ALBERT

Beschreibung: This study presents a cost effective and quantitative method for the characterization of flow units and prediction of hydrocarbon recovery of the reservoirs in wells D and E, “Aqua field”, Niger Delta. It involves petrophysical evaluation of well log data in order to obtain porosity and permeability values which were useful in identifying and characterizing flow units with the help of the Stratigraphic Modified Lorenz Plot (SMLP). This plot was then used to identify the number of flow units, key flow unit characteristics and anticipated production performance of the hydrocarbon bearing reservoir and the data subjected into a numerical simulator that allows better resolution characteristics of the well. The D-1 reservoir interval has five flow units, which comprise both speed zones and baffle intervals. Reservoirs E-1 to E-4 also have a total of 21 flow units. High values of flow unit speed and high angle flow capacity inflexion indicate speed zones which are prone to sharp decline, while baffles of low value flow unit speed and low angle flow capacity show shallow to steady production decline with time. A better understanding of the fluid flow variations within the reservoir intervals helps in the accurate design of reservoir simulation model for effective hydrocarbon recovery and management.

Beschreibung: The chemical composition of thermal springs from Siwana Ring Complex (SRC) of Barmer district, Rajasthan, India has been investigated for the first time. These springs are near neutral to mildly alkaline (pH = 6.8 to 7.8) in nature with surface temperatures varying between 31 to 39 °C. Piper diagram suggests that these thermal springs are dominated by Ca-HCO 3 type. Experimental results of water-rock interaction at 100 °C indicate that the thermal springs are circulating through tuff and a sedimentary formation extensively controlled by ring dykes of granites, felsic volcanics and mafic dyke and the fault systems associated with the host rock. Groundwater and thermal springs show similar characteristics. Estimated reservoir temperature suggests that Siwana area geothermal system is a low enthalpy system. Heat flow values of the area range from 83 to 205 mWm −2 , promise a viable potential for Enhanced Geothermal System (EGS).

Beschreibung: Study of komatiites for their structures and textures in cratonic blocks could provide more insights into the early Archaean volcanism, mantle processes and associated metallogeny. Jayachamarajapura (J.C.Pura) belt in Western Dharwar craton is a komatiitc milieu, where outcrop features display several flow characteristics and sub-volcanic emplacement features typical of well known komatiitic areas of the world. In spite of deformation, metamorphism and alterations the komatiites still preserve many of the primary cooling structures, which stand testimony for their extrusive volcanic nature. Distinct features like pillows, flow-top polyhedral joints, ocelli, vesicular, flow-top breccia and cumulate segregations and crude layering are observed. However, massive, undifferentiated nature of komatiitic flows is more predominant. Because of serpentinisation, carbonitization and chloritization, the original mineralogy and textures are obliterated and scantily preserved. Still, these observed features provide vital clues to imply the formation of komatiite sequences in a submarine to subaerial conditions when episodic pulses of komatiite lava piled up (about 3.35 Ga ago) to form the ultramafic milieu of J.C. Pura belt.

Beschreibung: Presence of Early Tertiary pyroclastic material (tephra) has been documented petrographically, for the first time, in the Mandi-Bilaspur Sector from Tileli area, Dharamsala basin of Himachal Pradesh. The tephra is reported from the red shale, identified as tuffaceous siltstone belonging to lower Dharamsala Formation that lies above the uraniferous sandstone body and occurs as thin layers of over 300m along the strike, close to the contact of lower and upper Dharamsala formations. The tuffaceous material shows crude but preferred orientation of minerals like biotite, muscovite, chlorite, clay, hematite and specularite. Various features indicating presence of tephra are, glass shards altered to clay but retaining ‘U’ shaped outline, spindle-shaped hematite with preferred orientation, spherical to sub-spherical clay and altered Feoxide rich balls, clay groundmass with flow pattern, flaky minerals in association with clast depicting asymmetrical ramp structure. A zone of approximately 300 m length containing tuffaceous material has been established at Tileli overlying the uraniferous sandstone body. Identification of tephra at Tileli has significant implications as it enabled in demarcating the boundary between the upper and lower Dharamsala formations in central part of the basin in Bilaspur-Mandi Sector of HP Himalaya and also in guiding the uranium exploration programme in the lower Dharamsala Formation.

Beschreibung: The Jajiya Member of Jaisalmer Formation yielded a foraminiferal assemblage comprising twenty-three species dominated by the family Vaginulinidae. An Oxfordian age is assigned to the foraminiferal assemblage based on the record of some characteristic Oxfordian species reported from different parts of the world. The foraminiferal assemblage suggests an open marine shelf environment of deposition.

Beschreibung: The benthic foraminifera from the Savitri estuary are being reported for the first time. The faunal analyses reveal the occurrence of mixed assemblage. It is observed that Trochammina inflata is the most dominant species and appears to be the indigenous to mangrove environment.

Beschreibung: Integrated geoelectric and geochemical investigation were carried out in the Canning and adjoining areas to assess the prevailing groundwater conditions and chemical quality of groundwater. Geologically, the area is constituted of alluvial sediments of Quaternary age. Vertical electrical soundings (VES) in the area of investigation mostly show six layers consisting of top soil, saline water, clay layer, brackish water, clay layer and fresh-water bearing zone of appreciable thicknesses at depths of 137 to 182 meter at six locations and from 370 to 430 meter for other two locations under confined conditions. The result of VES studies significantly correspond with the borehole litholog and well log data. A litho-resistivity relationship is established for this area of investigation A Fence diagram is constructed to show the spatial variation of the sub-surface lithology and hydrological characteristics. Chemically the ground water is fresh and mixed cation and anion type as revealed from Piper-Trilinear diagram with TDS ranging from 699 to 1547 mg/l. The geochemical parameters like Total hardness (TH), Sodium absorption ratio (SAR), Soluble sodium percentage (SSP), Percentage of sodium (PS), Kelley’s ratio (KR), Residual sodium carbonate (RSC), Corrosivity ratio (CR), Gibbs ratios (GR), Chloro alkaline indices (CAI), Sea water contamination (SWC) are also calculated for examining the quality of groundwater in the area. The depth of occurrences of freshwater bearing ground water zones for drinking and irrigation purposes are occurring at depths from 137 meter to 430 meter in this area.

Beschreibung: Numerical simulation of groundwater flow used for the estimation of hydraulic and hydrologic parameters which is an important tool for the management of aquifers. This study presents the results of a mathematical model developed for the simulation of groundwater flow in Nahavand plain aquifer in the southwest Hamadan province. For this purpose Groundwater Modeling Software (GMS) was used which supports the MODFLOW-2000 code. After gathering required data such as the hydrological, hydrogeological and topography maps, a 3D hydrogeological model of plain was constructed with borehole and surface elevation data. Then MODFLOW was used for simulation of flow. After initial simulation of the flow, the model was calibrated in steady state with trial-and-error and parameter estimation methods the observed head of groundwater table monitoring data of 1997. Results of calibration show that error between observed head and computed head is in allowable range. Also results of computed head with model show that groundwater flow is in the direction of the dominate slope (southeast to northwest). Finally MODPATH code which simulates advective transport of particles was used for estimation of flow path and source of contaminants.

Beschreibung: The objective of this paper is to estimate water seepage from the upper reservoir of Azad pumped storage power plant (PSPP), based on combined geotechnical investigations and geostatistical methods. Azad PSPP has been located in Sanandaj Province in Iran. In order to select the optimum water tightening alternative, such as clay blanket, concrete cover (or concrete lining), geomembrane, asphalt cover etc, estimation of water seepage from the reservoir is essential. Six exploratory boreholes were drilled at the pumped storage reservoir area and permeability tests (Lugeon tests) were conducted in all of them. Records at the boreholes have been considered as the main source for seepage calculations. Due to expansion of upper reservoir and a few boreholes, distribution of permeability and permeability changes in the reservoir area is not indicator of reservoir. In this research using geostatistical method (Kriging), lugeon values have been estimated for walls of reservoir. According to correspondence between estimated permeability distribution and geological conditions, the estimated values are acceptable. In addition results show that in about 60% of tests, permeability is very high and potential of water seepage is very high. Seepage was estimated for reservoir by using both analytical (vedernikov method) and numerical method. Results from both methods are very close and the average of seepage is around 280000 m 3 /day. From the results and general geological considerations, seepage is concentrated at fault zones. Results show that by using appropriate permeability distribution, the estimated values of water seepage are reliable. Due to the high amount of water seepage and economic importance of water in this region, water tightening is necessary.

Beschreibung: 3D Geological control in an area is a key to success for exploration of hydrocarbon. Any discrepancy in geological control leads towards dry wells and ultimately high economic loss. The aim of this study is to build a 3D subsurface geologic model of Punjab platform, Pakistan by integrating mud logs, wire line logs and seismic data for interpreting the structural trends of pre-tertiary geological formations. For this purpose, wire line and mud logs of eighteen wells and about 1500LKm 2D seismic data of Punjab platform was collected from Directorate General of Petroleum Concession (DGPC) Islamabad, Pakistan. A well correlation profile is developed using Petrel and CorelDraw software to assess the distribution of subsurface geological sequences. Synthetic seismograms were developed and then correlated with seismic stacks to pick the horizons of different formations. Time Contour, velocity contour, depth contour and isopach maps are constructed. These maps were then loaded in Structural Modeling window of Petrel software for final construction of 3D geological model. The proposed model indicates that there is a sub-surface monoclinal trend dipping towards a western side of the study area. Further, an anticline at Cambrian level near Fortabbas-Bijnot area is extending to the East in the neighbouring India. In addition, horst and graben structures are also identified at Cambrian level by seismic data. The proposed model is confirmed by results of earlier data, and it is, therefore, recommended that 3D seismic data should further be acquired to explore the structural and stratigraphic traps of Punjab platform, Pakistan.

