Showing papers in "Journal of The Geological Society of India in 2017"
TL;DR: An effort has been made to comprehend the groundwater quality of Raipur city for drinking purpose utilizing Water Quality Index (WQI) and Geographic Information System (GIS) techniques as discussed by the authors.
Abstract: An effort has been made to comprehend the groundwater quality of Raipur city for drinking purpose utilizing Water Quality Index (WQI) and Geographic Information System (GIS) techniques. In this study thirty four groundwater samples were collected during May, 2015. Standard methods has been adopted in groundwater sampling which are prescribed by the American Public Health Association (APHA, 1995). Eight water quality parameters have been considered to ascertained water quality index viz. pH, chloride, fluoride, calcium, magnesium, alkalinity, hardness and nitrate. The Bureau of Indian Standard (BIS, 2009) has been considered to assess the suitability of groundwater for drinking purposes and for the calculation of WQI. This study reveals that 76% area is falling under excellent, very good and good category and 24% area is falling under poor, very poor and unfit category as per the WQI classification. The predicted accuracy of the obtained result is around 97.05% reflecting capability of adopted techniques. Anthropogenic activities are influencing the groundwater quality of the study area. The present study is helpful in proper planning and management of available water resource for drinking purpose.
79 citations
TL;DR: In this paper, the authors investigated trace metal (Li, Be, B, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Sb and Pb) concentrations of drinking water samples in northeast Rajasthan, India.
Abstract: The present study was conducted to investigate trace metal (Li, Be, B, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As Se, Mo, Cd, Sb, Ba and Pb) concentrations of drinking water samples in northeast Rajasthan, India. Furthermore, the study aimed to ascertain carcinogenic and non-carcinogenic health risks of metals by ingestion and dermal absorption pathways to the local residents. Metal concentrations were analyzed by using high resolution inductively coupled plasma mass spectrometry and compared with permissible limits set by the Bureau of Indian Standards, United States Environmental Protection Agency and World Health Organization. The results indicate that the concentrations of Be, B, Al, Cr, Fe, Cu, Zn, As, Mo, Sb and Ba were lower than their respective permissible limits, whereas the concentrations of Mn, Ni, Se, Cd and Pb in some samples were higher than their permissible limits.The total hazard index (summing the hazard index through ingestion and dermal routes) at all the sampling sites exceeded or nearing unity, indicating the presence of non-carcinogenic health effects from ingestion of water and dermal contact with water. The results indicate that the total excess lifetime cancer risk (considering both ingestion and dermal exposure pathways) of metals exposure was in accordance to the acceptable lifetime risks for carcinogens in drinking water (10-6–10-4). Both carcinogenic and non-carcinogenic risks were mainly attributed to the ingestion pathways.
49 citations
TL;DR: In this article, the suitability of groundwater for drinking and agricultural purposes was carried out in the plain of upper Cheliff, which covers an area of 375 km2 and lies in a semi-arid climate.
Abstract: Assessment of groundwater suitability for drinking and agricultural purposes was carried out in the plain of upper Cheliff. The study area covers an area of 375 km2 and lies in a semiarid climate. Groundwater is the major source for domestic and agricultural activity in this area. Groundwater samples were collected from 19 wells during dry and wet periods in 2012, and they were analyzed for major cations and anions and compared with drinking and irrigation specification standards. The concentration of the majority of chemical constituents exceeds the standards of WHO as a result of various sources of pollution. It indicates the dominance of groundwater types: Ca-Mg-Cl, and Ca-Mg-HCO3. Suitability of groundwater for drinking was evaluated based on the water quality index; it shows more than 60% of samples have very poor quality for dry and wet periods, which means water is severely contaminated and unsuitable for drinking purpose. In terms of the irrigation usage, generally groundwater is suitable for both periods in the major part of the plain. The Mineralization processes in this area is determined by the lithology of the aquifer (exchange water-rock), by anthropogenic factors (discharges of urban sewage, use of fertilizers) and also by evaporation (semi-arid climate).
45 citations
TL;DR: In this article, the authors assessed arsenic health risk to the local residents through oral and dermal exposure pathways of drinking water and to investigate source apportionment of groundwater pollutants using multivariate statistical techniques in the Chapai-Nawabganj district, Bangladesh.
Abstract: This study assessed arsenic health risk to the local residents through oral and dermal exposure pathways of drinking water and to investigate source apportionment of groundwater pollutants using multivariate statistical techniques in the Chapai-Nawabganj district, Bangladesh. Groundwater samples collected from shallow tube well and dug well at the depth ranges (15-60 m) were analyzed for physio-chemical parameters and trace elements. Most of the studied physio-chemical parameters were found within their respective permissible limits. However, total As, Fe and Mn concentrations exceeded Bangladesh and WHO guideline values. The assessment of arsenic health risk reveals that children as compared to adults are found at a higher risk as the values of hazard quotients (HQ) >1 in the most of the groundwater samples. This level of arsenic contamination should have medium to high chronic risk and medium carcinogenic risk when compared with US EPA guidelines which can cause serious health hazard. The results of principal component analysis (PCA) and factor analysis (CA) indicate that geogenic (interaction of water and basement rock) and anthropogenic (agrochemicals, agricultural fertilizer and domestic sewage) sources are responsible for variation in arsenic and other physio-chemical parameters in the groundwater aquifer of the study area. Furthermore,the inter-correlation of arsenic with metals and ions were also calculated by correlation matrix and linear regression analysis. The outcomes of this study will help to meet the challenge of sustainable groundwater quality management in Bangladesh and enhancing better vision of potential health risk of local inhabitants in the study area.
