Artykuły w czasopismach na temat „Geological Sub-Surface study”
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Pradnya Andika, Putu, Adrin Tohari i Dadan Dani Wardhana. "Study of the sub-surface geological condition of the Sibalaya flow liquefaction using seismic refraction method". E3S Web of Conferences 464 (2023): 02008. http://dx.doi.org/10.1051/e3sconf/202346402008.
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Understanding the occurrence of flow liquefaction requires knowledge of the sub-surface condition controlling its occurrence. This paper presents the results of seismic refraction surveys conducted to evaluate the sub-surface geological condition in the Sibalaya flow liquefaction area. From the interpretation of the seismic refraction model, an inclined boundary presents between the near-surface sediment layers. Further examinations of the SRT images demonstrate the existence of localized basinal structures in the rock layer with the highest P-wave velocity. The basinal structure may be associated with a hidden normal fault system of horst-graben structures. Thus, this study indicates that such a complex sub-surface geological structure also contributed to the Sibalaya flow liquefaction occurrence.
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Hidayat, Hidayat, Marjiyono Marjiyono, Zulilmatul S. Praromadani, Januar H.Setiawan, G. M. Lucki Junursyah, Subagio Subagio, Ahmad Setiawan i Andrian Ibrahim. "Delineation of Banyumas Sub-Basins using Gravity Anomaly Based on Trend Surface Analysis Equation". Jurnal Geologi dan Sumberdaya Mineral 22, nr 4 (16.12.2021): 231. http://dx.doi.org/10.33332/jgsm.geologi.v22i4.651.
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A study using gravity methods in the Banyumas Basin, located in the southern part of Central Java, Indonesia had been conducted to generate a map for regional geological features in sub-volcanic basin related to petroleum system. This study used the first and second-order of Trend Surface Analysis (TSA) to separate gravity anomaly into regional and residual components. Matrix inversion is applied to obtain constants values for both the first and second-order of TSA. To interpret geological features related to oil and gas study, residual components are used for gravity anomaly. Residual anomaly is also compared for both first and second order of TSA with a regional geological map to validate the result. Residual anomaly from the second order of TSA showed a very comparable result to geological features, as shown in the regional geological map, compared to those of the first order of TSA. These results also showed a strong contrast of some important geological features such as the Gabon-Nusakambangan Formation outcrop, Karangbolong outcrop, and the eastern part of the south Serayu mountain arc. This study also displayed two potential subbasins i.e Citanduy and Majenang sub-Basin that might be a possible setting in which source rocks of the Banyumas Basin were deposited. From this study, it can be concluded that TSA showed a reliable result of separating gravity anomaly data set into regional and residual components.Keywords: Gravity anomaly, Banyumas Basin, petroleum system, trend surface analysis (TSA).
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Meng, Z., H. Wang, X. Li, T. Wang, Z. Cai, J. Ping i Z. Fu. "POTENTIAL GEOLOGICAL SIGNIFICATIONS OF CRISIUM BASIN REVEALED BY CE-2 CELMS DATA". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3 (30.04.2018): 1279–84. http://dx.doi.org/10.5194/isprs-archives-xlii-3-1279-2018.
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Mare Crisium is one of the most prominent multi-ring basins on the nearside of the Moon. In this study, the regolith thermophysical features of Mare Crisium are studied with the CELMS data from CE-2 satellite. Several important results are as follows. Firstly, the current geological interpretation only by optical data is not enough, and a new geological perspective is provided. Secondly, the analysis of the low <i>T<sub>B</sub></i> anomaly combined with the (FeO+TiO<sub>2</sub>) abundance and Rock abundance suggests a special unknown material in shallow layer of the Moon surface. At last, a new basaltic volcanism is presented for Crisium Basin. The study hints the potential significance of the CELMS data in understanding the geological units over the Moon surface.
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Muhammad Idris, Ahmad, Daniel Eshimiakhe, Shehu Ibrahim Adam, Jibrin Gambo i Hussaini Abubakar. "Exploring the Geological Formation and Sub-Surface Lithology Modelling of Hadejia, Jigawa State Nigeria". UMYU Scientifica 2, nr 1 (30.03.2023): 31–38. http://dx.doi.org/10.56919/usci.2123.005.
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This research aims to explore the geological formation and sub-surface lithology modelling of Hadejia, Jigawa State using the VES (vertical electrical sounding) method. The VES method is a geophysical technique that measures the electrical resistivity of the subsurface, which is related to the lithology of the rock units. The study area is located in the north-western part of Nigeria, on latitudes 12025’23.73‘‘N and longitudes 10°04’06.74‘‘E, and is characterized by a chad formation geological setting with a variety of rock units, including sandstones, shales, and limestone. The research was conducted using a total of 50 VES stations, which were distributed over the study area in a grid pattern. The data collected from the VES stations were analyzed using the IPI2WIN software. The results were used to create a subsurface electrical resistivity model, which was then used to infer the lithology units present in the subsurface. The results showed that the study area is characterized by a complex subsurface structure, with several rock units present, including sandstones, silt, and clay. The subsurface electrical resistivity model revealed that the sandstone units are located at shallow depths, while the silt units are found at deeper depths. The clay is present at intermediate depths and is interbedded with sandstones and clay. The results provide valuable information for hydro-geological and mineral exploration in the area.
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Andika, P. P., A. Tohari, T. Yudistira, E. Soebowo i J. Arifin. "Understanding of flow liquefaction in Lolu Village based on seismic refraction tomography method". IOP Conference Series: Earth and Environmental Science 1173, nr 1 (1.05.2023): 012029. http://dx.doi.org/10.1088/1755-1315/1173/1/012029.
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Abstract A big earthquake may induce flow liquefaction phenomena in lowland areas made up of sedimentary deposits. To understand the factors controlling such a hazard, it is necessary to have knowledge of the sub-surface geological conditions of the liquified area. This paper presents the results of a series of seismic refraction measurements in Lolu Village where flow liquefaction occurred during the 2018 Palu-Donggala earthquake. The results of seismic refraction tomography indicate the presence of horst-graben structures, probably associated with the localized pull-apart basin. The results of this study suggest that the sub-surface geological structure is also a governing factor for the occurrence of flow liquefaction phenomena in an area with a complex fault system.
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Dichiarante, Anna M., Ken J. W. McCaffrey, Robert E. Holdsworth, Tore I. Bjørnarå i Edward D. Dempsey. "Fracture attribute scaling and connectivity in the Devonian Orcadian Basin with implications for geologically equivalent sub-surface fractured reservoirs". Solid Earth 11, nr 6 (23.11.2020): 2221–44. http://dx.doi.org/10.5194/se-11-2221-2020.
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Abstract. Fracture attribute scaling and connectivity datasets from analogue systems are widely used to inform sub-surface fractured reservoir models in a range of geological settings. However, significant uncertainties are associated with the determination of reliable scaling parameters in surface outcrops. This has limited our ability to upscale key parameters that control fluid flow at reservoir to basin scales. In this study, we present nine 1D-transect (scanline) fault and fracture attribute datasets from Middle Devonian sandstones in Caithness (Scotland) that are used as an onshore analogue for nearby sub-surface reservoirs such as the Clair field, west of Shetland. By taking account of truncation and censoring effects in individual datasets, our multiscale analysis shows a preference for power-law scaling of fracture length over 8 orders of magnitude (10−4 to 104 m) and kinematic aperture over 4 orders of magnitude (10−6 to 10−2 m). Our assessment of the spatial organization (clustering and topology) provides a new basis for up-scaling fracture attributes collected in outcrop- to regional-scale analogues. We show how these relationships may inform knowledge of geologically equivalent sub-surface fractured reservoirs.
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Prasetyo, Yudo, Nurhadi Bashit i Reyhan Azeriansyah. "Analysis of Landslide Disaster Impact Identification Using Unmanned Aerial Vehicle (UAV) and Geographic Information System (GIS) (Case Study: Ngesrep Sub District, Semarang City)". MATEC Web of Conferences 159 (2018): 01041. http://dx.doi.org/10.1051/matecconf/201815901041.
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Landslide is a natural disaster that commonly happens in Indonesia, especially in Region of Semarang that geologically has hilly topography. In Semarang city, there are 22 Sub Districts classified as landslide potential areas, which one of them is Sub District Ngesrep, based on to BPBD Semarang. The disaster of landslides can cause human injuries and loss in infrastructure, life, and assets. Disaster management requires identifying for the impact of landslide disaster at a location. One of the methods to identifying the impact of landslide disaster uses UAV technology. UAV technology can be used to collect, map, extract information of landslide and build Digital Model in surface or elevation based on overlapping imageries. Elevation data from UAV are combined with data of rainfall, land cover and geological which will produce the map of the potential landslide disaster. The map of the potential landslide disaster is combined with the result of land cover digitation to determine the impact of landslide disaster.
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Sikdar, P. K., i P. Sahu. "Understanding wetland sub-surface hydrology using geologic and isotopic signatures". Hydrology and Earth System Sciences 13, nr 7 (28.07.2009): 1313–23. http://dx.doi.org/10.5194/hess-13-1313-2009.