Beschreibung: An attempt was made in the present study to delineate how the radon concentrations vary with respect to different geological formations and to evaluate annual effective dose exposure due to ingestion of radon. A total of 60 groundwater samples were collected from layered sequential aquifers in Chitradurga district having major rock types such as Bababudan Group, Charnockite, Chitradurga Group, Closepet granite, migmatites and granodiorite — tonalitic gneisses and Sargur Schist complex during pre-monsoon and post-season of the year 2011. Radon measurement was made using Durridge RAD-7 radon-in-air monitor, connected to RAD H 2 O accessory with closed loop aeration concept. In the present study, the radon activity ranged from 0 to 186.6 Bq/L and 0 to 150.6 Bq/L during pre- and post-monsoon seasons of the year 2011, with 56.67 % (17 samples) of samples during both the seasons exceeding the EPA’s MCL value of 11.1 Bq/L. The annual mean radon activity in the groundwater was higher in the area having Chitradurga rock group formations (78.1 Bq/L) followed by Sargur-Satyamangalam schist complex group (56.8 bq/L), migmatites and granodiorite — tonalitic Gneisses group (56.3 Bq/L), Closepet granite (42.7 Bq/L), Charnonkite (29.1 Bq/L) and Bababudan Group (22.2 Bq/L). It is inferred that radon concentration found to depend on the tectonic structure, geology of the area and on the presence of uranium minerals in these rocks. The annual effective dose resulting from radon in groundwater in the Chitradurga district were significantly lower than UNSCEAR and WHO recommended limit of 1 mSv/y.

Beschreibung: Zoned Apatite crystals with intrinsic radioactivity are widespread in the S-type basement granite around Govardhanagiri-Chinnakolumulapalli-L.Banda areas of Kurnool District, A.P. The granite is overlain by Gulcheru quartzite and in turn by Vempalle dolostone of Papaghni Group belonging to the Cuddapah Supergroup. The area (4 km x 6 km) is characterized by conjugate fracture system comprising ENE-WSW and WNW-ESE of varying extents, of which, ENE-WSW is sympathetic to the major deep seated Gani Kalva fault. The apatite crystals are frequently zoned and vary in size from few microns to 1000 microns, occur mostly as veins or associated with pulverized matrix of granite cataclasite. Veins (upto 2 cm. thick) generally follow the major fracture-trend (ENE-WSW) in the area. The apatites are also found intimately associated with fluorite, tourmaline and sulphides, which suggest their derivation from pneumatolytic fluids. The intrinsic accessory uranium as scarce grains of uraninite and other labile phases of granite were remobilized consequent upon the deformation and locked up as ferroan-oxy/hydroxyl inclusions in slowly growing apatite crystals under very low temperature conditions.

Beschreibung: Four legume fruits (Fabaceae) from the Siwalik sediments (middle Miocene to lower Pleistocene) of Darjeeling and Arunachal Pradesh of Eastern Himalaya are described here. One fossil fruit, Dalbergia prelatifolia sp. nov., is recovered from the lower part of the Siwalik succession (Gish Clay Formation of Sevok Group; middle to upper Miocene) of Darjeeling foothills. Mastertia neoassamica sp. nov. and Acacia miocatechuoides sp. nov. are collected from the lower part of the Siwalik succession (Dafla Formation; middle Miocene to upper Miocene), while Pongamia kathgodamensis Prasad is recovered from the upper part of the Siwalik succession (Kimin Formation; upper Pliocenelower Pleistocene) of Arunachal sub Himalaya. Their presence indicates a warm and humid tropical environment in the region during the Siwalik sedimentation.

Beschreibung: The phosphatized globular to sub-oval metazoan eggs with distinctively ornamented covering and phosphatized polar lobe forming embryos are recorded for the first time from the black phosphatic chert lenticles and bands of early Cambrian Chert Member of Deo ka Tibba Formation, Tal Group, Uttarakhand Lesser Himalaya. Similar metazoan eggs have been recorded earlier from early Cambrian rocks of Shaanxi Province, China, northwestern Canada, Australia, Mongolia, Siberia and Kazakhstan. These eggs are found in association with Small Shelly Fossils (SSF) and may belong to them. However, polar lobe forming embryos have been earlier recorded from Neoproterozoic rocks of southwestern China only. Similar embryos are common in modern molluscs and bilaterians.

Beschreibung: An integrated mineralogical-geochemical and stable isotopic study of Pb-Zn deposits located at Kayar-Ghugra (Zn-Pb ± Ag), Rampura-Agucha (Zn-Pb, Ag), Dariba-Bethumni (Zn-Pb) and Zawar (Pb-Zn ± Cd, Ag) in Rajasthan is presented in this paper. The Kayar Zn-Pb deposit hosted by (i) phlogopite-tremolite bearing dolomitic carbonates and (ii) scapolite bearing calc-silicates, both belonging to Mesoproterozoic Delhi Supergroup exhibit distinctly different δ 13 C signatures being close to zero permil for the former reflecting deposition in pristine marine environment and much depleted isotopic values for the latter possibly related to post-depositional alterations. The Zn-Pb sulphides of Agucha, hosted in amphibolite facies to lower granulite facies metasedimentary units belonging to the Bhilwara Supergroup have δ 34 S values that indicate (i) H 2 S dominated regime characterized by low fO 2 , low pH, wherein the δ 34 S (fluid) responsible for mineralisation approximates the δ 34 S (sulphide) ; (ii) the role of seawater in the generation of Agucha ores; (iii) the process of a low temperature oxidation of sulphides in the hydrothermal fluids resulting in the formation of sulphate, by the interaction of ground water; (iv) isotopic disequilibrium in sulphatesulphide pairs that explain oxidation of H 2 S by acid groundwater (low pH) and deposition of sulphides at higher temperatures and (v) equilibrium isotopic fractionation of the coexisting sulphides reflecting in a higher concentration of H 2 S (〉10 −5 m) in relation to the total metal content in the hydrothermal fluid $\left( {m_{H_2 S} \geqslant mS_{_{metals} } } \right)$ . Accordingly the concentration of sulphide-sulphate in the hydrothermal solution responsible for the mineralization in Agucha exceeds that of total metals. The sulphides of Bethumni-Rajpura-Dariba belt hosted in low to medium grade siliceous carbonates has a marginally positive (mean of +1.5‰) δ 13 C values. At Sindeswar, broad and widely scattered δ 34 S values indicate a polymodal sedimentary source of sulphur that recrystallised at rather low temperature of 〈 50°C possibly during the processes of low temperature bacterial reduction. The C and O-isotopic studies on mineralized and non-mineralized carbonates reveal (i) normal marine depositional signatures for non-mineralized carbonates with possible minor influence of biogenic carbon during deposition and (ii) ore zone carbonates exhibit depleted δ 13 C values presumably due either to the deeper mantle-like source of carbonates or due to post-depositional equilibration with isotopically light meteoric waters. In Zawar belt, sulphides hosted in dolomitic carbonate indicated (i) near identical δ 34 S values of disseminated galena and pyrite veinlets and depleted values of −4.6 ‰ for late veins of massive galena of Zawar Mala (ii) pyritepyrrhotite veinlet having enhanced δ 34 S values when compared to the PbS-ZnS veinlet in Morchia-Magra, Balaria and Baroi mines. The carbon isotopic values for carbonates of Zawar Mala mine area are mostly depleted and those from Balaria and Baroi mines exhibit values of 13 C close to zero. The generally depleted δ 18 O clustering around −15 ‰ tally well with the reported Paleoproterozoic carbonates and is attributed to the post-depositional equilibration reactions with isotopically light meteoric waters. It is summarized that the host carbonates for Zn-Pb deposits occurring in different tectono-stratigraphic units in Rajasthan have largely similar but bimodal distribution of δ 18 O and δ 13 C isotopic ratios that suggest normal marine values and much depleted values. Whereas the former seems to be in general agreement with the nature of distribution in the Palaeoproterozoic carbonates the latter is attributed to (i) depositional conditions of the basins that includes absence or presence of biogenic activity (ii) isotopic re-equilibration under different metamorphic recrystallization events and/or (iii) interaction with isotopically lighter meteoric waters. In contrast to the uniformity in the C and O distribution pattern, the S-isotopic distribution in the deposits of Rampura-Agucha, Bethumni-Rajpura-Darbia and Zawar mine areas show marked variations reflecting complex deposit-specific ore-forming processes in the said deposits.

Beschreibung: The Cenozoic and Quaternary sediments of Saurashtra basin encompass signatures of sea level fluctuations, environments of deposition and presence of hydrocarbons. These sediments are divided into seven formations that in order of superposition are: Deccan Trap (late Cretaceous to Eocene), Gaj (early Miocene), Dwarka (middle Miocene to early Pliocene), Miliolite (middle Pleistocene), Chaya (late Pleistocene to late Holocene), Katpur (middle Holocene) and Mahuva Formation (late Holocene). The fossil calcareous algae are significant constituents of these sediments and in all 88 species so far have been recorded by different workers from three prominent areas: Dwarka-Okha area (38 coralline algal species:28 nongeniculate and 10 geniculate), Porbandar area (37 coralline algal species:25 nongeniculate and 12 geniculate species) and Diu area (13 calcareous algal species:6 nongeniculate coralline algal species, 5 geniculate coralline algal species; 1 dasycladalean algal species and 1 halimedacean algal species) of the Saurashtra basin. The present paper provides a checklist of these 88 calcareous algal species documented from the different formations of this basin and their implications for paleoenvironments and petroleum exploration.

Beschreibung: Groundwater vulnerability assessments calculate the sensitivity of quality of groundwater to an imposed contaminant load which is essential element of the aquifer management plans. Seventy five groundwater samples have been analyzed for different chemical parameters to understand the groundwater quality of the lower Varuna river basin, Uttar Pradesh, India. The intrinsic groundwater vulnerability map of the lower Varuna catchment area in the north of the city of Varanasi (India) shows a high dependency on the depth to groundwater. The topmost layer of alluvial silty clay, protects the groundwater against contamination in this urban area, but the retention time in the unsaturated zone can be estimated to several months only. The input dataset is very sparse i.e. groundwater levels were measured twice (pre- and post-monsoon 2009) and the geological map shows only alluvium as the outcrop. Several boreholes in this area show, that the alluvium has a thickness of about 4 m and below that are fine grained sands. The surface information does not allow the development of a risk map since land use changes very fast and contamination areas can not be identified accurately. The vulnerability maps developed in this study have become important tools for environmental planning and predictive management of the groundwater resources in the fast urbanizing region in the Varanasi area.