43 citations
TL;DR: In this article, a 2D electrical resistivity tomography (ERT) technique has been used to detect underground mine workings, mainly air or water filled galleries, in Indian coalfields.
Abstract: Land subsidence is a serious problem in Indian coalfields due to old underground mine workings. Unfortunately, most of these are uncharted as no mine plans are available. The hidden galleries, goafs, shafts etc. may pose great threat for future mine development as well as to the local environment. The mine workings should be charted to undertake an effective preventive action. In the present study, 2D electrical resistivity tomography (ERT) technique has been used to detect underground mine workings, mainly air or water filled galleries. Initially, the whole exercise has been executed through a synthetic model study. Gaussian random noise of 5mV/A has been added with synthetic data to demonstrate field condition which provides realistic results. ERT survey was conducted over a part of Jogidih coal mine of Jharia coal field in India for a first time. Four electrode configurations, Wenner, Schlumberger, dipole-dipole and gradient were considered for this study. The results indicate the presence of sub-surface water and air filled cavity due to high resistivity contrast with surroundings.
41 citations
TL;DR: In this paper, an integrated approach of Geographic Information System (GIS) and numerical groundwater modeling techniques using MODFLOW software for the watershed located in the Kodaganar river basin, Dindigul district, Tamil Nadu.
Abstract: Groundwater is a dynamic and replenishable natural resource. The numerical modeling techniques serve as a tool to assess the effect of artificial recharge from the water conservation structures and its response with the aquifers under different recharge conditions. The objective of the present study is to identify the suitable sites for artificial recharge structures to augment groundwater resources and assess its performance through the integrated approach of Geographic Information System (GIS) and numerical groundwater modeling techniques using MODFLOW software for the watershed located in the Kodaganar river basin, Dindigul district, Tamil Nadu. Thematic layers such as geology, geomorphology, soil, runoff, land use and slope were integrated to prepare the groundwater prospect and recharge site map. These potential zones were categorized as good (23%), moderate (54%), and poor (23%) zones with respect to the assigned weightage of different thematic layers. The major artificial recharge structures like percolation ponds and check dams were recommended based on the drainage morphology in the watershed. Finally, a threelayer groundwater flow model was developed. The model was calibrated in two stages, which involved steady and transient state condition. The transient calibration was carried out for the time period from January 1989 to December 2008. The groundwater model was validated after model calibration. The prediction scenario was carried out after the transient calibration for the time period of year up to 2013. The results show that there is 15 to 38% increase in groundwater quantity due to artificial recharge. The present study is useful to assess the effect of artificial recharge from the proposed artificial structures by integrating GIS and groundwater model together to arrive at reasonable results.
41 citations
TL;DR: In this article, a study has been carried out to investigate the slope forming material and assess the stability of soil slopes by numerical approach, and five vulnerable soil slopes identified on the basis of degree of weathering and slope geometry.
Abstract: The section of about 12 km of National highway 222 passing through the Malshej Ghat experience frequent slope failure due to complex geological condition, heavy rainfall and slope geometry. The area is part of Western Ghat Deccan trap and slope masses are made of basalt and its weathered crust (debris/soil). The soil slope failure problem mainly occur in rainy seasons due to induced pore water pressure and reduced strength of the slope mass. The present study has been carried out to investigate the slope forming material and assess the stability of soil slopes by numerical approach. For the identification of the vulnerable zones, field study has been carried out and five vulnerable soil slopes identified namely MGS1, MGS2, MGS3, MGS4 and MGS5 on the basis of degree of weathering and slope geometry. The laboratory experiments were carried out to determine the strength properties of the geomaterials. All the input variables acquired from the field and laboratory experiments have been used for numerical simulation, which was performed with the help of limit equilibrium method (LEM) and finite element method (FEM). Numerical analysis provides understanding of the slope behaviour and illustrates that MGS1 and MGS3 are stable slopes, MGS2 and MGS4 are critically stable, whereas, slope MGS5 is unstable. This study recommend the protection of soil slopes and suggest that more detailed investigation is required for long term remedial measures to prevent risk of damage in Malshej Ghat.
38 citations
TL;DR: In this article, the authors analyzed the impacts of drought on groundwater table (GWT) during the period 1971-2011 in the Barind area, Bangladesh, using standardized precipitation index (SPI) and Mann-Kendall Trend Test (MK) trend test.
