Journal of Geoscience, Engineering, Environment, and Technology 2021-04-01T09:00:10+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 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 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 06 No 01 2021 2021-03-31T09:17:49+00:00 JGEET (J. Geoscience Eng. Environ. Technol.) <p>-</p> 2021-03-30T03:08:39+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Proxapertites from Walat Formation, Sukabumi, West Java, Indonesia 2021-04-01T08:56:43+00:00 Rizki Satria Rachman Winantris Budi Muljana <p><em>Proxapertites</em> have become one of the most significant indicators of ancient rock in Indonesia. Walat Formation is one of the oldest rocks exposed in Sukabumi, West Java, Indonesia. These <em>Proxapertites</em> have not been described in detail about their characteristics in previous studies, especially on Walat Formation. Therefore, knowing the characteristics of <em>Proxapertites</em> becomes interesting, especially in Walat Formation, which can be a reference for the characteristics of the late Eocene <em>Proxapertites</em> (37.8 - 33.9 million) in Indonesia. Acetolysis method was carried out for the preparation of pollen and spores; description and determination were carried out to see the characteristics of <em>Proxapertites</em> that present in Walat Formation. Result, there are three types of <em>Proxapertites</em>. <em>Proxapertites operculatus</em> have sizes 23 – 86 µ with average 40.5 (P) and 51.1 (E) µ, index PE 0,43 - 1, Peroblate – Subspheroidal – Oblate Spheroidal, Fine-Reticulate ornamentation, and Asymmetric Monosulcate aperture. <em>Proxapertites cursus</em> have sizes 23 – 86 µ with average 39.8 (P) and 49.8 (E) µ, index PE 0.51 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Reticulate ornamentation, and Asymmetric Monosulcate aperture. Whereas <em>Proxapertites psilatus</em> have sizes 29 – 75 µ with average 42.3 (P) and 52.5 (E) µ, index PE 0.58 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Psilate ornamentation, and Asymmetric Monosulcate aperture. These three <em>Proxapertites</em> can be distinguished by their type of ornamentation. Meanwhile, other aspects have similar characteristics and are affected by the appearance of individual pollen on the slide during preparation.</p> 2021-03-24T00:57:26+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Microscopy Observation of Samosir Formation Paleosoil, Tuktuk Sidaong, North Sumatera, Indonesia. 2021-04-01T08:57:06+00:00 Danni Gathot Harbowo Siti Zahra <p>Samosir is the islands that emerge and standing upon on Toba Caldera after it’s the last eruption at 74.000 years ago. Samosir Island known as the caldera floor that uplifts parallel with Toba’s caldera flooding. In this study, we have observed an outcrop in Tumutuk, Samosir Island that hypothesized as a lacustrine deposit, and we found a paleosoil layer that might give more answers about the geological process in this area at the past time. Based on this outcrop, we described it, followed to measure its stratigraphy section, and took representative samples from the paleosoil layer, then observed the samples under the stereo-microscope as polish rock section, in normal light &amp; negative images. As the result we identify several features of paleosoil &amp; its sedimentary grain that shown this paleosoil layer, two events of the volcanoclastic deposits flown, and exposed two-time, and forming soil, it may form in the shallow swamp in a lacustrine environment, coincide with caldera flooding and caldera floor uplift event.</p> 2021-03-24T00:00:00+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology The Soft Layer Thickness Estimation using Microtremor Measurement to Identify Landside Potential in Watukumpul, Central Java, Indonesia. 2021-04-01T08:56:53+00:00 Urip Nurwijayanto Prabowo Akmal Ferdiyan Ayu Fitri Amalia <p>Watukumpul is an area that is prone to landslides, so determining the soft layer thickness is very important to identify the landslide potential. The soft layer thickness can be estimated using microtremor signal measurements which analyzed using the Horizontal to Vertical Spectral Ratio (HVSR). In this study,we measured microtremor signal of 33location around Watukumpul, Pemalang, Central Java area to determine soft layer thickness. Micretremor signal was analyzed based on theHVSR method using Geopsy software and follow the standard of the Sesame Europan Project. The results of the HVSR method are the HVSR curve that fulfills the reliable curve standard. HVSR curve shows that the dominant frequency of soft layer ranges from 1.36 – 7.62 Hz and the amplification values ranges from 9.00 – 41.45. The soft layer thickness value in the study area ranges from 17.58 - 103.60 meters. The high landslide potential area are located at W7, W8, W18, W30 and W32 where has thin soft layer and high soil slope.</p> 2021-03-24T00:00:00+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Hydrothermal Alteration and Ore Metal Mineralisation at Temon, Pacitan, East Jawa, Indonesia. 