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131.
132.
Hemant Kumar Singh Aswathi Thankappan Poonam Mohite Satish Kumar Sinha Dornadula Chandrasekharam Trupti Chandrasekhar 《Arabian Journal of Geosciences》2018,11(6):137
Tulsishyam thermal springs are located in the Saurashtra region of Gujarat, India with discharge temperatures varying from 39 to 42 °C. The pH of these thermal springs varies from 7.1 to 7.4, indicating neutral character. Though these thermal springs propagate through the near surface layer of Deccan basalt, detailed geochemical analysis of the thermal waters using Piper diagram suggests that the water is interacting with the granitic basement rock. Silica and cation geothermometry estimates have reservoir temperature in the range of 138 to 207 °C categorizing it into a low to moderate enthalpy geothermal system. Furthermore, the area has high heat flow values of 53–90 mW/m2 because of shallow Moho depth. The prevailing conditions suggest that the geothermal energy can potentially be exploited through an enhanced geothermal system (EGS). The study also indicates different mineral phases that may precipitate out of water during exploitation of geothermal energy and it should be taken into account while designing an EGS for the area. 相似文献
133.
Nishi Kant Prasoon Kumar Singh Bijendra Kumar 《Journal of the Geological Society of India》2018,91(1):67-75
This paper reports petrography, geochemistry and Rb-Sr age data on the rare metal bearing Neoarchean fertile (Nb-Ta) granite at Allapatna and elucidates its petrogenesis and role in Nb-Ta-Li-Be mineralization. The Allapatna granite (AG) intrudes the Tonalitic-Trondhjemitic - Granodioritic (TTG) Peninsular Gneiss and analysed SiO2 (72.3-75.6 wt%), K2O (4.0-5.7wt%), Na2O (3.0-4.4wt%), CaO (0.7-1wt%), MgO (0.13-0.25wt%) and K2O/Na2O (>1) indicating evolved nature. The presence of muscovite, biotite and garnet in the mode, peraluminous nature and high initial 87Sr/86Sr ratio (0.7284±0.0083) attest to their S-type characteristics. Varying Nb/Ta ratio and high Li with moderate abundance of Cs further indicate affinity to Li-Cs-Ta (LCT) type granite-pegmatite system. TheAG showing whole rock Rb-Sr isochron age of 2803± 68 Ma, is the oldest reported fertile granite in India parental to rare metal pegmatites hosting Nb-Ta, Be, and Li resources. Partial melting of a mixed source consisting of both basement TTG rocks and metapelites has generated such type of granitic magma. Fractionation of such granitic magma possibly has given rise to the rare metal (Ta-Nb-Li-Be) bearing pegmatites intruding the nearby schist belt. 相似文献
134.
Pravin Kumar Sharma Nalin Kumar Johri Gagan Behari Raut G. Rangaswamy Brahma Kishore Pandey Anand Kumar Chaturvedi 《Journal of the Geological Society of India》2018,91(3):281-289
Characterization of the Panandhro lignite deposits from western Indian state of Gujarat, based on the geochemical and palynological evidences, has been performed to assess the floral composition, maturity and hydrocarbon potential of the sequence. Elementally, the lignites consist of moderate carbon, low hydrogen and moderate sulfur contents. The samples are characterized by high TOC contents (lignite: av. 46.43 wt.%, resin: 62.47 wt.%). The average HI values for the lignite is 136 mg HC/g TOC, and that of the associated resin is 671 mg HC/g TOC. The highest Tmax is recoded in lignite (422°C) and lowest in the resin (39°C) samples. The FTIR spectrum of lignite is characterized by highly intense OH stretching peak ~3350 cm-1, aliphatic CHx stretching peaks between 3000-2800 cm-1, aromatic C=O stretching and an aromatic C=C stretching. The spectrum of resin shows strongest absorption due to aliphatic CHx stretching between 2940-2915 cm-1 and 2870-2850 cm-1, and deformation by the medium peak between 1450 and 1650 cm-1. The recovered palynofloral assemblage indicates the dominance of angiosperm pollen grains with maximum abundance of Arecaceae family, and subdominant pteridophytic spores. Marine influence is indicated by the presence of abundant dinoflagellate cysts. The occurrence of flora from a variety of ecological niches suggests a luxuriant diverse vegetation pattern existed in the vicinity of depositional site under humid tropical conditions. The overall characteristics of the lignite deposits point towards their ability to generate (upon maturation) hydrocarbons as they have types III–II admixed kerogen (organic matters). 相似文献
135.