Beschreibung: An interesting bivalve fossil obtained from the Claystone Member of the Chhasra Formation (Burdigalian), Kachchh District, India was found conspecific with Anadara gourae Dey (Arcidae, Anadarinae) from the Quilon Beds (Burdigalian), Kerala. However, this form is feebly inequivalve and has dissimilar ornamentation on the two valves, a trapezoidal form and its maximum height is at the posterior. Also, there is a small but distinct median sulcus on the exterior of the umbonal region. These characteristics do not agree with definition of the genus Anadara . Hence it is described here under a new genus, Indarca . Subgenus Cunearca Dall of genus Scapharca Gray (Arcidae, Anadarinae), also shows dissimilar ornamentation on the two valves, but differs from Indarca in having an inflated form, left valve slightly larger and absence of a sulcus on the umbonal region. Indarca resembles Bentharca Verrill and Bush (Arcidae, Anadarinae) in certain respects, but differs from it in not having a markedly reduced anterior. Occurrence of Indarca gourae strengthens the faunal affinity between the Chhasra Formation of Kachchh and the Quilon Beds of Kerala.

Beschreibung: We report a new occurrence of thorianite from syenitic pegmatite near Bhaluchuan, Sambalpur district, Odisha. The thorianite is brown to deep-brown with round grains of 2 to 10 mm size. The chemical analysis of the investigated thorianite reveals 64.8% ThO 2 , 25% U 3 O 8 , 3.81% PbO and 1.7% Fe 2 O 3 . Calculated structural formula of the thorianite is (Th +4 0.61 U +4 0.14 U +6 0.08 ΣREE +3 0.017 Pb +2 0.04 Ca +2 0.01 Mn +2 0.001 Fe +3 0.05 Al +3 0.003 Sc +2 0.002 K +1 0.005 Na +1 0.008 Si +4 0.04 Ti +4 0.02 )O 2.08 . Chondrite-normalised rare-earth element (REE) plot of the thorianite reveals enrichment of light REE (LREE) over heavy REE (HREE) with pronounced negative Eu-anomaly (Eu/Eu* = 0.35). The (ΣLREE/ΣHREE) N ratio is perceptibly high (2.76). The (La/Lu) N (42.31), (La/Yb) N (27.49) and (Ce/Yb) N (21.58) ratios are also very high. X-ray diffraction (XRD) pattern of the investigated thorianite displays sharply-defined reflections. Corresponding interplanar spacings (d-spacings) of all the reflections are in very close agreement with those published for thorianite standard in International Centre for Diffraction Data (ICDD) Card No. 4-556. However, I/Io of two reflections (1.9694Å and 1.6787Å) are lower than those published for thorianite standard. The unit cell parameter (a o ) of the investigated thorianite (a o 5.5750Å) is also less than a o of thorianite standard (a o 5.6000Å and V 175.62Å 3 ), which is because of extensive substitution of Th by U.

Beschreibung: Water consumption is likely to increase substantially in the future on account of rising population, economic growth, and social development. Rapid urbanization and population growth of Allahabad city, has necessitated thinking about the declination in ground water level as well as supply of sufficient quantity of water for future either for drinking purpose or industrial use. In the present study, rainfall recharge of Allahabad city has been computed on GIS platform (ArcInfo). Groundwater recharge potential zones of Allahabad city have also been found out using GIS. Case study of recharge of ground water through roof top rainwater harvesting at Vikas Bhawan (a multistoryed building), Allahabad is discussed. An implementation of this analysis and decision making software is expected to work for sustainable water management.

Beschreibung: This study assessed the hydrocarbon generation potentials/timing of the Awgu source rock horizons encountered in Igbariam-1, Iji-1 and Ajire-1 wells drilled in the southern Benue Trough; using one-dimensional (1D) Genesis Zetaware basin modelling software. This software enabled the integration of burial and thermal influences on Awgu source rocks with kinetic parameters. Thermal and burial history models indicate that the Awgu source horizons encountered at 3249m in Igbariam-1 well (northern part of the basin), expelled 85mg/gtoc of oil and 12 mg/gtoc of gas and hydrocarbon generation began in early Eocene with maximum expulsion in the mid-Eocene (52my) at the rate of 7mg/gtoc/my. To the south of the basin, the Awgu source horizons were encountered at greater depths in Iji-1 and Ajire-1 wells and hydrocarbon generation began in the mid-Palaeocene and peaked in the late Palaeocene (58my) at the rate of 32–38mg/gtoc/my. This resulted in an increase in generated hydrocarbon volume to the south due to (a) increased burial depth and early maturation, and (b) changing source lithofacies -more marine. The fault system linking potential reservoirs such as the Agbani sandstone and the overlying Owelli sandstone to the source rock suggests a possible migration of the generated hydrocarbons to those reservoirs at that time.

Beschreibung: The Bundelkhand massif comprising a variety of Archean-Paleoproterozoic granitoids along with low grade and high-grade metamorphites and located in the centre of the Indian Plate, underwent extension during Paleoproterozoic period, resulting in the formation of homotaxial intracratonic Bijawar and Sonrai basins in the south and Gwalior basin in the northern margin. The Bijawar and Sonrai basins are typified by their characteristic sediments and basic volcanic rocks. A feature common to both the basins, is the overwhelming occurrence of phosphatic rocks across stratigraphy and lithotype in the Bijawar basin and its confinement to the basal part of the sedimentary column in Sonrai basin. Most of these rocks are primarily of marine origin, and later subjected to periods of repeated phosphatic redistribution. Multiple episodes of such phosphatisation culminates in the proliferation and enrichment of phosphate in the upper Bijawar rocks of Bijawar basin (phosphatic breccia of Hirapur-Mardeora) and lower Bijawar rocks of Sonrai basin (phosphatic breccia of Lalitpur). Apart from these established phosphatic rocks in both the basins, quartz reefs occurring in the basement as well as the lower Bijawar Malhera Chert Breccia Formation in Bijawar basin at places are endowed with anomalously high phosphate content. The phosphatic component in all the lithotypes is in the form of apatite varying in form from microcrystalline to well formed coarser crystal aggregate comprising cement, veins and botroidal encrustations. Irrespective of its spatial, temporal and paragenetic position, it invariably registers weak to moderate radioactivity, due to the presence of uranium within it, as is evident from microprobe data. Although intra-grain and inter-grain distribution of uranium is found to be random and erratic, in general, it is observed that uranium tends to be enriched in the later generation phosphates, due to secondary process of dissolution and reprecipitation. The present paper, with fresh inputs from petrological, geochemical, minerochemical and isotope data pertaining to apatite from all these diverse units, not only explores the already established association of uranium and phosphate in these basins but also provides new insight to the phosphatic quartz reef within the basement and the phosphatised arenaceous sediments of the lower Bijawar Formation.

Beschreibung: Hydogrochemical investigation of groundwater resources of Paragraph district has been carried out to assess the solute acquisition processes and water quality for domestic and irrigation uses. Fifty-five groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, hardness, major anions (F − , Cl − , NO 3 , HCO 3 − , SO 4 2− ) and cations (Ca 2+ , Mg 2+ , Na + , K + ). Study results reveal that groundwater of the area is alkaline in nature and HCO 3 − , Cl − , Mg 2+ , Na + and Ca 2+ are the major contributing ions to the dissolved solids. The hydrogeochemical data suggest that weathering of rock forming minerals along with secondary contributions from agricultural and anthropogenic sources are mainly controlling the groundwater composition of Pratapgarh district. Alkaline earth metals (Ca 2+ +Mg 2+ ) exceed alkalis (Na + +K + ) and weak acid (HCO 3 − ) dominate over strong acids (Cl − +SO 4 2− ) in majority of the groundwater samples. Ca-Mg-HCO 3 and Ca-Mg-Cl-HCO 3 are the dominant hydrogeochemical facies in the groundwater of the area. The computed saturation indices demonstrate oversaturated condition with respect to dolomite and calcite and undersaturated with gypsum and fluorite. A comparison of groundwater quality parameters in relation to specified limits for drinking water shows that concentrations of TDS, F − , NO 3 − and total hardness exceed the desirable limits in many water samples. Quality assessment for irrigation uses reveal that the groundwater is good for irrigation. However, values of salinity, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), %Na and Kelley index are exceeding the prescribed limit at some sites, demanding adequate drainage and water management plan for the area.

Beschreibung: The tannery effluents discharged by the existing units on either side of the Palar river at Ambur town (known for tannery industry), has resulted in vertical and lateral spread of pollution. The study area of 55.3 km 2 is situated on a granitic terrain of Archaean age with undulating topography and hillocks. The shallow aquifers, in flood plain and valley fills of the river are highly polluted (with EC: 15340 μS/cm) by tannery effluents making groundwater unfit for any use, hence the local population (20000) face health hazards and shortage of potable water. Hydrogeological, geophysical and in-situ groundwater quality measurement were carried out to demarcate fresh groundwater zones and to delineate lateral and vertical extent of pollution. The results show, brackish aquifer was characterized by low order of resistivity (〈20 Ω-m) with a thickness of 8.5 to 28 m located in the flood plains, valley fills, and partially in hard rock formations, whereas the fresh water aquifer resistivity varying from 23 to 216 Ω-m in hard rock. Further, these results were correlated with the water quality data and Ground Penetrating Radar (GPR) signals. The integrated studies revealed that pollution due to tannery effluents has spread over an area of 33.4 km 2 (60.4 %) on either side of the river and only a small area of 21.9 km 2 (39.6 %) was identified as fresh groundwater zone, which has to be conserved and exploited in sustainable manner for future generations.

