bluuebunny/crossref_metadata_2025_split huggingface dataset:
'Pseudo-Charnockites' from the Greenstone Terrain of Northeast Dharwar Craton
Authors: Ramakrishnan M. , Santosh M. , Reddy N. S. 
Published: November 2024

Abstract
Patches and oriented zones of 'pseudo-charnockites', similar in appearance to incipient charnockites from the granulite transition zones, are reported for the first time from the pink granites of Gadwal and Kurnool areas in the low-grade metamorphic terrain of northeast Dharwar craton. With a mineral assemblage of quartz, feldspars, micas and amphiboles showing varying degrees of alteration to chlorite and sericite, these zones preserve the signature of hydration following peak metamorphism. Though aqueous brine inclusions (average 6 wt % NaCl equivalent) constitute the dominant fluid phase in the granite and the retrograde zones, the occurrence of coexisting monophase inclusions with a near-pure carbonic fluid (density 0.70-0.80g/cm3) in the retrograde zones invoke special attention. Though carbonic inclusions generally typify dehydration reactions, it is suggested that retrograde reactions of the type which produced the pseudo-charnockite horizons could also result in the entrapment of nearpure CO2 of moderate to low densities. The carbonic inclusions have apparently resulted from the immiscible separation of a mixed carbonic-aqueous fluid which exsolved into brine and CO2 upon decompression following the rapid uplift of the Eastern Block along the Chitradurga boundary fault, concomitant with the copious intrusion of younger granitoids.
P - Wave Velocity Characteristics in Coal Measure Rocks of Eastern India Coalfields
Authors: Ramachandran C. , Ramachandran Nair M. , Datta S. 
Published: November 2024

Abstract
The P-wave velocities and their relation to depth of burial, density, porosity and electrical resistivity are studied for the coal measure rocks of Ranigunj and Jharia coalfields. From studies on the P-wave velocities in the dry and fluid saturated states, it is observed that the effect of fluid saturation is significantly more in a direction perpendicular to the bedding plane, than in the direction parallel to the bedding plane. The effect of fluid saturation is maximum in coarse-grained sandstones with low P-wave velocities. The anisotropy factor (Vp/? Vp), decreased after fluid saturation. The absorption-anisotropy relation for sandstones is found to depend on grain-size distribution as well as fluid saturation conditions. The results show that saturating conditions, direction of measurement and anisotropy assume importance in the interpretation of velocity data.
Gold Mineralisation in Uti Block of Hutti-Maski Supracrustal Belt, Karnataka
Authors: Biswas S. K. 
Published: November 2024

Abstract
Gold mineralisation, hosted by varied lithounits, is broadly classified into two types. 1) Syngenetic stratabound type, 2) Epigenetic lode type
Syngenetic stratabound type mineralisation, confined to pyritiferous carbonaceous schist, has little economic significance, whereas economic deposits belong to epigenetic type. Epigenetic lode type mineralisation is hosted by both mafic and felsic rocks. Mineralised zones are confined to structural dilatant zones (shear zones) and are characterised by wall-rock alteration. Mineralogical and geochemical changes are most conspicuous.
Geochemistry and Petrogenesis of the Malani Igneous Suite, North Peninsular India
Authors: Nelson Eby G. , Kochhar Naresh 
Published: November 2024

Abstract
Major and trace element data have been obtained for the ca. 730 Ma granites of the Siwana and Jalor complexes, Rajasthan and the Tosham complex, Haryana. On the basis of geologic, geochronologic and chemical data these granites are classified as anorogenic, and are believed to have been formed during a wide-spread thermal event centered around 800 Ma. All of the complexes show evidence of differentiation at high levels through fractionation of alkali feldspar, plagioclase, and amphibole. The granite from the Siwana complex is peralkaline and Shows high rare-earth (REE) contents with little fractionation between LREE and HREE. This granite may have been derived as a high temperature melt from an anhydrous granulitic source region from which a previous melt had been extracted or by melting of a metasomatized lower crustal source. The Jalor quartz syenites and granites are more primitive, metaluminous and have more fractionated REE patterns. These rocks are most likely differentiates of a mantle-derived magma. The Tosham granites are metaluminous to peraluminous and show isotopic and chemical characteristics typical of magmas derived from a high-grade metasedimentary source, These observations indicate that a variety of granite types can be formed during a period of anorogenic magmatism.
Earth Observing System (EOS)
Authors: Suresh R. 
Published: November 2024

