THE IMPACT OF SEASONAL CHANGES ON HEAVY MINERALS CONCENTRATION FROM A PART OF EAST COAST OF INDIA

Pre and post monsoonal changes in the environment have led to a noticeable variation in sediment characteristics, heavy mineral concentrations and their distribution. The current study aimed to find out the effect of seasonal fluctuations on the concentration of heavy minerals along the coast and the variations in sediment textures and distribution. The study has revealed the effect of seasons on the sediments supply and its distribution along coast in the study area. The total heavy minerals concentrations are more in post monsoon than in pre monsoon and the concentration also increases from south to north in parts of the study area because of seasonal circulation of currents from south to north along the shore. The micro textural study of the heavy mineral grains from different locations in the study area revealed the mechanical and chemical erosions on the grain surfaces.

2-DIMENSIONAL GROUND RESPONSE ANALYSIS: A REVIEW

Earthquake is one of the natural disasters that is caused by ground shaking in soil. Ground response analysis is conducted to obtain the ground motion acceleration on soil surface. Conventional 1-D ground response analysis often suggests that soils are horizontally layered, with little consideration for heterogeneous distribution of soil properties. In this study, literature on 2-D ground response analysis studies has been study as it covers vertically and horizontally waves. Therefore, researcher works were presented in numerical modelling as substantial parameters for studies in near-surface structure. Besides, aspects for future research in the area 2-Dimensional Ground Response Analysis are included. The paper contributes to the under- standing of 2-Dimensional Ground Response Analysis for the application of seismic risk mitigation.

GEOPHYSICAL EVALUATION OF SUBSURFACE PROTECTIVE CAPACITY AND GROUNDWATER PROSPECT IN A TYPICAL SEDIMENTARY ZONE, EASTERN DAHOMEY BASIN USING ELECTRICAL RESISTIVITY TECHNIQUE

Subsurface protective capacity evaluation is important in groundwater prospecting. With the aid of Dar-Zarrouk parameters which show direct relationship with contaminants infiltration time and transmissivity, joint interpretation of vertical electrical sounding (VES) and 2-D resistivity imaging were employed to evaluate overburden protective capacity and groundwater potentials at Mowe in Obafemi-Owode LGA, southwest Nigeria. Total longitudinal conductance S, total transverse resistance T, longitudinal resistivity ρL and transverse resistivity ρT were computed. Sand/clayey sand was delineated at 70% of the area either as confined aquifers (78%) or unconfined aquifers (22%). S values in 87% of locations has moderate protective rating (0.2071 – 0.5630), one location has good protective rating (0.7736), others have weak protective ratings (0.1053 – 0.1814). The entire area is characterized by low overburden thickness H (7.9 – 25.6 m), which agrees with a correlation coefficient of 0.58 between S and H. T values is in the range 235 – 2046 Ωm2 with high values indicating high transmissivity zones, suggesting high probability of pollutant contamination of aquifer, also agreeing with moderate correlation coefficient of 0.69 between T and H. The study area was grouped into three regions on the cross plot of T versus S: low S and high T – poor protection and high contaminant transmission; moderate/good S and low T – good protection with low contaminants transmission; moderate/low S and low T – weak protective capacity and poor transmissivity. Excellent correlation (0.99) exists between ρL and ρT, with ρT slightly higher than ρL, and low ρL signifying the presence of conductive clayey materials in the overburden.

MANIFESTATION OF OPTIMAL ROUTE ALIGNMENT SELECTION OF RURAL ROAD USING GIS AND LEAST COST PATH (LCP) MODEL WITH ENGINEERING AND ENVIRONMENTAL SUITABILITY PERSPECTIVE: A CASE STUDY IN NEPAL

For the economic growth and sustainable development of any country, the road networks play a pivotal role. Hence, the selection of best route alignment for the road networks becomes even more significant. The Geographical Information System (GIS) integration with the Least Cost Path (LCP) model is used to determine the optimum route to address sustainable road development. In this study, Dupcheswor Rural Municipality, Nuwakot, Nepal and part of Langtang National Park was taken as a study area; and engineering and environmental parameters were selected to create a cost layer. Using the Least Cost Path (LCP) model, fifteen routes were generated in the GIS. All the generated fifteen routes were compared based on cost, and the optimum route was selected based on the least cost. The optimum route in this study was derived from the hybrid theme of engineering and environmental perspectives. This study suggests further research can be done to improve preliminary to detailed road alignment planning and design coordination by considering other factors.

