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 Journal of Earth System ScienceJournal Prestige (SJR): 0.366 Citation Impact (citeScore): 1Number of Followers: 49     Open Access journal ISSN (Print) 0253-4126 - ISSN (Online) 0973-774X Published by Springer-Verlag  [2349 journals]
• Provenance analyses of the heavy-mineral beach sands of the Annaba coast,
northeast Algeria, and their consequences for the evaluation of fossil
placer deposit

• Authors: Asma Chemam; Soraya Hadjzobir; Menana Daif; Uwe Altenberger; Christina Günter
Abstract: The paper presents the first study of heavy-mineral sand beaches from the Mediterranean coast of Annaba/Algeria. The studied beaches run along the basement outcrops of the Edough massif, which are mainly composed by micaschists, tourmaline-rich quartzo-feldspathic veins, gneisses, skarns and marbles. Sand samples were taken from three localities (Ain Achir, Plage-Militaire and El Nasr). The heavy-mineral fraction comprises between 74 and 91 vol%. The garnets of the beaches are almandine rich and tourmalines vary with respect to their location from schorl to dravite. Tourmaline at Ain Achir and the Plage-Militaire is schorlits, while at El Nasr beach dravite is ubiquitous. The World Shale Average normalised REE of the sands and the basement outcrops reveal: (i) Ain Achir beach: REE pattern of sand and the coastal rocks from the studied beaches reflects a multiple sources; (ii) Plage-Militaire: the sand and the coastal outcrops show similar LREE and a strong enrichment in HREE, suggesting the presence HREE-rich phases found as inclusions in staurolite; (iii) El Nasr: two types of sand patterns are found: one with flat REE pattern similar to the proximal rocks and other one enriched in HREE suggesting a mixed source.
PubDate: 2018-10-26
DOI: 10.1007/s12040-018-1019-z
Issue No: Vol. 127, No. 8 (2018)

• Performance evaluation and parameters sensitivity of a distributed
hydrological model for a semi-arid catchment in India

• Authors: V D Loliyana; P L Patel
Abstract: In present study, a distributed physics based hydrological model, MIKE SHE coupled with MIKE 11, is calibrated using multi-objective approach, i.e., minimization of error in prediction of stream flows and groundwater levels, using the data of eight years from 1991 to 1998 of Yerli sub-catchment $$(\hbox {area} = 15{,}881\,\hbox {km}^{2})$$ of upper Tapi basin in India. The sensitivity analyses of thirteen model parameters related with overland flow, unsaturated and saturated zones have been undertaken while simulating the runoff volume, peak runoff at catchment outlet and groundwater levels within the catchment with wide variations $$(\pm 50\%)$$ in the model parameters. The calibrated model has also been validated for prediction of stream flow and groundwater levels within the Yerli sub-catchment for period 1999–2004. The simulated results revealed that calibrated model is able to simulate hydrographs satisfactorily for Yerli sub-catchment (NSE  $$=$$  0.65–0.89, $$r=0.80{-}0.95$$ ) at daily and monthly time scales. The ground water levels are predicted reasonably satisfactorily for the plain area (RMSE  $$=$$  0.50–6.50 m) in the study area. The results of total water balance indicated that about 78% of water is lost from the system through evapotranspiration, out of which about 3.5% is contributed from the groundwater zone.
PubDate: 2018-10-26
DOI: 10.1007/s12040-018-1021-5
Issue No: Vol. 127, No. 8 (2018)

• Physico-chemical conditions of four calc-alkaline granitoid plutons of
Chhotanagpur Gneissic Complex, eastern India: Tectonic implications