Abstract
The Earth Observing System (EOS) is the centerpiece of a comprehensive global change research program planned by the National Aeronautics and Space Administration (NASA) in the late 90s. As a part of this program, NASA is launching two series of polar platforms EOS A beginning 1997, and EOS B in 1999. The objective of this program is to make synergistic measurements of key environmental parameters of the Earth from a variety of sensors over a period of 15-25 years in order to understand and predict environmental changes.
Structures and their Succession in Peritidal Storm Microsequences: Rewa Formation, Bhainsrorgarh, Rajasthan, India
Authors: Chaudhuri Amit K. 
Published: November 2024

Abstract
Many of the storm microsequences start with a shale-pebble-conglomerate that grades upwards into sands with parallel lamination followed successively by hummocky cross-stratification, another set of parallel lamination and wave ripple crosslamination. Swarms of flute-and groove-casts are often present at the sole of the stormlaid units. The sequence of structures indicates gradual waning of tbe flows. The outcome of the analysis reveals that the order of vertical arrangement of structural elements in storm-laid microsequences is closely similar to those on the shelves. Nevertheless, the association of emergence features or features indicating late stage emergence run-off are distinctive for deposition in shallow water bodies like lakes and lagoons.
Porosity Types and Evolution in the Early Eocene Carbonate Rocks of Qatar
Authors: El-sayed Abdel-moktader A. 
Published: November 2024

Abstract
Sample-porosity of core samples of limestone for the Fahaihil section (Western part of Qatar peninsula) and refered to Early Eocene in age varies, widely from 3.0 to 30%. Different types of secondary porosity have been distinguished. The recognized types of secondary porosity which formed by dissolution and leaching of grains, cement, or pore fillings have economic significance.
Petrogenesis and the Mantle Source Characteristics of the Abor Volcanic Rocks, Eastern Himalayas
Authors: Bhat M. I. , Ahmad T. 
Published: November 2024

Abstract
The Late Palaeozoic Abor Volcanics of the eastern Himalayas have typical continental tholeiite chemistry in terms of rather high and variable Fe/Mg ratios and incompatible trace elements, except P, abundances. The compatible trace elements (Ni, Cr, Co) are low for their specific MgO levels. Variable abundances of incompatible elements at constant Mg numbers, lack of significant Eu anomalies and large range in the ratios of more incompatible to less incompatible elements (e.g. La/Yb) suggest that fractionation was not significant in their compositional evolution. Fe-Mg relations indicate that the melts were generated from a mantle source with enriched Fe/Mg ratio compared to pyrolitic mantle; melting was followed by separation of an immiscible sulphide phase which resulted in lowering of Ni and P contents, and some clinopyroxene fractionation. Model calculations on REE data suggest that the source was enriched by about l1x and 4x chondrite in light REE (La) and heavy REE (Yb) respectively. This enrichment of the source was probably due to an undersaturated silicate melt and a CO2-rich fluid phase.
Kinematic Framework of Heterogeneous Deformation Within Pratapnagar Thrust Sheet, Bhagirathi Valley, in Lesser Garhwal Himalaya. U.P.
Authors: Bhatt S. C. , Saklani P. S. 
Published: November 2024

Abstract
The Pratapnagar quartzite constituting Pratapnagar thrust sheet was subjected to strain analysis Assuming the foliation (S1) in the quartzite as XY plane for strain estimation. sections parallel to XY, XZ and YZ of the quartzite exposed at the base of the Pratapnagar thrust sheet and away from It were prepared The specimens of the quartzite belong to the proximity of the Pratapnagar thrust sheet and witnessed increasing trend of flattening as indicated by two dimensional strain ratio (Rs) The three dimensional finite strain Was higher in intensity (Es = 0676 to 0937) and is marked by oblate type of ellipsoid (k).
In contrast to this, the quartzite located away from the thrust was subjected to progressive plane and constrictional type of strain and the shape of the ellipsoid Was prolate This indicates that away from the thrust the strain was variable but it acquired unidirectional trend with greater amount of intensity giving rise to extreme flattening parallel to Z. The stretching of the quartz grams was maximum along X, more or less, comciding with the NESW trending thrust transport direction.
Stratigraphy of the Late Proterozoic Rewa Group and Palaeogeography of the Vindhyan Basin in Central India During Rewa Sedimentation
Authors: Chakraborty Tapan , Chaudhuri Asru K. 
Published: November 2024