WELL LOGS ANALYSIS TO ESTIMATE THE PARAMETERS OF SAWAN-2 AND SAWAN-3 GAS FIELD

The lower Indus basin is leading hydrocarbon carriage sedimentary basin in Pakistan. Evaluation of two sorts out wells namely Sawan-2 and Sawan-3 has been assumed in this work for estimation and dispensation of petro physical framework using well log data. The systematic formation assessment by using petro physical studies and neutron density cross plots reveal that lithofacies mainly composed of sandstone. The hydrocarbon capability of the formation zone have been mark through several isometric maps such as water saturation, picket plots, cross plots, log analysis Phie vs depth and composite log analysis. The estimated petro physical properties shows that reservoir have volume of shale 6.1% and 14.0%, total porosity is observed between 14.6% and 18.2%, effective porosity ranges 12.5-16.5%, water saturation exhibits between 14.05% and 31.58%, hydrocarbon saturation ranges 68.42% -86.9%, The lithology of lower goru formation is dominated by very fine to fine and silty sandstone. The study method can be use within the vicinity of central Indus basin and similar basin elsewhere in the globe to quantify petro physical properties of oil and gas wells and comprehend the reservoir potential.

DELINEATION OF HYDROCARBON SATURATED RESERVOIR SAND USING INTEGRATED 3D PRE-STACK SEISMIC AND WELL LOG DATA IN BONGA – FIELD, CENTRAL SWAMP DEPOBELT, ONSHORE NIGER DELTA, NIGERIA

This study has successfully delineated the lateral continuity of hydrocarbon saturated sand reservoir in Bonga field, Niger Delta. 3D pre-stack seismic volume and well logs from two (2) exploratory wells were employed in the pre-stack seismic inversion analysis. The delineated BGA reservoir sand spans across the two (2) wells labelled Bonga-26 and Bonga-30. The reservoir depth ranges from 10490 ft to 10620 ft in Bonga-26 while the reservoir depth ranges from 10390 ft to 10490 ft in Bonga-30. The delineated reservoir is characterized by low gamma ray (< 75 API), water saturation, shale volume and high resistivity as deciphered in their respective well log curves signature. Rock attribute crossplot was carried out to discriminate between the formation fluid and lithology. The crossplot space of VP-VS ratio versus acoustic impedance (AI), discriminates the formation properties into lithology and fluid (gas and brine sand) based on clusters inferring the presence of each formation fluid properties. The inversion cross sections of P-impedance, S-impedance, density (ρ) and VP-VS ratio depicts the spread and lateral continuity of the reservoir sand across the well locations. The delineated zones reveal low P-impedance, density, VP-VS ratio and slight increase in S-impedance which further validate the presence of hydrocarbon in the field.

THE INTEGRATION OF GIS, AHP, AND REMOTE SENSING METHODS FOR POTENTIAL AREAS GROUNDWATER: CASE STUDY FOR PONTIAN DISTRICT, JOHOR, MALAYSIA

In Malaysia, production and conservation of groundwater are essential to the ecosystem’s climate and sustainability. The decline of groundwater level data is a related problem for managing water supplies in the Pontian District, Johor, particularly in rural areas. With demand for household water, agriculture and industrial use is still increasing. Studies-based Remote Sensing (RS) and Geographic Information System (GIS) have gained more advantages in groundwater exploration as it is rapid knowledge about the research and development tool. Therefore, the present study has conducted an example of mapping potential groundwater zones in the Pontian District, Johor, and assessing the factors leading to explore future groundwater opportunities. To identify possible groundwater areas, RS data and GIS are being used, and the data collected by the Department of Mineral and Geoscience Malaysia (JMG). The present study utilized integration between GIS through analytical hierarchy process techniques (AHP). Five different maps were prepared and studied for the potential groundwater area, such as Roughness, Topographic Wetness Index (TWI), Elevation, Curvature, and Slope. Weights in all the thematic maps assigned to each class using the AHP method on their characteristics and potential water capability. The production accuracy has checked using groundwater prospects information, and the process is approximately 87.5 percent accurate. The resulting map of groundwater capacity was graded into five groups-very good, good, moderate, low, and very low. The analysis shows that about 57.3 percent of the area occupies the low potential groundwater area. The potential zones of good and moderate groundwater are observed in 1.28 percent and 18.94 percent, respectively. Only in minimal areas is the area under perfect potential areas registered. The results from this study can be useful in the preparation and growth planning of related agencies in Malaysia, for possible groundwater exploration to provide a fast system and cost reduction and a shorter period.

