bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geochemistry of Carbonate Precipitation from the Ground Waters in Basaltic Aquifers: An Equilibrium Thermodynamic Approach
Authors: Pawar N. J. 
Published: November 2024

Abstract
The geochemistry of ground waters in the basaltic aquifers is considerably modified by the incongruent dissolution of augite and plagioclase from basalts. The analyses of the water chemistry data by using the WATSPEC aqueous-model computer programme for computing the ionic species abundances, the partial pressures of CO2 (PCO2) and mineral Saturation Indices (SIc and SId) suggest. that the ground waters are supersaturated with respect to calcite and dolomite. The modeling has indicated a state of equilibrium with respect to dolomite first followed by calcite. This state of equilibrium can be linked with the selective dissolution of augite leading to Mg-rich alkaline environment. which is also favourable for the formation of montmorillonite clays. The clays in turn act as a buffer and as a result the levels of Ca and Na do not exceed 1.8 mmol/L concentration. Due to the early dolomite saturation the Ca/Mg ratios areless than unity, whereas Na/Ca ratios are above unity suggesting precipitation of calcite and possibility of input from zeolites and mixing of difierent sources of water with local ground water.
The precipitation of calcite is under high PCO2 conditions related to degassing and diffusion of CO2 at the water-table and along cracks, joints and fissures in the basalts. The high PCO2, dissolved oxygen content, presence of contaminants and fluctuations in the water table suggest that the ground water has chemically evolved under open system conditions.
Stochastic Modelling of Lead - Zinc Deposit at Rampura Agucha, Rajasthan
Authors: Sahu B. K. , Bagchi J. 
Published: November 2024

Abstract
The irregularly spaced assay values of lead and zinc in different boreholes of Rampura-Agucha Pb-Zn deposit (Rajasthan), have been interpolated at equal intervals of one meter using cubic splines to obtain a constant lag, discrete spatial (time) series. The time series has been used subsequently for stochastic modelling of assay values along the drill holes. Univariate stationary models under the integrated autoregressive moving average scheme - ARIMA (p,d,q) - were established for each assay series along four borehole based on statistical analyses of their auto (acl-) and their partial (pacf) correlation functions. These models can be used for univariate forecasting of assay values at different distances. Among the candidate ARlMA (p,d,q) models, ARLMA (1,1,1)and ARIMA (1,1,0) were found to fit spatial distributions of Zn and Pb, respectiveIy, using the principle of parsimony.
Though linear stochastic models were developed for Rampura - Agucha Pb-Zn deposit, a brief review of the scope and use of non-linear stochastic model for modelling of complex ore mineralisation has also been attempted.
Geochemical interpretation has been carried out on the petrochemical data of the amphibolites interlayered with the footwall and the hanging wall rocks using partial correlation coefficients between various oxides. This has led to comprehensive characterisation of the geochemistry and mineralogy of the amphibolites.
Uranium Mineralization in the Siwaliks of Northwestern Himalaya, India
Authors: Kaul Ravi , Umamaheswar K. , Chandrasekaran S. , Deshmukh R. D. , Swarnkar B. M. 
Published: November 2024

Abstract
The Siwalik Group constituting about 6000m of fluvial sedimentary rocks of Middle Miocene to Pleistocene age has been under exploration for uranium over the last two decades using different techniques including exploratory drilling, mining. More than 350 uranium occurrences forming eight major clusters between Poonch (Jammu, Kashmir) in the west and Tanakpur (Uttar Pradesh) in the east have been identified. A majority of these occurrences are confined to three distinct stratigraphic horizons: (1) lower part of Upper Siwaliks corresponding to the upper part of Garchandi energy sequence; (2) upper part of Middle Siwaliks (the middle part of Garchandi energy sequence); and (3) upper part of Lower Siwaliks (Jwalamukhi energy sequence).
Uranium mineralization occurs as small peneconcordant lensoid bodies with the longer dimension of individual lenses traceable from a few tens of metres to 700m, sub-parallel to strike or dip. The average grade of different occurrences in Siwaliks varies from 0.02-0.06% U3O8 and thickness less than a metre to 4m. Uraninite, pitchblende, coffinite, and a variety of secondary uranium minerals including tyuyamunite, uranophane, bayleyite, andersonite, schoepite, liebigite, swarlzite, and schroeckingerite have been identified. Azurite and malachite are also associated in some of the uranium occurrences in Lower Siwaliks. The sedimentological, geochrmical, and tectonic attributes of the Siwaliks indicate a sedimentary uranium province.
Uranium mineralization in Siwaliks is attributed to concentration of intrinsic uranium in the sediments derived from fertile Himalayan provenance and subsequent remobilisation by groundwater. Enrichment of uranium is controlled by sedimentary and lithological characteristics such as porosity-permeability barriers and abundance of reductants such as organic carbon, pyrite, and anaerobic bacteria. A secondary control by faults has also been observed at some places. Relatively higher concentrations of Se, Mo, Cu, Co, V, and Au have been noted in some of the uraniferous zones.
Neogene-Quaternary Sequence in Gujarat: A Review
Authors: Merh S. S. 
Published: November 2024