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Abstract. This paper attempts to utilize hydrogeology and isotope composition of groundwater to understand the present hydrological processes prevalent in a freshwater wetland, source of wetland groundwater, surface water/groundwater interaction and mixing of groundwater of various depth zones in the aquifer. This study considers East Calcutta Wetlands (ECW) – a freshwater peri-urban inland wetland ecosystem located at the lower part of the deltaic alluvial plain of South Bengal Basin and east of Kolkata city. This wetland is well known over the world for its resource recovery systems, developed by local people through ages, using wastewater of the city. Geological investigations reveal that the sub-surface geology is completely blanketed by the Quaternary sediments comprising a succession of silty clay, sand of various grades and sand mixed with occasional gravels and thin intercalations of silty clay. At few places the top silty clay layer is absent due to scouring action of past channels. In these areas sand is present throughout the geological column and the areas are vulnerable to groundwater pollution. Groundwater mainly flows from east to west and is being over-extracted to the tune of 65×103 m3/day. δ18O and δD values of shallow and deep groundwater are similar indicating resemblance in hydrostratigraphy and climate of the recharge areas. Groundwater originates mainly from monsoonal rain with some evaporation prior to or during infiltration and partly from bottom of ponds, canals and infiltration of groundwater withdrawn for irrigation. Relatively high tritium content of the shallow groundwater indicates local recharge, while the deep groundwater with very low tritium is recharged mainly from distant areas. At places the deep aquifer has relatively high tritium, indicating mixing of groundwater of shallow and deep aquifers. Metals such as copper, lead, arsenic, cadmium, aluminium, nickel and chromium are also present in groundwater of various depths. Therefore, aquifers of wetland and surrounding urban areas which are heavily dependent on groundwater are vulnerable to pollution. In the area south of ECW isotope data indicates no interaction between shallow and deep aquifer and hence this area may be a better location to treat sewage water than within ECW. To reduce the threat of pollution in ECW's aquifer, surface water-groundwater interaction should be minimized by regulating tubewell operation time, introducing treated surface water supply system and artificial recharging of the aquifer.
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Nguyen, Manh Duc, Nguyen Van Thang, Akihiko Wakai, Go Sato, Jessada Karnjana, Hoang Viet Hung, Lanh Si Ho, Indra Prakash, Hoc Tran Quang i Binh Thai Pham. "Identification, Monitoring, and Assessment of an Active Landslide in Tavan-Hauthao, Sapa, Laocai, Vietnam – A Multidisciplinary Approach". Journal of Disaster Research 16, nr 4 (1.06.2021): 501–11. http://dx.doi.org/10.20965/jdr.2021.p0501.
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The active landslide located in the Tavan-Hauthao, Sapa district, Laocai province, Vietnam was investigated using geophysical methods (2D Electrical Resistivity and Tomography), geotechnical investigations, and a ground survey to assess the geologic condition of the sliding block and surrounding ground. Landslide displacement was measured using 15 surface monitoring points. Numerical modeling was done to assess the behavior of an active landslide. This multi-disciplinary approach helped in interpreting landslide stratigraphy, geotechnical characteristics of the sliding groundmass, depth, and nature of the sliding plane. The surface area of the slide is approximately 1200 m2. Studying this active landslide is important as it affects the road No. 152, which is an important road connecting the Sapa Ancient Rock Field. This study involved surface topographical survey, surface and sub-surface geological, and geotechnical investigations including Standard Penetration Test and Electrical Resistivity Tomography. Geologic and geotechnical data were used to characterize an active landslide block, which is composed of different soil layers underlaid by granitic rock. The surface electrical-resistivity measurements across the Sapa landslide resulted in inverted-resistivity sections with distinct resistivity contrasts that correlated well with the geology and geo-hydrology observed in boreholes.
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Frery, Emanuelle, Conor Byrne, Russell Crosbie, Alec Deslandes, Tim Evans, Christoph Gerber, Cameron Huddlestone-Holmes i in. "Fault-Related Fluid Flow Implications for Unconventional Hydrocarbon Development, Beetaloo Sub-Basin (Northern Territory, Australia)". Geosciences 12, nr 1 (12.01.2022): 37. http://dx.doi.org/10.3390/geosciences12010037.
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This study assesses potential geological connections between the unconventional petroleum plays in the Beetaloo Sub-basin, regional aquifers in overlying basins, and the near surface water assets in the Beetaloo Sub-basin Northern Territory, Australia. To do so, we built an innovative multi-disciplinary toolbox including multi-physics and multi-depth imaging of the geological formations, as well as the study of potentially active tectonic surface features, which we combined with measurement of the helium content in water sampled in the aquifer systems and a comparative analysis of the surface drainage network and fault lineaments orientation. Structures, as well as potential natural active and paleo-fluid or gas leakage pathways, were imaged with a reprocessing and interpretation of existing and newly acquired Beetaloo seismic reflection 2D profiles and magnetic datasets to determine potential connections and paleo-leakages. North to north-northwest trending strike slip faults, which have been reactivated in recent geological history, are controlling the deposition at the edges of the Beetaloo Sub-basin. There are two spring complexes associated with this system, the Hot Spring Valley at the northern edge of the eastern Beetaloo Sub-basin and the Mataranka Springs 10 km north of the western sub-basin. Significant rectangular stream diversions in the Hot Spring Valley also indicates current or recently active tectonics. This suggests that those deep-rooted fault systems are likely to locally connect the shallow unconfined aquifer with a deeper gas or fluid source component, possibly without connection with the Beetaloo unconventional prospective plays. However, the origin and flux of this deeper source is unknown and needs to be further investigated to assess if deep circulation is happening through the identified stratigraphic connections. Few north-west trending post-Cambrian fault segments have been interpreted in prospective zones for dry gas plays of the Velkerri Formation. The segments located in the northern part of the eastern Beetaloo Sub-basin do not show any evidence of modern leakages. The segments located around Elliot, in the south of the eastern Beetaloo Sub-basin, as well as low-quality seismic imaging of potential faults in the central part of the western sub-basin, could have been recently reactivated. They could act as open pathways of fluid and gas leakage, sourced from the unconventional plays, deeper formations of the Beetaloo Sub-basin or even much deeper origin, excluding the mantle on the basis of low 3He/4He ratios. In those areas, the data are sparse and of poor quality; further field work is necessary to assess whether such pathways are currently active.
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Adhitya, Bagus, Yunior Ryandri Putra i Arsyad Ar. "MANIFESTASI PANAS BUMI SERTA REKOMENDASI PEMANFAATANNYA DI DESA KOTO SANI DAN SEKITARNYA, KECAMATAN X KOTO SINGKARAK, KABUPATEN SOLOK, PROVINSI SUMATRA BARAT". JOURNAL ONLINE OF PHYSICS 8, nr 2 (1.04.2023): 12–22. http://dx.doi.org/10.22437/jop.v8i2.22184.
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The volcanic arc or volcanic arc that extends along the western side of Sumatra Island. Koto Sani Village, Kec. X Koto Singkarak, Solok Regency, West Sumatra Province is one of the areas on Sumatra Island that has geothermal potential. In terms of the developing tectonic order, namely in the form of a geological structure in the form of the Sumani segment of the Sumatra Fault which moves in a strike slip to the right or dextral. This geological structure is one of the main components forming the geothermal system apart from the heat source, reservoir rock, stratigraphic characteristics and the cap layer. This study aims to determine the geological setting, any geothermal manifestations found in the study area and estimate the temperature below the surface for recommendations for its use. The research method used was the interpretation of satellite imagery on the 1:25,000 scale of the Indonesian Rupa Bumi map (RBI), surface geological mapping, measurement of the physical characteristics of geothermal fluids, geochemical analysis of geothermal fluids (anion-cation) and then plotting Giggenbach's triangle diagram (1991). and geothermal geothermal calculations, as well as analysis of 18O and 2H isotopes. The research area generally forms a landscape of elongated hills with quite steep valleys as a result of tectonic activity in the form of geological structures as migration routes of hot fluids from the reservoir to the surface. This is reinforced by the results of the interpretation of river flow patterns, namely meandering or sub-dendritic and elongated or called parallel as an indication of disturbance from faults or faults. Geothermal manifestations found are hot springs, sintered silica and hydrothermal alteration rocks. The estimated temperature below the surface is 407.64°C with a high temperature category and is recommended for direct use, such as the tourism and fisheries sector, as well as indirect use, such as geothermal energy power plants.
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Setiadi, I., J. Widodo i T. B. Nainggolan. "Geological interpretation of offshore Central Sumatra basin using topex satellite gravity data". IOP Conference Series: Earth and Environmental Science 944, nr 1 (1.12.2021): 012034. http://dx.doi.org/10.1088/1755-1315/944/1/012034.
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Abstract Topex is a geodetic satellite to map earth surface topography with very high precision. Two types of data can be obtained from Topex satellite, namely topographic and free-air gravity field data. Then, it is processed to produce Bouguer anomaly which will be used to interpret the subsurface geology of a specific study area. The purpose of this study was to delineate sedimentary basin and basement configurations. The methods used in this research are spectral analysis, band-pass filter and 2D forward modeling. The spectral analysis results show the average thickness of the sedimentary rocks is 2.1 km. Sub-basin patterns based on the band-pass filter are 7 sedimentary sub-basins and the structural patterns found in this area comprise basement height, graben and fault. The 2D modeling results show that the bedrock in the eastern part of the Central Sumatra basin is granitic with a mass density value of 2.67 gr/cc and the layer above the bedrock is interpreted as a sedimentary rock with a mass density value of 2.35 gr/cc. Analysis of the gravity data shows significant results as initial information to delineate sedimentary sub-basin and regional structure to enhance information to the next stage of hydrocarbon exploration.
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Hermawan, Irfan Berrizki, Mohammad Rachmat, Afnimar, Angga Bakti Pratama, Fernando Lawrens, Billy Sugiartono Prabowo, Rendy Delliansyah i in. "Preliminary Estimation of Geological Structure Based on Relocated Hypocenter of Microearthquake: Case Study at “X” Geothermal Field". IOP Conference Series: Earth and Environmental Science 1159, nr 1 (1.03.2023): 012010. http://dx.doi.org/10.1088/1755-1315/1159/1/012010.
