer's household income the responsive internal factors that influence it are the farmer's household income in the business. then what influences household expenditure is outflow of work in business, farmer education, wife education and total rubber farmer income. The policy implications of increasing rubber prices and outpouring of family work in the business have the most positive impact. While the increase in wages for workers outside the family has a negative impact on the household economy.</p> 2020-06-26T02:10:05+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Subsurface Shallow Modelling Based on Resistivity Data in The Hot Springs Area of Libungo Geothermal, Gorontalo 2020-07-01T02:25:27+00:00 Intan Noviantari Manyoe Ronal Hutagalung <p>Volcano-tectonic events in Libungo can be the cause of the presence of geothermal potential. There is no detailed research on shallow subsurface conditions in Libungo that can show the distribution of subsurface fluids. This research aims to create a shallow subsurface model of the Libungo geothermal area based on resistivity data. Resistivity data collection was carried out in the Libungo hot springs area. The electrode configuration used is the Schlumberger configuration. The variation in resistivity values is calculated using current data, potential difference data and geometry factors. The results of the calculation of the resistivity values variation are plotted versus depth. Variations of resistivity value versus depth are then displayed in the form of a single log, lithology distribution and 3D lithology model. The results showed that the shallow subsurface of the Libungo geothermal area was composed of andesite, volcanic breccia, silty clay and clay. Andesite in the research area has resistivity values ranging from 320 - 349 Ωm, has slightly fracture and is andesite dry. Volcanic breccia has a resistivity value of 177-198 Ωm, has a well to slightly fracture and is a volcanic breccia moist. Silty clay has a resistivity value of 3.25-37.99 Ωm and is a wet to moist silty clay. Clay has resistivity values in the range 1.56-2.78 Ωm and is wet to moist clay. Fluid distribution in the shallow subsurface area occurs in volcanic breccia, silty clay and clay. Shallow subsurface fluids accumulate mostly in the northern part of the Libungo geothermal area.</p> 2020-06-26T03:34:10+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Geochemical and Geomechanical Study on Gumai and Talangakar Formation to Determine Potential of Shale Gas in Jambi Sub-Basin, South Sumatra Basin 2020-07-01T02:26:28+00:00 Reddy Setyawan Edy Ariyono Subroto Benyamin Sapiie Randy Condronegoro Beiruny Syam <p>Jambi sub-basin, which is located in South Sumatra, Indonesia has enormous potential of shale gas play. Yet, detailed geological studies are rarely undertaken to understand this relatively new hydrocarbon play concept. This paper presents a combination of geochemical and geomechanical studies with the aim to better understand: (1) the maturity level of source rock; (2) the mechanical properties of shale; and (3) the quality of hydrocarbon source rock. This research began with determination of wells that penetrate the Talangakar and Gumai Formations that have shale in it. Source rock analysis was done by using TOC (total organic carbon), S1, S2, S3, Tmax, and Ro (vitrinite reflectance) data. Geomechanical evaluation was done by using XRD and well logs data. Brittleness index was obtained by using Jarvie et al. (2007) formula, based on the XRD data. S-wave and P-wave are used to calculate the rock strength, Young's modulus and Poisson's ratio with UCS-To methods.Source rock in the Geragai belongs to the of moderate-to-good category because it has more than 0.5% TOC and potentially forms gas because it has a type III kerogen. JTBS-2 well is the only well in the Geragai area which already mature and has been able to produce hydrocarbons, because it passed the oil and gas windows. Source rock in the Betara belongs to moderate-to-good category because it has more than 0.5% TOC potentially forms gas because it has a type III kerogen. Most formations in the Betara are not yet mature based on the value of Ro and Tmax. In wells that have not reached the oil window nor gas windows, the prediction line drawn on the Petroleum Source Rock Summary chart, estimated that they would pass the gas window at Lower Talangakar Formation or Lahat Formation at depth of more than 8000 feet. The results of XRD analysis showed that the Betara had a high brittleness index with an average of 0.809. Talangakar Formation has a higher rock strength values than Gumai Formation, both in Betara high and Geragai deep. The principle that say the rocks which have high TOC values will have a high value of BI can be proven in the study area, the rocks that have high Ro will have a high value of BI, cannot be identified in the study area. With sufficient high value of rock strength and low abundance of clay minerals, the rocks at Talangakar Formation is good for hydraulic stimulation.