Abstract The underground city beneath the Nevşehir Castle located in the middle of Cappadocia region in Turkey with approximately cone shape is investigated by jointly utilizing the modern geophysical techniques of seismic surface waves and electrical resistivity. The systematic void structure under the Nevşehir Castle of Cappadocia, which is known to have widespread underground cities, is studied by the use of 33 separate two-dimensional profiles ~4-km long where electrical resistivities and seismic surface waves are concurrently measured. Seismic surface wave measurements are inverted to establish the shear-wave velocity distribution while resistivity measurements are inverted to resolve the resistivity distribution. Several high-resistivity anomalies with a depth range 8-20 m point to a systematic void structure beneath the Nevşehir Castle. We were able to effectively isolate the void structure from the embedding structure since the currently employed resistivity instrument has provided us high resolution quality measurements. Associated with the high resistivity anomalies there exist low-velocity depth zones acquired from the surface wave inversions also pointing to a systematic void structure where three-dimensional visualization techniques are used to show the extension of the void structure under the studied area.
{"title":"Nevşehir Castle Region in Turkey Interpreted by the Use of Seismic Surface Wave and Electrical Resistance Measurements Together","authors":"Ö. Çakır, N. Coşkun, M. Erduran","doi":"10.2478/pjg-2019-0007","DOIUrl":"https://doi.org/10.2478/pjg-2019-0007","url":null,"abstract":"Abstract The underground city beneath the Nevşehir Castle located in the middle of Cappadocia region in Turkey with approximately cone shape is investigated by jointly utilizing the modern geophysical techniques of seismic surface waves and electrical resistivity. The systematic void structure under the Nevşehir Castle of Cappadocia, which is known to have widespread underground cities, is studied by the use of 33 separate two-dimensional profiles ~4-km long where electrical resistivities and seismic surface waves are concurrently measured. Seismic surface wave measurements are inverted to establish the shear-wave velocity distribution while resistivity measurements are inverted to resolve the resistivity distribution. Several high-resistivity anomalies with a depth range 8-20 m point to a systematic void structure beneath the Nevşehir Castle. We were able to effectively isolate the void structure from the embedding structure since the currently employed resistivity instrument has provided us high resolution quality measurements. Associated with the high resistivity anomalies there exist low-velocity depth zones acquired from the surface wave inversions also pointing to a systematic void structure where three-dimensional visualization techniques are used to show the extension of the void structure under the studied area.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"19 - 9"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46961784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abid T. Javed, S. Ghazi, Shahid Ali, Shafiq Muhammad, Umair Rasool, Q. Dar
Abstract The present research describes a method of combining geostatistical analysis with geophysical inversion of electrical resistivity data conducted in Pakhli Plain, northwestern Himalayas, Pakistan. The raw data has been collected from the Technical Report VII-I on Ground Water Resources in Pakhli Plain, Mansehra District. Subsequently, the data has been deciphered and broadened from one dimensional resistivity data into a 2D model that can be entirely visualized and deduced in a spatial sense. Interpretation and calibration of the electrical resistivity curves with the lithologies and geophysical logs of boreholes suggests possible identification of distinctive sedimentary accumulations occurring within the Pakhli Plain. The 2D and 3D gridding and visualization is imperative to map the extents of the alluvial deposits within the Pakhli Plain formed during the periods of extreme tectonic activity. The coarser sediments are associated with lower levels of resistivity as measured in the electrical surveys, whereas the finer sediments exhibit characteristically lower resistivities. Therefore, the zones of low and high resistivity values are indicative of particles associated with coarser and finer sediments, respectively. It has been mentioned that the Pakhli Plain has remained a lacustrine zone during some time in the geological past as indicated by low resistivities representing finer sediments in the middle of the Plain. Consequently, the overall transmissivity of the sediments is low, which imply poor conditions for commercial groundwater production in the Pakhli Plain. Moreover, high resistivity zones of coarse material could be further investigated for groundwater potential areas. In particular, the prime objectives of the present study include 3D modeling of underground resistivity and its exploration in terms of groundwater potential on the basis of distribution of low resistivity zones.