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Abstract Generally, analysis of geological structure in the geothermal field is carried out using remote sensing methods, geological mapping, and gravity analysis. These methods can provide the distribution of geological structure on the surface but cannot provide information on whether the structure is active or not. This study aims to utilize improved hypocenter location which can be used to delineate the distribution of active faults. This is useful for obtain a better interpretation of geological structures in geothermal areas. Hypocenter locations are determined by picking the arrival time of the P-wave and S-wave. This method sometimes leads to uncertainty of hypocenter location due to subjectivity of picking arrival time. The double-difference method is applied with additional input pairing events from waveform cross-correlation (WCC) to overcome the uncertainty of hypocenter location. The result shows 3 microearthquake clusters formed in the western, central, and eastern parts of the “X” Geothermal Field. The cluster formed in the western area shows that there are two orientations of conjugated hypocenter distribution with the orientation of NW-SE and NE-SW. These hypocenters reveal the presence of geological structures which provide permeability pathways for fluids rising in the western part of the geothermal field. Multiplet-clustering analysis in the middle cluster which coincides with the reservoir zone shows two different sub-clusters indicating the possibility of two different sources mechanism working in the area. By integrating all the analysis and hypocenter distribution, these methods provide a better interpretation of structure’s distribution in the “X” Geothermal Field.
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Sikdar, P. K., i P. Sahu. "Understanding wetland sub-surface hydrology using geologic and isotopic signatures". Hydrology and Earth System Sciences Discussions 6, nr 2 (8.04.2009): 3143–73. http://dx.doi.org/10.5194/hessd-6-3143-2009.
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Abstract. This paper attempts to utilize hydrogeoloy and isotope composition of groundwater to understand the present hydrological processes prevalent in a freshwater wetland, source of wetland groundwater, surface water/groundwater interaction and mixing of groundwater of various depth zones in the aquifer. This study considers East Calcutta Wetlands (ECW) – a freshwater peri-urban inland wetland ecosystem located at the lower part of the deltaic alluvial plain of South Bengal Basin and east of Kolkata city. This wetland is well known over the world for its resource recovery systems, developed by local people through ages, using wastewater from the city. Geological investigations reveal that the sub-surface geology is completely blanketed by the Quaternary sediments comprising a succession of silty clay, sand of various grades and sand mixed with occasional gravels and thin intercalations of silty clay. Aquifer within the depths of 80 m to 120 m has the maximum potential to supply water. Groundwater mainly flows from east to west and is being over-extracted to the tune of 65×103 m3/day. δ18O and δD values of shallow and deep groundwater are similar indicating resemblance in hydrostratigraphy and climate of the recharge areas. Groundwater originates mainly from monsoonal rain with some evaporation prior to or during infiltration and partly from bottom of ponds, canals and infiltration of groundwater withdrawn for irrigation. Relatively high tritium content of the shallow groundwater indicates local recharge, while the deeper groundwater with very low tritium is recharged mainly from distant areas. At places the deeper aquifer has relatively high tritium, indicating mixing of groundwater of shallow and deep aquifers. Metals such as copper, lead, arsenic, cadmium, aluminum, nickel and chromium are also present in groundwater of various depths. Therefore, aquifers of wetland and surrounding urban areas which are heavily dependent on groundwater are vulnerable to pollution and hence surface water-groundwater interaction should be minimized by regulating tubewell operation time, introducing treated surface water supply system and artificially recharging the aquifer.
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Almeida-Filho, Raimundo, Dilce F. Rossetti, Fernando P. Miranda, Francisco J. Ferreira, Clauzionor Silva i Carlos Beisl. "Quaternary reactivation of a basement structure in the Barreirinhas Basin, Brazilian Equatorial Margin". Quaternary Research 72, nr 1 (lipiec 2009): 103–10. http://dx.doi.org/10.1016/j.yqres.2009.02.010.
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AbstractThe Pirapemas Lineament is a remarkable 200-km-long, NE–SW trending structure in the Barreirinhas Basin, one of the several Brazilian coastal basins. This lineament splits the study area in two sectors of distinctive morphology, drainage patterns, and sedimentary covers. Terrain northward of the lineament presents a smooth topography with sub-parallel to sub-dendritic drainage patterns, whereas a dissected plateau characterized by incised valleys and rectangular drainage pattern occurs southward, suggesting a structural control by joints and faults. Geological field data, crossed with thermal luminescence (TL) and optically stimulated luminescence (OSL) dating, revealed that the surface southward of the lineament consists mostly of Miocene and late Pleistocene sedimentary deposits, represented by the Barreiras Formation and the Post-Barreiras sediments, respectively. In contrast, relatively younger sands mantle most of the northward terrain, as indicated by well-preserved paleodune deposits that grade into active aeolian dunes of the Lençóis Maranhenses National Park. Geomorphological and geological data analysis suggests that the northern sector is under the effect of subsidence, proving that the Pirapemas Lineament is an active agent modeling the landscape in the region. Geophysical data (gravity and seismic) confirm that such a structural feature is the surface expression of an active deep-seated basement fault.
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Karunianto, Adhika Junara, Dwi Haryanto i Ngadenin Ngadenin. "Sub-surface Geological Modeling Based on Gravity Residual Data in Adang Volcanic Rock Area, Mamuju, West Sulawesi Province". EKSPLORIUM 43, nr 1 (31.05.2022): 23. http://dx.doi.org/10.17146/eksplorium.2022.43.1.6089.
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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.
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Melwyn, Joshua R., R. Rajaperumal, J. Saravanavel, S. M. Ramasamy i K. Palanivel. "Centrifugal radial drainages and their geological significance in southern Kerala, India". Disaster Advances 16, nr 2 (15.01.2023): 25–29. http://dx.doi.org/10.25303/1602da025029.
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The drainage fabric is the reflection of the surface and sub-surface geological systems and processes of the Earth. In this context, the State of Kerala, has prolific network of drainages due to the unique physiographic conditions and it was studied to map the drainage fabric and the anomalies using IRS FCC wrapped DEM of SRTM data of the Southern parts of Kerala. The study revealed the occurrence of larger centrifugal radial drainages conspicuously in a number of places. Such drainages seem to indicate the phenomenon of doming due to the still prevalent northerly directed compressive force related to the post collision tectonics and the east north easterly compressive force due to the rising of the Carlsberg ridge in the Arabian Sea. These both forces in combination might have resulted in the phenomenon of simultaneous cross folding leading to the formation of the domes. The active tectonics have serious implications on the natural disasters in general and the tectonically vibrant Kerala State in particular, therefore the drainage anomalies of Kerala warrant demanding studies.
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Peacock, D. C. P., David J. Sanderson i Bernd Leiss. "Use of Analogue Exposures of Fractured Rock for Enhanced Geothermal Systems". Geosciences 12, nr 9 (26.08.2022): 318. http://dx.doi.org/10.3390/geosciences12090318.
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Field exposures are often used to provide useful information about sub-surface reservoirs. This paper discusses general lessons learnt about the use of deformed Devonian and Carboniferous meta-sedimentary rocks in the Harz Mountains, Germany, as analogues for a proposed enhanced geothermal reservoir (EGS) at Göttingen. The aims of any analogue study must be clarified, including agreeing with people from other disciplines (especially reservoir modellers) about the information that can and cannot be obtained from surface exposures. Choice of an analogue may not simply involve selection of the nearest exposures of rocks of a similar age and type, but should involve consideration of such factors as the quality and geological setting of the analogue and reservoir, and of any processes that need to be understood. Fieldwork should focus on solving particular problems relating to understanding the EGS, with care being needed to avoid becoming distracted by broader geological issues. It is suggested that appropriate questions should be asked and appropriate analyses used when planning a study of a geothermal reservoir, including studies of exposed analogues.
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Stafilov, Trajce, Biljana Balabanova, Robert Sajn i Claudiu Tánáselia. "Multivariate factor assessment for lithogenic and anthropogenic distribution of macro and trace elements in surface water. Case study: Basin of the Bregalnica river, Republic of Macedonia". Macedonian Journal of Chemistry and Chemical Engineering 35, nr 2 (29.11.2016): 235. http://dx.doi.org/10.20450/mjcce.2016.899.
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<p class="Default">This study presents the spatial distribution of 69 elements in the surface water of the Bregalnica river basin. The concentration of elements was determined using inductively coupled plasma with mass spectrometry (ICP-MS) and inductively coupled plasma - atomic emission spectrometry (ICP-AES). The data summary results were reduced with the application of multivariate factor analysis, whereupon three dominant geochemical associations were obtained: F1 (Ca-K-Mg-Na-Ba-Li-Mn-Sr-V), F2 (Al-Fe) and F3 (Sb). Anthropogenic enrichments of Pb and Zn occur in the Pb-Zn mine area. The obtained data exceeded the maximum allowed concentrations in accordance with the national regulation for surface water quality. Trace elements including REEs were significantly correlated with the dominant geological formations characteristic of the different sub-regions in the investigated area.</p>
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Listyani R.A., T., i Ev Budiadi. "Drainage Pattern at Kaligesing Area, Purworejo District, Central Java". E3S Web of Conferences 232 (2021): 03014. http://dx.doi.org/10.1051/e3sconf/202123203014.
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The Kaligesing area is part of the western part of the West Progo Dome. As the hard water area, water resources should be important problem to support rural development. The characteristics of the drainage as an indicator of water resources potential need to be understood in order to assess water potential. This paper wants to describe drainage characteristics as one of potential water resources indicators. The sufficient water resource is important for rural development. Result of the research shows that geological conditions allow this area to have relatively little water potential, but surface water can develop through rock-controlled flow patterns and geological structures. The flow characteristics in the area show rectangular, sub dendritic, and trellis patterns. Rivers develop genetically with consequent and subsequent types. Based on the quantity of water, the rivers in the study area include the intermittent and ephemeral rivers. Meanwhile, based on tectonics these rivers can be classified as superimposed rivers, where geological structures facilitate the formation of rivers in the research area. The river order in the study area shows the order of 1 - 4. Meanwhile, the density of the river is 0.81 - 1.86 km/km2 with young to mature river stages.
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Szente, István, Bence Takács, Erzsébet Harman-Tóth i Tamás G. Weiszburg. "Managing and Surveying the Geological Garden at Tata (Northern Transdanubia, Hungary)". Geoheritage 11, nr 4 (14.11.2019): 1353–65. http://dx.doi.org/10.1007/s12371-019-00407-9.