Abstract: The study analyzes drought using Standardized Precipitation Index (SPI) and Mann-Kendall (MK) Trend Test in the context of the impacts of drought on groundwater table (GWT) during the period 1971-2011 in the Barind area, Bangladesh. The area experienced twelve moderate to extreme agricultural droughts in the years 1972, 1975, 1979, 1982, 1986, 1989, 1992, 1994, 2003, 2005, 2009 and 2010. Some of them coincide with El Nino events. Hydrological drought also occurred almost in the same years. However, relationship between all drought events and El Nino is not clear. Southern and central parts of the area frequently suffer from hydrological drought, northern part is affected by agricultural drought. Trends in SPI values indicate that the area has an insignificant trend towards drought, and numbers of mild and moderate drought are increasing. GWT depth shows strong correlation with rainy season SPI values such that GWT regaining corresponds with rising SPI values and vice versa. However, 2000 onwards, GWT depth is continuously increasing even with positive SPI values. This is due to over-exploitation of groundwater and changes in cropping patterns. Agricultural practice in Barind area based on groundwater irrigation is vulnerable to drought. Hence, adaptation measures to minimize effects of drought on groundwater ought to be taken.
38 citations
TL;DR: In this paper, two seismic sections, X and Y oriented N-S passing through wells W-1 and W-2 respectively, are considered for seismic attribute analysis and porosity prediction.
Abstract: Seismic attributes such as: amplitude envelope, instantaneous phase and cosine of instantaneous phase of 2D post-stack seismic data facilitates structural and stratigraphic interpretation of shallow marine offshore, Krishna-Godavari basin. Two seismic sections namely, X and Y oriented N-S passing through wells W-1 andW-2 respectively are considered for seismic attribute analysis and porosity prediction. The gamma ray log trend indicates deposition of cleaning upward sediment. Coarsening upward, clayey-silty-sandy bodies, making a series of about 50-60 m thickness, have been evidenced from the gamma ray log. An extensional structural style comprising growth faults is associated with the progradational style of deposition. Four seismic zones have been distinguished. These zones differ in amplitude, frequency and continuity of the reflectors. Channel sands of Cretaceous age of Raghavapuram shale are identified in well log, seismic section and its acoustic impedance section. Major stratigraphic horizons along with faults extending to basement are marked with the help of attribute analysis. Porosity is mapped from transformation of acoustic impedance. The shales/unconsolidated sediments measure a high porosity with low impedance and the more porous sands are in an intermediate range. The predicted impedance and porosity values may be erroneous beyond the drilled depth because of non availability of well log data for calibration.
31 citations
TL;DR: In this article, a detailed survey was carried out and a total 88 numbers of groundwater samples were collected from different locations of the Durg district in order to evaluate and characterize groundwater quality using Geographical Information System (GIS) and Multi Criteria Decision Analysis (MCDA) techniques.
Abstract: Present study is carried out to evaluate and characterize groundwater quality using Geographical Information System (GIS) and Multi-Criteria Decision Analysis (MCDA) Techniques. In order to ascertain the groundwater quality a detailed survey was carried-out and a total 88 numbers of groundwater samples were collected from different locations of the Durg district. Various physicochemical parameters of collected groundwater samples were analyzed for the periods of 5-years from 2007 to 2011 during premonsoon period. Six criteria viz. pH, calcium (Ca++), magnesium (Mg++), chloride (Cl–), nitrate (NO–
3) and fluoride (F–) were used for the determination of groundwater quality index. The analytical hierarchical process (AHP) used to determine the weight of various parameters and their classes for identifying the groundwater quality index. Present study is helpful for long-term planning and management of groundwater resources of the study area.
31 citations
TL;DR: In this article, the authors used the drill core from borehole KBH-1 near Rasati village in the southwestern part of the Deccan Volcanic Province (DVP) enabling a rare access to the basement beneath the thick (typically 1-2 km) lava pile, the nature of which has been enigmatic for long.
Abstract: Deep boreholes around the Koyna-Warna seismic zone in the southwestern part of the Deccan Volcanic Province (DVP) enable a rare access to the basement beneath the thick (typically 1-2 km) lava pile, the nature of which has been enigmatic for long. Utilizing the drill core from borehole KBH-1 near Rasati village, we present here in situ Laser Ablation — Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) and LA-MC (multi collector)-ICPMS zircon U-Pb age and Hf-isotopic composition for two samples along with a brief description of the petrology and geochemistry of the representative lithounits of the basement section. The KBH-1 basement section comprises predominantly grey migmatite gneisses of granodiorite, tonalite and quartz monzodiorite composition apart from minor pink monzogranite. The grey gneisses show geochemical affinity to Neoarchean Tonalite-Trondhjemite-Granodiorite (TTG) suites and modern calc-alkalic granitoids. Zircons from a granodiorite and a monzogranite samples yield consistent U-Pb ages of 2710±63 Ma and 2700±49 Ma (2σ errors). The initial 176Hf/177Hf values lie in a narrow range (0.281162 to 0.281283) corresponding to eHf(T) values of +3.7 to +8.0 indicating that the magmatic precursors of the KBH-1 gneisses represent juvenile magmatism around 2700 Ma. In terms of the composition and age, a correlation between the gneisses in the KBH-1 borehole and the Neoarchean basement gneisses of the Eastern Dharwar Craton (EDC) is emphasized arguing for the extension of the EDC to the Koyna-Warna region.