Abstract
The Rewa Group of the Son Valley has been reclassified into five formations, i.e., Panna Shale, Asan Sandstone, Jhiri Shale, Drammondganj Sandstone and Govindgarh Sandstone in the ascending order. While two basal formations are developed only in the central and eastern part of the northern outcrop belt, the upper three are much more extensive than the underlying formations. Drammondganj Sandstone and Govindgarh Sandstone are newly defined formations, and the two constitute the 'Upper Rewa Sandstone' of earlier classifications. The scarp section at Drammondganj is the type area of the former, while the latter has its type area on the northern slope of the hills south of Govindgarh.
Analysis of palaeocurrent in Drammondganj Sandstone, trend of thickness variation as well as of the regional stratigraphic relations collectively point to a northeasterly slope of the marine Rewa basin. The basin was replaced by a westerly sloping fluvial basin during the late phase of Rewa sedimentation.
Unusual Concentric Structures in Komatiite of Kibbanahalli Arm of Chitradurga Supracrustal Belt near Banasandra, Karnataka
Authors: Srikantia S. V. , Rao M. S. 
Published: November 2024

Abstract
The occurrence of unusual concentric structures in a serpentinite band of the Banasandra Komatiite Complex of the Kibbanahalli arm, Chitradurga Supracrustal belt is recorded. These structures, along with spinifex textured and pillowed serpentinite appear to be flow-related.
Crustal Velocity Model in the Eastern Part of the Indian Peninsular Shield
Authors: Tewari H. C. , Rao V. K. 
Published: November 2024

Abstract
The velocity analysis of the first arrival refraction data, along the two deep seismic sounding profiles in the eastern part of the Indian Peninsular shield has yielded a zone of high velocity at 3 to 15km depth within the limits of the Eastern Ghat Mobile Belt towards east of the Cuddapah basin. The analysis also indicates that the crustmantle boundary in the eastern part of the Indian shield is highly disturbed due to the intrusion from the upper mantle through the lower crust and, therefore, can be termed as transitional.
Graphical Solution to the Discharge-Drawdown Relationship in Rectangular Confined Aquifers in Steady State Flow
Authors: Mohapatra P. C. , Anjaneyulu B. 
Published: November 2024

Abstract
Establishing discharge-drawdown relationship for steady state flow in limited confined aquifers by established methods is difficult. A graphical solution for establishing this relationship in rectangular aquifers, with well at the centre and at least a portion of the boundary with constant potentials, is proposed. The method has been worked out from studies of finite element method which can beextended to any shape of the aquifer and eccentric positioning of the wells in the aquifer. Results obtained from FEM have been varified by field studies.
Petrography and Geochemistry of the Sandstones of Murree Group Around Laren, Udhampur, Jammu Himalaya
Authors: Singh B. P. , Fotedar B. K. , Rao A. S. 
Published: November 2024

Abstract
The importance of the sandstones of Murree Group is becoming more and more due to the possibilities of occurrence of hydrocarbons. It is evident from the petrographic and geochemical studies that these sandstones are of sublitharenite type. Probably low to medium grade metamorphic, intermediate to acid igneous and preexisting sedimentary rocks were sources for these rocks. A cratonic near-shore depositional environment is suggested for these sediments. The palaeoclimatic conditions were mild as indicated by their mineralogy.
Permo-Triassic Fossils from the Tandi Group of Lahaul Himalaya, Himachal Pradesh: Their Stratigraphic and Palaeogeographic Significance
Authors: Prashra K. C. , Raj Des 
Published: November 2024

Abstract
The reported fossil assemblage, when integrated together with earlier known fossils, indicates an age range of Permian to middle Jurassic for the Tandi Group. The deposition of the Tandi Group over the Precambrian rocks represents a major Permian (Djulfian) transgression in the area from Kashmir-Bhallesh-Charnba region, whereafter deposition in the area continued till Jurassic.
Petrology of the Nepheline Syenites from Santuri Purulia District, West Bengal
Authors: Bhaumik Tandra , Mukherjee S. , Basu Abhijit 
Published: November 2024

Abstract
A nepheline syenite pluton is reported from the area around Santuri, Purulia District. Microcline, phenocrystic mesoperthite, sodic oligoclase and nepheline are the predominant minerals. Biotite, barkevikite, apatite and calcite are the common accessory minerals. Nine rock samples have been chemically analysed. The nepheline syenites are miaskitic. Available data suggest a magmatic origin. The alkaline melt was emplaced latetectonically along fissures developed during the last stage of deformation. The alkaline rocks of the present area exhibit a striking resemblance to many of the nepheline syenites occurring along the Eastern Ghats.
Nishikhal Manganese Deposit, Koraput District, Orissa
Authors: Acharya B. C. , Rao D. S. , Sahoo R. K. 
Published: November 2024