ASSESSMENT OF VADOSE ZONE CHARACTERISTICS FOR ENVIRONMENTAL IMPACT AUDIT OF SELECTED CEMETERIES AROUND OSUN STATE, SOUTH-WESTERN PART OF NIGERIA

Cemeteries have been identified as a possible source of groundwater and environmental pollution. This may be due to wrong siting of cemeteries, poor soil selection and very thin vadose zone. Over the years, most communities around Osun State experience a number of communicable diseases like dysentery, diarrhea and typhoid, especially after episodes of flash floods. Therefore, this study was carried out to audit the impact of burial practices on the immediate environment viz-a-viz their interaction with both surface and groundwater which forms the main source of potable water for the communities. Method of approach include; assessing possible water contamination, studying the vadose hydrological characteristics as well as studying the geotechnical properties of soils within the vadose zone. Water samples from the vicinity of both cemeteries shows probable contamination with an average pH of 6.19 for Ede and 6.57 for Iragbiji, EC with an average 480μS for Ede and 1210μS for Iragbiji. Biological constituents found within the area include; enterobacteriaceae (salmonella spp., serratia spp., proteus spp., shigella spp.), suggesting likely contamination of both surface and groundwater around the vicinity of the cemeteries. Most cations and anions analysed for (Mg2+, NO3-, SO42-, and PO43-) comply with the WHO standards based on their maximum permissible limits (MPL). Geotechnical investigations revealed that soils within the study areas are largely unsuitable for a standard cemetery due to their high moisture content, poor grading characteristics, low compaction value, poor hydraulic characteristics and shallow water level. The study concluded that cemeteries from both towns have a negative impact on their immediate environment due to poor selection of soil materials (porous and permeable sandy soil) as reflected in the quality of surface and groundwater.

IS MAKRAN A SEPARATE MICROPLATE? A SHORT REVIEW

Makran Subduction Zone (MZS) is important as this region lies on both sides of the border of Iran and Pakistan along the coastline. Makran Subduction complex has pervasive seismicity and diverse focal mechanism solutions and being in the vicinity of Triple Junction where three major Tectonic plates; Arabian, Eurasian and Indian plates are connecting. Both of Chabahar and Gwadar ports are located in this vicinity, on which China is investing for CPEC, Belt and Road Initiative. The whole world is looking at these projects of Makran, as this may define and transform the future of trade. Hence Geoscience point of view is notable as well in consideration for the successful execution of these projects. Several Microplates/blocks have been proposed around the vicinity MSZ and Indian-Eurasian Plate boundary including the Ormara microplate, Lut Block, Helmand Block, and Pakistan-Iran Makran microplate (PIMM). The purpose of this review is to shed light on PIMM. Despite previous researches related to Makran, still many researchers are working to solve puzzles related to the complexity of MSZ. It is divided into Eastern and Western Makran due to seismicity and North to South into four parts based on stratigraphy, thrusts and folds. This review aims to give suggestions for the hypothesis on PIMM which was inferred as a separate microplate.

DELINEATION OF FAULTS AND CAVITIES USING GRAVITY TECHNIQUES: AN IMPLICATION FOR ROAD CONSTRUCTION, SOUTH-SOUTH NIGERIA

This study was carried out using five digitized aerogravity data to delineate near-surface structural faults, cavities, low-density zones and estimate the mass balance unit in foundations. Qualitative and quantitative analysis were performed in order to examines the depths to anomalous bodies, density/mass and stratigraphic features such as faults and cavities. The techniques employed were: Source parameter imaging (SPI), 3D Euler deconvolution, forward and inverse modeling. The results of the SPI shallow values range from -5.62 to -53.74 m and deep values range from 3.33 to 120 m. The 3D Euler deconvolution results range from -1892.2 to -1278.3 m for obscure and -12264 to 644.6 m for superficial formations. The forward and inverse modeling result shows the values of depth ranging from 2.5 to 4.8 km, density/mass range from (0.7 to 2.4) x 10-3 kg/m3 and (27 to 133) x 1010 kg of three profiles which is the parameter contrast of the gravity surveys. This shows sequential depths and density/mass contrast between the body of interest and the surrounding material which depicts the presents of faults, sedimentary basins and rock bearing minerals of shale/marble which comprises of air, water and sediment-filled formations. The information from this study has revealed the true nature of the subsurface and this will serve as a guide during road construction.