TL;DR: In this paper, chemical analysis of thermal spring's waters and their geological settings, the use of different statistical methods to evaluate the origin of the dissolved constituents of spring waters and the estimation of the reservoir temperature of the associated geothermal fields of the Guelma region, Algeria.
Abstract: This paper reports the results of our studies, the chemical analysis of thermal spring’s waters and their geological settings, the use of different statistical methods to evaluate the origin of the dissolved constituents of spring waters and the estimation of the reservoir temperature of the associated geothermal fields of the Guelma region, Algeria. A major component in 13 spring water samples was analyzed using various techniques. The waters of the thermal springs at Guelma basin vary in temperature between 20 and 94oC. Q-mode hierarchical cluster analysis suggests three groups. The water springs were classified as low, moderate and high salinity. Mineral saturation indices (SI) calculated from major ions indicate the spring waters are supersaturated with the most of the carbonate minerals, and all of the spring water samples are under-saturated with evaporite minerals. The thermal spring waters have a meteoric origin, and all samples are immature with strong mixing between warm and shallow waters, where the temperatures of reservoirs to which the thermal waters are related ranged between 64° and 124°C. The deep circulation of meteoric waters in the study area is supplied by the high geothermal gradient around 4.5°C per 100 m and reaches a high temperature before rising to the surface. The estimated circulation depths ranged from 1425 and 3542 m.
TL;DR: A detailed sediment chemistry investigation of the Manasbal lake, Srinagar, Jammu and Kashmir, India, which is one of the high altitude lakes in the Kashmir valley is presented in this paper.
Abstract: This paper presents a detailed sediment chemistry investigation of the Manasbal lake, Srinagar, Jammu and Kashmir, India, which is one of the high altitude lakes in the Kashmir valley. 22 lake floor sediment samples covering the entire lake were collected and analyzed for textural characteristics, CaCO3, organic matter, TOC, TN contents, C/N ratio, major and trace element chemistry. These analyses were conducted to trace the provenance of the sediments. Textural parameters reveal that the lake sediments consist predominantly clay and silt fractions. The C/N ratio of the sediments indicates a mixed source of TOC, both autochthonous and allochthonous in origin. The log (Fe2O3/K2O) Vs. log (SiO2/ Al2O3) graph of the sediments discriminates the rock types of the catchment area that are Fe-shale, Fe-sand, wacke, shale and litharenite. The Chemical Index of Alteration (CIA) falls between 59.11 to 90.16% and Chemical Index of Weathering (CIW) between 63.97 to 99.68% and these values are higher than the Post-Archaean Australian Shale (PAAS), indicating moderate to highly chemically weathered lake floor sediments. Plagioclase Index of Alteration (PIA) values (60.74-99.63%) suggests the occurrence of plagioclase feldspars in the lake floor sediments. Geochemical characteristics signify a mixed-nature of provenance of the lake floor sediments due to the tectonic settings of the lake basin in a complex catchment area.
TL;DR: The impact of increased groundwater irrigation on groundwater levels has not been studied both spatially and temporally as discussed by the authors, and a study has been undertaken to investigate the groundwater level fluctuations in the state using geographical information system (GIS) from the groundwater level data of 893 observation wells obtained from Groundwater Cell, Department of Agriculture, Government of Haryana, Panchkula, for the period 2004-12.
Abstract: Groundwater irrigation is the most predominant method used across India and about 50% of the total irrigated area is dependent on it. The state of Haryana has witnessed a spectacular increase in agricultural production in the last few decades, and is largely dependent on groundwater for irrigation. Groundwater mining for irrigation has become a reality in the state over the years as the number of tube wells has increased from 0.02 million in 1966 to 0.73 million in 2012, showing alarming signs of over-exploitation. The impact of increased groundwater irrigation on groundwater levels has not been studied both spatially and temporally. Therefore, this study has been undertaken to investigate the groundwater level fluctuations in the state using geographical information system (GIS) from the groundwater level data of 893 observation wells obtained from Groundwater Cell, Department of Agriculture, Government of Haryana, Panchkula, for the period 2004-12. Many researchers have applied GIS to reveal the spatial and temporal structure of groundwater level fluctuation and as a management and decision tool. The analysis of results indicated a mix of negative and positive trends in the groundwater levels. However, the negative trends were much more pronounced than positive ones. Groundwater level in the state ranged between 0.16 to 65.97 m from the ground surface and per cent area with groundwater level depth more than 10 meter (critical category) was about 56% in 2004 and has increased to 64% by 2012. The average annual decline in groundwater level was observed to be above 32 cm/year, with the strongest decline (108.9 cm/year) in Kurukshetra district.
TL;DR: In this paper, the authors carried out scientific drilling carried out to 1522 m depth in the vicinity of the seismogenic zone exposed the granitic basement that lay below the Deccan Traps and provided a unique opportunity to study the rock types, petrological characteristics and microstructures.