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AbstractThe Geological Garden at Tata is an open-air geological museum where a spectacular succession of Tethyan Mesozoic sedimentary rocks, characteristic of the Alpine-Carpathian region, is finely exposed in abandoned quarries and cleaned rock surfaces. In addition to geological values, the area houses copper-age chert mines, the only ones accessible to the wider public in Hungary. Due to financial problems, however, maintenance of the site was more or less confined to mowing for more than 20 years. Renewal of the Geological Garden began in 2015 when large-scale cleaning as well as detailed surveying was carried out. Removing the soil and loose rock debris provided opportunity to study the effects of weathering and growth of vegetation. Near 60 m3 of rock debris and soil had been accumulated on approx. 5000 m2 rock surface over the decades of obligate deterioration. Lower Jurassic marl and Middle Jurassic radiolarite chert beds as well as Middle Jurassic limestones proved to be especially deeply weathered. The cleaning action raised the question whether the sub-horizontal rock surfaces can be conserved for a long time in their present state or not. Lessons drawn from the latter can serve as a basis for future maintenance activities as well as for plans aiming at developing geosites.
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Hamad, Nali Jawad, Saya Salam Sabir i Jwanro Azad Aziz. "Locating the surface catchments sites in Shoresh sub-district (Koya district - Erbil governorate) using (AHP) model". Halabja University Journal 7, nr 3 (30.09.2022): 97–123. http://dx.doi.org/10.32410/huj-10424.
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The population of the study area in particular, and population of the Kurdistan region in general have been facing water scarcity, and especially since the 1960s, due to climate change. Thus, the residents of the areas affected by water shortages have been forced to resort to drilling private water wells on their own properties. However, those wells do not provide sufficient quantities of water. To overcome water scarcity, this study tries to identify potential sites to build dams and reservoirs using geographic information systems (GIS) and accurate field data.
The area under study is the southeastern part of Erbil Province which is approximately 689.90 km2 in area and has a height of 358 to 1321 m above the sea level. In this study, we have used an environmental impact assessment to evaluate the soil type، geological formations، climate، and land use in the area in order to locate the best sites to construct dams. We have also relied on contour maps with 50 m intervals to analyze the elevation of the area, and used geographic information systems such as ArcGIS10.8 and AHP that enabled us to identify suitablable dam construction sites to collect rainwater. This study recommends the construction of a number of dams and reservoirs in the area to harvest rainwater and use the water for a prolonged period of time during the dry seasons.
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Baik, H., i J. Kim. "THE DEVELOPMENT OF 3D SUB-SURFACE MAPPING SCHEME AND ITS APPLICATION TO MARTIAN LOBATE DEBRIS APRONS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W1 (25.07.2017): 1–5. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w1-1-2017.
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The Shallow Subsurface Radar (SHARAD), a sounding radar equipped on the Mars Reconnaissance Orbiter (MRO), has produced highly valuable information about the Martian subsurface. In particular, the complicated substructures of Mars such as polar deposit, pedestal crater and the other geomorphic features involving possible subsurface ice body has been successfully investigated by SHARAD. In this study, we established a 3D subsurface mapping strategy employing the multiple SHARAD profiles. A number of interpretation components of SHARAD signals were integrated into a subsurface mapping scheme using radargram information and topographic data, then applied over a few mid latitude Lobate Debris Aprons (LDAs). From the identified subsurface layers of LDA, and the GIS data base incorporating the other interpretation outcomes, we are expecting to trace the origin of LDAs. Also, the subsurface mapping scheme developed in this study will be further applied to other interesting Martian geological features such as inter crater structures, aeolian deposits and fluvial sediments. To achieve higher precision sub-surface mapping, the clutter simulation employing the high resolution topographic data and the upgraded clustering algorithms assuming multiple sub-surface layers will be also developed.
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Kelloway, Sarah J., Colin R. Ward, Christopher E. Marjo, Irene E. Wainwright i David R. Cohen. "Calibration for ED-XRF profiling of coal cores for the Itrax Core Scanner". Powder Diffraction 29, S1 (20.10.2014): S28—S34. http://dx.doi.org/10.1017/s088571561400089x.
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Recent developments in instrumentation mean that chemical analysis of large drill cores taken for geological purposes can be performed rapidly at sub-millimetre scales using core scanners equipped with energy-dispersive X-ray fluorescence spectrometers. The present study describes the development of a calibration for the Itrax Core Scanner (Cox Analytical, Sweden), intended for whole cores of coal-seam sections, without the need for sample preparation. The calibration was developed for key major elements (Al, Si, P, S, K, Ca, Ti, and Fe) based on pressed pellets of reference coals, allowing semi-quantitative and, at times, quantitative analyses. The influence of core curvature and surface roughness compared with an ideal flat-surface was also examined using model samples, and their influence on the apparent sample composition evaluated.
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Chahal, Raman, i Saurabh Datta Gupta. "Capture the variation of the pore pressure with different geological age from seismic inversion study in the Jaisalmer sub-basin, India". Petroleum Science 17, nr 6 (20.10.2020): 1556–78. http://dx.doi.org/10.1007/s12182-020-00517-y.
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AbstractGeoscientific evidence shows that various parameters such as compaction, buoyancy effect, hydrocarbon maturation, gas effect and tectonic activities control the pore pressure of sub-surface geology. Spatially controlled geoscientific data in the tectonically active areas is significantly useful for robust estimation of pre-drill pore pressure. The reservoir which is tectonically complex and pore pressure is changing frequently that circumference motivated us to conduct this study. The changes in pore pressure have been captured from the fine-scale to the broad scale in the Jaisalmer sub-basin. Pore pressure variation has been distinctly observed in pre- and post-Jurassic age based on the current study. Post-stack seismic inversion study was conducted to capturing the variation of pore pressure. Analysis of low-frequency spectrum and integrated interval velocity model provided a detailed feature of pore pressure in each compartment of the study area. Pore pressure estimated from well log data was correlated with seismic inversion based result. Based on the current study one well has been proposed where pore pressure was estimated and two distinguished trends are identified in the study zone. The approaches of the current study were analysed thoroughly and it will be highly useful in complex reservoir condition where pore pressure varies frequently.
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Kumar, C., A. Shetty, S. Raval, P. K. Champatiray i R. Sharma. "Sub-pixel mineral mapping using EO-1 Hyperion hyperspectral data". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (28.11.2014): 455–61. http://dx.doi.org/10.5194/isprsarchives-xl-8-455-2014.
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This study describes the utility of Earth Observation (EO)-1 Hyperion data for sub-pixel mineral investigation using Mixture Tuned Target Constrained Interference Minimized Filter (MTTCIMF) algorithm in hostile mountainous terrain of Rajsamand district of Rajasthan, which hosts economic mineralization such as lead, zinc, and copper etc. The study encompasses pre-processing, data reduction, Pixel Purity Index (PPI) and endmember extraction from reflectance image of surface minerals such as illite, montmorillonite, phlogopite, dolomite and chlorite. These endmembers were then assessed with USGS mineral spectral library and lab spectra of rock samples collected from field for spectral inspection. Subsequently, MTTCIMF algorithm was implemented on processed image to obtain mineral distribution map of each detected mineral. A virtual verification method has been adopted to evaluate the classified image, which uses directly image information to evaluate the result and confirm the overall accuracy and kappa coefficient of 68 % and 0.6 respectively. The sub-pixel level mineral information with reasonable accuracy could be a valuable guide to geological and exploration community for expensive ground and/or lab experiments to discover economic deposits. Thus, the study demonstrates the feasibility of Hyperion data for sub-pixel mineral mapping using MTTCIMF algorithm with cost and time effective approach.
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Baron, Julie, Ilaria Primofiore, Peter Klin, Giovanna Vessia i Giovanna Laurenzano. "Investigation of topographic site effects using 3D waveform modelling: amplification, polarization and torsional motions in the case study of Arquata del Tronto (Italy)". Bulletin of Earthquake Engineering 20, nr 2 (3.12.2021): 677–710. http://dx.doi.org/10.1007/s10518-021-01270-2.
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AbstractThe combined effect of topography and near-surface heterogeneities on the seismic response is hardly predictable and may lead to an aggravation of the ground motion. We apply physics-based numerical simulations of 3D seismic wave propagation to highlight these effects in the case study of Arquata del Tronto, a municipality in the Apennines that includes a historical village on a hill and a hamlet on the flat terrain of an alluvial basin. The two hamlets suffered different damage during the 2016 seismic sequence in Central Italy. We analyze the linear visco-elastic seismic response for vertically incident plane waves in terms of spectral amplification, polarization and induced torsional motion within the frequency band 1–8 Hz over a 1 km2 square area, with spatial resolution 25 m. To discern the effects of topography from those of the sub-surface structure we iterate the numerical simulations for three different versions of the sub-surface model: one homogeneous, one with a surficial weathering layer and a soil basin and one with a complex internal setting. The numerical results confirm the correlation between topographic curvature and amplification and support a correlation between the induced torsional motion and the topographic slope. On the other hand we find that polarization does not necessarily imply ground motion amplification. In the frequency band above 4 Hz the topography-related effects are mainly aggravated by the presence of the weathering layer, even though they do not exceed the soil-related effects in the flat-topography basin. The geological setting below the weathering layer plays a recognizable role in the topography-related site response only for frequencies below 4 Hz.
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Alimah, Siti, Euis Etty Alhakim, Hadi Suntoko, Sunarko Sunarko i Mudjiono Mudjiono. "STUDY ON HYDROGEOLOGICAL ASPECT OF GALANG SUB-DISTRICT, BATAM CITY FOR ACCEPTANCE OF PROSPECTIVE NPP SITES". Majalah Ilmiah Pengkajian Industri 14, nr 2 (31.08.2020): 172–81. http://dx.doi.org/10.29122/mipi.v14i2.4200.