• Authors: B Goswami; P Roy; A Basak; S Das; C Bhattacharyya
Abstract: Petrography and mineralogy of four calc-alkaline granitoid plutons Agarpur, Sindurpur, Raghunathpur and Sarpahari located from west to east of northern Purulia of Chhotanagpur Gneissic Complex, eastern India, are investigated. The plutons, as a whole, are composed of varying proportions of Qtz–Pl–Kfs–Bt–Hbl±Px–Ttn–Mag–Ap–Zrn±Ep. The composition of biotite is consistent with those of calc-alkaline granitoids. Hornblende–plagioclase thermometry, aluminium-in-hornblende barometry and the assemblage sphene–magnetite–quartz were used to determine the P, T and $$f_{\mathrm{O}_2}$$ during the crystallisation of the parent magmas in different plutons. The plutons are crystallised under varying pressures (6.2–2.4 kbar) and a wide range of temperatures (896– $$718{^{\circ }}\hbox {C}$$ ) from highly oxidised magmas (log $$f_{\mathrm{O}_2}$$ $$-11.2$$ to $$-15.4$$ bar). The water content of the magma of different plutons varied from 5.0 to 6.5 wt%, consistent with the calc-alkaline nature of the magma. Calc-alkaline nature, high oxygen fugacity and high $$\hbox {H}_{2}\hbox {O}_{{\mathrm{melt}}}$$ suggest that these plutons were emplaced in subduction zone environment. The depths of emplacement of these plutons seem to increase from west to east. Petrologic compositions of these granitoids continuously change from enderbite (opx-tonalite: Sarpahari) in the east to monzogranite (Raghunathpur) to syenogranite (Sindurpur) to alkali feldspar granite (Agarpur) in the west. The water contents of the parental magmas of different plutons also increase systematically from east to west. No substantial increase in the depth of emplacement is found in these plutons lying south and north of the major shear zone passing through the study area suggesting the strike-slip nature of the east–west shear zone.
PubDate: 2018-10-26
DOI: 10.1007/s12040-018-1022-4
Issue No: Vol. 127, No. 8 (2018)

• Fluvial geochemistry of Subarnarekha River basin, India

• Authors: Abhay Kumar Singh; Soma Giri; Aaditya Chaturvedi
Abstract: The fluvial geochemistry of the Subarnarekha River and its major tributaries has been studied on a seasonal basis in order to assess the geochemical processes that explain the water composition and estimate solute fluxes. The analytical results show the mildly acidic to alkaline nature of the Subarnarekha River water and the dominance of $$\hbox {Ca}^{2+}$$ and $$\hbox {Na}^{+}$$ in cationic and $$\hbox {HCO}_{3}^{-}$$ and $${\hbox {Cl}}^{-}$$ in anionic composition. Minimum ionic concentration during the monsoon and maximum concentration in the pre-monsoon seasons reflect concentrating effects due to decrease in the river discharge and increase in the base flow contribution during the pre-monsoon and dilution effects of atmospheric precipitation in the monsoon season. The solute acquisition processes are mainly controlled by weathering of rocks, with minor contribution from marine and anthropogenic sources. Higher contribution of alkaline earth $$(\hbox {Ca}^{2+}{+}\,\hbox {Mg}^{2+})$$ to the total cations $$(\hbox {TZ}^{+})$$ and high $$(\hbox {Na}^{+}+\hbox {K}^{+})/\hbox {Cl}^{-}$$ , $$(\hbox {Na}^{+}+\hbox {K}^{+})/\hbox {TZ}^{+}$$ , $$\hbox {HCO}_{3}^{-}/(\hbox {SO}_{4}^{2-}+\hbox {Cl}^{-})$$ and low $$(\hbox {Ca}^{2+}+\hbox {Mg}^{2+})/(\hbox {Na}^{+}+\hbox {K}^{+})$$ equivalent ratios suggest that the Subarnarekha River water is under the combined influence of carbonate and silicate weathering. The river water is undersaturated with respect to dolomite and calcite during the post-monsoon and monsoon seasons and oversaturated in the pre-monsoon season. The pH–log $$\hbox {H}_{4}\hbox {SiO}_{4}$$ stability diagram demonstrates that the water chemistry is in equilibrium with the kaolinite. The Subarnarekha River annually delivered $$1.477\times 10^{6}$$ ton of dissolved loads to the Bay of Bengal, with an estimated chemical denudation rate of $$77\hbox { ton km}^{-2}\hbox { yr}^{-1}$$ . Sodium adsorption ratio, residual sodium carbonate and per cent sodium values placed the studied river water in the ‘excellent to good quality’ category and it can be safely used for irrigation.
PubDate: 2018-10-26
DOI: 10.1007/s12040-018-1020-6
Issue No: Vol. 127, No. 8 (2018)

• Evaluation of indicators for desertification risk assessment in part of
Thar Desert Region of Rajasthan using geospatial techniques