Abstract: The Koyna region, located in the Deccan Flood Basalt Province of western peninsular India has been experiencing reservoir triggered seismicity since the impoundment of the Shivajisagar water reservoir in 1962. Scientific drilling carried out to 1522 m depth in the vicinity of the seismogenic zone exposed the granitic basement that lay below the Deccan Traps and provided a unique opportunity to study the rock types, petrological characteristics and microstructures. Cores obtained from drilling at four sites considered to be representative of the Koyna region, were studied. The boreholes include KBH-1 (Rasati) in the northern part, KBH-5 (Phansavle) in the western part, KBH-6 (Ukhalu) and KBH-7 (Panchgani) in the eastern part of the region. Each borehole penetrates the entire pile of Deccan basalt and pass through a few hundred metres of the granitic basement. The salient results are as follows: (i) The basement granitoids are dominantly composed of granite-gneiss, granite and migmatitic gneiss, typical of cratonic gneiss exposed in peninsular India. (ii) Petrology and microstructure study confirm the occurrence of strained quartz and unstrained plagioclase feldspars in the basement granitoids. (iii) Localized fault zones within the basement section, with prominent evidences of fault breccia, fault gouge, slicken lines with slickensides and pseudotachylite veins are observed in the individual boreholes. (iv) Anastomosing fracture network within these fault zones are good pathways for water channelization, which is supported by the higher abundances of ferruginous and siliceous secondary precipitations following the fractures.
TL;DR: In this article, the major and trace elements pollution levels in groundwater of Tuticorin city of Tamil Nadu was investigated and correlation matrix and factor analysis was used to indicate the contribution from industrial and irrigation fields.
Abstract: In this work the major and trace elements pollution levels in groundwater of Tuticorin city of Tamil Nadu was investigated. This coastal city with numerous large and small scale industries has increasingly affected the water quality by dumping effluents. The mean major and trace elements levels in groundwater in descending order: Si > Sr > Zn > Fe > Rb > Se > Al > Mn > Cu > As > Cr > Ba > V > Ni > Pb > Mo > Co > Sb > Cd > Ag. The concentrations of As, Se, Pb, Ba, Al, Fe and V (0.084, 0.150, 0.057, 0.837, 0.357 and 0.052) in some of the groundwater samples exceed the standard value of world health organization (WHO, 2004). Interrelationship between the elements was done by correlation matrix and factor analysis which indicates the contribution from industrial and irrigation fields. Spatial interpolation of inverse distance method (IDW) maps of all the elements suggested that discharge of effluents from chemical factory (STERLITE, TAC, SPIC, HEAVY WATER PLANT, NILA SEA FOODS), municipal wastewater, fertilizers were added to the natural sources. Results of this research suggests that proper measures should be taken to protect the vital groundwater resources in the Tuticorin city.
TL;DR: In this paper, simple linear regression and principal component analysis were employed to relate the factors controlling erosion and landslide to the erosion and slide densities, and to determine the pattern that exists in the data and as well express the data in such a way as to highlight their similarities and differences.
Abstract: Environmental degradations caused by erosion and landslide within an area in the South-eastern part of Nigeria were assessed, and also an attempt to characterize the underlying soils based on their degree of susceptibility to erosion and landslide. Factors affecting soil erodibility such as physical and chemical properties of soil, as well as vegetation density and slope gradient was determined in 20 different areas. Simple linear regression and principal component analysis were employed to relate the factors controlling erosion and landslide to the erosion and slide densities, and to determine the pattern that exists in the data and as well express the data in such a way as to highlight their similarities and differences. Four vertical horizons and two horizontal zones of soil were distinguished based on their degree of weathering as well as their chemical and mineralogical composition; hence the soils were classified into six different types based on their degree of susceptibility to erosion and landslide. Variations in their degree of susceptibility to erosion and landslide were majorly controlled by its chemical and mineralogical composition rather than its particle size distribution.
TL;DR: In this paper, a study was carried out to assess the distribution of uranium in groundwater by using LED fluorimeter LF-2a and chemical and radiological risks associated with its consumption in Sirsa district, Haryana, India.
Abstract: This study was carried out to assess the distribution of uranium in groundwater by using LED fluorimeter LF-2a and chemical and radiological risks associated with its consumption in Sirsa district, Haryana, India Uranium concentration ranged between 093 and 290μg l-1 with an average value of 49 μg l-1 About 44% of the groundwater samples had uranium concentration above the maximum contamination level of 30 μg l-1 prescribed by the World Health Organization and United States Environmental Protection Agency and 22% of the samples exceeded the permissible limit of 60 μgl-1 prescribed by the Atomic Energy Regulatory Board, India The average cancer morbidity and mortality risks are determined to be 110 × 10-4 and 717 × 10-5 respectively, indicating the negligible carcinogenic risk Hazard quotient for 44% samples is greater than unity which indicates health risk due to chemical toxicity of uranium in groundwater The associated age-dependent annual effective dose is estimated by taking the prescribed water intake values of different age groups
TL;DR: In this paper, the authors carried out a study in Mulugu-Venkatapur Mandals of Warangal district, Telangana state, India to find out the causes of high fluorides in groundwater and surface water causing a widespread incidence of fluorosis in local population.