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This is a preliminary study in the selection of Nuclear Power Plant (NPP) site in Batam's Barelang area to support industrial growth in the area in the future. The initial site selection was conducted in 2015 and 2017 in the pre-survey phase, considering hydrogeological aspect. The results of previous research showed four potential areas, namely Pasir Panjang Beach, Tanjung Batu, Dapur 3 and Tanjung Rame. The hydrogeological aspect plays an important role in the consideration of site acceptance. This is related to the consideration of potential flow of radioactively contaminated groundwater seepage in the site area, in the event of a potential release. The acceptance of the NPP site from the hydrogeological aspect is based on the site’s permeable geological formation and porosity condition, where groundwater can be stored. The purpose of the study was to assess the potential site in Galang Sub-district, Batam City based on hydrogeological aspects which include surface geology, groundwater productivity and rock porosity. Research methods include primary and secondary data collection, literature review and ranking analysis. The results showed that Tanjung Batu, Dapur 3 and Tanjung Rame could be chosen as the potential sites for NPP based on the hydrogeological aspect. The three regions have surface geology in the form of sandstone, clay and claystone rock with medium rock porosity level and medium groundwater productivity. Pasir Panjang Beach is less preferable because it has a high porosity of rocks with the productivity of aquifers is being spread widely. Key Words: Hydrogeology; Site selection; Acceptance of NPP site
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Kumar, Luitel Keshar, V. Thirukumaran i Luitel Homnath. "Estimation of soil overburden thickness/depth of rock strata using geo-physical survey at Himalayan region". Journal of Geology, Geography and Geoecology 31, nr 4 (10.01.2023): 659–67. http://dx.doi.org/10.15421/112262.
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Estimation of soil overburden and depth of competent strata for construction of infrastructures in hilly terrain is a challenging job for engineers. Modern technologies like Electrical Resistivity Survey (ERS) techniques with site geological mapping have been carried out at the ridge area near Palace, Gangtok. Two independent 2D-electrical resistivity surveys profile sections using hybrid Schlumberger-Wenner method were conducted along the ridge line trending in the North-South direction. The ERS profile sections were taken on both the slopes of the ridge along its eastern and western flanks. With the collective information from field and geo-technical data, a comparatively stable slope has been identified with respect to geological conditions in the present work, which focuses on the vulnerable slope failure with respect to slope direction, local geological condition, depth of competent strata, thickness of soil overburden, water saturation zones and resistivity of the materials. Diamond core drilling of 15meters each was carried out at both the flanks of the slope to understand the sub-surface strata and correlate it with resistivity data generated by ERS survey. The result indicates that Sandy/silty soil with flakes of mica having resistivity of 107 ohm-m and weathered mica schist having resistivity more than 300 ohm-m in the present study area. Geological mapping in 1:3000 scale was carried in the area demarcation with various litho-units and rock type. The area is characterized by medium grade metamorphic rock sequence represented in the area by mica schist having dip of foliations towards NE direction and three sets of joint planes. The geometry of the rock orientation and slope direction plays a vital role for determining the overall stability condition of the area. The present study will provide technical input for structural engineers to design the structures in such geological conditions. Further, the thickness of overburden estimated from ERS has been validated by drilling data.
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Ondréas, Hélène, Carla Scalabrin, Yves Fouquet i Anne Godfroy. "Recent high-resolution mapping of Guaymas hydrothermal fields (Southern Trough)". BSGF - Earth Sciences Bulletin 189, nr 1 (2018): 6. http://dx.doi.org/10.1051/bsgf/2018005.
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Insights into the factors controlling fluid circulation through the crust and the nature of fluid venting at the seafloor are first steps in understanding their effect on ocean properties and climate change. New data on the seafloor morphology, sub-surface sedimentary stratification, and water column of the sedimented Southern Trough hydrothermal field (Guaymas basin) were acquired during the BIG cruise in 2010. These data provide accurate and high-resolution information on the geological context of the vents, on the distribution of acoustic anomalies in the water column, and on the possible nature of the fluid generating these echoes. More than 40 hydrothermal edifices were observed. The southern zone of the study area hosts hydrothermal sites that differ from the northern area. The southern vents are located inside or at the edge of small sub-circular depressions and the relationship between active edifices and collapsed areas involves different steps in the continous hydrothermal setting. Sub-bottom data show surface and sub-surface events, with some reflection layers possibly indicating subsurface hydrothermal precipitates or lithification with an estimated age of approximately 10 000 to 20 000 years. Based on the position and maximum altitude of the acoustic anomalies above the seafloor, two types of fluid emission echoes are distinguished: 1) anomalies reaching a maximal altitude of ∼350 m above the seafloor and seen both at the northern and southern fields and 2) strong, narrow and straight anomalies reaching 1334 or 1702 m above the seafloor that are only present in the southern hydrothermal fields of the studied area. We suggest that there are two types of echoes reflecting different fluid escapes based on the physical conditions of fluid venting and degassing and their relationship to geologic features: hydrothermal fluids or hydrothermal fluid mixed with hydrocarbon gas, oil or condensates rising through the water column. The collapsed depressions observed in the southern part facilitate the release of light hydrocarbon (gas, oil, and condensates) soluble at a high temperature and transported by hydrothermal fluids towards the shallow sedimentary levels where they accumulate. These light hydrocarbons rapidly migrate at high levels in the water column. This contrasts with the northern fields where hydrothermal circulation linked to deeper faults, re-mobilize heavier non-soluble hydrocarbons which do not migrate at high levels in the water column.
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Yigui, Lionel Cedric, Theophile Ndougsa-Mbarga, Arsène Meying i Olivier Ulrich-Igor Owono-Amougou. "Detection of sub-surface fractures based on filtering, modeling, and interpreting aeromagnetic data in the Deng Deng – Garga Sarali area, Eastern Cameroon". Open Geosciences 14, nr 1 (1.01.2022): 646–62. http://dx.doi.org/10.1515/geo-2022-0357.
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Abstract The aeromagnetic anomalies existing in the Deng Deng – Garga Sarali region in Eastern Cameroon were filtered for a structural study of the region’s subsoil. This study presents the results of lineaments and fractures extracted by aeromagnetic image processing methods and compared with scientific data to obtain potential terrain models in the study area. The methodological approach used is based on the filtering of aeromagnetic image by using the analytical signal, the Euler deconvolution, and 2D3/4 modeling, to establish the maps of the lineaments and faults of the study area and their characteristics, and also to propose three models from three previously chosen profiles. Analytical signal and Euler deconvolution techniques have been applied to aeromagnetic anomalies to highlight the relationship between the depth and the source of magnetic anomalies, two parameters whose importance in geoexploration and modeling of the body is essential. We identified the potential contacts by interpretation of the deep Euler anomalies, these are highlighted on the basis of a certain similarity between the maps of the total magnetic field, the map of the analytical signal, the map of the maxima of the gradient horizontal, and geological map. Euler’s map of solutions correlates well with the edges of certain superficial and deep causative bodies.
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Syed Zainal, Sharifah Farah Fariza, Mohd Ashraf Mohamad Ismail, Roslanzairi Mostafa i Romziah Azit. "Groundwater Inflows Characterization in the Pahang-Selangor Raw Water Transfer Tunnel Using δ2H and δ18O as Tracers". Applied Mechanics and Materials 802 (październik 2015): 22–27. http://dx.doi.org/10.4028/www.scientific.net/amm.802.22.
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Groundwater inflows represent a very important element in hydrological circulation. Water inflows in Pahang-Selangor Raw Water Transfer Tunnel have been analyzed for isotopes stable of δ2H and δ18O. 61 samples were collected, including Tunnel Seepage Water (TSW), surface water and hot spring water samples within the study area which to understand the effect of multi topographical scale and geological characteristic. Deuterium (δ2H) and Oxygen-18 (δ18O) contributes the understanding of the origin and flow paths of water in the mountainous region. The δ2H and δ18O data obtained from TSW samples ranging from-45.73%0to-54.68%0and-46.01%0to-58.49%0are clustered along the local meteoric water line (LMWL) indicating that the groundwater originated from meteoric water. δ2H and δ18O data, primarily indicate the recharge altitude from 100m–550m which control by the sub vertical flow path mainly from geological structures (i.e. fractures and faults) followed by the groundwater. The altitude effect is indicated by the relation between the stable isotope values and elevation in meters highlighting a depletion of the heavy stable isotope with the increase of the tunnel overburden. The general trend obtained is δ2H and δ18O decreased with the increase of the overburden. The deviation of the δ2H and δ18O data from the expected trends may reflect the recharges are coming from the sub-horizontal flow path such as rivers or water infiltration from the valley. The results show that environmental isotopes indicates a better understanding of the complex hydrogeological system in a mountainous region and interaction between groundwater in granitic and meta-sedimentary rock formation along the tunnel project.
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Hammad, M., L. Mucsi i B. V. Leeuwen. "LANDSLIDE INVESTIGATION USING DIFFERENTIAL SYNTHETIC APERTURE RADAR INTERFEROMETRY: A CASE STUDY OF BALLORAN DAM AREA IN SYRIA". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W8 (20.08.2019): 133–38. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w8-133-2019.
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<p><strong>Abstract.</strong> Landslides are one of the main geological hazards that can cause critical damage to the infrastructure in an area and can result in serious risks to the people’s safety there. Landslides can be investigated and monitored using field survey, aerial mapping and high resolution optical satellite data analysis. However, these methods are relatively time-consuming. Interferometric synthetic aperture radar (InSAR) can investigate and monitor landslides and provide sub-centimetre accuracy for ground-surface deformation when time series analysis techniques are employed. In this research, differential synthetic aperture radar interferometry was applied on Sentinel-1 data of two Single Look Complex (SLC) images from 16 October 2018 and 21 March 2019 in the Interferometric Wide (IW) swath mode using the Sentinel application platform (SNAP) to determine the extreme ground-surface deformations, as a prelude to landslides occurrence in Balloran dam area in the north-west of Syria, where the ophiolite complex deposits of the Maastrichtian are exposed causing, due to the heavy rains, several landslides affecting the road network in this area every year. The results reveal ground-surface deformations during the study period along the satellite line of sight near to the main road in Balloran dam area with a maximum value reaches to around 20 cm. The D-InSAR results were compared to the D-GPS results of 10 validation points along the main road in the study area, where the RMS difference value was 20 cm.</p>
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Zhou, Qingjie, Xianfeng Li, Jianglong Zheng, Xishuang Li, Guangming Kan i Baohua Liu. "Inversion of Sub-Bottom Profile Based on the Sediment Acoustic Empirical Relationship in the Northern South China Sea". Remote Sensing 16, nr 4 (8.02.2024): 631. http://dx.doi.org/10.3390/rs16040631.