{"title":"3D Interpretation of Resistivity Data for Groundwater Potential Assessment of Pakhli Plain, Mansehra District, Pakistan","authors":"Abid T. Javed, S. Ghazi, Shahid Ali, Shafiq Muhammad, Umair Rasool, Q. Dar","doi":"10.2478/pjg-2019-0010","DOIUrl":"https://doi.org/10.2478/pjg-2019-0010","url":null,"abstract":"Abstract The present research describes a method of combining geostatistical analysis with geophysical inversion of electrical resistivity data conducted in Pakhli Plain, northwestern Himalayas, Pakistan. The raw data has been collected from the Technical Report VII-I on Ground Water Resources in Pakhli Plain, Mansehra District. Subsequently, the data has been deciphered and broadened from one dimensional resistivity data into a 2D model that can be entirely visualized and deduced in a spatial sense. Interpretation and calibration of the electrical resistivity curves with the lithologies and geophysical logs of boreholes suggests possible identification of distinctive sedimentary accumulations occurring within the Pakhli Plain. The 2D and 3D gridding and visualization is imperative to map the extents of the alluvial deposits within the Pakhli Plain formed during the periods of extreme tectonic activity. The coarser sediments are associated with lower levels of resistivity as measured in the electrical surveys, whereas the finer sediments exhibit characteristically lower resistivities. Therefore, the zones of low and high resistivity values are indicative of particles associated with coarser and finer sediments, respectively. It has been mentioned that the Pakhli Plain has remained a lacustrine zone during some time in the geological past as indicated by low resistivities representing finer sediments in the middle of the Plain. Consequently, the overall transmissivity of the sediments is low, which imply poor conditions for commercial groundwater production in the Pakhli Plain. Moreover, high resistivity zones of coarse material could be further investigated for groundwater potential areas. In particular, the prime objectives of the present study include 3D modeling of underground resistivity and its exploration in terms of groundwater potential on the basis of distribution of low resistivity zones.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"51 - 58"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41989729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The IGRF filtered Aeromagnetic data over Iwo, southwestern part of Nigeria within the basement complex was subjected to reduction to magnetic equator filtering, residual filtering, upward and downward continuation filtering, automatic gain control filtering, tilt angle derivative, second vertical derivative, analytical signal and Euler deconvolution. This reveals the geologic information such as structural trend. Based on the result of the total magnetic intensity map, reduction to equator map, analytical signal map and residual magnetic intensity map, it can be concluded that; The rocks in the study area have a trend of approximately northeast-southwest direction as seen on the upward continuation map. Most of the delineated lineaments found within the study area strike mostly in NNE-SSW, NE-SW and NW-SE with minor trend of E-W and ENE-WSW direction. Structural lineament orientation suggested that they were products of Pan-African orogeny (NE-SW, NW-SE and NNE-SSW trends) and pre-Pan-African orogeny (NNW-SSE and E-W trend). The interpretation of the aeromagnetic dataset gave an insight into the regional geology and structural trends of the area.