Abstract: Hydrochemical studies were carried out in Mulugu-Venkatapur Mandals of Warangal district, Telangana state, India to find out the causes of high fluorides in groundwater and surface water causing a widespread incidence of fluorosis in local population. The fluoride concentration in groundwater ranges from 0.28 to 5.48 mg/l with a mean of 1.26 mg/l in pre-monsoon and 0.21 to 4.43 mg/l with a mean 1.45 mg/l in post-monsoon. About 32% and 34% of samples in pre and post-monsoon containing fluoride concentrations that exceed the permissible limit. The Modified Piper diagram reflects that, water belong to Ca+2-Mg+2-HCO3 - to Na+-HCO3 - facies. Negative chloroalkali indices in both the seasons prove that ion exchange took place between Na+ & K+ with Ca+2 and Mg+2 in aquatic solution in host rock. Different plots for major ions and molar ratios suggest that weathering of silicate rocks and water-rock interaction is responsible for major ion chemistry of water. High fluoride content in groundwater attributed to continuous water-rock interaction during the process of percolation with fluorite bearing country rocks under arid, low precipitation, and high evaporation conditions. The low calcium content in rocks and soils, and the presence of high content of sodium bicarbonate in soils and waters are important factors favouring high levels of fluoride in waters. The basement rocks provide abundant mineral sources of fluoride in the form of amphibole, biotite, fluorite, mica and apatite.
TL;DR: In this paper, the parent rock assemblages, their tectonic provenance, mineralogy, weathering intensity, hydraulic sorting and depositional setting of the upper Kaimur Group (UKG) of the Vindhyan Supergroup in central India are reconstructed.
Abstract: The upper Kaimur Group (UKG) of the Vindhyan Supergroup in central India, primarily consists of three rock types-Dhandraul sandstone, Scarp sandstone and Bijaigarh shale. The present study aims to reconstruct the parent rock assemblages, their tectonic provenance, mineralogy, weathering intensity, hydraulic sorting and depositional tectonic setting. Samples from the UKG rocks representing the Dhandraul sandstone, Scarp sandstone and Bijaigarh shale were studied using a combination of petrographic, mineralogical, and geochemical techniques. Texturally, medium to coarse grained UKG sandstones are mature and moderate to well sorted. Deficiency of feldspars in these sandstones indicates that the rocks are extensively recycled from distant sources. Their average modal composition for Scarp (avg. Qt99 F0.2L0.8) and Dhandraul (avg. Qt99 F0.1L0.8) sandstones, classifies them as quartz arenite to sub-litharenite types, which is consistent with geochemical study. Major element concentrations revealed that sandstones have high SiO2, K2O < Na2O, and low Fe2O3, which are supported by the modal data. On the other hand, sandstone samples are enriched in most trace elements such as Ce, Sr, V, Sc and Zr and depleted in U and Th. The CIA values (43.17–76.48) of the UKG rocks indicate low to moderate weathering, either of the original source or during transport before deposition, which may have related to low-relief and humid climatic conditions in the source area. Further, petrographic and geochemical interpretations indicate that they are derived from craton interior to quartzose recycled sedimentary rocks and deposited in a passive continental margin. Therefore, granitic and low grade metamorphic rocks of Mahakoshal Group and Chotanagpur granite-gneiss, situated on the southern and south-eastern side of the Vindhyan basin are suggested as possible provenance for the UKG rocks.
TL;DR: In this article, three widely used digital elevation models (SRTM 30m, ASTER 30m and SRTM 90m) are analyzed to evaluate their suitability to delineate river network and basin boundary area.
Abstract: Digital elevation model (DEM) is one of the input data derived from different satellite sensors for hydrologic and hydraulic modelings. Two prime questions could be answered before using these DEMs. First, the acceptability of datasets for our use and second appropriate resolution of the dataset. Three widely used DEMs SRTM 30m, ASTER 30m and SRTM 90m are analyzed to evaluate their suitability to delineate river network and basin boundary area. The hydrology tool of spatial analyst extension inbuilt in ArcGIS 10.2 (which uses the D8 method for calculation of flow direction) has been used for the delineation of both river networks and basin boundary. The assessment of river network alignment and boundary delineation is carried out in the seven sub-catchments of Gandak river basin having different morphological characteristics. The automatically delineated boundary area for all the three DEMs reflects a significant difference when compared with the digitized basin area from the Ganga flood control commission (GFCC) map. The maximum boundary area delineation error is 39137.20 km2 forASTER 30m, and minimum delineation error of 13239.28 km2 for SRTM 90m. In the stream network, delineation accuracy is good for SRTM 90m while, except Gandak trunk, ASTER 30m DEM shows better delineation accuracy indicated by mean absolute error (MAE) and standard deviation (SD).
TL;DR: In this article, Wular lake, located in north Kashmir, is one of the largest fresh water lake in India, situated at an average elevation of 1580m ASL.