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This study focuses on the inversion of sub-bottom profile (SBP) data in the northern South China Sea using an empirical relationship derived from sediment acoustic data. The sub-bottom profile is primarily utilized for various marine applications, such as geological mapping and resource exploration. In this research, we present a study conducted in the northern slope canyon of the South China Sea. Firstly, we obtained the seabed reflection coefficient from sub-bottom profiles obtained by the autonomous underwater vehicle (AUV) detection system. Secondly, we utilized the acoustic empirical relationship in the northern South China Sea to establish relationship equations between the seabed reflection coefficient and the porosity, density, and average particle size of the sediment at a main frequency of 4 kHz (the AUV shallow profile main frequency). Then, using these equations, we were able to invert the physical parameters such as porosity, density, and average particle size of the seabed surface sediments. Finally, the inverted results are compared and analyzed by using the sediment samples test data. The overall deviation rate of the inverted physical parameters is within the range of ±10% when compared. The inverted results closely match the measured values, accurately reflecting the dynamic changes in the physical properties of seabed surface sediments. Notably, the average grain size is a direct indicator of the sediment particles size with smaller particles found in deeper water. The variation characteristics of sediment physical parameters align well with the variation of sediment types in the canyon, which is consistent with changes in the water depth, topography, and hydrodynamic conditions of the area. This further demonstrates the reliability of the inversion results.
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Putranto, Thomas Triadi, Narulitas Santi, Aldino Maulana Rizki i Nestri Martini. "Aplikasi Metode GALDIT Untuk Analisis Kerentanan Airtanah Terhadap Intrusi Air Laut di Kabupaten Rembang, Jawa Tengah". Jurnal Ilmu Lingkungan 20, nr 4 (1.07.2022): 925–36. http://dx.doi.org/10.14710/jil.20.4.925-936.
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Groundwater is water that is found below the ground surface or in rock layers. Seawater intrusion is a problem caused by excessive groundwater extraction which often occurs in coastal areas. Rembang is an area located in the coastal area. Rembang Regency has the potential for seawater intrusion. The impact of seawater intrusion can affect economic, social and cultural development in coastal areas as well as the quantity and quality of groundwater. The purpose of this study is to determine areas that have potential for seawater intrusion in the study area. The methods were geological mapping, groundwater quality analysis, GALDIT approach and its validation using TDS, DHL and Chloride. The interpretation of the area that has the potential for seawater intrusion is carried out with validation in the research area. The results conducted that in the research area consists of limestone, sandstone, claystone, the presence of porphyry andesite and alluvium. Based on the analysis of the vulnerability of seawater intrusion using the GALDIT method, it was found that there are 3 levels of vulnerability, namely middle to very high vulnerability. High vulnerability has GALDIT index > 7.5, located on the north coast of Rembang and Kaliori sub-districts.. The high vulnerable is 5-7.5, located mostly in Kaliori and Rembang sub-districts, and a little in Sulang, Sumber, Bulu, and Gunem sub-districts. The middle vulnerable is in the range of 2.5-5 mostly in Bulu, Gunem, Sumber, Sulang sub-districts, and a little in Rembang and Kaliori sub-districts. The validation carried out has a high match in the north of the study area. The very high level of vulnerability is in accordance with the distribution of the population and the land use map where the Kaliori and Rembang sub-districts have a large population and the land use is filled with buildings and settlements.
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Putra, Ahmad Pratama. "EARTHQUAKE HAZARD ASSESSMENT IN CENTER OF JAKARTA BASED ON SEISMICITY DATA, DEM, SLOPE, FAULT, AND GIS". Jurnal Sains dan Teknologi Mitigasi Bencana 14, nr 1 (5.08.2019): 16–26. http://dx.doi.org/10.29122/jstmb.v14i1.3559.
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The newest finding in 2016 about Baribis thrust, if it is pulled straight from Cibatu to Tangerang, it is roughly found that this fault passes through several sub-districts in Jakarta. Meanwhile, Center of Jakarta as the capital city, many governmental, economic, and business activities are conducted in this area. And also Geographic Information System (GIS) techniques are commonly used for monitoring and damage assessment for many natural and geological hazards. The present study, GIS techniques have been used to generate various thematic layers to assess earthquake hazard with a suitable numerical ranking scheme, mesh processing, and spatial data integration. The results also show that the proposed model provides reasonable earthquake potential index (EPI) from elevation, slope, magnitude, active fault, and epicentre parameters compared to the peak ground acceleration (PGA) in Center of Jakarta. The result of the EPI map explained just a little area in Center of Jakarta has very high EPI. Very high EPI area mostly in southeastern part in the study area, exactly in Menteng sub-district. And also illustrated, spatially in the more northward area indicate the smaller of the EPI in the study area. EPI resulted from the calculation of surface parameter have the same indication or same trend with PGA.
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Barlass, David, Ruth Hamilton, Sabine Mehay, Adeline Parent, Ivan Pei, Oliver Schenk, Merrie-Ellen Gunning i Adam Vonk. "Building a carbon dioxide storage portfolio for the Barrow-Dampier sub-basins through regional screening – an integrated geoscience approach". Australian Energy Producers Journal 64, nr 2 (16.05.2024): S314—S319. http://dx.doi.org/10.1071/ep23224.
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Safe geological carbon dioxide (CO2) storage (GCS) requires rocks with suitable injectivity, capacity and sealing properties to ensure secure long-term containment of injected CO2. A regional understanding of the subsurface is essential to determine the potential for GCS of a basin and to select target sites. This is best addressed by integrating the basin’s tectono-stratigraphic evolution, its gross depositional environment, and its hydrodynamic, thermal and stress regimes. A basin-scale GCS assessment for the Barrow-Dampier sub-basins was conducted by Geoscience Australia and SLB. The objective of the study is to high-grade geological intervals and sites for potential GCS and to understand potential storage capacity and key risk factors. Stratigraphic and structural mapping of key storage intervals was performed using the reprocessed seismic volume and well database associated with the project. Analysis of critically stressed faults was used to estimate the likelihood of reactivation based on the far-field regional stress field and fault mechanical properties. Pressure, temperature, porosity, permeability, and water geochemistry data have been screened for >500 wells for assessing the storage unit intervals and predicting the hydrodynamic regime. Calibrated 2D basin models provide information on the regional pressure-temperature regime, porosity/permeability distribution, and sealing effectiveness. Potentiometric surface maps for the aquifer systems inform the distribution of potential CO2 plume migration. Results of this integrated regional basin study are used to quantify the risk of identified storage containers and to map the chance of success for GCS at a regional scale. The project results are publicly available via NOPIMS.
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Tan, Lei, Xuan Zhan, Hu Zhen, Jiaren Chen i Hai Wu. "Asymmetrical Deformation Mechanisms in Layered Inclined Surrounding Rock of Roadways". GeoStruct Innovations 1, nr 1 (30.09.2023): 17–31. http://dx.doi.org/10.56578/gsi010102.
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In the context of layered inclined surrounding rock in roadways, this study presents a comprehensive analysis focusing on the asymmetrical deformation characteristics inherent to such geological structures. The intersection of layered surrounding rock with roadways forms the basis for constructing a deformation partition model, encompassing distinct sub-regions around the roadway. This model facilitates a detailed mechanical analysis, wherein the stress exerted on rock formations within each sub-region is meticulously examined. Consequently, specific mechanical formulas correlating to the stress in different sub-regions are established. This approach yields insights into the failure modes of the layered surrounding rock across various sub-regions. Notably, the roadway's high side predominantly exhibits tensile failure, whereas the low side is characterized by shear failure. The application of the Goodman model enables a simulation of interlayer slip occurring between the surrounding rock of the roadway, distributed across different partitions. This study delineates the deformation of the layered inclined surrounding rock road-way as a process with pronounced temporal characteristics. The progression of deformation and failure in the surrounding rock typically initiates at the tangent point between the roadway roof and the rock layer, extending to the roadway floor, the high-top bottom angle, and subsequently the low-top bottom angle. This sequence culminates in the development toward the high-top shoulder angle. The research further establishes a direct correlation between the onset of asymmetrical deformation and the angle of shear stress on the roadway surface relative to the inclination of the rock formation; a smaller angle precipitates an earlier onset of this deformation.
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Heidbach, Oliver, Karsten Reiter, Moritz O. Ziegler i Birgit Müller. "How to estimate the 3D stress state for a deep geological repository". Safety of Nuclear Waste Disposal 2 (6.09.2023): 185. http://dx.doi.org/10.5194/sand-2-185-2023.