{"title":"Aeromagnetic Mapping of Iwo Region of Southwestern Nigeria for Lithostructural Delineation","authors":"C. Okpoli, D. Oludeyi","doi":"10.2478/pjg-2019-0008","DOIUrl":"https://doi.org/10.2478/pjg-2019-0008","url":null,"abstract":"Abstract The IGRF filtered Aeromagnetic data over Iwo, southwestern part of Nigeria within the basement complex was subjected to reduction to magnetic equator filtering, residual filtering, upward and downward continuation filtering, automatic gain control filtering, tilt angle derivative, second vertical derivative, analytical signal and Euler deconvolution. This reveals the geologic information such as structural trend. Based on the result of the total magnetic intensity map, reduction to equator map, analytical signal map and residual magnetic intensity map, it can be concluded that; The rocks in the study area have a trend of approximately northeast-southwest direction as seen on the upward continuation map. Most of the delineated lineaments found within the study area strike mostly in NNE-SSW, NE-SW and NW-SE with minor trend of E-W and ENE-WSW direction. Structural lineament orientation suggested that they were products of Pan-African orogeny (NE-SW, NW-SE and NNE-SSW trends) and pre-Pan-African orogeny (NNW-SSE and E-W trend). The interpretation of the aeromagnetic dataset gave an insight into the regional geology and structural trends of the area.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"20 - 30"},"PeriodicalIF":0.0,"publicationDate":"2019-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48991541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. C. Ekeh, E. Uko, Ejiro F. Eleluwor, F. B. Sigalo
Abstract Geophysical well logs were used to delineate the stratigraphic units and system tracks in the XYZ Field of the Niger Delta. The gross percentages for sand levels range from 93-96% in the shallow levels to 60-66% in the deeper levels. Porosity values ranged between 27% at shallower sections and 9% at deeper depths. Six depositional sequences were identified and categorized into their associated system tracts. Porosity decreases with depth in normal compacted formation for both sandstone and shale units. Surface porosity for sandstone is 42%, and for shale it is 38.7% from extrapolation of sub-surface porosity values to the surface. The depth to the base of Benin Formation is highly variable ranging between 1300 and 2600m. This study reveals the possibility to correlate sand levels over long distances which enables inferring porosity values laterally. The knowledge of the existent stratigraphic units, the Benin, Agbada and Akata Formations and their petrophysical parameters such as porosity, lateral continuity of the sands and shales, the variation of the net-to-gross of sands with depth, enables the reservoir engineer to develop a plan for the number and location of the wells to be drilled into the reservoir, the rates of production that can be sustained for optimum recovery. The reservoir engineer can also estimate the productivity and ultimate recovery (reserves) using the results on this work.
{"title":"Delineation of Stratigraphic Units in Xyz Field of Niger Delta Using Geophysical Logs","authors":"C. C. Ekeh, E. Uko, Ejiro F. Eleluwor, F. B. Sigalo","doi":"10.2478/pjg-2019-0005","DOIUrl":"https://doi.org/10.2478/pjg-2019-0005","url":null,"abstract":"Abstract Geophysical well logs were used to delineate the stratigraphic units and system tracks in the XYZ Field of the Niger Delta. The gross percentages for sand levels range from 93-96% in the shallow levels to 60-66% in the deeper levels. Porosity values ranged between 27% at shallower sections and 9% at deeper depths. Six depositional sequences were identified and categorized into their associated system tracts. Porosity decreases with depth in normal compacted formation for both sandstone and shale units. Surface porosity for sandstone is 42%, and for shale it is 38.7% from extrapolation of sub-surface porosity values to the surface. The depth to the base of Benin Formation is highly variable ranging between 1300 and 2600m. This study reveals the possibility to correlate sand levels over long distances which enables inferring porosity values laterally. The knowledge of the existent stratigraphic units, the Benin, Agbada and Akata Formations and their petrophysical parameters such as porosity, lateral continuity of the sands and shales, the variation of the net-to-gross of sands with depth, enables the reservoir engineer to develop a plan for the number and location of the wells to be drilled into the reservoir, the rates of production that can be sustained for optimum recovery. The reservoir engineer can also estimate the productivity and ultimate recovery (reserves) using the results on this work.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"38 - 49"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44158156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract One of the areas that have geothermal potential in Indonesia is Tiris because there are found some manifestation in the form of hot springs. Several studies are needed to determine its geothermal potential before exploitation is carried out. Some previous studies have been carried out in the area, one of which uses Landsat 7 remote sensing data. There are other studies that state that knowledge of geology is needed to implement remote sensing in determining geothermal areas. This study uses 3-years data from Landsat 8 and geological information from the regional geological map of the study area. The result show changes in the value of Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) from year to year, where each year the NDVI value decrease which is interpreted as reduced vegetation in the study area. From the distribution of LST values in the study area, it was found that there were hot spots that had higher temperatures than the surrounding area. When geological information and LST distribution map overlaid with regional geological maps, it is known that the hot spots inside the research area are possible to be a geothermal reservoir.