Abstract: Lakes and wetlands are dynamic geomorphic units of a landscape that hold geochemical signatures of sediment provenance and paleo-environmental shifts and are major sinks for organic matter accumulation. The source of organic matter is diverse in lake sediments and varies widely with the type and size of the lake and hence it is important to understand the source of organic carbon (terrestrial or in situ) in lake systems in order to monitor the health of the lake. Wular lake, located in north Kashmir, is one of the largest fresh water lake in India, situated at an average elevation of 1580m ASL. The lake is fed by a number of watersheds that bring a diverse type of sediments and organic matter and thus deposit them into the Wular lake basin. In order to understand sediment distribution pattern, content and source of organic matter, sediment provenance and the persisting environment in the Wular lake, 32 lake floor sediment samples covering the entire lake were collected and analyzed for organic element analysis, CaCO3, organic matter, sediment texture and diatom analysis. The results indicated that sediments in the lake are dominated by silt and silty clay. The organic carbon in the lake ranged from 0.83%-4.52% and nitrogen varied from 0.06%-0.5%. The Carbon to Nitrogen (C/N) ratios (9.04 to 22.03) indicate a mixed source of organic carbon but dominated by in situ lake sources from the vascular and lake biota accumulation. The diatom analysis revealed the occurrence of a diverse type of species along the sampling sites present within the lake. The wide distribution of the diatom species such as Cymbella, Cyclotella and Tabularia etc. in the lake indicate high organic pollution and alkaline fresh water environment prevailing in the lake.
TL;DR: In this article, the morphological evolution of classical pāhoehoe to transitional flow-type in a compound basalt flow occurring in the lower pile of Deccan traps is described.
Abstract: Morphological evolution of classical pāhoehoe to transitional flow-type in a compound basalt flow occurring in the lower pile of Deccan traps is described here from the southern slope of Mesan Dongar in Manmad-Chandwad area, western part of Maharashtra plateau, India. The transitional flow lobes, largely identified as rubbly pāhoehoe-type, are characterized by a crust of breccias, with thickness ranging from 10 to 20 m. The breccia is generally a welded one and consists of mm to m-size, angular to sub-angular basaltic clasts that vary in vesiculation (vesicle size, shape and population). The crust, at times, is supported by an inner vesicular zone coherently developed above a persistent core that varies in thickness from 10 to 15 m. Base of these lobes is smooth, sparsely vesicular, without any basal breccia.
TL;DR: In this paper, the results of the petrological study carried out on the lignites of the Saurashtra basin were presented and the results revealed that these lignite are dominantly composed of huminite group macerals while liptinite and inertinite groups occur in subordinate amounts.
Abstract: The Tertiary basins of Gujarat have always been a potential target for their hydrocarbon resources. The lignite resources of the region have also been an important field of research. The present paper presents the results of the petrological study carried out on the lignites of the Saurashtra basin. For this purpose samples were collected from lower and upper lignite seams from the Surkha lignite mine of Bhavnagar, Saurashtra. These samples were subjected to detailed petrographic analysis (both maceral and microlithotype). The study reveals that these lignites are dominantly composed of huminite group macerals while liptinite and inertinite group macerals occur in subordinate amounts. These lignites have attained a thermal maturity up to 0.28-0.30 percent vitrinite reflectance (VRr) which classifies them as ‘low rank C’ coals. Moreover, Bhavnagar lower lignite seam shows relatively less gelification as compared to the upper seam which suffered relatively more biochemical degradation. These lignites are characterized by high gelification index (GI) and low tissue preservation index (TPI).With the help of petrography based facies models an attempt has been made to reconstruct the environment of the paleomire of these lignites.
TL;DR: In this article, flow mapping and physical volcanology of 15 basaltic lavas exposed in three critical road pass sections (ghats) in the Koyna-Warna region of the western Deccan Traps is presented.
Abstract: Flow mapping and physical volcanology of 15 basaltic lavas exposed in three critical road pass sections (ghats) in the Koyna-Warna region of the western Deccan Traps is presented in this paper. Transitional lavas like rubbly pahoehoe are most common morpho-type exposed in these ghat sections. Sinking of rubbly breccia into flow interiors and formation of breccia-cored rosette are common in some lava flows. Few rubbly lavas exhibit slabby tendencies. The amount and nature of the associated rubble is variable and result from the mechanical fracturing and auto-brecciation of the upper vesicular crust in response to distinctive stages in the cooling, crystallization and emplacement history of individual lava flows. Occurrence of aa and pahoehoe morpho-types in the lava flow sequence is subordinate. Three prominent pahoehoe flows separated by red bole horizons are seen in the upper parts of the Kumbharli ghat. These are thick, P-type sheet pahoehoe. The pahoehoe lavas represent compound flow fields that grew by budding, endogenous lava transfer and inflation. Presence of pahoehoe lavas in the Koyna-Warna region hints at possible hitherto unrecorded southern extension of Bushe-like flow fields. This study reconfirms the existence of pahoehoe-slabby-rubbly-aa flow fields and transitions even in the upper echelons of the Deccan Trap stratigraphy. The study of morphology and internal structure of lava flows exposed at the ghat sections in the Koyna-Warna region could guide subsurface core-logging that is critical in deciphering the physical volcanology and emplacement dynamics of basaltic lava flows penetrated by drill holes sunk under the scientific deep drilling programme.