The drainage basin of the Kalyani river, a tributary of Gomati river has been mapped and delineated using Survey of India toposheets (1:50,000 scale) and remote sensing satellite data. The digitization, slope map preparation and statistical calculations have been carried out with the help of geographical information system (Arc GIS 10). Kalyani a fifth order river exhibits meandering behavior having 2.45 sinuosity index (SI). The Kalyani river basin has about 1235 km2area with NW-SE sloping trend. The total number of first, second, third, and fourth order streams are 373, 71, 12 and 2 respectively, showing dominance of first order streams in the basin. The mean bifurcation ratio (Rb) of the entire basin is 4.8, which indicates that the drainage is not much influenced by geological structures and exhibits dendritic drainage pattern. Relief ratio (Rr) indicates low to medium surface run-off, and low stream power for erosion. The analysis of river bank height ‘r’ (escarpment) and longitudinal profile of the river closely reveals neotectonic activity at some locations in the basin. To prepare a comprehensive watershed development and management plan, it is important to understand the topography and drainage characteristics of the region. 相似文献
136.
Anettsungla Vikoleno Rino Santosh Kumar 《Journal of the Geological Society of India》2018,91(5):601-612
The Karbi Anglong hills (erstwhile Mikir hills) in northeast India are detached and separated from the Meghalaya plateau by a NW-SE trending Kopili rift. The Karbi Anglong hills granitoids (KAHG) and its granite gneissic variants belong to Cambrian plutons formed during Pan-African orogenic cycle, which commonly intrude the basement granite gneisses and Shillong Group metasediments. The KAHG can be broadly classified into three major granitoid facies viz., coarse grained porphyritic granitoid, medium grained massive non-porphyritic granitoid, and granite gneiss, which share a common mineral assemblage of plagioclase-K-feldspar-quartz-biotite±hornblende-apatite-titanite-zircon-magnetite but differ greatly in mineral proportion and texture. Modal mineralogy of KAHG, granite gneiss and basement granite gneiss largely represents monzogranite and syenogranite. The magnetic susceptibility (MS) of the KAHG, granite gneiss and basement granite gneiss varies widely between 0.11×10-3 and 43.144×10-3 SI units, corresponding to ilmenite series (<3×10-3 SI; reduced type) and magnetite series (>3×10-3 SI; oxidized type) of granitoids respectively. The observed MS variations are most likely intrinsic to heterogeneous source regions, modal variations of orthomagnetic and ferromagnetic minerals, and tectonothermal and deformational processes that acted upon these rocks. The primary and re-equilibrated compositions of biotites from the KAHG, granite gneiss and basement granite gneiss suggest calcalkaline, metaluminous (I-type) nature of felsic host magma formed in a subduction or post-collisional to peraluminous (S-type) host magma originated in syn-collisional tectonic settings, which were evolved and stabilized between FMQ and NNO buffers typically corresponding to reducing and oxidising magma environments respectively. 相似文献
137.
K. Satish Kumar K. N. S. S. S. Srinivas V. Pradeep Kumar P. Prabhakara Prasad T. Seshunarayana 《Journal of the Geological Society of India》2018,91(2):174-180
High ground magnetic anomalies are observed at western basin of the Sandur schist belt (SSB) near Muraripura village, Karnataka. Sources for these anomalies are inferred due to presence of exposed banded iron formations hosted by metabasalts, arenaous and argillaceous rocks associated with the Donimali Formation of the schist belt. Two varieties of BIF bands are observed in the study area viz. Band 1 and Band 2. The bands 1 and 2 are displaced by lateral strike-slip fault. Band 1 is dominantly composed of banded iron formation, rich in iron ore minerals and silica chert. Band 2 is largely composed of ferruginous quartzite and quartz arenites. Qualitative analysis of the magnetic data indicates that the study area can be divided into three lithologically important BIF/BQ formations. Spectral and quantitative analysis of the magnetic data indicates, the average depth of band 1 is 70 m and band 2 is 130 m. The magnetic data results are well correlated with chemical analysis of borehole and surface rock samples data. 相似文献
138.