Abstract
The constituent rocks of Neogene are conglomerates, grits, silty sandstones, marls and argillaceous limestones. Marine Quaternaries are represented by the miliolite rocks of Saurashtra (Middle Pleistocene) and younger Holocene Rann sediments, mudflats and beach rocks. The transition of Neogene to Quaternary is not fully understood. Perhaps regressive conditions prevailed during the close of Pliocene and in the early Pleistocene. Evidences point to a bw strandline during the Lower Pleistocene. The Quaternary period is marked by two major transgressions-one in Ihe Middle Pleistocene and the other at the advent of Holocene. The Middle Pleistocene transgression gave rise to the miliolites, whereas the Holocene marine deposits are related to the last post glacial transgression.
The Neogene-Quaternary sequence requires further examination, particularly the so-called Pliocene, Plio-Pleistocene and Lower Pleistocene rocks. As the N-Q sea levels were related to climatic changes, a close scrutiny of the onshore continental record just above the marine Neogene rocks might provide some information towards fixing the nature of transition of Neogene to Quaternary. It would be essential to apply alternative criteria such as palaecmagnetic and therrnoluminiscence measurements and radicmetric age determinations for obtaining a clearer picture.
Status of Hydrocarbon Exploration in Western Offshore Basins, India
Authors: Mathur R. B. 
Published: November 2024

Abstract
Following the discovery of Bombay High field in 1974 by OiZ & Natural Gas Commission about 60 oil and gas strikes have been made including a couple of giant fields.
Western offshore comprises five contiguous sedimentary basins all of which are under active exploration. Hydrocarbon resources of 9.5 billion tonnes have been prognosticated in the area upto 200 m isobath, off the west coast of India. About 35% of these have already been established and sufficient scope exists for the continued thrust on exploration.
Two owned survey vessels capable of carrying out state of the art geophysical surveys coupled with inhouse computer facilities and expertise have dispensed with foreign dependence on seismic data acquisition, processing and interpretation faced in the seventies. Advanced techniques of 3-D surveys and evaluation of reservoir parameters from seismic have alteady found place for subtle exploration and exploitation needs.
Today Western offshore is the most active drilling area of the country. Ten offshore rigs owned by ONGC and 18 charter hired rigs are operating. About 250 km per year of exploratory and development drilling is being carried out currently which is likely toincrease 11/2 fold during the Eighth Five Year plan.
Starting from a meagre 0.4 MMT per annum the current production rate of over 20 MMT has been achieved from Western Offshore which-accounts for about 65% of the country's oil from indigenous sources.
Conglomerate Horizons in South-Central Rajasthan and their Significance on Proterozoic Stratigraphy and Tectonics of the Aravalli and Delhi Fold Belts
Authors: Sinha-Roy S. , Mohanty M. , Malhotra G. , Sharma V. P. , Joshi D. W. 
Published: November 2024

Abstract
The Proterozoic sequences of South-Central Rajasthan are contained in the Lower to Middle Proterozoic Aravalli and Middle to Upper Proterozoic Delhi fold belts. The stratigraphic relations within these fold belts as well as the basement-cover relations are beset with several problems. The conglomerate horizons have been studied to address some of these problems. Based on the conglomerate horizons, representing erosional unconformities, the Aravalli Supergroup has been sub-divided into three groups and the Delhi Supergroup of the South Delhi fold belt into two groups with constituent formations. These horizons are also useful in identifying three stages of basin evolution for the Aravalli fold belt. The Middle Aravalli Conglomerate is the most prominent representing mid-Aravalli hiatus, and corresponding to the Debari Transgressive Stage which followed the Delwara Rifting Stage in the Lower Aravalli in a system of ensialic distensional tectonics where triple-junctions and pull-apart basins are formed. The Upper Aravalli has been the Jharol Ocean Opening Stage, the oceanic/transitional crust having been consumed at a median ultramafic suture line during the formation of the Aravalli fold belt. The South Delhi fold belt has also multi-stage development history with the Barr Conglomerate representing the base of the youngest Delhi sequence.
Geophysical Methods for Subsurface Geological Mapping in Bethunmi-Dariba-Bhopalsagar Belt of Rajasthan-A Case Study
Authors: Gopal Ram , Agarwal R. N. 
Published: November 2024

