Role of groundwater protection planning in groundwater governance: A case study from North India

In the present case study, impact of urbanization and industrial development on the shallow groundwater regime of Saharanpur town of Uttar Pradesh in India is examined with the aim of planning groundwater protection for better governance. The hazardous physicochemical and bacteriological parameters and heavy metals detected in the shallow aquifer include harmful pathogens like fecal coliforms, heavy metals like cadmium, chromium, nitrates and sulphates. An assessment of ground water vulnerability using the well known DRASTIC method has confirmed that the shallow groundwater in some central and southern localities of Saharanpur town fall in the medium risk zones. Further, using field data of 32 electrical resistivity soundings, the protective capacity of the unconfined aquifer is assessed in terms of a ‘total longitudinal conductance’ of the semi-pervious to impervious sediments overlying the unconfined aquifer. However, some areas aligned along a northwest-southeast and in the western parts of the town seem to have relatively higher protective capacity against infiltrating waste pollutants. A ground water protection planning map prepared by combining the DRASTIC map and the ‘potentially hazardous pollutants’ map has brought out the need to install eleven new groundwater quality monitoring wells in the town at locations near the line sources and point sources of pollution. This approach can be readily employed by the decision makers in framing sound guidelines for groundwater protection and governance.     

Construction and Characterization of Transportable Calibration Pads for Calibration of Portable and Airborne Gamma Ray Spectrometers in India

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 T_max 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 CH_x 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).     

Calibration of AGRS System Using Transportable Pads in India: An Application to AGRS Data of Aravalli Basin,Banswada Block,South Rajasthan

Calibration of airborne gamma ray spectrometric system (AGRS) over standard radioactive sources of known elemental abundances is essential before carrying out airborne surveys. In India, fixed calibration pads were constructed in 1985. Since then calibration of AGRS system was carried out over the fixed pads. However the fixed pads are expensive to build and maintain. Also the large pads are subject to variations in radiation output due to variable moisture content and radon loss. Alternate approach is to construct transportable calibration pads which are discussed in this paper.Atomic Minerals Directorate for Exploration & Research (AMD) under Department of Atomic Energy has recently constructed five transportable calibration pads. Three pads i.e. K, U and Th have been spiked with the respective radioelements while keeping the minor radioelements to the least in order to obtain pure spectra. A composite pad has been constructed which contains all the three radioelements. This helps in cross verifying the obtained calibration results. A background pad has also been constructed which is helpful to obtain the background values during calibration.Analysis of the data acquired over the transportable pads with airborne gamma ray spectrometer (16.8 ltr) has been carried out and presented in this paper. A comparison with the data acquired over the fixed calibration pads is also included. There is a good agreement of results which suggests the use of transportable pads in future.     

Rainfall flood hazard at nuclear power plants in India

Flood hazard evaluation is an important input for Nuclear Power Plants external events safety studies. In the present study, flood hazard at various nuclear sites in India due to rainfall has been evaluated. Hazard estimation is a statistical procedure by which rainfall intensity versus occurrence frequency is estimated from historical records of rainfall data and extrapolated with asymptotic extreme value distribution. Rainfall data needed for flood hazard assessment are daily annual maximum rainfall (24?h data). The observed data points have been fitted using Gumbel, power law and exponential distribution, and return period has been estimated. To study the stationarity of rainfall data, a moving window estimate of the parameters has been performed. The rainfall pattern is stationary in both coastal and inland regions over the period of observation. The coastal regions show intense rainfall and higher variability than inland regions. Based on the plant layout, catchment area and drainage capacity, the prototype fast breeder reactor (PFBR) site is unlikely to be flooded.     

Incursion of the Pacific Ocean Water into the Indian Ocean

Using the data collected during the International Indian Ocean Expedition, maps showing the distribution of depth, acceleration potential, salinity and oxyty were prepared for the northeast monsoon for the four potential thermosteric anomaly surfaces: 160, 120, 80 and 60 cl/t. Zonal components of current along 84°E were computed from the geopotential dynamic heights. From such an analysis, it became clear that low-salinity water from the Pacific intrudes into the western Indian Ocean through the Banda and Timor seas in the upper layers above 100 cl/t surface, while the North Indian Ocean Water penetrates towards the Eastern Archipelago below 100 cl/t surface. The South Equatorial Countercurrent and the Tropical Countercurrent are well depicted on the vertical section of zonal components as well as on the distribution of acceleration potential.     