Beschreibung: The upper Jurassic carbonate settings in Iran are widely exposed in north and northeastern parts. Five stratigraphic columns were selected in the north eastern Iran. Their thickness ranges from 330 to 500 m. The various diagenetic processes identified include, micritization, cementation, compaction (physical and chemical), dissolution, neomorphism, pyritization, hematitization, silicification and dolomitization, which affected these carbonates. Elemental and stable isotopes analysis indicated that these deposits have undergone both meteoric and burial diagenesis in a relatively open system with moderate water-rock interaction. The positive trend between trace elements and oxygen isotope depletion also support these burial conditions. Lighter δ l8 O values of the dolomite samples may be related to an increase in temperature during the burial, which correspond to coarser euhedral crystals. Relatively higher δ 18 O values in finer dolomite crystals indicate their formation at lower burial depths relative to coarser crystals. Petrographic evidences such as coarse euhedral crystals with bright and dull zonation prove this interpretation. Chert nodules also have lighter 18 O values relative to carbonate host rock, thus indicating the influence of burial diagenetic processes in their formation. The average environmental palaeotemperature was estimated to be 26°C on the basis of oxygen isotope values of less altered lime-mudstones.

Beschreibung: Widespread distribution of mafic dykes and scanty occurrence of ultrabasic intrusives of kimberlitic affinity around Proterozoic Cuddapah basin, parts of Eastern Dharwar craton of south India has been the focus of attention since their discovery, to understand the structural fabric in relation to their emplacement in geological time. Satellite Imagery, geomorphological, geophysical and radiometric age data of Narayanpet area, northwest of Cuddappah basin, have clearly displayed the alignments and structures of geological significance, such as deep seated fault / fracture / shear zones, stratigraphic / lithological contacts, basic / ultrabasic intrusives and younger granites etc,. Based on the field observations such as emplacement of mafic dykes, their cross cutting relationship, study of morphological and geophysical signatures, inferred linears drawn from satellite imagery, aeromagnetic and gravity maps are arranged in a chronological order. A system of long, narrow and widely spaced dykes trending NW-SE direction conformable to gneissic foliation, typically associated with migmatites in the southwestern part of the study area are the oldest. Followed by E-W dykes, cut across by the sparsely distributed dykes associated with NW-SE and N-S features and in turn off set by dykes of NE-SW trends are the youngest. Kimberlites of Narayanpet area, belongs to hypabysal facies, which are essentially controlled by E-W to ENE-WSW deep seated fault / fracture zone, their intersection with NW-SE, NE-SW to N-S trends, which may have been reactivated during Proterozoic period as indicated by the intrusion of mafic dykes (∼2270 to 1701 Ma) and emplacement of kimberlitic magmatism (∼1300 to 1100 Ma) suggesting different intrusive episodes. Kimberlite pipes of Narayanpet field, falls in an ellipsoid form trending WNW-ESE direction in the northern part of the area, associated with radial drainage / topographic high and a gravity low. In addition, physical properties such as density and magnetic susceptibilities of mafic dykes and kimberlites, their geophysical signatures, emplacement of kimberlites at the close vicinity of mafic dykes or at their intersections have also been discussed.

Beschreibung: Present study examines the utility of gamma rays of energies 1.12 MeV and 1.76 MeV of uranium in estimation of uranium in airborne gamma ray spectrometric survey (AGRS) in comparison to the conventional 1.76 MeV alone used world wide. As a case study, the AGRS data of northern part of Cuddapah Basin is considered. Multi-channel processing is applied on this dataset to reduce the spectral noise and use of combined 1.12 MeV and 1.76 MeV has reduced the Poisson’s related statistical error. Uranium is estimated using above two energies individually and in combination, using multi-channel processing followed by standard corrections procedure. Result indicates that a combination of both energies has given best estimation due to a reduction in overall noise which helped in demarcating geological entities and litho-contacts. This indicates the efficacy of this technique which improved the radio-geochemistry of study area in understanding the radio-elemental variation.

Beschreibung: Landslide is one of the prominent geohazards in the Himalayas where loss of lives and property are common. Owing to the complicated geomorphic and tectono-stratigraphic setting of this active Fold-thrust belt (FTB), landsliding of all possible types and spatial scales observed exhibit conspicuous spatio-temporal signatures and evolution. This evolution of landslides is commonly studied by regional assessment and by examining the multi-temporal landslide inventories of a particular area. The success of creating such multi-temporal landslide inventory depends on (i) the availability of relevant past source data (e.g., images, post event maps, air photos etc.) of suitable resolution, scale and quality, (ii) time of generation of source data with respect to the time of landsliding event, (iii) skill of the investigators in interpreting the old images, air photos etc. However, this method is of restricted use in studying the spatio-temporal evolution of a single landslide which is perennially active in the Himalayan terrain, where rapid changes in land use and land cover patterns readily obliterate the signatures of past landsliding. Moreover because of scale constraints, subtle and frequent changes in the spatial dimensions of these individual landslides, and their temporal activity become difficult to identify in such regional assessment carried out over a larger area. In this study therefore, a different approach is adopted whereby the spatio-temporal activity and style of Lanta Khola landslide, a perennially active and large (0.25 km 2 ) debris flow in the Eastern Himalayas, has been studied in detail through detailed scale (1:1000) site-specific geological mapping in phases during the last 28 years (1983–2011). Such site-specific geological observations coupled with numerical slope stability analysis utilising the limit equilibrium method facilitate in detailed understanding of the temporal and spatial evolution and inherent mechanism of this perennial landslide.

Beschreibung: India has a rich and impressive heritage in the production and use of base and precious metals. The presence of extensive ancient mine workings and debris, enormous heaps of slags and retorts, ruins of temples and townships of the major mining centres of modern India, bear mute testimony to the art of exploitative and extractive processes in vogue in the early period. The Aravalli range, trending NE-SW, in northwest India, hosts about 80% of the known base metal deposits and 95% of the zinc-lead resources of India. The ancient workings extend to considerable depths, the deepest being at 250 m below surface, which is perhaps the greatest ever achieved by miners in the ancient world. Radiocarbon dating of the materials /artifacts recovered, indicated that many of the mines in Aravalli belt were worked as far back as 400 BC and certainly flourished in the medieval period. The exploitative and quite sophisticated extraction processes of base metals and silver, practiced by the ancients in various areas of this belt are described. Detailed literary evidences of finding different ores, exploitative and extraction techniques practiced by the ancients fromVedic to post-Vedic Sanskrit texts and the archaeo-metallurgical evidences are described. The investigations showed that there are no analogies in the world for smelting processes in general and zinc, in particular, practiced by the ancient metal workers, in this part of the world.

Beschreibung: This article presents the results of investigating triggered earthquakes in the vicinity of Tranh River No.2 Hydropower Reservoir in recent years. It is found that earthquakes occurred in the vicinity of Tranh River Hydropower Reservoir, probably associated with the Trà My — Trà BÓng fault zone. It is estimated that this fault is capable of hosting an earthquake of M~6.1. The ‘b’ value for this earthquake sequence is 0.83, which is higher than the regional ‘b’ value of 0.60. We estimate that the return period of earthquakes of M=4.5, 5.0, 5.5 and 6.0 is 11, 29, 76 and 198 months respectively. On October 22, 2012 an earthquake M S =4.6, I 0 =6.0 (MSK-64) occurred at 13:41:28 hrs GMT. The epicenter of the earthquake was located at a distance of 5.5 km away from the center of the dam towards the west. The focal depth is about 4.5 km, and the rupture length is about 1.8 km.

Beschreibung: The Vempalle Formation of the Proterozoic Cuddapah basin has a well developed sequence of carbonate rocks, which are interbedded with shales, siltstones and chert. The stromatolitic carbonates are conspicuous at many places but the oolitic carbonates are less prominent and are present only in some areas. All the carbonates are pervasively dolomitized. Petrographic examination of these carbonates revealed that they are predominantly made up of fine grained micrite with patchy development of sparite and chert/quartz. The stromatolitic carbonates show distinct banding of alternate carbonate and cherty layers. The latter are rich in organic matter indicating prevalence of profuse biogenic activity. The oolitic carbonates comprise of ooids showing both concentric and radial patterns and made up of carbonate/chert and cemented by micro/mega quartz or carbonate itself. Diagenetic and post depositional features are reflected in cementation, recrystallization, compaction, stylolite formation and silicification processes. Various stages of cementing material are observed. Secondary vein fillings of carbonate or quartz traverse the carbonate/cherty groundmass. Intraclasts present suggest occasional erosional destruction of associated sediments, short lived transport and local redeposition. Accessory silicate minerals represent terrigenous influx during deposition. Dolomitization of the carbonates was fabric retentive and early diagenetic. The environmental conditions were characterised by low energy, within a shallow water zone, in occasional higher energy events and turbulence. The carbonates appear to have been deposited on a shallow water ramp within a tidal regime.

Beschreibung: The late Miocene-early Pliocene fossil deposits of Hasnot in northern Pakistan have yielded a very rich vertebrate fauna. In this paper we describe the remains of Cervidae from six of these localities. By dental remains, at least four species of cervids are documented. These remains significantly widen the time distribution of the cervids and draw back the first appearance of cervids in the Dhok Pathan Formation of the Siwaliks. The data indicate a diverse set of coexisting ungulates in the area, subsisting within a mosaic of habitats.

Beschreibung: Determination of different facies in an underground reservoir with the aid of various applicable neural network methods can improve the reservoir modeling. Accordingly facies identification from well logs and cores data information is considered as the most prominent recent tasks of geological engineering. The aim of this study is to analyze and compare the five artificial neural networks (ANN) approaches with identification of various structures in a rock facies and evaluate their capability in contrast to the labor intensive conventional method. The selected networks considered are Backpropagation Neural Networks (BPNN), Radial Basis Function (RBF), Probabilistic Neural Networks (PNN), Competitive Learning (CL) and Learning Vector Quantizer (LVQ). All these methods have been applied in four wells of South Pars field, Iran. Data of three wells were employed for the networks training purpose and the fourth one was used to test and verify the trained network predictions. The results have demonstrated that all approaches have the ability of facies modeling with more than 65% of precision. According to the performed analysis, RBF, CL and LVQ methods could model the facies with the accuracy between 66 and 68 percent while PNN and BPNN techniques are capable of making predictions with more than 72% and 88.5% of precision, respectively. It can be concluded that the BPNN can generate most accurate results in comparison to the other type of networks but it is important to note that the other factors such as consuming the amount of time taken, simplicity and the less adjusted parameters as well as the acquired precisions should be considered. As a result, the model evaluation analysis used in this study can be useful for prospective surveys and cost benefit facies identification.