{"title":"Spatio-Temporal Change of Land Surface Temperature at Tiris Geothermal Potential Area, East Java, Indonesia.","authors":"Andre Prayogo, S. Maryanto, A. Nadhir","doi":"10.2478/pjg-2019-0002","DOIUrl":"https://doi.org/10.2478/pjg-2019-0002","url":null,"abstract":"Abstract One of the areas that have geothermal potential in Indonesia is Tiris because there are found some manifestation in the form of hot springs. Several studies are needed to determine its geothermal potential before exploitation is carried out. Some previous studies have been carried out in the area, one of which uses Landsat 7 remote sensing data. There are other studies that state that knowledge of geology is needed to implement remote sensing in determining geothermal areas. This study uses 3-years data from Landsat 8 and geological information from the regional geological map of the study area. The result show changes in the value of Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) from year to year, where each year the NDVI value decrease which is interpreted as reduced vegetation in the study area. From the distribution of LST values in the study area, it was found that there were hot spots that had higher temperatures than the surrounding area. When geological information and LST distribution map overlaid with regional geological maps, it is known that the hot spots inside the research area are possible to be a geothermal reservoir.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"13 - 21"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47513628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Groundwater samples were evaluated for irrigation purpose, within selected part of Oju area of Benue State, Nigeria. The study area lies within Asu River Group of the Lower Benue Trough, southern part of Nigeria. Physicochemical parameters were analyzed using APHA, 2012 method. Results from the study showed that pH falls within slightly basic to acidic, with Ec value ranging from 127 to 760 μS/cm, SSP ranges from 1.53 to 43.78, Sodium Percentage ranges from 1.55 to 77.8 %, Kelly Ratio ranges from 0.01 to 0.77, Magnesium Absorption Ratio ranges from 0.00 to 61.98 and total hardness Total Hardness ranges from 72.00 to 425.5 within the study area. The above listed parameters were below various permissible standard value for irrigation except for MAR at LBT/04, Na % at LBT/09, 13 and 14, SAR at 01 and 04 and TH at LBT/04 that were slightly above various permissible standard values. From Gibbs plot it was observed that rock dominance is the major factor that influences groundwater except for few sampling point were precipitation dominance was observed to have influence on groundwater within the study area.
{"title":"Use of Modelling Approach in evaluation of Fractured Shale Aquifers for irrigation purpose; a case study of Oju, Lower Benue Trough Nigeria","authors":"M. Eyankware, C. Ogwah","doi":"10.2478/pjg-2019-0001","DOIUrl":"https://doi.org/10.2478/pjg-2019-0001","url":null,"abstract":"Abstract Groundwater samples were evaluated for irrigation purpose, within selected part of Oju area of Benue State, Nigeria. The study area lies within Asu River Group of the Lower Benue Trough, southern part of Nigeria. Physicochemical parameters were analyzed using APHA, 2012 method. Results from the study showed that pH falls within slightly basic to acidic, with Ec value ranging from 127 to 760 μS/cm, SSP ranges from 1.53 to 43.78, Sodium Percentage ranges from 1.55 to 77.8 %, Kelly Ratio ranges from 0.01 to 0.77, Magnesium Absorption Ratio ranges from 0.00 to 61.98 and total hardness Total Hardness ranges from 72.00 to 425.5 within the study area. The above listed parameters were below various permissible standard value for irrigation except for MAR at LBT/04, Na % at LBT/09, 13 and 14, SAR at 01 and 04 and TH at LBT/04 that were slightly above various permissible standard values. From Gibbs plot it was observed that rock dominance is the major factor that influences groundwater except for few sampling point were precipitation dominance was observed to have influence on groundwater within the study area.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"1 - 12"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47487563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The lower Indus basin is one of the prolific basins in Pakistan in which the C-interval of lower Goru formation act as a reservoir. With the help of petrophysical interpretation production zone is recognized and also porosity is calculated at the reservoir level. Through porosity we are able to calculate Ksat. A model based inversion of 2D seismic inversion was performed to ascertain three dimensional dispersion of acoustic impedance in the investigation zone and we have recognized new areas where porosity distribution is maximum and site which is suitable for new well. Porosity and Acoustic impedance are typically contrarily relative to each other. Presently porosity can be anticipated in seismic reservoir characterization by utilizing acoustic impedance from seismic inversion far from well position.