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Abstract. When stresses yield a critical value, rock breaks or pre-existing faults are reactivated, generating pathways for fluid migration. Thus, the contemporary undisturbed stress state is a key parameter for assessing the stability of deep geological repositories and for quantifying whether stress changes induced by sub-surface constructions and storage of heat-generating waste lead to a critical state. The prediction of the contemporary 3D stress state is achieved with geomechanical–numerical models that are based on the static geological models. These are based on 3D seismic imaging and borehole data and describe the 3D structure and distribution of rock properties. Furthermore, pointwise measurements of the stress state are needed to fit the model to these data. The workshop is divided into three parts. Each part will have a short introduction to the specific topic, followed by dedicated hands-on exercise in small groups and discussions of the exercise outcome and its implications. 1. How do we formally describe the stress field? Here you will learn that the stress field is different from other physical field quantities such as temperature or displacement. The latter can be described with a scalar or a vector at a point. In contrast, the stress state at a point is described with the so-called Cauchy stress tensor that has nine components. We will give a quick tour through this concept, starting from very basic physics, and explain why the tensor is needed. In particular, you will learn in the exercises that stress cannot be measured directly with most methods but that strain is observed, from which stress is inferred.2. How do we actually measure stress? We present a range of methods that determine individual components of the stress state. In the exercise you will analyse borehole image logs to identify borehole breakouts and drilling-induced tensile fractures at the borehole wall. These are used to derive the orientation of the minimum and maximum horizontal stresses. Furthermore, we will present methods for the estimation of stress magnitudes. These are essential data for the calibration of a 3D geomechanical model. We will give a brief overview of different methods and in the exercise on the analysis of mini-hydraulic fracture tests as well as on the sleeve-fracturing and sleeve re-opening methods.3. From a viewpoint to a 3D description. If rock properties in the sub-surface were homogenous and isotropic and were to follow a simple linear behaviour between stress and strain, we could estimate the stress state analytically. However, this is not the case, and we will discuss three questions. a. How many pointwise stress data are needed to efficiently constrain a 3D model?b. How do I know whether a data point taken from less than a cubic metre is a good representation of a large rock volume, i.e. a whole lithological layer?c. How can we quantify the uncertainties of the model stress state, and what is the typical range? You will use a case study in northern Switzerland to explore these questions.
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Han, L., C. Y. Du i Z. H. Liu. "NEOTECTONIC SIGNIFICANCE REVEALED BY STREAM LENGTH – GRADIENT INDEX OF THE DAXI RIVER BASIN IN THE SOUTHERN MARGIN OF ORDOS, CHINA". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W10 (8.02.2020): 967–73. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w10-967-2020.
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Abstract. Since the late Cenozoic era, due to the impact of the Indo- Eurasian plate collision and the northeasterward compression of the Tibetan Plateau, a series of extensional sub-basins and tectonic belts have been formed at the periphery of the Ordos block. Watershed geomorphology plays an important role in studying the formation of rock uplift and river erosion, and are recording the surface evidence on landforms evolution. In this paper, twenty-eight sub-basins and tributaries around Daxihe River, locating at the southern margin of Ordos, were extracted from SRTM1 DEM data. Combined with Hack profile and related river parameters, the tectonic and geomorphic morphology were evaluated synthetically. The results show that (1) The mean SL of this area is 93.9, indicating that the tectonic activities are strong in Daxihe River Basin; (2) The SL values of the northern and southern are 58.9–152 and 66–137.4, respectively, showing that the uplift rate of eastern margin larger than the southern margin; (3) There are positive power functions between K and drainage area, also between landform relief and slope. This study plays an auxiliary role in regional geological background, structural activity analysis and disaster prediction.
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Sabbar Abdullah Salih i Mohammed Abdulfattah Ali. "Hydrogeological Conditions, and Surface Water Drainage System of Wadi Al-Murr Sub Basin, Northernwest of Iraq". Tikrit Journal of Pure Science 22, nr 10 (2.02.2023): 164–75. http://dx.doi.org/10.25130/tjps.v22i10.902.
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Al-Murr valley is one of the intermittent valleys in the northernwest of Iraq, in which the water flows in short flood waves after rainfall storms, and eventually flows into Tigris River at the Aski Mosul Town.
The surface drainage watershed of the basin was derived using (Arc GIS 10) based on the space shuttle radar data (SRTM-DEM) which called Digital Elevation Model (DEM), with discriminatory accuracy of (30x30) meters, according to contour lines and surface water divides, the stream orders reached to six, they varied in their numbers from order to another.
The geological and hydrogeological conditions of the basin were studied, and two aquifers were distinguished; Injana as semi-confined aquifer and Quaternary sediments as unconfined aquifer, also groundwater table map was plotted according to data of (101) wells, and then flow net of groundwater were derived and indicate that there are to main groundwater flow directions; the first from the north and northeast toward the center of the area, from Ain Zala and Butma anticlines as recharge areas to Wadi al-Murr as discharge area, the hydraulic gradient is about (0.0087) in the recharge area and (0.0037) in the drainage area, while the second flow direction is from south and southwest toward the center of the study area, from Sinjar, Shkaft, Sasan and Shaikh Ibrahim anticlines as recharge areas to Wadi al-Murr as discharge area, the hydraulic gradient is about (0.01) at the recharge area and (0.0053) in drainage area, and this trend is compatible with the direction of the surface drainage system (valleys) and the slope of land topography of the area.
The hydraulic properties were evaluated according to the pumping rate and groundwater table drawdown data in (81) pumping wells, it was observed that the values of the Transmssivity (T) ranged from (3- 414) m2/day, either hydraulic conductivity (K) ranged from (0.2-12.7) m/day.
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Rizqi, A. F., i G. I. Sastrawiguna. "Petrography of quartz sandstone in Nanggulan formation at Sermo area, Kulon Progo Regency, Daerah Istimewa Yogyakarta, Indonesia: implications on provenance and basin origin". IOP Conference Series: Earth and Environmental Science 1151, nr 1 (1.03.2023): 012027. http://dx.doi.org/10.1088/1755-1315/1151/1/012027.
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Abstract Provenance can be used to determine how the sedimentary rock formed, as reflected in the mineral composition of lithology as the composition of sedimentary minerals. The Research area is located in the Hargowilis area, Kokap district, Kulon Progo Regency, Daerah Istimewa Yogyakarta Province. This Study uses a surface geological mapping method supported by laboratory analysis in the form of petrographic analysis. Based on the analysis of the sandstone provenance in the study area, the results show the research area is included in the Recycled orogenic provenance zone, foreland uplift sub-zone to continental block provenance with a dominant quartz percentage (92%). The tectonic setting in the research area was controlled by an orogenous process during the Eocene showing that the analysis is very relevant to the provenance in the research area which shows the source of recycled rock due to the orogenous process which is then deposited in the basins formed as a result of the process.
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Jung, Jaewoo, Youngtak Ko, Joohan Lee, Kiho Yang, Young Kyu Park, Sunghan Kim, Heungsoo Moon, Hyoung Jun Kim i Kyu-Cheul Yoo. "Multibeam Bathymetry and Distribution of Clay Minerals on Surface Sediments of a Small Bay in Terra Nova Bay, Antarctica". Minerals 11, nr 1 (13.01.2021): 72. http://dx.doi.org/10.3390/min11010072.
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The second Antarctic station of South Korea was constructed at Terra Nova Bay, East Antarctica, but local seafloor morphology and clay mineralogical characteristics are still not fully understood. Its small bay is connected to a modern Campbell Glacier, cliffs, and raised beaches along the coastline. Fourteen sampling sites to collect surface sediments were chosen in the small bay for grain size and clay mineral analyses to study the sediment source and sediment-transport process with multibeam bathymetry and sub-bottom profiles. Under the dominant erosional features (streamlined feature and meltwater channel), icebergs are the major geological agent for transport and deposition of coarse-sized sediments along the edge of glaciers in summer, and thus the study area can reveal the trajectory of transport by icebergs. Glacier meltwater is an important agent to deposit the clay-sized detritus and it results from the dominance of the illite content occurring along the edge of Campbell Glacier Tongue. The high smectite content compared to Antarctic sediments may be a result of the source of the surrounding volcanic rocks around within the Melbourne Volcanic Province.
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Ivana, Jessica, L. Supriatna i Tri Rani Puji Astuti. "Identification of Potential Groundwater Recharge Zone Using Remote Sensing and GIS in Upstream Cibeet Sub-watershed, Bogor, West Java". IOP Conference Series: Earth and Environmental Science 1111, nr 1 (1.12.2022): 012025. http://dx.doi.org/10.1088/1755-1315/1111/1/012025.
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Abstract The Upstream Cibeet sub-watershed is part of the Citarum watershed and Cibeet sub-watershed with an area of 69.35 km2. Hydrologically, the upstream part of the watershed usually functions as a recharge area, and its development should be geared towards land conservation and erosion mitigation. Parameters of rainfall, soil type and texture, geology, lineament density, drainage density, geomorphology, and land cover are used in predicting the most potential catchment area. Thematic maps were made for each parameter. Weighting is carried out using the Analytical Hierarchy Process (AHP) with the following results: rainfall 0 %, soil type and texture 34.62 %, geology 24.98 %, lineament density 17.66 %, drainage density 8.57 %, geomorphology 9.34 %, and land cover 4.83 %. The integration of each thematic map resulted in a map with four zonations, namely zone of poor (4.93 %), fair (32.67 %), good (60.58 %), and very good (1.81 %) recharge potential. Based on the groundwater table contour, groundwater mimics the surface topography and flows from the south to the north and northeast part of the study area. Geological structures in the study area possess a NE-SW and NW-SE trend with a normal oblique regime. Structural damage zones are predicted to function as conduits for water movement, especially in volcanic and intrusion lithology.
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Troup, Alison, i Sally Edwards. "Old basins, new seismic data – architecture of Proterozoic basins in Northwest Queensland". APPEA Journal 62, nr 2 (13.05.2022): S502—S507. http://dx.doi.org/10.1071/aj21167.