• Authors: Sagar S Salunkhe; A K Bera; S S Rao; V Raghu Venkataraman; Uday Raj; Y V N Krishna Murthy
Abstract: Desertification has emerged as a major economic, social and environmental problem in the western part of India. The best way of dealing with desertification is to take appropriate measures to arrest land degradation, especially in areas prone to desertification. This requires an early warning system for desertification based on scientific inputs. Hence, in the present study, an attempt has been made to develop a comprehensive model for the assessment of desertification risk in the Jodhpur district of Rajasthan, India, using 23 desertification indicators. Indicators including soil, climate, vegetation and socio-economic parameters were integrated into a GIS environment to get environmental sensitive areas (ESAs) to desertification. Desertification risk index (DRI) was calculated based on ESAs to desertification, the degree of land degradation and significant desertification indicators obtained from the stepwise multiple regression model. DRI was validated by using independent indicators such as soil organic matter content and cation exchange capacity. Multiple regression analysis shows that 16 indicators out of 23 were found to be significant for assessing desertification risk at a 99% confidence interval with $$R^{2}=0.83$$ . The proposed methodology provides a series of effective indicators that would help to identify where desertification is a current or potential problem, and what could be the actions to alleviate the problem over time.
PubDate: 2018-10-16
DOI: 10.1007/s12040-018-1016-2
Issue No: Vol. 127, No. 8 (2018)

• Gypsum–anhydrites in 1.9 Ga Vempalle Formation, Cuddapah basin, India: A
note on the Palaeoproterozoic environment and diagenetic condition

• Authors: Purnajit Bhattacharjee; Sukanta Goswami; Sangeeta Bhagat; M B Verma
Abstract: The Cuddapah basin consists of generally well-preserved Palaeoproterozoic–Neoproterozoic sedimentary and associated volcanic rocks. The detailed lithological studies of sedimentary rocks of Vempalle Formation from the narrow linear belt of 15 km, in the southern margin, show the occurrence of layered gypsum in the cherty dolostone–shale intercalated facies, red shale and phosphatic dolostone facies of the Vempalle Formation. The petromineralogical studies reveal that gypsum is in close association with anhydrites. Microscopically, three different types of gypsum and anhydrite are identified, viz., lath-shaped, equant-shaped and anhedral-shaped grains. The equant variety corresponds to a granular gypsum, whereas the anhedral grains of gypsum exist as the granular and fibrous variety as seen in the hand specimen. The presence of gypsum/anhydrite has been confirmed by the petromineralogical, X-ray diffraction and chemical analytical data. The phosphatic dolostone is the host rock for stratabound type of uranium deposit at Tummalapalle, Cuddapah district, Andhra Pradesh, which is one of the most unique types of uranium mineralisation in the world. Abundant pseudomorphs of gypsum and anhydrite relicts and discontinuous gypsum layers within these dolostones, nodules of chert and gypsum indicate the interrelationship between the diagenesis and genesis of uranium mineralisation which indicates the carbonate precipitation in the sulphate-rich hypersaline environments.
PubDate: 2018-10-05
DOI: 10.1007/s12040-018-1012-6
Issue No: Vol. 127, No. 8 (2018)

• Reliability of reanalyses products in simulating precipitation and
temperature characteristics over India

• Authors: Nikhil Ghodichore; R Vinnarasi; C T Dhanya; Somnath Baidya Roy
Abstract: Various reanalyses have been utilized in numerous climate related researches around the globe, however, there exists considerable biasedness in these products, especially in precipitation and temperature data. The ability of these reanalysis products to simulate the precipitation and temperature patterns is observed to be satisfactory at global scale, while it differs significantly at regional scale, especially over regions of high spatio-temporal heterogeneity such as India. Therefore, it is essential to evaluate the applicability and robustness of reanalyses in climate related research. The annual and seasonal variability in spatio-temporal patterns and trends of precipitation and temperature data, with respect to the IMD gridded data over 34 yrs, are evaluated for six global reanalyses namely, NCEP/NCAR Reanalysis (NCEP R1), NCEP-DOE AMIP-2 Reanalysis (NCEP R2), Climate Forecast System Reanalysis (CFSR), ECMWF Interim Reanalysis (ERA-Interim), Modern Era Retrospective Analysis for Research and Application Land only model (MERRA-Land) and JMA 55-year Reanalysis (JRA-55). The ability of the reanalyses was tested based on several factors such as statistical and categorical indices, spells and trends, for annual and seasonal daily values. Several regional and seasonal differences were observed, particularly over high rainfall regions such as Western Ghats and northeastern India. MERRA-Land is found to give the best results for precipitation over India, which is attributed to the updated forcing data using gauge-based precipitation observations. Similarly, ERA-Interim and JRA-55 exhibit better performance for temperature than other datasets. All reanalyses failed to correctly reproduce the trends in IMD data, for both precipitation and temperature. These observations will provide a better perception on the reliability and applicability of reanalyses for climate and hydrological studies over India.
PubDate: 2018-10-05
DOI: 10.1007/s12040-018-1024-2
Issue No: Vol. 127, No. 8 (2018)