The paper examines the quality of Tropical Rainfall Monitoring Mission (TRMM) 3B42 V7 precipitation product to simulate the streamflow using Soil Water Assessment Tool (SWAT) model for various rainfall intensities over the Himalayan region. The SWAT model has been set up for Gandak River Basin with 41 sub-basins and 420 HRUs. Five stream gauge locations are used to simulate the streamflow for a time span of 10 years (2000–2010). Daily streamflow for the simulation period is collected from Central Water Commission (CWC), India and Department of Hydrology and Meteorology (DHM), Nepal. The simulation results are found good in terms of Nash–Sutcliffe efficiency \((\hbox {NSE}) {>}0.65\), coefficient of determination \((R^{2}) {>}0.67\) and Percentage Bias \(\hbox {(PBIAS)}{<}15\%\), at each stream gauge sites. Thereafter, we have calculated the PBIAS and RMSE-observations standard deviation ratio (RSR) statistics between TRMM simulated and observed streamflow for various rainfall intensity classes, viz., light (\({<}7.5 \, \hbox {mm}/\hbox {d}\)), moderate (7.5 to 35.4 mm/d), heavy (35.5 to 124.4 mm/d) and extremely heavy (\({>}124.4 \, \hbox {mm}/\hbox {d}\)). The PBIAS and RSR show that TRMM simulated streamflow is suitable for moderate to heavy rainfall intensities. However, it does not perform well for light- and extremely-heavy rainfall intensities. The finding of the present work is useful for the problems related to water resources management, irrigation planning and hazard analysis over the Himalayan regions. 相似文献
139.
Pedotransfer functions to estimate soil water content at field capacity and permanent wilting point in hot Arid Western India 总被引:1,自引:0,他引:1
Priyabrata Santra Mahesh Kumar R N Kumawat D K Painuli K M Hati G B M Heuvelink N H Batjes 《Journal of Earth System Science》2018,127(3):35
Characterization of soil water retention, e.g., water content at field capacity (FC) and permanent wilting point (PWP) over a landscape plays a key role in efficient utilization of available scarce water resources in dry land agriculture; however, direct measurement thereof for multiple locations in the field is not always feasible. Therefore, pedotransfer functions (PTFs) were developed to estimate soil water retention at FC and PWP for dryland soils of India. A soil database available for Arid Western India (N=370) was used to develop PTFs. The developed PTFs were tested in two independent datasets from arid regions of India (N=36) and an arid region of USA (N=1789). While testing these PTFs using independent data from India, root mean square error (RMSE) was found to be 2.65 and 1.08 for FC and PWP, respectively, whereas for most of the tested ‘established’ PTFs, the RMSE was >3.41 and >1.15, respectively. Performance of the developed PTFs from the independent dataset from USA was comparable with estimates derived from ‘established’ PTFs. For wide applicability of the developed PTFs, a user-friendly soil moisture calculator was developed. The PTFs developed in this study may be quite useful to farmers for scheduling irrigation water as per soil type. 相似文献
140.
Deformation of the Champaner Group of rocks that form a part of Southern Aravalli Mountain Belt, western India, occurred during the Grenville orogeny (ca. 1400–935 Ma). Two phases of deformation are recorded: \(\hbox {D}_{1}\), persistent throughout the group and characterised by westerly plunging tight isoclinal folds and \(\hbox {D}_{2}\), a localized phase of deformation associated with shortening of the earlier folds from the eastern margin. Both the phases of deformation are in association with the syn-tectonically emplaced Godhra granite. The present work records rootless calc-silicate folds in granite belonging to the older formation, located at the eastern fringe of the Champaner Group. Field evidences suggest superimposition of Type 2 interference pattern trending NE–SW over rootless Type 0 of varying trends from NW–SE to N–S. The superposed pattern obtained from the field study differs in terms of structural trends with the neighbouring Precambrian stratigraphic units. These stratigraphic units include the Champaner Group to which the study area belongs, the Kadana Formation of the Lunavada Group and Pre-Chamapaner Gneissic Complex. Rootless character of folds found within the study area imply syn-post plutonic emplacement of Godhra granite. 相似文献