Abstract
Geophysical Surveys employing, magnetic, self-potential and resistivity methods in Bethunmi-Bhopalsagar belt in Rajasthan have proved to be effective in identifying and mapping the various litho-units largely concealed under soil cover. An important discovery in the area was a striking closure of a local structure to the south of Dariba by magnetic suryeys. The disappearance of the graphitic mica schist and amphibolite to the south of Dariba may be explained by the structural closure brought out by these surveys rather than by faulting as invoked from geological evidences.
Sedimentary Structures in the Archean Sediments of Gadag Schist Belt, Karnataka
Authors: Chkrabarti C. , Reddy U. S. , Natarman W. K. 
Published: November 2024

Abstract
Gadag schist belt consists of more than 2000 m thick pile of sediments, least metamorphosed, and with abundant well preserved sedimentary sturctures, The principal types of structures are discussed and an attempt has been made to interpret the environment of deposition. Sedimentary structures and the lithotectonic sedimentary assemblage broadly indicate an unstable environment of deposition under geosynclinal conditon.
Application of Hornblende Fabric in Fold Analysis
Authors: Prasannakumar V. , Nair P. K. R. 
Published: November 2024

Abstract
The optic direction Y in hornblende in the lower amphibolite facies rocks of the southern part of the Chitradurga schist belt is parallel to the hinge lines of the earliest folds. Hornblende orientation and the temporal relations between crystallisation, folding and formation of foliation point to ENE- WSW compression at the time of deformation.
Siwalik Mammalian Faunas from Ramnagar (J. & K.) and Nurpur (H.P.) and Lower Limit of Hipparion
Authors: Nanda A. C. , Sehgal R. K. 
Published: November 2024

Abstract
Recent collections of mammalian fossils from the Siwalik sediments of Ramnagar (J.& K.) and Nurpur (Kangra, H. P.) indicate the presence of Chinji Fauna in the red bed sequence exposed in the vicinity of Ramnagar, but in Nurpur despite the dominance of the red clays which are usually considered as characteristic for the Lower Siwalik Subgroup, the fauna indicates an age equivalent to the Middle Siwalik. The mammalian fossils collected by the earlier workers are reinterpreted and the fossils, which include Propotamochoerus hysudricus. Merycopolamus dissimilis and Bramatherium megacephalumminus, are found to be indicative of Middle Siwalik age rather than the Lower Siwalik or the Lower-Middle Siwalik transitional age as was considered earlier. Hipparion (includes Hipparion and Cormohipparion) has been recorded by all the workers in Nurpur and now its arrival in India is considered at about 10m.y. The 12.5 m.y. dispersal event of hipparion in the Old World is found missing in the Siwalik Group. Though hipparion has been recorded from the so-called Lower Siwalik sequence of Kalagarh, U. P. but so far it is not recorded from the type section of Chinji in Potwar and in Dang Valley, Nepal. In the present collection, the presence of hipparion along with Dicoryphochocrus vinayaki, Hydaspifherium megacephalum, etc. from Nurpur is indicative of the Middle Siwalik age for the Nurpur Local Fauna. It is inferred that the red clays considered characterisitic of the Lower Siwalik are time transgressive and even the fauna colIected by earlier workers from Haritalyangar (Himachal) and Kalagarh (U.P.) is (at least a part of it) of Middle Siwalik age.
Ramnagar Fauna, recently collected by the authors, is true Chinji Fauna and is characterised by the presence of Dicoryphochoerus haydeni, Conohyus chinjiensis, Anthracotherium punjabiense, Dorcabune anthracotherioides, Hemimeryx pusillus, Giraffa priscilla etc. In Ramnagar area the Lower Siwalik Subgroup and the underlying Murree Formation have a conformable contact and fauna collected at the base of the Lower Siwalik Subgroup is found to be of Chinji age. So there are all possibilities that upper part of the Murree Formation may be of Kamlial age (i.e., lower part of the Lower Siwalik).
Taxonomy and Intraspecific Variation of Macrocephalites Formosus (Sowerby) from the Jurassic Chari Formation, Kutch, Western India
Authors: Bhaumik Debasish , Datta Kalyanbrata , Jana Sudipta Kumar , Bardhan Subhendu 
Published: November 2024