Geologic and tectonic evolution of the Himalaya before and after the India-Asia collision

The geology and tectonics of the Himalaya has been reviewed in the light of new data and recent studies by the author. The data suggest that the Lesser Himalayan Gneissic Basement (LHGB) represents the northern extension of the Bundelkhand craton, Northern Indian shield and the large scale granite magmatism in the LHGB towards the end of the Palæoproterozoic Wangtu Orogeny, stabilized the early crust in this region between 2-1.9 Ga. The region witnessed rapid uplift and development of the Lesser Himalayan rift basin, wherein the cyclic sedimentation continued during the Palæoproterozoic and Mesoproterozoic. The Tethys basin with the Vaikrita rocks at its base is suggested to have developed as a younger rift basin (～ 900 Ma ago) to the north of the Lesser Himalayan basin, floored by the LHGB. The southward shifting of the Lesser Himalayan basin marked by the deposition of Jaunsar-Simla and Blaini-Krol-Tal cycles in a confined basin, the changes in the sedimentation pattern in the Tethys basin during late Precambrian-Cambrian, deformation and the large scale granite activity (～ 500 ± 50 Ma), suggests a strong possibility of late Precambrian-Cambrian Kinnar Kailas Orogeny in the Himalaya. From the records of the oceanic crust of the Neo-Tethys basin, subduction, arc growth and collision, well documented from the Indus-Tsangpo suture zone north of the Tethys basin, it is evident that the Himalayan region has been growing gradually since Proterozoic, with a northward shift of the depocentre induced by N-S directed alternating compression and extension. During the Himalayan collision scenario, the 10–12km thick unconsolidated sedimentary pile of the Tethys basin (TSS), trapped between the subducting continental crust of the Indian plate and the southward thrusting of the oceanic crust of the Neo-Tethys and the arc components of the Indus-Tangpo collision zone, got considerably thickened through large scale folding and intra-formational thrusting, and moved southward as the Kashmir Thrust Sheet along the Panjal Thrust. This brought about early phase (M1) Barrovian type metamorphism of underlying Vaikrita rocks. With the continued northward push of the Indian Plate, the Vaikrita rocks suffered maximum compression, deformation and remobilization, and exhumed rapidly as the Higher Himalayan Crystallines (HHC) during Oligo-Miocene, inducing gravity gliding of its Tethyan sedimentary cover. Further, it is the continental crust of the LHGB that is suggested to have underthrust the Himalaya and southern Tibet, its cover rocks stacked as thrust slices formed the Himalayan mountain and its decollement surface reflected as the Main Himalayan Thrust (MHT), in the INDEPTH profile.     

Geophysical anomalies associated with uranium mineralization from Beldih mine, South Purulia Shear Zone, India

Beldih mine at the central part of the South Purulia Shear Zone (SPSZ) has been reported with low grade uranium-bearing formation within quartz-magnetite-apatite host in kaolinized formation. Therefore, the present integrated geophysical study with gravity, magnetic, radiometric, very low frequency electromagnetic (VLF) and gradient resistivity profiling methods around the known mineralized zones aimed at identifying the exact geophysical signatures and lateral extent of these uranium mineralization bands. The closely spaced gravity-magnetic contours over the low to high anomaly transition zones of Bouguer, reduced-to-pole magnetic, and trend surface separated residual gravity-magnetic anomaly maps indicate the possibility of high altered zone(s) along NW-SE direction at the central part of the study area. High current density plots of VLF method and the low resistive zones in gradient resistivity study depict the coincidence with low gravity, moderately high magnetic and low resistivity anomalies at the same locations. Moderate high radioactive zones have also been observed over these locations. This also suggests the existence of radioactive mineralization over this region. Along profile P2, drilled borehole data revealed the presence of uranium mineralization at a depth of ～100 m. The vertical projection of this mineralization band also identified as low gravity, low resistivity and high magnetic anomaly zone. Thus, the application of integrated geophysical techniques supported by geological information successfully recognized the nature of geophysical signatures associated with the uranium mineralization of this region. This enhances the scope of further integrated geophysical investigations in the unexplored regions of SPSZ.     

Suggestion for Search of Malononitrile (CH2(CN)2) in a Cosmic Object: Potential Spectral Lines

Astronomy Reports - Though accurate laboratory studies of malononitrile (CH2(CN)2), a dinitrile molecule, have been carried out from time to time, and it has large electric dipole moment $$\mu =...     

Magnetic method applied to mineral exploration

Developments which have led to an enormous increase in the use of magnetic surveys for mineral exploration during the past 30 years are reviewed here. Advances in instrumentation and digital compilation of data have come about largely due to the extensive use of the airborne magnetometer as a geologic mapping tool. Currently there is a growing interest in the use of the aeromagnetic gradiometer for exploration surveys in the Precambrian Shield areas. The advantages of gradiometry as a complement to total field surveys is becoming well recognized. Miniaturized electronics has reduced the cost and size of many magnetic survey instruments and ancillary equipments. Advanced compensation techniques have made it possible to make optimum use of the increased sensitivity of magnetometers for various high-resolution applications.Quantitative interpretation of magnetic data in terms of models of causative bodies has advanced largely due to the development of computerized multiparameter inversion methods. Many of these permit interpreter interaction through computer-graphic display system to impose sensible geologic constraints. Several survey contractors have the software and hardware facilities to perform various data enhancement techniques and also interactive modelling. Susceptibility mapping and magnetization mapping techniques are of great potential utility in mineral exploration. There is still a great need for studies into the relationship between rock magnetism and magnetic anomalies.