• Interaction study of clay-bearing amphibolite–crude oil–saline water:
Molecular level implications for enhanced oil recovery during low saline
water flooding

• Authors: Saheli Sanyal; Kumar Abhishek Singh; Harshil Parekh; Vishrut Chokshi; Uttam K Bhui
Abstract: Low saline water flooding (LSWF) had proved to be an efficient method for enhanced oil recovery in clay-bearing hydrocarbon reservoirs, but the interaction mechanisms among in-situ rocks – fluids and injection fluids within the reservoir – are not yet known properly. Understanding the molecular level interaction among these components is critical for designing and field scale implementation of LSWF in clay-bearing crystalline reservoir rocks, which is very limited in the existing literature. A weathered amphibolite rock and one dead crude oil from the Bakrol field (Cambay basin, India) have been used in this study. The presence of clay minerals in the weathered amphibolite rock was observed using a polarising microscope and characterised by the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. The crude oil and its fractionated SARA components have been extensively studied by spectroscopic techniques for their characterisation. The interaction study among the rock powder, hydrocarbon crude oil and saline water has been performed in the present work for gaining better insight for designing the injection fluid for LSWF. The weathered amphibolite rock powder was mixed with the dead crude oil and kept for 30 days in room temperature (T) and pressure (P) for proper interaction. The XRD, FTIR and cation exchange capacity results clearly demonstrated the incorporation of crude oil components in the interlayer surfaces of clay minerals. The oil removal efficiency, from the oil-treated rock powder of three saline water samples having NaCl concentration of 3000, 5000 and 8000 ppm, was investigated using the UV–Vis and fluorescence spectroscopies. The low saline NaCl water is capable of removing the maximum amount of polar components from the oil-treated rock powder. These molecular level insights are valuable for designing effective injection fluid for enhancing the oil recovery from the clay-rich crystalline reservoir rock.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1011-7
Issue No: Vol. 127, No. 8 (2018)

• The age of the Nodular Limestone Formation (Late Cretaceous), Narmada
Basin, central India

• Authors: Susheel Kumar; Deo Brat Pathak; Bindhyachal Pandey; Anand Kumar Jaitly; Jai Prakash Gautam
Abstract: The age of the marine Nodular Limestone Formation of the Bagh Group is refined at Substage level through ammonoid and inoceramid index taxa. The study is based on the fresh collections from three well-defined successive intervals (Lower Karondia, Upper Karondia and Chirakhan members) of this formation having excellent exposures in different localities of the Narmada Basin, central India. The first record of the widely distributed Turonian ammonoid genera Spathites Kummel and Decker and Collignoniceras Breistroffer from the Nodular Limestone Formation constrained its age exclusively to Turonian. The Early Turonian species Spathites (Jeanrogericeras) aff. revelieranus (Courtiller) and Mytiloides labiatus (Sclotheim) occur in the lower part, while the Middle Turonian marker Collignoniceras cf. carolinum (d’Obrbigny) and Inoceramus hobetsensis (Nagao and Matsumoto) occurs in the upper part of the Karondia Member. The record of the index species Inoceramus teshioensis (Nagao and Matsumoto) in association with Placenticeras mintoi Vredenburg from Chirakhan Member allows a definite Late Turonian age. The present contribution is an attempt to resolve the controversies in the age of the Nodular Limestone Formation and also demarcation of the three divisions (Early, Middle and Late) of the Turonian Stage in the Narmada Basin, central India.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1017-1
Issue No: Vol. 127, No. 8 (2018)