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As part of the Strategic Resources Exploration Program and to complement surveys acquired under Geoscience Australia’s Exploring for the Future (EFTF) initiative, the Geological Survey of Queensland acquired the Camooweal 2D seismic survey in 2019. This survey was designed to support exploration for hydrocarbons in the Georgina and South Nicholson Basins and Isa Superbasin in Northwest Queensland (NWQ) by providing precompetitive sub-surface data to enable interpretation of basin and basement architecture and to examine structures interpreted in the 2018 North West Queensland SEEBASE Study. The Camooweal 2D seismic survey extends Geoscience Australia’s L210 South Nicholson Seismic Survey into an underexplored region of NWQ. It also ties into and complements the 1994 and 2004 Mount Isa seismic surveys, and the 2019 L212 Barkly Seismic Survey in the Northern Territory. The South Nicholson survey highlighted a significant thickness of sedimentary strata and identified a new depocenter of probable Proterozoic age, now referred to as the Carrara Sub-basin. The Camooweal and Barkly surveys extended the seismic coverage in this region and possibly increase the Carrara Sub-basin’s extent underneath the Georgina Basin. This work will present an interpretation of the basin architecture of the Camooweal 2D seismic in light of the recent drilling at NDI Cararra 1 and tie into interpretation of the Barkly Seismic Survey to provide a regional interpretation of NWQ’s Proterozoic basins in the region.
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Ullah, Hadayat, Mubashir Mehmood, Muhammad Jehangir Khan, Sami Ullah, Shahzada Khurram, Murtaza Ali Shah i Abdur Rehman. "Subsurface Structural and Crustal Assessment on the Basis of Gravity Data Along Bagh, Dir Kot and Adjoining Areas of Azad Jammu and Kashmir, Pakistan". International Journal of Economic and Environmental Geology 10, nr 4 (19.02.2020): 19–24. http://dx.doi.org/10.46660/ijeeg.vol10.iss4.2019.347.
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The research work is based on gravity data is taken from numerous parts of an active tectonic belt of AzadKashmir to delineate the crustal thickness and demarcation of thin- skin and thick-skin structures in the study area. Thestudy area includes Bagh, Dhirkot, Arja, Kohala, Sudhan Gali, Ghazi Abad, Chikkar and Chakoti. The study areabounded by the latitude 33°59′3″ and 34°9′22″ N and longitude 73°37′26″ and 73°40′16″ E. The proposed study area isa complex geological entity and is an active zone. This study has been focused to assess the subsurface lithology andstructural geometry present in Bagh and surrounding areas. For this purpose the gravity data has been acquired with thehelp of CG-5 Auto-grav using multi-profile survey technique. Gravity model suggested that Riasi Thrust in the studyzone is plunging at an angle of 42° NE and pierces to a depth of 7 km in the sub-surface. The model also suggested thatBagh Basement Fault in the study area is dipping at an angle of 75° NE in the crystalline basement up to Moho depth.Shaheed Galli Thrust has been delineated in Dhirkot area. The fault dips at 49° NE and penetrated up to a depth of 8km in the sedimentary/meta-sedimentary wedge. The geological model demarcated, 11 km depth of sedimentary/metasedimentary wedge in the southwest and 13 km in the northeast area. The crustal thickness increases from 51 km in thesouthwest area to about 53.17 km in the northeast area.
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Ullah, Hadayat, Mubashir Mehmood, Muhammad Jehangir Khan, Sami Ullah, Shahzada Khurram, Murtaza Ali Shah i Abdur Rehman. "Subsurface Structural and Crustal Assessment on the Basis of Gravity Data Along Bagh, Dir Kot and Adjoining Areas of Azad Jammu and Kashmir, Pakistan". International Journal of Economic and Environmental Geology 10, nr 4 (19.02.2020): 19–24. http://dx.doi.org/10.46660/ojs.v10i4.347.
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The research work is based on gravity data is taken from numerous parts of an active tectonic belt of AzadKashmir to delineate the crustal thickness and demarcation of thin- skin and thick-skin structures in the study area. Thestudy area includes Bagh, Dhirkot, Arja, Kohala, Sudhan Gali, Ghazi Abad, Chikkar and Chakoti. The study areabounded by the latitude 33°59′3″ and 34°9′22″ N and longitude 73°37′26″ and 73°40′16″ E. The proposed study area isa complex geological entity and is an active zone. This study has been focused to assess the subsurface lithology andstructural geometry present in Bagh and surrounding areas. For this purpose the gravity data has been acquired with thehelp of CG-5 Auto-grav using multi-profile survey technique. Gravity model suggested that Riasi Thrust in the studyzone is plunging at an angle of 42° NE and pierces to a depth of 7 km in the sub-surface. The model also suggested thatBagh Basement Fault in the study area is dipping at an angle of 75° NE in the crystalline basement up to Moho depth.Shaheed Galli Thrust has been delineated in Dhirkot area. The fault dips at 49° NE and penetrated up to a depth of 8km in the sedimentary/meta-sedimentary wedge. The geological model demarcated, 11 km depth of sedimentary/metasedimentary wedge in the southwest and 13 km in the northeast area. The crustal thickness increases from 51 km in thesouthwest area to about 53.17 km in the northeast area.
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Handyarso, A. "Caldera-Like Delineation and Geological Resources Identification of Majenang Area, Indonesia by Gravity and Magnetic Data Inversions". IOP Conference Series: Earth and Environmental Science 1227, nr 1 (1.08.2023): 012027. http://dx.doi.org/10.1088/1755-1315/1227/1/012027.
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Abstract Indonesia’s archipelago formed by the tectonic evolution proceeded with subduction, which was accompanied by volcanism. The systematic subduction zones produce the magmatic arcs with different periods since the Permian up to the Tertiary. However, only the recent Quaternary volcanic arc is recognized and lacked of information about the ancient volcanic environment. Calderas are a crucial feature in any volcanic environment due to the prospect site of geological resources. The Gravity and Magnetic methods are commonly used for preliminary study in almost any cases due to their light-weight, low-cost, and ability to map a wide area rapidly. The inverse-modeling scheme was invoked to estimate the sub-surface situation during the interpretation processes. The study intended to show the ability of both gravity and magnetic method for delineating of caldera-like environment including geological resources prospective site identification. According to the research, a northwest-southeast dextral strike-slip fault found in the area and belongs to the Pamanukan-Cilacap Fault Zone (PCFZ). A circular caldera-like anomaly delineated and interpreted as the ring fault of an ancient volcanic caldera in the study area. Several high gravity anomalies found within the caldera rims are interpreted as lava domes or intrusion rocks, while the high-density found following the outer part of the ring-fault terrain is interpreted as the buried lava. The ancient eruption point inferred around Majenang city, thus the study area proposed as the Majenang Caldera. A mineralization zone identified around the study area, which is comparable with the Cihonje people’s gold mining site as the proven prospective area.
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Adill Elkrail, Adill Balla, Fathelrahman Ali Bireir i Khalid Elsir Ahmed Nayl. "Groundwater Assessment using Numerical Flow Model: A Case Study in Gash Sub-Basin-Kassala State, Sudan". ASM Science Journal 18 (12.04.2023): 1–14. http://dx.doi.org/10.32802/asmscj.2023.1459.
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The main objective of groundwater modelling in Gash River Sub-basin, is to investigate the effect of hydrologic, hydrogeological parameters and stresses on hydrodynamic behaviour through the implementation of a realistic three-dimensional groundwater flow model. Severe decline of water level due to uncontrollable heavy abstraction, exposes a water scarcity problem especially in summer seasons. The model was developed for four geological layers encompassing two aquifer zones. The improved three-dimensional visual MODFLOW Code was selected, implemented and run using WHS method to solve the finite difference equation using trail-and-error calibration procedure at Kassala Area. The transient model was successfully calibrated with acceptable results of model calibration criteria. The contour maps of the simulated heads were performed as potentiometric surface. The general flow direction of the groundwater is from southeast towards northwest part of the area and from Gash River course towards the east and west directions as detected from gradual decreasing of potential line’s values in those directions, confirming the aquifer recharge from Gash River. The similarity of potentiometric surface contour maps of the two aquifers confirm the aquifers hydraulic interactions. It is found that the increasing pumping rate caused considerable increase in drawdown as detected from pumping rate incremental scenarios. Moreover, incremental pumping rate scenarios also reflected increasing river leakage into the aquifer system due to disturbance of water balance due to water level decline. The components of water budgets were calculated and its percentage was performed for the hydrologic balance. The difference between inflow and outflow of the water balance shows a deficit in most stress periods of the model simulations. Calibration fitness was accomplished at most of the observation wells suggesting that the groundwater model is an accurate representation of the actual historic groundwater system and confirm the validity of the model to forecasting purposes. It was found that the model is more sensitive to hydraulic conductivity and least sensitive to specific yield (Sy). Hence, precaution should be revealed for hydraulic conductivity in forecasting model usage.
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Pearce, Julie K., Grant K. W. Dawson, Silvano Sommacal i Suzanne D. Golding. "Micro CT and Experimental Study of Carbonate Precipitation from CO2 and Produced Water Co-Injection into Sandstone". Energies 14, nr 21 (26.10.2021): 6998. http://dx.doi.org/10.3390/en14216998.
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Carbon dioxide geological storage involves injecting captured CO2 streams into a suitable reservoir. Subsequent mineral trapping of the CO2 as carbonate minerals is one of the most secure forms of trapping. Injection of CO2 dissolved in water or co-injection of CO2 with water may enhance trapping mechanisms. Produced waters are already re-injected into reservoirs worldwide, and their co-injection with CO2 could enhance mineral trapping in low reactivity rock by providing a source of cations. Sandstone drill core from a reservoir proposed for CO2 storage was experimentally reacted with supercritical CO2 and a synthetic produced water. Micro computed tomography (CT), QEMSCAN, and SEM were performed before and after the reaction. The sandstone sample was predominantly quartz with minor illite/muscovite and kaolinite. The sandstone sub-plug micro-CT porosity was 11.1% and 11.4% after the reaction. Dissolved Ca, Mg, and Sr decreased during the reaction. After the reaction with CO2 and synthetic produced water, precipitation of crystalline carbonate minerals calcite and dolomite was observed in the pore space and on the rock surface. In addition, the movement of pore filling and bridging clays, as well as grains was observed. Co-injection of CO2 with produced waters into suitable reservoirs has the potential to encourage CO2 mineral trapping.