Abstract
Manganese ores of Nishikhal occur as distinctly conformable bands in the khondalite suite of rocks. Presence of phosphorus, iron and silica beyond desirable limit in most of the ores makes them unsuitable for industrial purposes. The dominant ore minerals are psilornelane, cryptomelane, pyrolusite and goethite. These ores are formed by supergene enrichment of primary syngenetic metamorphosed assemblages. Phosphorus is present as a discrete mineral phase in the form of apatite contained in the silicate minerals, as well as fixed in the crystal structure of goethite, cryptomelane and psilomelane. Physical beneficiation may be employed to remove the silicate minerals which will ultimately reduce a part of phosphorus. Removal of iron by this method may be difficult because of the fine grain-size and complex intergrowth with goethite.
Quantitative Hydrocarbon Resource Assessment of Krishna-Godavari Basin, India
Authors: Sikka S. N. 
Published: November 2024

Abstract
The paper deals with estimation of hydrocarbon resources of the basin. Krishna-Godavari basin occupies the southern part of east coast of India adjoining the Bay of Bengal. The basin has an area of about 45,000 sq km.
The hydrocarbon resources of the basin are assessed considering play analysis and probabilistic model. The plays identified are of Cretaceous, Early Tertiary and Late Tertiary based on geological analysis of the basin. Discovery probability for each of the plays is estimated separately by risk analysis.
Results of resource estimation indicate hydrocarbon resources for the basin as 257 MMt at 90% probability: 726 MMt as the mean value; 1347MMt at 10% probability and 2158 MMt at 5% probability.
Conditional pool size distribution curves-indicate range of individual pool size from 3.00 to 28 MMt, with mean pool size of 6.50 MMt for Late Tertiary play. In case of Early 'Tertiary play, the individual pool sizes may range from 5.00 to 32.00 MMt with an average pool size of about 10.00 MMt. For the Cretaceous play, pool sizes range from 3.00 to 24.00 MMt with an average pool size of 5.00 MMt.
Intensity of Pollution of Groundwater in Visakhapatnam Area, Andhra Pradesh, India
Authors: Subba Rao N. , Krishna Rao G. 
Published: November 2024

Abstract
Hydrogeochemical study indicates that the intensity of pollution of groundwater was not so alarming up to 1975 in Visakhapatnarn area, but after that it rapidly increased due to sweeping growth of industrial and urban activities and lack of environmental protection.
Seismic Stratigraphic Modelling of Subsurface Godavari Limestone of Godavari Delta Region and Its Importance in Oil Exploration
Authors: Dewan P. K. 
Published: November 2024

Abstract
A particular limestone named Godavari Limestone is encountered in Godavari delta region of Early Eocene age. This limestone has been mapped and used as a marker horizon in seismic stratigraphic studies of the area because of its high acoustic impedance contrast with the surrounding clastics. The limestone has been interpreted to be of the platform type deposHed in a shallow marine shelf environment. Shelf edge has also been mapped which can consist of good petroliferous deposits of carbonate buildups.
Mechanism Solution of Nepal-Bihar Eartbquake of August 20, 1988
Authors: Banghar A. R. 
Published: November 2024

Abstract
This paper presents the focal mechanism solution of the Nepal Bihar earthquake of August 20, 1988. Use was made of the first motions of P waves and polarization (or first motions) of S waves. The mechanism solution is characterized by a predominent component of strike-slip faulting. The deduced orientation of the axis of compression is nearly north south. This orientation of the axis of compression is in agreement with the axis of compression deduced from the mechanism studies for Himalayan earthquakes.
Nongchram Fault: A Major Dislocation Zone from Western Megbalaya
Authors: Golani P. R. 
Published: November 2024

Abstract
A zone of fault breccia. gouge, silicification and rare mylonite reveals the presence of a 20 km long north-south trending tensional fault in the granitoid-gneiss terrain of Western Meghalaya. Emplacement of alkaline magmatic rocks including carbonatite, in the form of thin dykes along the fault and associated fractures in the vicinity, indicate deep seated nature of the dislocation. Changes in the drainage pattern in recent past and high microseismicity along the fault zone provide evidences of recent reactivation.
Thermodynamics and Oxygen-Sulpbur Fugacity Variations of Mosaboni Sulphide Mineralisation, Singhbhum, Bibar
Authors: Nayak B. K. , Panchapakesan V. 
Published: November 2024