Beschreibung: Uranium mineralization in Madyalabodu area, Cuddapah district, Andhra Pradesh, is spatially related to chloritized and brecciated quartzite of the Gulcheru Formation in the immediate vicinity of E-W to ESE-WNW trending basic dyke. Chloritization transgresses the lithological boundaries. Whole-rock geochemical data indicate enrichment of MgO and Al 2 O 3 coupled with depletion of SiO 2 , Na 2 O, K 2 O, CaO and TiO 2 in the chlorite-rich zone. Fe 2 O 3 and FeO do not vary significantly in the altered and the unaltered zones. Electron Probe Microanalysis (EPMA) data reveal that the chlorites in contact with uranium minerals are enriched in MgO and depleted in FeO than in the others. Considering the petrological evidence, geochemical signature and structural constraints, it appears that chlorite acted more as an adsorbent rather than as a reductant in facilitating uranium mineralization. Uraninite crystallized later from the uranium originally adsorbed on chlorites. Chloritization might also have facilitated mineralization through the generation of nascent hydrogen, H 2 S and lowering pH of uranium-bearing solution.

Beschreibung: Fluoride (F − ) is essential for normal bone growth, but higher concentration in the drinking water causes health problems which are reported in many states of India. Andhra Pradesh is one of the states which suffer from excess fluoride in groundwater particularly in the hard rock terrain. In this context, a study was conducted in Andhra Pradesh based on chemical analysis of water samples from hydrograph net work stations (dug wells) and exploratory bore wells. The concentration of fluoride in groundwaters ranges from traces to 9.75 mg/l. The occurrence of fluoride is mostly sporadic, uneven and varies with depth. The highly affected districts include Nalgonda and Warangal in Telangana region, Prakasam in coastal region, Anantapur and Kurnool in Rayalaseema region. In certain areas of Nalgonda district, 85% of wells have fluoride more than permissible limit (〉 1.5 mg/l) for drinking water. High F − is present in all the geological formations, predominantly in granitic aquifers, compared to the other formations. The average value of fluoride is high in the deeper zone (1.10 mg/L), compared to the shallow zone (0.69 mg/L). The fluoride-rich minerals present are the main sources for fluoride concentrations in groundwater. Residence time, evapotranspiration and weathering processes are some of the other supplementary factors for high fluoride concentrations in groundwater. Long-term data of hydrograph net work stations (dug wells) reveal that fluoride concentrations do not show any marked change of trend with respect to time. The concentration of fluoride is found to increase with increase of Na + and HCO 3 − , and decrease with increase of Ca 2+ . Sodium bicarbonate waters are more effective in releasing fluoride from minerals into groundwater. High fluoride waters are of Na + type. The paper presents a brief account of the study and its results.

Beschreibung: A detailed hydrogeological investigations comprising well inventory, water level monitoring, lake bathymetry, infiltration and pump tests were carried out in a few selected observation wells in order to estimate transmissivity (T) and storativity (S) in all major lakes which are highly polluted by the discharge of sewage and other chemical effluents in greater Hyderabad. The salient features of results are presented lake wise which would be of immense use in restoration of all lakes. Also, the outcome of this study along with infiltration rates may be used for modeling in future to simulate the surface water-ground water interaction.

Beschreibung: Surface exploration techniques have been key contributors in discovering mineral deposits over the past three decades. However, in the last decade there has been a growing emphasis on integrating remote sensing, geological, geophysical and geochemical exploration techniques to compliment them in identifying concealed deposits. Successful integrated exploration requires putting mappable petrophysical property contrasts in terms of geological and geochemical process that could be associated with different mineralisation environment. The Precambrian Gangpur basin comprising volcanic free sedimentary sequence is considered as a potential geological setting for hosting uranium mineralisation. The Gangpur basin with metasediments of low to medium metamorphic grade classified as the Gangpur Group are known for hosting manganese, limestone and lead-zinc deposits. Uranium mineralization is reported in limonitic carbonaceous phyllite and sheared quartzite of Kumarmunda Formation at Jhamankele-Bhalulata areas. Several uranium anomalies have been associated with gossan at Kaedarpani, Jamdra and in ferruginised laterite at Badekachar, Jarmal, Jhagarpur, Kadorpani, Karamabahal, Tetelkela & Kumtinunda. In the present study geological, geophysical and remote sensing data sets are processed and integrated with other available data to delineate target zones for uranium exploration. Even though direct detection of uranium mineralisation remains unresolved in exploration strategy, instead it is becoming increasingly instructive to focus on mapping suitable depositional environments. The enhanced satellite imagery is interpreted in terms of thematic layers viz. trend lines, lineaments, faults and geological contacts. The aeromagnetic data is processed and interpreted thematic layers of magnetic breaks and linears from total magnetic intensity (TMI), the reduced to pole (RTP), tilt derivative and amplitude of analytical signal grid images. The radiometric data is processed based on their broad lithology and radio-elemental distribution maps viz. count maps, ratio maps, ternary (%K-eTh-eU) and eU/K − eU/eTh − eU images are generated to aid in mapping uranium favourability zones. The favourability image zones with high eU/K, eU/eTh and eU counts zones are classified into class based on statistics and anomalous high zones are picked up as uranium favourable locales. The thematic layers of geological contacts, lineaments and faults interpreted from satellite imagery, magnetic linears interpreted from aeromagnetic data and uranium favourability zone extracted from Airborne Gamma Ray Spectrometric (AGRS) data are overlaid. Based on spatial association of favourable features few locals are delineated for uranium exploration.

Beschreibung: An assemblage of structurally preserved organic-walled microfossils (OWMs) from the macerated residue of black carbonaceous shale belonging to Saradih Formation, the youngest carbonate horizon of the Raipur Group, Chhattisgarh Supergroup exposed at on the right bank of Mahanadi River, NE of Sarangarh township in Raigarh district, Chhattisgarh is being reported for the first time. The assemblage is comprised of 19 taxa of 13 genera belong to eukaryotes and prokaryotes viz. Leiosphaeridia, Stictosphaeridium, Dictyotidium, Synsphaeridium, Symplassosphaeridium, Satka, Trachysphaeridium, Goniosphaeridium, Trachyhystrichosphaera, Vandalosphaeridium, Siphonophycus, Oscillatoriopsis and Polythrichoides . The comprehensive account of recovered microbiotic assemblage can be correlated with globally known Neoproterozoic (early Cryogenian) assemblages, deposited in tidal complexes of shallow sea.

Beschreibung: The graphite-tungsten deposits under consideration in this study are located in the Burugubanda, Pydiputta, Tapasikonda, Marripalem and Madyaratigudem areas of the East Godavari district of Andhra Pradesh, India. These deposits were formed due to wide spread tectonothermal events associated with the evolution of Eastern Ghats Mobile Belt (EGMB). The graphite deposits of East Godavari district are epigenetic, rhombohedral fluid deposited type and are one of the four deposits of such type reported so far from Srilanka, Spain and England. The graphite deposits were formed due to granodioritic intrusion into the Narsipatnam shear zone, which caused migmatisation of khondalites along with mobilisation and concentration of graphite, as veins and lenses, into the graphite gneisses. The graphite gneisses were subsequently intruded by quartz rich pegmatites that were laden with tungsten mineralisation. The tungsten mineralisation occurs as thin bands, lenses, stringers and vein lets within the quartz matrix and also dispersed in the graphite gneisses. Inclusions of tungsten in graphite indicate that tungsten mineralisation succeeded graphite mineralisation. However, the low P-T phenomenon of tungsten (wolframite-ferberite) mineralisation resulted in low tenor of tungsten ore deposits (WO 3 : 0.10%). Rare earth elements (REE) are associated with tungsten mineralisation in these areas. During the present study, these graphite-tungsten deposits have been re-examined, in the backdrop of shelving graphite-tungsten projects in these areas. The feed for mineral beneficiation tests was decided on the basis of dispersion of tungsten in quartz and graphite rich fractions of the ore zone. The feed (ROM material) on beneficiation gave recovery of +75% graphite concentrate, tungsten concentrate of consistent chemical grade, besides recovery of sizeable REE concentrate. It also rendered use of unutilised graphite tailing dumps at beneficiation plants, thereby effecting conservation. Thus, the association of tungsten and REE with the entire graphite deposits along with their value addition during beneficiation, as by-product, revived opportunities to restart graphite mining in the Burugubanda, Pydiputta and Tapasikonda areas in particular and East Godavari district, in general, as an economically viable venture. This will initiate opening of graphite mines in other districts of Andhra Pradesh and energise economics of working graphite mines within EGMB, in the states of Jharkhand, Odisha and Tamil Nadu.

Beschreibung: Heavy mineral analysis of the late Paleozoic Barakar and Raniganj sandstones from the Singrauli Gondwana sub-basin shows relative abundance of garnet, epidote, zircon, tourmaline and muscovite in the Raniganj Sandstone and epidote, garnet, rutile and tourmaline in the Barakar sandstones. Stratigraphically, the heavy mineral crops donot exhibit marked variation in their relative abundance, though garnet, epidote and muscovite form the bulk of the heavy minerals. Significant interspecific association among heavy minerals and provenance of the Barakar and Raniganj sandstones are evaluated by using σ-M multivariate model. Quantitative result suggests that the Barakar Sandstone are characterized by the basic pair match significantly more than expected due to chance alone (p value 〈〈0.05) are garnet-tourmaline and epidote-rutile, whereas, the succeeding Raniganj sandstone are characterized by zircon-rutile and epidote-garnet. These basic pairs may be regarded as interspecific association among the heavy minerals. The basic pairs deduced from heavy mineral suites suggest that the source rocks of late Paleozoic Barakar and Raniganj sandstones have been principally derived from the acid plutonic rocks and low to high grade metasediments lying to the south and southeast of the Singrauli Gondwana sub-basin.