2021-04-01T08:56:49+00:00 Sri Mulyaningsih Yoyok Ragowo Siswomijoyo Sukisman Radhitya Adzan Hidayah <p>Pacitan area is known as Tertiary volcanic arc in Java, as the result of subduction zone of the Indian-Australian Plate beneath the Eurasian Plate since Oligocene. It was superimposed volcanism which formed a wide area of hydrothermal alteration zone, resulting potential ore metals mineralization, such at Temon and its vicinities, Pacitan Regency, East Java Province, Indonesia. The aim of study was to analyze hydrothermal alteration and ore metal mineralization zones. Method was surface mapping, thin section analyses, mineragraphic analyses and X-Ray Diffraction (XRD) analyses. Field study observed denuded and deformed volcanic crater geomorphology. There are ore placer deposits within the sand dunes of Grindulu River, which it consists of andesitic lava and breccia of Early Oligocene Mandalika Formation; Early Miocene lithic and vitric tuffs; and dacitic intrusion. The dikes of dacite as the last of volcanism was the host rock controlling the zonation of alteration and mineralization stages. Oblique normal faults and shear faults were cross over dilating formed fractures, which were as bodies to depositing the ore metals. There are (zone 1<sup>st</sup>) the argillic clay consists of quartz+alunite+dickite+kaolinite±illite with vuggy structures, (zone 2<sup>nd</sup>) the argillic clay consists of quartz+montmorillonite±illite zone with quartz vents, brecciated and sulfide massive, and (zone 3<sup>rd</sup>) as the chloritized zone with low grade and supergene on the edge of hydrothermal alteration. It was fluid overprinted that very acid to the core of zone 1<sup>st</sup> (pH2-4) into more netral pH 4-6 (zone 2<sup>nd</sup>) and (pH5-6) in the edge zone 3<sup>rd</sup>. The potentials ore metal mineralization are Fe and Cu by pyrite, chalcopyrite, hematite, and covellite. Other potential ore metal mineralization was also from enargite by the supergene alteration.</p> 2021-03-24T00:00:00+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Hydrocarbon Prospectivity in the undrilled area of AIMA Field in the Niger Delta Basin, Nigeria. 2021-04-01T08:56:57+00:00 Alexander Ogbamikhumi John Elvis Ighodalo <p>Field development is a very costly endeavor that requires drilling several wells in an attempt to understanding potential prospects. To help reduce the associated cost, this study integrates well and seismic based rock physics analysis with artificial neural network to evaluation identified prospects in the field.</p> <p>&nbsp;Results of structural and amplitude maps of three major reservoir levels revealed structural highs typical of roll over anticlines with amplitude expression that conforms to structure at the exploited zone where production is currently ongoing. Across the bounding fault to the prospective zones, only the D_2 reservoir possessed the desired amplitude expression, typical of hydrocarbon presence. To validate the observed amplitude expression at the prospective zone, well and seismic based rock physics analyses were performed. Results from the analysis presented Poisson ratio, Lambda-Rho and Lambda/Mu-Rho ratio as good fluid indicator while Mu-Rho was the preferred lithology indicator.</p> <p>&nbsp;These rock physics attributes were employed to validate the observed prospective direct hydrocarbon indicator &nbsp;expressions on seismic. Reservoir properties maps generated for porosity and water saturation prediction using Probability Neural Network gave values of 20-30% and 25-35% for water saturation and porosity respectively, indicating&nbsp; the presence of good quality hydrocarbon bearing reservoir at the prospective zone.</p> 2021-03-24T00:00:00+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Evaluation of Groundwater Quality Status Around Gunung Tugel Landfill In Kedungrandu Village, Patikraja District, Banyumas Regency, Central Java, Indonesia. 2021-04-01T08:56:33+00:00 Ekha Yogafanny Annete Ratnagreha Nandinia Andi Sungkowo <p>Gunung Tugel Disposal Site (GTDS) is one of the final land disposal sites established in 1983 in the Banyumas Regency, and it operates with an open-dumping system. In this system, the base of the disposal site is neither coated with an impermeable layer nor equipped with leachate collection and drainage channels, for which leachate can percolate through the soil and pollute groundwater. In March 2016, GTDS was closed because its capacity had been exceeded. The closure of GTDS was not followed by appropriate waste and environmental management, prompting the formation of leachate that can contaminate the environment, particularly groundwater. This research set out to identify the leachate quality of GTDS, assess the groundwater quality, and determine the groundwater quality status around the disposal site. It employed a field survey and mapping to plot and display the groundwater well points in the study area, laboratory analysis to identify the groundwater quality, and pollution index calculation to determine the groundwater quality status. The groundwater samples were tested in the laboratory for their physical (turbidity and TDS), chemical (pH, COD, BOD, iron (Fe), cadmium (Cd)), and biological properties (total coliform). The results showed that the cadmium (Cd) levels in several groundwater well points had exceeded the quality standards. Based on the analysis and calculation results, the groundwater quality status in the study area is mildly contaminated, with the pollution index ranging between 2.571 and 4.099.</p> 2021-03-24T08:02:14+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Analysis of gravity anomaly decomposition and depth to basement, case study: Cenozoic Bogor Basin, Indonesia. 