TL;DR: In this article, the Balkassar anticline is bounded by two thrust faults one from southeast and the other from northwest, and the seismic interpretation indicates the presence of well-developed anticline bounded by three faults in the cover sequence and one fault in basement and thus the structure may act as a trap for hydrocarbons.
Abstract: The Balkassar oil field is situated in the eastern Potwar sub-basin, lies on the southern flank of Soan syncline in Himalayan collisional regime. The area represents Indo-Pak and Eurasian blocks of Precambrian to recent time. Thrusting and folding of Himalayan, Indo-Pak plate movement and Salt Range uplift form the structural trap in Balkassar sub-surface (Balkassar anticline). On the basis of information from eleven seismic 2D lines and wells data six reflectors well data, four faults were identified and marked. The structural trend is northeast southwest. Interpretation of seismic 2D data reveals that the study area has undergone intense deformation as a consequence of development of thrusts and backthrusts.The Balkassar anticline is bounded by two thrust faults one from southeast and the other from northwest. Time and depth contour models shows that anticline limbs at north-western side are steep as compared to south-eastern limbs. Seismic interpretation indicates the presence of well-developed anticline bounded by three faults in the cover sequence and one fault in basement and thus the structure may act as a trap for hydrocarbons. The petrophysical analysis of Balkassar-OXY-1 well shows about 83.1% hydrocarbons saturation in the reservoir rocks, hence this study suggest that Balkassar Oilfield has potential to produce hydrocarbons.
TL;DR: In this paper, a study has been carried out in the Sanghar oil field to evaluate the hydrocarbon prospects of basal sand zone of lower Goru Formation of Cretaceous by using complete suite of geophysical logs of different wells.
Abstract: The lower Indus basin is one of the largest hydrocarbon producing sedimentary basins in Pakistan. It is characterized by the presence of many hydrocarbon-bearing fields including clastic and carbonates proven reservoirs from the Cretaceous to the Eocene age. This study has been carried out in the Sanghar oil field to evaluate the hydrocarbon prospects of basal sand zone of lower Goru Formation of Cretaceous by using complete suite of geophysical logs of different wells. The analytical formation evaluation by using petrophysical studies and neutron-density crossplots unveils that litho-facies mainly comprising of sandstone. The hydrocarbons potentialities of the formation zone have been characterized through various isoparameteric maps such as gross reservoir and net pay thickness, net-to-gross ratio, total and effective porosity, shaliness, and water and hydrocarbons saturation. The evaluated petrophysical studies show that the reservoir has net pay zone of thickness range 5 to 10 m, net-togross ratio range of 0.17 to 0.75, effective porosity range of 07 to 12 %, shaliness range of 27 to 40 % and hydrocarbon saturation range of 12 to 31 %. However, in the net pay zone hydrocarbon saturation reaches up to 95%. The isoparametric charts of petrophysically derived parameters reveal the aerial distribution of hydrocarbons accumulation in basal sand unit of the lower Goru Formation which may be helpful for further exploration.
TL;DR: The 3 km deep Pilot Borehole was spudded on December 20, 2016 and completed on June 11, 2017 as mentioned in this paper, which totally supported setting up a borehole laboratory for near field investigations at Koyna.
Abstract: The Koyna earthquake of M 6.3 on December 10, 1967 is the largest artificial water reservoir triggered earthquake globally. It claimed ∼ 200 human lives and devastated the Koyna township. Before the impoundment of the Shivaji Sagar Lake created by the Koyna Dam, there were no earthquakes reported from the region. Initially a few stations were operated in the region by the CentralWater and Power Research Station (CWPRS). The seismic station network grew with time and currently the National Geophysical Research Institute (NGRI), Hyderabad is operating 23 broadband seismographs and 6 bore hole seismic stations. Another reservoir, Warna, was created in 1985, which provided a further impetus to Reservoir Triggered Seismicity (RTS). Every year following the monsoon, water levels rise in the two reservoirs and there is an immediate increase in triggered earthquakes in the vicinity of Koyna-Warna reservoirs in the months of August–September. Peak RTS is observed in September and later during December.Another spurt in triggered earthquakes is observed during the draining of the reservoirs in the months of April- May. A comparative study of RTS earthquake sequences and the ones occurring in nearby regions made it possible to identify four common characteristics of RTS sequences that discriminate them from normal earthquake sequences. As the RTS events continue to occur at Koyna in a large number in a limited area of 20 km x 30 km, at shallow depths (mostly 2 to 9 km), the region being accessible for all possible observations and there being no other source of earthquakes within 100 km of Koyna Dam, it was suggested to be an ideal site for near field observations of earthquakes. This suggestion was discussed by the global community at an ICDP sponsored workshop held at Hyderabad and Koyna in 2011. There was an unanimous agreement about the suitability of the site for deep scientific drilling; however, a few additional observations/experiments were suggested. These were carried out in the following three years and another ICDP workshop was held in 2014, which totally supported setting up a borehole laboratory for near field investigations at Koyna. Location of a Pilot Bore-hole was decided on the basis of seismic activity and other logistics. The 3 km deep Pilot Borehole was spudded on December 20, 2016 and completed on June 11, 2017.