Beschreibung: Palaeoclimate and Palaeoecological study was carried out in ∼2 m sediment core deposited since 4 ka in an estuarine environment along Uppanar River mouth, Cauvery Delta. Palynological and thecamoebian evidences indicate (1) a basal fluvial lacustrine depositional environment (∼4–3 ka) characterized by sandy sediment, with low salinity and dominance of non-pollen forms like foraminiferal linings and thecamoebians with a low percentage of pollen and spores and (2) an estuarine environment (since 3 ka) characterized by clayey sediment with high salinity and a good percentage of mangrove and terrestrial pollen along with non-pollen forms. A shift in the depositional environment since ∼3 ka indicates monsoonal and geomorphological changes in the coastal wetland. During this period dominance of Avicennia and Cheno/Ams indicate low freshwater runoff from land suggesting a weakened monsoon condition enhanced by anthropogenic activity.

Beschreibung: In the salinity affected lower Atrai floodplain aquifer in the NW Bangladesh, geoelectric resistivity survey and hydrochemical analysis are carried out with an aim to identify fresh and saline groundwater zones; investigate the status of salinity; evaluate hydrochemical processes involved and suggest management approaches for irrigation. Here a two-fold aquifer system, inter-layered by silt, clay and silty-clay aquitard and aquiclude is classified as: upper aquifer — spatially affected by salinity of varying degrees; and lower aquifer — generally characterized by high salinity. The aquifer with resistivity values greater than 69 Ωm is safe for irrigation use. Concentrations of major ions vary as: Ca 2+ 〉Na + 〉Mg 2+ 〉K + and HCO 3 〉Cl〉NO 3 〉SO 4 2− . Groundwater is dominated by Na-Ca to Ca-Na, HCO 3 -Cl-SO 4 , Cl-SO 4 -HCO 3 and Cl-SO 4 2− facies where Ca 2+ , Mg 2+ , SO 4 2− , HCO 3 − , Cl − and NO 3 2− ion concentrations are statistically dominant and water is of Ca-Mg, HCO 3 -SO 4 -Cl and NO 3 types. Geochemically, groundwater is hard and saline to fresh water type. Salinity increases with depth, but spatially towards the southern part. Groundwater quality is a product of water-rock interaction, direct mixing and marine spraying, or fall-out of airborne marine salts, where silicate weathering is the primary source of bivalent cations. Sediment provenance of alkaline earth silicates and higher concentrations of alkalis are derived from sources other than precipitation. In general partially or fully salinity affected upper and lower aquifers in the area except in its eastern part are not suitable for tubewell irrigation. As groundwater demand for irrigation is increasing, the saline water has progressively invaded relatively fresher parts of the aquifer by upconning. So, special salinity control management approaches can be adopted through engineering techniques such as groundwater abstraction optimization, as also through scientific behavioral approaches like groundwater demand management, salt tolerant crops production. In this context, surface water conservation and rain water harvesting for domestic and irrigational uses are recommended in the salinity affected area.

Beschreibung: Hydrogeochemical studies have been carried out in a coastal region, using multivariate statistical model, for better understanding the controlling processes that influence the aquifer chemistry. Two principal components (PC1 and PC2) are extracted from the data set of chemical variables (pH, TDS, Ca 2+ , Mg 2+ , Na + , K + , HCO 3 − , Cl − , SO 4 2− , NO 3 − and F − ), which account for 79% of the total variation in the quality of groundwater. The PC1 (salinity controlled process) includes the concentrations of TDS, Mg 2+ , Na + , K + , Cl − , SO 4 2− and NO 3 − , while the PC2 (alkalinity controlled process) comprises the concentrations of pH, HCO 3 − and F − . The spatial distribution of PC scores identifies the locations of high salinity and alkalinity processes. The first process corresponds to the influences of geogenic, anthropogenic and marine sources, and the second one to the influence of water-soil-rock interaction. Thus, the present study shows the usefulness of multivariate statistical model as an effective means of interpretation of spatial controlling processes of groundwater chemistry.

Beschreibung: Crack-initiation stress of a rock under compression is the stress level that marks the initiation of the rock microfracturing process or in other words, the onset of new damage to the rock. This paper proposed a simple methodology with justifications to explore the feasibility of using total and effective porosities as estimators of crack-initiation stress of brittle crystalline rock materials under uniaxial compression. The validity/applicability of the proposed method was examined by an experimental study of granitic materials from Malanjkhand, Madhya Pradesh. It was found that effective porosity depicts better correlation with crack-initiation stress than with uniaxial compressive strength of the granitic materials. On the other hand, total porosity does not show any perceptible correlation with uniaxial compressive strength and crack-initiation stress. Plausible reasons for the nature of the obtained results were also explained in view of rock failure process under compression. It is concluded that following the proposed method, effective porosity can be used as a physical index to obtain a quick estimate of crack-initiation stress of the investigated rocks empirically.

Beschreibung: The aim of this study is to illustrate the soil conditions encountered at the proposed bridge sites to analyze and evaluate the test conducted, submit recommendations regarding foundation design. At first by field investigation, the required data was collected and after primary processing the acceptable data was selected. For nonlinear analysis of elastic and rigid half space bed rock, standard hyperbolic model was selected and performed, and the results were compared. The study clearly showed that the effect of bed rock on soil behavior during earthquake is one of the main factors controlling prediction of ground response. A critical aspect of this work was to develop and use a computer code “Abbas Converter” developed by the authors that has several advantages, such as quick installation, acting as a connecter function between the used softwares which can generate the input data corresponding to a defined format and finally, the results of this computer code can be easily exported to the other softwares used in this study. Moreover this code can make it easy to solve the problems encountered.

Beschreibung: The circular structure at Mohar (Dhala structure) in the western part of Bundelkhand Gneissic Complex, is marked by a prominent outlier of Kaimur sediments surrounded by low lying concentric sequence of sediments of Dhala Formation and basement granite breccia. This has been interpreted as a volcanic eruption related cauldron structure and meteoritic impact crater structure by various authors, on the basis of absence or presence of shock indicators in the clasts of a rhyolite-like rock that crops out scantily in the north western part of the structure. During the course of extensive sub-surface uranium exploration in this structure, the geoscientists of Atomic Minerals Directorate for Exploration and Research observed unequivocal and rampant evidences of shock metamorphic features for the first time in drill core samples of basement granitoids which constitute the bed rock for the rhyolite-like melt breccia, which overlies it. Published data of shock metamorphic features from this area are largely confined to the surface samples of the rhyolite-like melt rock, exposed in sparse outcrops. The shock metamorphic features recorded in the sub-surface granitoid bed rock samples during the present study, comprise planar deformation features (PDF) in quartz, feldspar, apatite and zircon, toasted, diaplectic, ladder-textured feldspars, selectively shock-melted feldspars and melt-veined quartz. The shock metamorphic features recorded in surface and sub-surface samples of the melt rock include ballen quartz, PDF in quartz clasts, toasted and diaplectic feldspar clasts shocked basic rock fragments with isotropised feldspars. Both the shocked bedrock granitoid and the melt rock bear uncharacteristic geochemical signatures with elevated K 2 O, MgO and depleted CaO. The study also observes that the melt breccia overlying the granitoid bedrock also occurs as pocket-like patches at various depths within the granitoids. Thus, the present findings have helped in understanding the attributes of the basement granitoid and associated melt breccia, thereby linking the genesis of the latter by selective melting of the former, due to the process of impact. It reinforces the already propounded theory of impact as the likely cause for the development of the structure in the basement Bundelkhand granitoid that was later filled by sediments standing out presently as a mesa.

Beschreibung: The Ganurgarh shale, a formation belonging to the Bhander Group of Vindhyan basin is investigated using field based detailed lithofacies and petrofacies analyses in order to interpret the depositional environment in a sequence stratigraphic context. Five major lithofacies have been recognized consisting of calcareous sandstones, laminated mudstones, rippled siltstones, red-grey shales and sandy limestones characterized by small to large-scale cross-bedding, ripple cross-lamination of wave and current origin, parallel lamination, low-angle horizontal bedding, flaser and lenticular bedding, mud-cracks, salt pseudomorphs, convolute bedding and load structures. The constituent lithofacies are recurring and grouped into three lithofacies associations where, the association A is composed of fining upwards and B with coarsening upwards cycles at the lower and middle levels of the succession respectively, are dominantly arenaceous whereas, the association C occurring at upper levels is fining upwards (FU) and becomes calcareous with meager representation of clastics. Petrographically, the section offers three main petrofacies viz., (a) sandstone- (b) siltstone- (c) sandy limestone-petrofacies. Lithofacies characters complimented with petrography show that deposition occurred within the shoreface (subtidal) to foreshore intertidal domain involving tidal flats with sub-environments ranging from intertidal to supratidal. However, lithofacies associations within the Ganurgarh shale of Maihar area represent a case of normal regression during sea level transgression. In the beginning, probably because of excessive sediment supply the sea level had a falling trend during an overall transgressive phase ultimately culminating into limestone sedimentation.

Beschreibung: Landslides are the most established geological hazards in the Siwalik and Murree strata of Jammu region. The prolonged rainfall in the area frequently trigger landslides and has become a common phenomenon in hilly areas of Jammu region due to over saturation of slope forming material and cause considerable damage to life and property. The landslide that occurred on the Katra-Qazigund railway track alongside of portal (P2) of tunnel-47 on 25 th September 2010 at village Dharam in Sangaldan area of Ramban district caused extensive damage to buildings. The water sensitive lithology (alteration of sandstone and mudstone beds) within the Murree thrust zone has made the area more vulnerable to landslides. Most of the landslides in the area are activated mainly during prolonged rainfall due to increase in pore water pressure as a result of seepage. The present paper is an attempt to study various geological factors along with physio-mechanical properties of slope forming materials to understand their role in failure mechanism.