• Neotectonic activity of the Bomdila Fault in northeastern India from
geomorphological evidences using remote sensing and GIS

• Authors: Jogendra Nath Sarma; Sangeeta Sharma
Abstract: One of the major geological structures across the Brahmaputra valley, which stretches from the Eastern Himalayas up to the Naga Hills, is the Bomdila Fault. Parts of the courses of the rivers – the Brahmaputra, Dhansiri (south-S), Bargang and many others – are aligned along this structure. The influence of this structure on the courses of these rivers has been studied in detail using topographic maps, satellite data and field evidences. The signatures obtained such as: (a) an unusually linear course of the lower part of the Dhansiri (S) river from Golaghat up to Dhansirimukh, (b) the abandonment of the westerly course of the earlier Dhansiri (S) river (flowing through Kaziranga) towards the present NW direction by avulsion, (c) knick bends in the MBT–MCT and Naga Thrust of Belt of Schuppen, (d) a linear 15 m high topographic scarp on the left bank of the Dhansiri (S) near Numaligarh and (e) an anomalous SE–NW trending course of the Brahmaputra from Dhansirimukh up to Hartamuli along with the parts of the rivers Buroi and Bargang on the north in the same trend infers the influence of a fault-type structure. Since all these linear segments of the rivers align along the NW–SE trending Bomdila Fault, it infers the influence of the later on the courses of these rivers. The neotectonic activity along this fault might have caused the linear high scarp and abandonment of earlier river courses.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1008-2
Issue No: Vol. 127, No. 8 (2018)

• An assessment on oil spill trajectory prediction: Case study on oil spill
off Ennore Port

• Authors: S J Prasad; T M Balakrishnan Nair; Hasibur Rahaman; S S C Shenoi; T Vijayalakshmi
Abstract: A Liquefied Petroleum Gas (LPG) tanker and a chemical tanker collided two nautical miles off Ennore port on 28 January, 2017. Around 196.4 metric tons (MT) of Heavy Furnace Oil (HFO) was spilled and drifted towards the shore. Oil spill drift advisory and prediction was made by Indian National Centre for Ocean Information Services (INCOIS) using General National Oceanic and Atmospheric Administration (NOAA) Operational Modeling Environment (GNOME), an oil spill trajectory model. The trajectory model was forced with analysed and forecasted ocean currents from Global Ocean Data Assimilation System (GODAS) based on Modular Ocean Model 4p1 (GM4p1). It was found that spread of HFO obtained from oil spill trajectory model GNOME, has matched well with the observed spread from Sentinel-1A satellite dataset. However, the spread of the HFO was underestimated by the trajectory model, when forced with forecasted GM4p1 currents. Additional ground truth observation from Indian Coast Guard also corroborates this finding.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1015-3
Issue No: Vol. 127, No. 8 (2018)

• Detection and delineation of coal mine fire in Jharia coal field, India
using geophysical approach: A case study

• Authors: Rakesh Kumar Mishra; P N S Roy; Virendra Kumar Singh; Jai Krishna Pandey
Abstract: Coal mine fire is a serious problem in Jharia coal field, India. The coal mine fire can be detected with different techniques such as borehole temperature measurement, thermo-compositional analysis, remote sensing techniques, thermo-graphic measurement and geophysical methods. In this study, various geophysical methods were used to detect the surface and subsurface coal mine fires. Geophysical techniques used in the present study are apparent resistivity, self-potential (SP), magnetic method and thermography. Geophysical anomalies such as low SP value of $$-60\hbox { mV}$$ , high negative magnetic response and low apparent resistivity value helped us to detect and delineate the fire and non-fire areas laterally as well as depthwise. Furthermore, the thermography survey was carried out in the coal field using thermal imaging camera in order to substantiate the geophysical methods. This integrated approach was found to be more advantageous for the detection and delineation of surface and subsurface fire with respect to use of any specific techniques. Moreover, the level of threat towards the locality, national railway line was also assessed unambiguously using the above techniques. Hence, proper planning and implementation towards the mitigation of hazard can be achieved on the basis of the reported results.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1010-8
Issue No: Vol. 127, No. 8 (2018)