2021-04-01T09:00:10+00:00 Muhammad Hanif Lina Handayani Ilham Arisbaya Atin Nur Aulia Karit L. Gaol <p class="body">The Cenozoic Bogor Basin situated on the SE edge part of Sunda shelf is presumed to have hydrocarbon potential on its turbidite deep-water play. The deep subsurface geometry of this basin may play an important role, yet unexplored, to the hydrocarbon exploration. The gravity method is advantageous to illuminate the subsurface structure on the arbitrary depth and various sources. Eight-hundred-thirty-eight points of ground-based gravity survey were collected on roughly one kilometer spacing in the North of Bandung to Pamanukan region covering the Cenozoic Bogor Basin on the Subang-Purwakarta segment to generate complete Bouguer anomaly (CBA) map. This study examines the two robust methods of gravity anomaly decomposition (i.e., polynomial trend surface and upward continuation) by using multiple parameters to match the geological background. Radially averaged power spectrum was used to estimate the depth of anomalous source corresponds to the top of basement layer and resulting 4 km basement depth in North West Java basin and below 1 km on Tangkuban Parahu volcanic zone. The resulting estimated depth of Cenozoic Bogor Basin was evaluated by the matched <em>a priori </em>published data on those two areas and revealed the depth of depocenter (deepest sediment) on the Cenozoic Bogor Basin is up to 9 km, quite a deeper extent than previously assumed.</p> 2021-03-29T01:36:59+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Integrated Subsurface Analysis of Thickness and Density for Liquefaction Hazard: Case Study of South Cilacap Region, Indonesia. 2021-04-01T08:56:26+00:00 Maulana Rizki Aditama Huzaely Latief Sunan FX Anjar Tri Laksono Gumilar Ramadhan Sachrul Iswahyudi Fadlin <p>The thickness of the liquefable layer can be the factor inducing liquefaction hazard, apart from seismicity. Several studies have been conducted to predict the possibility of the liquefable layer based on the filed sampling. However, a detailed investigation of the subsurface interpretation has not been defined, in particular the thickness estimation of the liquefable layer. This study is carried out in south Cilacap area where potential liquefaction is exists due to the earthquake history data and near surface condition. The aim of this study is to investigate the physical properties and thickness distribution using GGMplus gravity data and resistivity data. This research is conducted by spectrum analysis of gravity model and 2D resistivity model . This study’s main results is by performing the residual gravity anomaly with the associated SRTM/DEM data to define the subsurface physical distribution and structural orientation of the area. Residual gravity anomaly is also separated through the low pass filter in order to have robust interpretation. The residual anomaly indicates that the area has identical structural pattern with geological and SRTM map. The results show a pattern of high gravity index in the northeast area of ​​the study having range of 70 – 115 MGal gravity index, associated with the volcanic breccia, and a low gravity profile with less than 65 in the southwest, associated with the alluvial and water table dominated distribution. The thickness of Alluvial is determined by resistivity model with H1 at a range of 3 meters and H2 at a range of 4 m. This research is included in the potential liquefaction category with the potential for a large earthquake.</p> 2021-03-29T02:23:40+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Geology, Rock Geochemistry and Ore Fluid Characteristics of the Brambang Copper-Gold Porphyry Prospect, Lombok Island, Indonesia. 2021-04-01T08:56:21+00:00 Arifudin Idrus Aji Syailendra Ubaidillah I Wayan Warmada Syafruddin Maula <p>Brambang is one of the porphyry copper-gold prospects/deposits situated along eastern Sunda arc. This study is aimed to understand geological framework, alteration geochemistry and ore fluid characteristics of the prospect. Fieldworks and various laboratory analyses were performed including petrography, ore microscopy, rock geochemistry, chlorite chemistry and fluid inclusion microthermometry. The prospect is composed of andesitic tuff and diorite which are intruded by tonalite porphyries. Tonalite porphyries are interpreted as ore mineralisation-bearing intrusion. Various hydrothermal alterations are identified including potassic, phyllic, propylitic, advanced argillic and argillic types. Ore mineralisation is characterized by magnetite and copper sulfides such as bornite and chalcopyrite. Potassic alteration is typified by secondary biotite, and associated with ore mineralisation. Mass balance calculation indicates SiO<sub>2</sub>, Fe<sub>2</sub>O<sub>3</sub>, K<sub>2</sub>O, Cu and Au are added during potassic alteration process. Ore forming fluid is dominated by magmatic fluid at high temperature (450-600ºC) and high salinity (60-70 wt. % NaCl eq.). Hydrothermal fluid was diluted by meteoric water incursion at low-moderate temperature of 150-400ºC and salinity of 0.5-7 wt. % NaCl eq.</p> 2021-03-29T07:55:08+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology Back matter JGEET Vol 06 No 01 2021 2021-03-31T09:17:51+00:00 JGEET (J. Geoscience Eng. Environ. Technol.) <p>-</p> 2021-03-30T03:21:41+00:00 Copyright (c) 2021 Journal of Geoscience, Engineering, Environment, and Technology