Beschreibung: Dr. B.P. Radhakrishna in his Anthology of Editorials (Memois 51, 61 and 81) had covered wide range of topics such as Geoscience, Mineral Exploration & Exploitation, Mining Industry, Science, Impending Water Crisis in Bengaluru city, Climate and Monsoon, Natural Disasters, Extra-terrestrial Phenomena, outstanding contributions of some eminent persons and important subjects like rural employment, sanitation, environment and human waste disposal. On these subjects he had listed our failures with analysis of what went wrong. In the following pages I have tried to summarize and highlight with occasional comments on mineral exploration, resources, reserves, mining environment, economics of mining and on policy matters related to Acts and Rules published in JGSI .

Beschreibung: The shear controlled, epigenetic Cu-Au mineralization at Dhani Basri area in Dausa district of Rajasthan is hosted within silicified zones traversing Mangalwar complex of rocks, of Archaean age. The mineralisation here is distinctly associated with the hydrothermal alteration manifested in the form of phyllic, propyllic, potassic and silicification alteration domains. The field and microscopic evidences are in conformity with the geochemical variation in the parameters within the mineralized zone, in the hanging wall and footwall alteration zones. Besides using the conventional method of presentation of the alteration data, the author on an experimental basis has used Alteration Box plot (Large et al. 2001) and the Alteration Index (AI) (Ishikawa, 1969) to depict the hydrothermal alteration in the environment other than the volcanic hosted massive sulphide depositional environment, for which these ratios and diagrams have been recommended by Ishikawa (1969) and Large et al. (2001). In the present case the author has been able to demonstrate the alteration very effectively with the help of these ratios and indices and has observed that these could very well be utilized in the environments other than the one, for which these diagrams are prescribed. The different trends described by Large et al. (2001) in their alteration box plot very clearly discriminate between the hydrothermal trends and the diagenetic trends of alteration, hence even if there is slight contamination by the meteoric fluids in the environments other then the volcanic hosted massive sulphide that can be separated out in the diagram. The author in his effort has observed that using the Al can very well bring out the trends of various alteration types and CCPI (carbonate-chlorite-pyrite index) in combination with the alteration mineralogy. A case study of hydrothermal alteration at Dhani Basri copper gold mineralization has been presented here.

Beschreibung: Two new fossil woods resembling Eucalyptus L’ H’erit of the family Myrtaceae are described from the Palaeocene and Eocene successions of Gujarat and Rajasthan, respectively. They are characterized by diffuse-porous wood, heavily tylosed vessels arranged in echelon, vasicentic tracheids, simple perforations, thin rays and non septate fibres with bordered pits. Eucalyptus is considered native to Australia as most of its species are found there. The fossil records of Eucalyptus are hitherto known from the Cenozoic successions of Argentina, New Zealand, Australia and India. The genus is phytogeographically important as it has a wide range of distribution in the geologic past which suggests its long history affiliated with different Gondwanaland continents. A warm and humid coastal environment is inferred in western India during the Palaeogene on the basis of the earlier records of the genus.

Beschreibung: This research work is an attempt to confirm the sub-surface Jurassic sequence present in the Meyal field and to delineate promising location for test drilling. The Meyal field, one of the major oil and gas producing fields, lies in the active foreland and thrust belt in the Potwar basin of Pakistan. Petroleum play components of the Jurassic sequence encountered in the Meyal field were analyzed by seismic and well log data, acquired in this area. Based on lithological interpretation, Jurassic sequence was divided into upper and lower parts. Petrophysical interpretation including formation water resistivity, water saturation, hydrocarbon saturation, and permeability suggests presence of potential reservoir in lower sandstone part of the Jurassic sequence. Wells are drilled at the top of the pop-up structure which are indicated by the time and depth contour maps to obtain overall structure of the area.

Beschreibung: During a random radiometric survey, nuclear radiation was detected near exposed rocks in an open-pit phosphate-mine at Beldih (Purulia, W.B.), India. Radiometric analysis of rock samples reveals a significant concentration of uranium. Geological study suggests that Beldih phosphate mine lies near the South Purulia Shear Zone (SPSZ). Shear zones in the region are E-W striking elongated zone and associated with uranium mineralization (famous Singhbhum shear zone for several uranium mines). Electrical resistivity (profiling and sounding) and Very Low Frequency (VLF) electromagnetic surveys were performed around Beldih mine to delineate the suitable conducting zones which may be associated with uranium mineralization. Significant lateral extension of possible source is delineated; it could be exploited later on a large scale for commercial utilization. It is observed that gradient resistivity profiling (GRP) survey is the most suitable technique to explore the nearly vertical conducting structure. The GRP measurements were carried out at different locations. A good correlation of low resistive zones on various GRP was observed from the measured data. The study concludes that subsurface structures are nearly vertical and have alternate resistive and conducting bands. An inclined bore-hole drilled confirms the presence of alternate resistive and conducting structures and uranium mineralization is detected in conducting bands. This suggests that GRP can be conducted for precise location of the target zone. This will help in planning bore holes for drilling to find the exact thickness, lateral and vertical extent of the deposit for commercial utilization. VLF measurements were also carried out along various profiles. Even though VLF observation was quite noisy due to presence of power lines in the area; this method can be used to map the area and model the data for actual sub-surface conducting zones in less noisy areas as a support for drilling works.

Beschreibung: The Deccan basalts of Anantagiri hills near Vikarabad are characterized by the occurrence of a complete and continuous sequence of colonnade structures below the laterites. These structures have enabled division of flow units 2, 3, 4, 5, 6 from the bottom upwards, into three well defined zones — Lower Colonnade Zone (LCZ); Middle Entablature Zone (MEZ) and Upper Colonnade Zone (UCZ) underlying a 5–10 m thick laterite cover. These fine to medium grained basalts composed of plagioclase, clinopyroxene, ± olivine, Ti-magnetite, ilmenite, glass, cholorophaeite and zeolites commonly show intersertal, glomeroporphyritic and rare sub-ophitic and porphyritic textures. On the A-F-M ternary plot these basalts plot in the iron rich tholeiitic field. REE plots of these rocks define patterns with mild LREE enrichment and negative Eu anomaly. Their primitive mantle normalized multi-element patterns show mild positive LREE coupled with slight LILE depletion, positive Ba, Ta and Pb peaks. The TiO 2 /Yb vs Nb/Yb ratios in these tholeiites suggest a slightly enriched source with an MORB affinity. The major and trace element signatures of these tholeiitic basalts occurring at Anantagiri hills and the adjacent low lying areas in south-eastern Deccan Volcanic Province, have broad affinities with the basalts of Ambenali Formation with an overlap on basalts of Poladpur Formation, though with minor variations suggesting geochemical similarity with these two type area basalt formations.

Beschreibung: The marsh zones of Sunderban coast were examined for modern benthic marsh foraminiferal assemblages and correlated with the typical mangrove vegetation. A total of 14 genera of foraminifera and 8 genera of mangrove plants were recorded from the region. The assemblage is characterised by agglutinated and calcareous foraminifera. The high, middle and low marshes are identified on the basis of position of tides. The agglutinated foraminifera Trochammina inflata , Miliammina fusca and Haplophragmoides canarienses with mangroves species of Ceriops tagal , Phoeniz paludosa and Excoecaria agollacha characterize the high marsh zones and the calcareous foraminiferal assemblage comprising Ammonia beccarii , Haynesina germanica , Rosalina bradyi and Elphidium sp. with mangroves including Avicennia spp., Bruiera gymnomorrhiza , Aegialitis roundifolia and Sonneratia apetala indicates low marsh environments.

Beschreibung: Multi-parametric and systematic exploration for kimberlite search was made in the vicinity of the Kalyandurg area within the Closepet granite, Dharwar craton, south India involving Remote Sensing and Airborne Geophysical Surveys (100 and 200 m spacing; 60 m AGL), Stream Sediment Sampling as well as Electron Probe analysis of heavy indicator minerals. The bipolar aeromagnetic anomaly (pronounced by high-low pair) falls in the positive drainage catchment delineated by stream sediment sampling. Subsequent drilling by a private party over the suspected anomalous zone resulted in the discovery of kimberlite. This is being reported here as the KL-7 kimberlite of the Kalyandurg cluster. Petrographically, the kimberlite shows typical porphyritic texture with macrocrystal olivine grains (~ 500–4500 μm) set in a groundmass composed of abundant phlogopite, perovskite and microcrystal olivine and clinopyroxene. Xenocrystic chromite grains were also observed. Preliminary studies on the mineral chemistry indicates that the olivine grains are foresterite-rich (Fo = 88–92) with an average MgO wt. % of 49.61. Groundmass phlogopites are of kimberlitic affinity with high Mg# (Mg/Mg+Fe 2+ ) ranging between 0.88 and 0.91. The Cr-spinel macrocrysts with high Cr 2 O 3 (〉 62 wt. %) are considered to have formed from a primary garnet-peridotite-derived melt. The ilmenites have 8 to 12 wt % MgO and indicate kimberlitic affinity. Based on the current discovery, a suitable investigation strategy is also being suggested here for future kimberlite exploration in the area within the Closepet granite of the Dharwar craton, South India.

Beschreibung: The micro-morphological shell characters (both in optical microscope and SEM) have been used to discriminate in between oyster’s sub-families Pycnodonteinae Stenzel 1959, Exogyrinae Vyalov 1936, Ostreinae Refinesque 1815 and Lophinae Vyalov 1936. These sub-families are represented by six constituent genera Phygraea (Phygarea) vesicularis (Lamarck 1806), Hyotissa semiplana (Sowerby1813), Curvostrea rouvellei (Coquand 1862), Ceratostreon pliciferum (Dujardin 1837), Agerostrea ungulata (Schlotheim 1813) and Rastellum (Arctostrea) pectinatum (Lamarck 1810) in the late Cretaceous (Maastrichtian) sediments of the Ariyalur area of Tamil Nadu, south India. The optical microscopic observations and SEM studies of the shells of these six genera clearly indicate that all the four sub-families consist of distinctive set of shell-microstructures. Sub-family Pycnodonteinae is characterized by predominance of vesicular, exogyrinae by prismatic, Ostreinae by cross foliated and Lophinae by foliated shell microstructures. Besides their characteristic shell microstructures, some additional microstructures are also visible in the shells of some of the genera of these four sub-families.