{"title":"Porosity Distribution and Differentiation of Different Types of Fluids in Reservoir of Sawan Gas Field, Lower Indus Basin, Pakistan","authors":"M. Asad, H. Rahim","doi":"10.2478/pjg-2019-0004","DOIUrl":"https://doi.org/10.2478/pjg-2019-0004","url":null,"abstract":"Abstract The lower Indus basin is one of the prolific basins in Pakistan in which the C-interval of lower Goru formation act as a reservoir. With the help of petrophysical interpretation production zone is recognized and also porosity is calculated at the reservoir level. Through porosity we are able to calculate Ksat. A model based inversion of 2D seismic inversion was performed to ascertain three dimensional dispersion of acoustic impedance in the investigation zone and we have recognized new areas where porosity distribution is maximum and site which is suitable for new well. Porosity and Acoustic impedance are typically contrarily relative to each other. Presently porosity can be anticipated in seismic reservoir characterization by utilizing acoustic impedance from seismic inversion far from well position.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"28 - 37"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42796037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Some oil samples from various Nigerian oil fields were examined for the presence of Thermochemical Sulphate Reduction (TSR) derived organo sulphur compounds. Oil samples were diluted with DCM and injected into the GC–MS for full scan analysis. The GC–MS results show the presence 2–thiaadamantane, 1–methyl-2-thiaadamanatane and 5–methyl-2-thiaadamanatane, the compounds were identified by comparison of extracted spectras with literature. The presence of these compounds in oils has been accepted on a wider horizon as indicators of reservoir souring. The plot of 5–Methyl-2-thiaadamantane/Adamantane and Dibenzothiophene/Adamanatane showed a fair correlation, corroborating the presence of 5–Methyl-2-thiaadamantane and fairly high abundance of Dibenzothiophene, the plot of 2-thiaadamantane/Adamantane and 5–Methyl-2-Thiaadamantane/Adamantane corroborating the presence of 2-thiaadamantane and 5–Methyl-2-Thiaadamantane inferring that the presence of 2-thiaadamantane and 5–Methyl-2-Thiaadamantane indicate that reservoir souring is active.
{"title":"The Presence of 2-Thiaadamantane in Niger Delta Oils may indicate Souring in Niger Delta Reservoirs","authors":"S. Abrakasa, H. Nwankwoala","doi":"10.2478/pjg-2019-0003","DOIUrl":"https://doi.org/10.2478/pjg-2019-0003","url":null,"abstract":"Abstract Some oil samples from various Nigerian oil fields were examined for the presence of Thermochemical Sulphate Reduction (TSR) derived organo sulphur compounds. Oil samples were diluted with DCM and injected into the GC–MS for full scan analysis. The GC–MS results show the presence 2–thiaadamantane, 1–methyl-2-thiaadamanatane and 5–methyl-2-thiaadamanatane, the compounds were identified by comparison of extracted spectras with literature. The presence of these compounds in oils has been accepted on a wider horizon as indicators of reservoir souring. The plot of 5–Methyl-2-thiaadamantane/Adamantane and Dibenzothiophene/Adamanatane showed a fair correlation, corroborating the presence of 5–Methyl-2-thiaadamantane and fairly high abundance of Dibenzothiophene, the plot of 2-thiaadamantane/Adamantane and 5–Methyl-2-Thiaadamantane/Adamantane corroborating the presence of 2-thiaadamantane and 5–Methyl-2-Thiaadamantane inferring that the presence of 2-thiaadamantane and 5–Methyl-2-Thiaadamantane indicate that reservoir souring is active.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"3 1","pages":"22 - 27"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41742996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.26480/pjg.02.2018.18.21
Kekwaru M.M, N. H.O.