• An analytical model for the prediction of rip spacing in intermediate
beaches

• Authors: A Valipour; A A Bidokhti
Abstract: Considering the diversity of rip currents based on the classification of Castelle et al. (2016), it is crucial to study the characteristics of each individual rip current type, which are classified based on different dominant controlling forces and physical driving mechanisms. In this study, an analytical model was presented to predict the spacing of channel rip currents $$(S_{\mathrm{rip}})$$ in intermediate beaches using the equations of continuity and momentum. Then, the analytical model predictions were compared with the results of numerical simulations calibrated with field studies of other researchers, that showed good agreements. The main results of this study showed that rip spacing was simultaneously related to the characteristics of wave and bed in the surf zone. In addition, it was shown that due to inevitable changes of the hydrodynamic and morphological conditions of rip channel in the beach, the parameter $$H_{b0}/h_{c}$$ (where $$H_{b0}$$ is the wave height before approaching the sand bar and $$h_{c}$$ is channel depth) is an important factor in predicting the rip current situation and the changes of the beach state with time.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1013-5
Issue No: Vol. 127, No. 8 (2018)

• Bathymetry and sediments on the carbonate platform off western India:
Significance of Halimeda bioherms in carbonate sedimentation

• Authors: V Purnachandra Rao; V P Mahale; B Chakraborty
Abstract: Bathymetry across the carbonate platform off western India indicated small-size pinnacles and their lateral coalescence into 2 -6-m high mounds landward, and linear elongated carbonate ridges and troughs, mounds and banks up to a height of 20-m seaward of the platform. Seismic data indicated that these mounds were transparent with no rigid internal structure and can be defined as bioherms. The sediments were abundantly aragonite faecal pellets, Halimeda grains and ooids and their radiocarbon ages ranged from 11 to 7.5 ka BP. It appears that the growth of Halimeda bioherms on the platform was facilitated by intense upwelling during the early Holocene. The terrigenous sediments brought by rivers were deposited in the inner shelf and have not affected the growth of bioherms. It is estimated that the platform comprises at least 1.85 Gt of mass CaCO $$_3$$ accumulated during the early Holocene and comparable to those on the Great Barrier Reef. Halimeda bioherms produce abundant carbonate sediments and their growth period represents a geological carbonate sink and release of high CO $$_2$$ to the atmosphere. Detailed shallow seismic studies and sediment cores are needed to quantify the exact mass content of CaCO $$_3$$ and model climate change during the early Holocene.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1014-4
Issue No: Vol. 127, No. 8 (2018)

• Structural and luminescent characterisation of uraniferous fluorapatite
and haematite associated with phosphatic rocks of the Bijawar group in

• Authors: Pragya Pandit; Shailendra Kumar; Pargin Bangotra; Rohit Mehra; Manoj Mohapatra; Madhuparna Roy; A K Singh
Abstract: The structural and spectroscopic characteristics of phosphatic ferruginous shale samples from the Bijawar Group rocks from Sagar District of Madhya Pradesh (India) have been probed for identification of uranium species. Fluorapatite ( $$\hbox {Ca}_{5}\hbox {(PO}_{4})_{3}\hbox {F}$$ , FAP) and haematite ( $$\upalpha$$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ ) were identified as the main phases in the separated mineral concentrates. The photoluminescence (PL) and X-ray absorption near edge spectroscopy (XANES) studies pointed to a strong experimental evidence of both U(IV) and U(VI) oxidation states in the mineral concentrate portion obtained from the same parent host rock. The PL spectrum has confirmed the charge transfer (f–d) transition bands in UV and near-UV regions with emission peaks at ca. 290, 313, 336, 399 and 416 nm, which has been attributed to the substitution of $$\hbox {Ca}^{2+}$$ ions by U(IV) in FAP and broad structureless emission due to stabilisation of U(VI) as $$\hbox {UO}_{6}^{6-}$$ in haematite. Time-resolved spectroscopy studies have revealed biexponential decay components lasting 2–5 ns for U(IV) species and $$10\,\upmu \hbox {s}$$ for U(VI) species. These characterisations revealed the fundamental information about the oxidation state and form of uranium in this region. Remediation measures for the Bijawar region are also suggested.
PubDate: 2018-09-29
DOI: 10.1007/s12040-018-1009-1
Issue No: Vol. 127, No. 8 (2018)