Beschreibung: We present field and petrographic data on Mafic Magmatic Enclaves (MME), hybrid enclaves and synplutonic mafic dykes in the calc-alkaline granitoid plutons from the Dharwar craton to characterize coeval felsic and mafic magmas including interaction of mafic and felsic magmas. The composite host granitoids comprise of voluminous juvenile intrusive facies and minor anatectic facies. MME, hybrid enclaves and synplutonic mafic dykes are common but more abundant along the marginal zone of individual plutons. Circular to ellipsoidal MME are fine to medium grained with occasional chilled margins and frequently contain small alkali feldspar xenocrysts incorporated from host. Hybrid magmatic enclaves are intermediate in composition showing sharp to diffused contacts with adjoining host. Spectacular synplutonic mafic dykes commonly occur as fragmented dykes with necking and back veining. Similar magmatic textures of mafic rocks and their felsic host together with cuspate contacts, magmatic flow structures, mixing, mingling and hybridization suggest their coeval nature. Petrographic evidences such as disequilibrium assemblages, resorption, quartz ocelli, rapakivi-like texture and poikilitically enclosed alkali feldspar in amphibole and plagioclase suggest interaction, mixing/mingling of mafic and felsic magmas. Combined field and petrographic evidences reveal convection and divergent flow in the host magma chamber following the introduction of mafic magmas. Mixing occurs when mafic magma is introduced into host felsic magma before initiation of crystallization leading to formation of hybrid magma under the influence of convection. On the other hand when mafic magmas inject into host magma containing 30–40% crystals, the viscosities of the two magmas are sufficiently different to permit mixing but permit only mingling. Finally, if the mafic magmas are injected when felsic host was largely crystallized (~70% or more crystals), they fill early fractures and interact with the last residual liquids locally resulting in fragmented dykes. The latent heat associated with these mafic injections probably cause reversal of crystallization of adjoining host in magma chamber resulting in back veining in synplutonic mafic dykes. Our field data suggest that substantial volume of mafic magmas were injected into host magma chamber during different stages of crystallization. The origin of mafic magmas may be attributed to decompression melting of mantle associated with development of mantle scale fractures as a consequence of crystallization of voluminous felsic magmas in magma chambers at deep crustal levels.

Beschreibung: We report the occurrence of sillimanite in sapphirine-bearing granulites near Pedapalli town in the north eastern part of the Eastern Dharwar Craton (EDC). The sapphirine-bearing granulites of the Pedapalli area display evidence of metamorphic reactions involved in the formation of diverse mineral assemblages documented in different types of reaction textures. The common stable assemblage contains sapphirine-spinel-orthopyroxene-cordieriteplagioclage-corundum-sillimanite. The P-T evolution of these sapphirine granulites has been constrained by using the TWEEQU program. Temperature of formation of sapphirine-spinel assemblages is high, around 800 °C, and pressure ca. 8 kbar. The assemblage reported in this study has important bearing on the high-temperature metamorphism and exhumation history of the EDC.

Beschreibung: In order to understand the post-depositional history of carbonate rocks of Guri Member (Lower to Middle Miocene), three stratigraphic sections were selected in north Bandar-Abbas in southeast of Iran. Sampling was carried out, analyzed for selective parameters such as oxygen and carbon isotopic compositions (δ 18 O and δ 13 C) and interpreted in the present study. We recognized several diagenetic processes including micritization, cementation, neomorphism, compaction, dissolution, silicification, dolomitization, fracturing and vein filling. Some of the diagenetic processes occurred at different conditions, so in order to achieve precise interpretation, samples from different carbonate components such as, micrite, fracture cement, solution pore cement, intergranular cement, and some biotic allochems were analyzed. In this study micrite samples were subdivided into two groups including micro-spary and micrite. They were recognized under Cathodoluminescence microscope. In addition, micrite samples were classified into five groups based on their depositional environments: supratidal, lagoon, coral bar, open sea, and open basin. There were minor changes in stable isotope ratios based on the sedimentary environments, stratigraphy successions, and micro-spary or micrite properties. In this study, similar calcite cements in petrography studies were differentiated by stable isotope data. Those calcite cements have formed in different diagenetic environments such as meteoric and burial cements. Paragenetic sequence of carbonate rocks were interpreted by integration of petrographic and isotopic studies. We have reconstructed diagenetic models of Guri Member into four stages including marine, meteoric, burial, and uplifting.

Beschreibung: Arsenic sometimes found in ground water which has adverse effect on human health at levels as low as 10μg/L. Arsenic is known to be one of the most toxic element that cannot be destroyed once it has entered to the environment. It is a dangerous poison at high doses but can cure diseases such as syphilis and leukaemia at low doses. The present study comprises a low cost technique for determination of arsenic concentration in groundwater up to 1000μg/L. The method is based on the reaction of arsenic (V) with potassium iodide and stannous chloride in concentrated hydrochloric acid medium to convert to arsenic (III) and needs 15 to 20 minutes time for complete conversion. After reaction with the granulated zinc (arsenic free), the evolved arsine gas is passed through wet cotton wool of lead acetate for absorbing any sulphide impurities and is finally absorbed by wet filter paper of silver nitrate which gives brown colour. The intensity of the colour varies with respect to the arsenic concentration present in ground water. A master colour chart is prepared by the known arsenic standard solution from 0 to 1000 μg/L for measuring the concentration range of arsenic in contaminated ground water. The quantitative arsenic determination is done with the help of colorimetric study. The absorbed colour of filter paper is thoroughly scanned and Red, Green and Blue (R-G-B) values are obtained by colour picking technique with the help of the software ‘Microsoft Paint’ under the operating system ‘Microsoft Windows 7’. The known arsenic concentrations are plotted against the R-G-B values of the corresponding absorbed colour and three master curves are drawn by the software ‘Mat lab’ for measuring the exact concentration of arsenic in groundwater. For validation, arsenic contamination test is conducted for the ground water samples collected from different areas of 24 Parganas district using our very low cost kit and other costly instruments like Digital Arsenator and Atomic Absorption Spectrometer.

Beschreibung: Landslide susceptibility zonation mapping assists researchers greatly to understand the spatial distribution of slope failure probability in a region. Being extremely useful in reducing landslide hazards, such maps could simply be produced using both qualitative and quantitative methods. In the present study, a multivariate statistical method called ‘logistic regression’ was used to assess landslide susceptibility in Hashtchin region, situated in west of Alborz Mountainsnorthwest of Iran. In this study, two independent variables, categorical (predictor) and continuous, were drawn on together in the model. To identify the region’s landslides use was made of aerial photographs, field studies and topographic maps. To prepare the database of factors affecting the region’s landslides and to determine landslide zones, geographic information system (GIS) was used. Using such information, landslide susceptibility modeling was accomplished. The data related to factors causing landslides were extracted as independent variables in each cell (in 50 m×50 m cells). Then, the whole data were input into the SPSS, Version 18. The prepared database was later analyzed using logistic regression, the forward stepwise method and based on maximum likelihood estimation. Regression equation was determined using obtained constants and coefficients and the landslide susceptibility of the area in grid-cells (pixels) was computed between 0 and 0.9954. The Receiver Operating Characteristic (ROC) curve was used to assess the accuracy of the logistic regression model. The predicting ability of the model was 84.1% given the area under ROC curve. Finally, the degree of success of landslide susceptibility zonation mapping was estimated to be 79%.

Beschreibung: Radon is a naturally occurring colourless and odourless radioactive gas that is soluble in water and is the main source of radioactivity of groundwater. Use of radon contaminated groundwater increased the radon levels in the air, especially in poorly ventilated houses, which is hazardous to health. Ingestion of such water for quite long period may lead to stomach cancer. The drinking water standards proposed by the Bureau of Indian Standards (BIS) exclude the permissible concentration of radon in drinking water. The US Environmental Protection Agency (USEPA) in 1991 proposed a Maximum Concentration Level (MCL) of 11.1 Bq/l for public water supply. The water samples from the bore wells in Tumkur district of Karnataka show radon concentrations in the range of 5 to 250 Bq/l. Ninety percentages of the samples show radon levels above the permissible limit as per USEPA. The spatial variation and geological control over radon concentration in groundwater in the area and sampling sensitivity are discussed here. The study was conducted during March 2012.

Beschreibung: While constraining Cenozoic evolution of the Himalaya through enlightening fossils we find that Dharmsala Group (intervening Subathu Group and Siwalik Group) in Kangra Valley and adjoining coevals yield sporadic fossils. Hence, this first record of fossil rodents from Dharmsala Group is an important addition to an earlier report of dinothere from these horizons. The rodent material from grey facies of the Dharmsala Group comprises of an isolated premolar and fragments of a tooth and an incisor. Available crown details in conjunction with distinctive dimensions of the premolar lead to its assignment to Hodsahibia , a baluchimyine taxon; this taxon of Eocene lineage of south Asian-African distribution is already on record from early Oligocene horizons in Bugti area, Pakistan.

Beschreibung: The present paper records for the first time the bryozoan fragments from 4 m core of the Godhra Formation (early Miocene) and from 4m core and 5 m core of the Chhasra Formation (early middle Miocene) of the Kachchh Offshore Basin, Western India. The Godhra Formation has presence of three bryozoans, viz., ? Crassimarginatella sp., Thalamoporella sp. and Vincularia sp. while the Chhasra Formation has presence of four bryozoans, namely, ? Margaretta sp., Steginoporella sp., ? Thalamoporella sp. and Vincularia sp.