Abstract
Macrocephalites Zittel, 1884, an important genus in Kutch biostratigraphy, shows considerable diversity at species level. Macrocephalites formosus (Sowerby) is one species which shows a wide range of variability of different morphological characters. A detailed statistical analysis of the principal biocharacters of 140 individuals collected from different localities of Kutch was made to assess quantitatively the range of variation of the species. "Macrocephalites chariensis (Waagen)", which was previously designated as a separate species, is demonstrated here to be a variant of Macrocephalites formosus and is incorporated into the latter species. An attempt is made to delineate the generic characters of Macrocephaliles and describe the diagnostic characters of the species M. formosus in detail. The variability of the species has no obvious adaptive significance.
India and Ur
Authors: Rogers John J.W. 
Published: November 2024

Abstract
Estimates of stabilization ages of the world's Precambrian cratons reveal a pattern in which all blocks stabilized at ages = 3.0 Ga occur in one area of the end- Paleozoic supercontinent Pangea. These blocks center around India, where at least two cratons (Western Dharwar and Singhbhum) show evidence of crustal growth terminating at or before ~3.0 Ga. This concentration of =3.0-Ga blocks is regarded as an Archean supercontinent referred to as "Ur."
Some Contributions to the Stratigraphy of the Yerrapalli Formation, Pranhita-Godavari Valley, Deccan, India
Authors: Dasgupta Kasturi 
Published: November 2024

Abstract
The mappability, distinctive lithology and fossil content of the Yerrapalli Formation of the Pranhita-Gcrdavari valley, Deccan, India show that it is a vatid lithostraligraphic unit of the rank of Formation. The vertebrate fossils give all early Middle Triassic age. The Gondwanas of Pranhita- Godavari valley provide one of the most complete Triassic Gondwana sequence in India as well as in the world. The importance of the Middle Triassic continental deposits of the valley in stratigraphic correlation is also discussed.
Geochemistry of Archaean Arenites Formed by Anoxic Exogenic Processes-An Example from Bababudan Schist Belt, India
Authors: Arora M. , Naqvi S. M. 
Published: November 2024

Abstract
Sandy matrix of QPC of Archaean Bababudan schist belt is distinguished, by the abundance of well rounded detrital pyrite, uraninite, chromite, zircon, rutile and micas, and clasts of fuchsite quartzite. Presence of detrital pyrite and uraninite in mature arenites deposited during the initial stage of shallow stable basin, indicate the anoxic nature of ambient atmosphere. Compositional characteristics such as the abundance of Al2O3, K2O, MgO, Cr, Ni, Co, Zr, V, Sc, Rb, Sr and ?REE reveal that only restites could survive intense chemical weathering and strong hydrodynamic action. High to moderately fractionated REE patterns (LaN/LuN-10) with essentially negative Eu anomalies of the matrix of QPC, typically resemble the Archaean arenitic and pelitic rocks. These characlcristics of the QPC indicate removal of mafic-ultramafic and other unstable constituents of provenance to the deeper part of the basin. Silicic and other resistive part of provenance were deposited on the margin of the basin. Geochemical parameters of these rocks show that initial anoxic stage was changed to rhythmically oxidizing environment, in which very thick oxide facies of BIF got precipitated. Stable tectonic condition was changed to active margin setting, in which immature Kaldurga polymictic conglomerate (KCM) with greywacke matrix was deposited. Available data on various rock types of the Bababudan basin, demonstrate that the composition of atmosphere changes in tectonic setting and depositional environment resulted in the deposition of sediments of divergent type in the basin at various stratigraphic levels.
Petrography and Geochemistry of the Pipe-7 Kimberlite, Anantapur District, Andhra Pradesh, India
Authors: Mallikharjuna Rao J. , Nirmal Charan S. 
Published: November 2024