{"title":"DETERMINATION OF GROUNDWATER AND OVERLAND FLOW DIRECTION IN NDELE, RIVERS STATE, NIGERIA","authors":"Kekwaru M.M, N. H.O.","doi":"10.26480/pjg.02.2018.18.21","DOIUrl":"https://doi.org/10.26480/pjg.02.2018.18.21","url":null,"abstract":"","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69337222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.26480/PJG.02.2018.01.10
R. Roslee, F. Tongkul
The geology in the mountainous area of Sabah western provides a favourable setting for engineering geological instability. The area is underlain by the Trusmadi Formation (Palaeocene to Eocene age), the Crocker Formation (Late Eocene to Early Miocene age) and vary recent Quaternary alluvial materials which are still being deposited. The argillaceous nature and intense deformation suffered by the Trusmadi Formation and the highly jointed sandstone and mudstone beds of the arenaceous Crocker Formation makes them highly susceptible to weathering and instability. The weathered materials are unstable and may experience sliding due to by high pore pressure and intensively of geomorphological processes. In this study, a total of 20 selected critical slope failures were studied and classified into two main groups; rock slope (ten) and soil slope (ten). Soil slope failures normally involved large volumes of failed material as compared much rock slopes, where the failures are mostly small to medium. Kinematics rock slope analyses indicates that the variable potential of circular, planar, wedges, and toppling failures modes as well as the combination of more than one mode of aforementioned failure. Rock and soil slopes stability analysis indicates that the factor of safety value as unsafe (0.56 to 0.95). The geological influence had transformed the slopes in the Sabah mountainous area to be highly unstable and susceptible to landslide occurrences. Six (6) related main parameters to the landslide occurrence in the study area were attributed; 1) local and regional geology, 2) hydrological and geohydrological, 3) mineralogical and micro structures, 4) local discontinuities structures, 5) physical and engineering properties of soil and rock, and 6) geomorphological processes which can help in evaluating landslide problems. Therefore, development planning has to consider the slope hazard and risk management. This engineering geological mapping may play a vital role in disaster risk reduction programme in Sabah to ensure the public safety and to be extend with different environment.
{"title":"ENGINEERING GEOLOGICAL MAPPING ON SLOPE DESIGN IN THE MOUNTAINOUS AREA OF SABAH WESTERN, MALAYSIA","authors":"R. Roslee, F. Tongkul","doi":"10.26480/PJG.02.2018.01.10","DOIUrl":"https://doi.org/10.26480/PJG.02.2018.01.10","url":null,"abstract":"The geology in the mountainous area of Sabah western provides a favourable setting for engineering geological instability. The area is underlain by the Trusmadi Formation (Palaeocene to Eocene age), the Crocker Formation (Late Eocene to Early Miocene age) and vary recent Quaternary alluvial materials which are still being deposited. The argillaceous nature and intense deformation suffered by the Trusmadi Formation and the highly jointed sandstone and mudstone beds of the arenaceous Crocker Formation makes them highly susceptible to weathering and instability. The weathered materials are unstable and may experience sliding due to by high pore pressure and intensively of geomorphological processes. In this study, a total of 20 selected critical slope failures were studied and classified into two main groups; rock slope (ten) and soil slope (ten). Soil slope failures normally involved large volumes of failed material as compared much rock slopes, where the failures are mostly small to medium. Kinematics rock slope analyses indicates that the variable potential of circular, planar, wedges, and toppling failures modes as well as the combination of more than one mode of aforementioned failure. Rock and soil slopes stability analysis indicates that the factor of safety value as unsafe (0.56 to 0.95). The geological influence had transformed the slopes in the Sabah mountainous area to be highly unstable and susceptible to landslide occurrences. Six (6) related main parameters to the landslide occurrence in the study area were attributed; 1) local and regional geology, 2) hydrological and geohydrological, 3) mineralogical and micro structures, 4) local discontinuities structures, 5) physical and engineering properties of soil and rock, and 6) geomorphological processes which can help in evaluating landslide problems. Therefore, development planning has to consider the slope hazard and risk management. This engineering geological mapping may play a vital role in disaster risk reduction programme in Sabah to ensure the public safety and to be extend with different environment.","PeriodicalId":32520,"journal":{"name":"Pakistan Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45315491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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