• Palaeocene–Eocene carbon isotopic excursion from the
shallow-marine-carbonate sequence of northeast India: Implications on the
CIE magnitude and geometry

• Authors: Sruthi P Sreenivasan; Melinda Kumar Bera; Arpita Samanta; Ravikant Vadlamani
Abstract: The exact magnitude of the carbon isotopic excursion (CIE) for the Palaeocene–Eocene Thermal Maximum (PETM) is essential for our understanding of the carbon cycle perturbation. Global compilation of the PETM CIE magnitudes indicates that the shallow-marine inorganic carbonate could be a potential candidate to decipher the actual CIE magnitude. The present study, therefore, made an attempt to explore the thick Palaeogene shallow-marine carbonate sequence of the Sylhet Limestone exposed in the Jaintia Hills of northeast (NE) India, in terms of the preservation and magnitude of the PETM CIE. Exploratory sampling carried out across the Sylhet Limestone suggests that this sequence was deposited during the Late Palaeocene and Early Eocene, as evident from the age-diagnostic foraminifera. The observed $${\sim }3.4\permille$$ CIE at the top of the Lakadong Limestone, resting above the Miscellanea miscella and Ranikothalia nuttalli foraminifera-bearing horizon, can, therefore, be correlated with the PETM CIE. Although the magnitude of the CIE from our limited data set agrees well with the global compilation, the absence of a stepped profile questions the preservation of the CIE reported elsewhere from the Tethyan sequence. Further work is needed for a better understanding of the PETM interval in NE India.
PubDate: 2018-09-27
DOI: 10.1007/s12040-018-1018-0
Issue No: Vol. 127, No. 8 (2018)

• Geochemical assessment of fluoride enrichment and nitrate contamination in
groundwater in hard-rock aquifer by using graphical and statistical
methods

• Authors: Sunil Kumar Srivastava; A L Ramanathan
Abstract: This systematic study was carried out with objective to delineate the various sources responsible for $$\hbox {NO}_{3}^{-}$$ contamination and $$\hbox {F}^{-}$$ enrichment by utilizing statistical and graphical methods. Since Central Ground Water Board, India, indicated susceptibility of $$\hbox {NO}_{3}^{-}$$ contamination and $$\hbox {F}^{-}$$ enrichment, in most of the groundwater, $$\hbox {NO}_{3}^{-}$$ and $$\hbox {F}^{-}$$ concentration primarily observed $${>}45$$ and $${>}1.5~\hbox {mg/L}$$ , respectively, i.e., higher than the permissible limit for drinking water. Water Quality Index (WQI) indicates $${\sim }22.81\%$$ groundwater are good-water, $${\sim }71.14\%$$ groundwater poor-water, $${\sim }5.37\%$$ very poor-water and 0.67% unsuitable for drinking purpose. Piper diagram indicates $${\sim }59.73\%$$ groundwater hydrogeochemical facies are Ca–Mg– $$\hbox {HCO}_{3 }$$ water-types, $${\sim }28.19\%$$ Ca–Mg– $$\hbox {SO}_{4}$$ –Cl water-types, $${\sim }8.72\%$$ Na–K– $$\hbox {SO}_{4}$$ –Cl water-types and 3.36% Na–K– $$\hbox {HCO}_{3 }$$ water-types. This classification indicates dissolution and mixing are mainly controlling groundwater chemistry. Salinity diagram indicate $${\sim }44.30\%$$ groundwater under in low sodium and medium salinity hazard, $${\sim }49.66\%$$ groundwater fall under low sodium and high salinity hazard, $${\sim }3.36\%$$ groundwater fall under very-high salinity hazard. Sodium adsorption ratio indicates $${\sim }97\%$$ groundwater are in excellent condition for irrigation. The spatial distribution of $$\hbox {NO}_{3}^{-}$$ indicates significant contribution of fertilizer from agriculture lands. Fluoride enrichment occurs in groundwater through the dissolution of fluoride-rich minerals. By reducing the consumption of fertilizer and stress over groundwater, the water quality can be improved.
PubDate: 2018-09-10
DOI: 10.1007/s12040-018-1006-4
Issue No: Vol. 127, No. 7 (2018)