Abstract
The diamond-rich Pipe-7 kimberlite found about l0km east of Lattavaram in Anantapur district, Andhra Pradesh in south India is an elongated dyke - like body, that extends over a length of 450 m and has a maximum width of 25 m. It is porphyritic in texture and contains sub-angular to rounded xenoliths of peridotite, garnet-clinopyroxene rocks, websterite, amphibolite, metabasic rocks and granite. Petrographic studies reveal that it is porphyritic in texture and contains euhedral to sub-hedral altered olivine. phlogopite, garnet, clinopyroxene (chrome diopside), chromite, perovskite and ilmenite which are the uneqvivocal primary liquitlus phases whereas serpentine, chlorite, phlogopite, calcite, amphibole, magetite, monticellite, clay minerals and others represent secondary alteration assemblages. Chrome-diopsides and garnets represent an important megacryst suite.
The Pipe-7 kimbeerlite has higher CaO and lower MgO, Al2O3, K2O and iron contents compared to rhe other six known kimberlites in the vicinity. Fe/Mg ratio in coexisting garnets and clinopyroxenes, indicates the equilibration temperature for (a) the nodules to be 1040 - 1070°C and for (b) the megacrysts of garnet and clinapyroxene to be 1350°C respectively.
Pyrope garnets from titis kimberlite show a positive correlation between CaO and Cr2O3 and are similar in nature to those of the low calcium garnets reported from the diamondiferousSouth African kimberlites.
Strain Transition and Microstructural-Fabric Analysis of Qaurtz-Mylonites Exposed within Pratapnagar Nappe Garhwal Himalaya, India
Authors: Bhatt S. C. , Saklani P. S. 
Published: November 2024

Abstract
The Pratapnagar Thrust sheet in the Lesser Garhwal Himalaya consists of massive, white mylonitized Pratapnagar Quartzite and is delineated at its base by the Pratapnagar Thrust which brings this rock group to rest over the parautochthonous Argillocalc-arenite Group.
The estimated three-dimensional finite strain (¯Ss) in the specimens located close to the Pratapnagar Thrust was 0.937 while away from the thrust it was 0.412. The quartzite exposed within the mylonitized zone of Pratapnagar Thrust underwent non-coaxial (= simple shear) deformation revealed by asymmetrical (unpopulated) C-axes girdles and rotation of mylonitic foliation (S3), lineation (Lm) and C-axes girdles, The variable orientation of C-axes girdles, mylonitic foliation, lineation and microstructural shear indicators (asymmetrical porphyroclasts and pressure shadows) noticed within the rock exposed along the thrust zone indicate sinistral (-ve) sense of shear movement (NE-SW) with respect to N. The quartzite away from the thrust were initialy subjected to coaxial (= pure shear) deformation as is indicated by scattered globular and tabular host quartz grains and symmetrical cross and small circle girdle patterns of C-axes. The microstructural transition and asymmetrical orientation of C-axes fabrics indicate that the mylonitized Pratapnagar Quartzite was formed by deformation under ductile flow and low grade metamorphic conditions.
Desert Quaternary Formations and their Morphostratigraphy: Implications for the Evolutionary History of the Thar
Authors: Dhir R. P. , Rajaguru S. N. , Singhvi A. K. 
Published: November 2024

Abstract
Morphogenetic manifestations and stratigraphy of the Quaternary alluvial and aeolian formations of the desertic tract of Rajasthan have been described. The stratigraphy is based on a study of deep sections (-15 m) from different locations. Additionally, well-logs have been used to prepare the isopach maps of these formations. It is inferred that during the major part of the Pleistocene, the region witnessed widespread alluvial sedimentation. Though the region was well-watered then, the presence of large masses of lime coupled with negligible in-situ weathering suggests, that over-all the environment must have been predominantly semi-arid. Presence of nodular and lithic calcrete bands suggests an episodic character of this sedimentation. The form and distribution of surficial calcretes (including polycyclic lime nodules) suggest several cycles of calcrete formation.
Thermoluminescence dating of aeolian sands sampled from 28 to 65 metre depths suggest that the antiquity of the aeolian dynamism extends to atleast 100 ka B.P. The period from c.25 to 50 ka B.P. consistently shows the presence of wetter interludes with weaker aeolian dynamism, a fluvial redistribution of sediments and formation of nodular calcretes and gypcretes. The last major aeolian activity peaked at LGM in the Sahara, the Australian and the Kalahari deserts. However, the evidence on Thar suggests a peak in aeolian activity post-dating the LGM.