</p> 2020-06-26T07:01:50+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Settlement and Capacity Analysis of Land Support Development on Flyover in Large City; Pekanbaru, Indonesia 2020-07-01T02:26:46+00:00 Husnul Kausarian evan trionaldi taufan Khalif Arrahman dewandra bagus eka putra Batara <p>The study area located on the street of Soebrantas to Soekarno Hatta Street, with the coordinate position of 0 ° 30 ' 0.79&nbsp; "N 101 ° 24 ' 57.88 "E - 0 ° 30 ' 0.16 "N 101 ° 24 ' 53.17 "E in Pekanbaru City, Indonesia. The development that will Conduct flyovers in this area became the basis of this research. The main study of this research is to find out how an Atterberg's boundaries, compressibility, and the likelihood of a ground decline in drill 1 use the value of N SPT to match with the purpose of this study. Which is (1) to know the large grain size of soil samples, (2) Knowing the value of the liquid limit, the plastic boundary, and the plastic index of the soil samples, (3) Knowing the possibility of land degradation in the research area, (4) Power capacity analysis of ground support (5) Knowing the decline of modeling using the Plaxis 2D method (6) knows the relationship of decreasing values based on NSPT and Plaxis (7) Knowing the relationship of sieve analysis and Attaberg limit with decreased results. Methods of data retrieval have done with soil testing in the field and soil testing in the laboratories. A comprehensive analysis of the grain has done with sieve analysis. Plastic boundary, liquid, and plastic boundary indices with method Attaberg limit. Decreased analysis and Power capacity analysis of ground support with NSPT value tests.</p> 2020-06-26T00:00:00+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Effect of Porphyritic Andesite Intrusion on The Formation of Metamorphic Aureole Zone in Clastic Limestone of Selo Gajah Hill, Bojonegoro Regency, East Java 2020-07-01T02:27:43+00:00 Tri Winarno Jenian Marin Wisnu Wijaya Jati <p>At Selo Gajah Hill, Jari Village, Gondang Sub-district, Bojonegoro Regency, East Java there are limestone intruded by porphyritic andesite. The intrusion produces contact metamorphisms in the wall rocks. It is very interesting to study the protolith&nbsp; rock, facies of metamorphism and&nbsp; the zonation of contact metamorphism aureole. This research uses field observation method and laboratory analysis i.e.&nbsp; petrographic analysis. Field observation is conducted by doing geological mapping in the Bukit Selo Gajah area and rock sampling for&nbsp; petrographic analysis.&nbsp; Petrographic analysis aims to describe the texture of the rocks and the percentage of minerals, which will be used to determine the protolith rock, metamorphism facies and the determination of contact metamorphism zone. The lithology found in Mount Selo Gajah from oldest to youngest &nbsp;are clastic limestone with intercalation of marl, marl with intercalation of sandstone, porphyritic andesite intrusions, hornfels, and pyroclastic breccia. Metamorphic rocks on Selo Gajah Hill is the product of contact metamorphism of carbonate rock which was intruded by porphyritic andesite intrusion. The metamorphism facies found in the research area are hornblende hornfels and pyroxene hornfels with the protolith rock is carbonate rocks. Metamorphism zone in Selo Gajah Hill is divided into two zones: The zone closest to the intrusion body is vesuvianite zone or idiocrase zone with a radius of 40-140 m from the outer part of the intrusion body and the monticellite zone with radius ranging from 25 to 75 m from the outside of the vesuvianite zone.</p> 2020-06-29T02:53:46+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology Back matter JGEET Vol 05 No 02 2020 2020-06-30T08:31:41+00:00 JGEET (J. Geoscience Eng. Environ. Technol.) <p>Back matter JGEET Vol 05 No 02 2020</p> 2020-06-29T00:00:00+00:00 Copyright (c) 2020 Journal of Geoscience, Engineering, Environment, and Technology