Abstract
The thermodynamical calculations for the oxygen and sulphur fugacities of Mosaboni mineralisation have been made based on the equilibrium reactions for various mineralogical associations like, (a) bornite-pyrite-chalcopyrite. (b) pyrite-pyrrhotite. (c) pyrite-magnetite, (d) pyrrhotite-magnetite and (e) pyrite-pyrrhotite-magnetite and the temperatures determined by fluid inclusion studies. The association of pyrite-pyrrhotite-magnetite indicates that oxygen fugacity was 10-24.3 atmosphere at 450°C and this got reduced to 10-32.5 atmosphere at 300°C. Presence of bornite in place of magnetite shows that there was fluctuation in the fugacity of sulphur. This might be varying from 10-6.3 to -1.6 atmosphere at 450°C and from 10-11.6 to 10-6.4 atmosphere at 300°C.
Framboidal-Colloform-Recrystallized Pyrite in Volcanic Tuffs of Barsu an Valley, Orissa
Authors: Mohapatra B. K. , Paul A. K. , Sahoo R. K. 
Published: November 2024

Abstract
Petrographic studies of pyritiferous tuff forming a part of Precambrian lron-Ore Volcanics of Bausuan valley, Sundergarh district, Orissa, reveal interesting textural peculiarities of pyrite. The three textural varieties: framboidal, colloform banded and recrystallized appear both in composite association and as independent units in highly carbonatized tuff. In composite association, the frarnboidal variety constitutes more or less the central part of the globules of colloform banded pyrite (gel pyrite) which in turn is enveloped at the periphery by discontinuous crusts of recrystallized variety. Different intermediate textures of pyrite are described and variations in reflectivity, microhardness, etch behaviour and elemental distribution visMaavis the varieties have been discussed. Average Co/Ni ratio along with the textural manifestations of the pyrite attests its sedimentary origin. Different stages of process of formation of textural varieties are also briefly outlined.
A Diffuse Reflectance Study of Synthetic Acanthite, Stibnite and Bournonite
Authors: Mishra B. , Pruseth K. L. , Sarkar S. 
Published: November 2024

Abstract
Acanthite (Ag2S), Stibnite (Sb2S3) and Boumonite (CuPbSbS3) were synthesized by the evacuated silica tube method under dry conditions. Boumonite was synthesized both from its elemental composition and from the component sulfides. All the products were characterized by the optical and XRD methods and were found to be pure, homogeneous and direct semiconductors.
Diffuse reflectance studies were undertaken on these synthetic mineral phases. The forbidden energy gap (Eg) was calculated by a2 vs. h? plots and linear extrapolation to a2 = zero. Eg was also deduced by calculating the Kubelka - Munk remission function, and plotting it against the photon energy. The Eg values obtained were: acanthite 0.98, 1.0 eV; stibnite 1.50, 1.55 eV and boumonite 1.15, 1.23 eV. Possible industrial application of these syntheti~ semiconducting mineral phases are discussed.
Cuddapah Basin Configuration - Another Account Based on Gravity and Aeromagnetics
Authors: Ramakrishna T. S. 
Published: November 2024

Abstract
The gravity and aeromagnetic maps of the Cuddapah basin present some very interesting results that may help in understanding the configuration of the basin better and also plan exploration strategies. Based on the gravity field along 79"E longitude, the Nallamalai sub-basin can be divided into three minor basins separated by two ridges along Obalam-Vanipenta and Racherla-Nandikotkur axis, besides the Palnad basin at the northeastern end which also might be underlain by Nallamalais.
The aeromagnetic picture divides the basin and adjoining crystallines on the east into two domains roughly along a line joining Srisailam and Srikalshasti. To the east of this magnetic divide, the dense high frequency contours inside the basin, like those on the outside, suggest a shallow basement for the Nallamalais. To the west of it, it is the low frequency E-W regional trends that dominate. The corresponding magnetic profile (along 79°E) brings out a major E-W regional magnetic high with a width of about 10km at its peak; along Pedda Ahobilam-Panem axis. While this high falls off regionally both towards south and north, the northern fall is interrupted by two low closures, one west of Racherla and the other corresponding to the Srisailam basin. The Macherla-Agnigundala gravity ridge and the associated dipolar magnetic anomaly could be due to sources responsible for mineralisation near Agnigundala and as such the entire ridge trending NW-SE needs a closer geological scrutiny.