• Effect of uncertainty in $$V_{\mathrm{S}}{-}N$$ V S - N correlations on
seismic site response analysis

• Authors: Narayan Roy; Amit Shiuly; R B Sahu; Ravi S Jakka
Abstract: This paper studies the reliability of the calculated shear-wave velocity ( $$V_{\mathrm{S}}$$ ) from different available $$V_{\mathrm{S}}$$ and SPT-N correlations in terms of seismic site response analysis. In the present study, various $$V_{\mathrm{S}}$$ –N correlations developed for different regions around the globe have been used to calculate the bound of $$V_{\mathrm{S}}$$ variations with depth at three different sites in Kolkata city. This bound has later been used to generate the random $$V_{\mathrm{S}}$$ profiles using the Monte Carlo simulation. Equivalent linear site response analysis has been performed to study the response of those generated profiles under different input motion excitations. Strong-to-weak ground motion records have been used for this purpose. The amplification spectra of the generated $$V_{\mathrm{S}}$$ profiles using all soil types and specific soil-type $$V_{\mathrm{S}}$$ –N correlations show significant variations. The study also shows that the $$V_{\mathrm{S}}$$ –N correlation may result in quite different $$V_{\mathrm{S},30}$$ values and subsequently it may lead to the different site classes according to the NEHRP 2003 classification. So, the random choice of the $$V_{\mathrm{S}}$$ –N correlation, where the direct measurement of $$V_{\mathrm{S}}$$ is not available, may affect the outcome of seismic hazard analysis significantly. The study points out the need for accurate estimation of the $$V_{\mathrm{S}}$$ profile either from in-situ determination or using site-specific correlation.
PubDate: 2018-09-08
DOI: 10.1007/s12040-018-1007-3
Issue No: Vol. 127, No. 7 (2018)

• Interaction between felsic granitoids and mafic dykes in Bundelkhand
Craton: A field, petrographic and crystal size distribution study

• Authors: Tanwita Deb; Tapas Bhattacharyya
Abstract: In Bundelkhand Craton of central India, mafic dykes intruded when granitoids was partly crystallized. Cuspate–lobate boundary along the contact of granitoids and mafic magma indicates magma mingling in outcrop scale while textural evidence of mingling is represented by acicular apatite morphologies, titanite–plagioclase ocelli and ophitic–subophitic texture, mafic clots, resorbed plagioclase, and hornblende–zircon associations. Mingling also caused thermal exchange and fluid activity along the boundary between two coeval magmas. Crystal size distribution analyses for hornblende in the mafic rocks yield concave up curves which is also consistent with interaction of felsic and mafic magmas.
PubDate: 2018-09-05
DOI: 10.1007/s12040-018-1003-7
Issue No: Vol. 127, No. 7 (2018)

• Spatio-temporal variations in precipitation on the Huang-Huai-Hai Plain
from 1963 to 2012

• Authors: Yanan Li; Zhixiang Xie; Yaochen Qin; Shenghui Zhou
Abstract: Spatio-temporal variations in precipitation are affecting agricultural production in China in the context of climate change. Based on daily precipitation data from 63 national meteorological stations on the Huang-Huai-Hai Plain from 1963 to 2012, this paper analysed the spatio-temporal variations in precipitation in terms of precipitation days and intensity, using spatial interpolation, linear trend estimation and wavelet analysis. The results indicated that: (i) from 1963 to 2012, the number of annual precipitation days and intensity decreased gradually from the southeast to the northwest. Additionally, the distribution of the extreme precipitation index was similar to that of the annual precipitation index; (ii) the number of annual precipitation days and heavy precipitation days gradually decreased, while precipitation intensity and extreme precipitation days and extreme rainfall intensity remained relatively stable or decreased. The spatial patterns of annual variation trends were considerably different. The annual precipitation days and intensity trends are consistent with the overall trend, while that of the extreme rainfall index in some regions differs from the overall trend; (iii) the precipitation index displayed different periodic oscillations during the period, and the precipitation index values differed at different time scales. However, all the precipitation index values exhibited a 28-yr oscillation.
PubDate: 2018-08-29
DOI: 10.1007/s12040-018-0996-2
Issue No: Vol. 127, No. 7 (2018)

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