bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ooids in the Trikuta Limestones of Jammu, J & K State, India
Authors: Chadha S. K. 
Published: November 2024

Abstract
The ooids and peloids show diverse morphological characters, and diverse nature of their nuclei and rims. The growth, shape and size of ooids depend upon the method of sorting, formative environments and degree of sphericity they attain during rolling. The compound ooids, on the contrary, are the product of a complex method of aggregation, cementation, reworking of the grains, recementation, and finally their packing under a common envelope. The ooid bearing rocks appear to have been formed in ephemeral lagoons or playas under fluctuating conditions of formative environments with fairly high values of pH, Eh, CO3 ionic concentration and a widely ranging hydrodynamic energy conditions of the basin.
Early Miocene Planktonic Foraminiferal and Radiolarian Zonation, Colebrook Island, Andaman Sea
Authors: Srinivasan M. S. , Lombari Gail , Dave Alok 
Published: November 2024

Abstract
This contribution is the first of the series of investigations on integrated radiolarian and planktonic foraminiferal biostratigraphy of the Andaman-Nicobar region. Fifty species of radiolaria and thirty-one species of planktonic foraminifera have been recorded from the Early Miocene sequence exposed at Piu Bay, Colebrook Island, Andaman Sea (Northern Indian Ocean). The planktonic foraminiferal assemblage is referable to the Upper Catapsydrax dissimilis Zone and Lower Catapsydrax stainforthi Zone representing the interval from the Upper Andamanian to Lower Jarawaian Stages (Lower Archipelago Series). The radiolarian assemblage is referable to the Stichocorys wolffii Zone which corresponds with Paleomagnetic Epoch 18 with an estimated age of 18.5 to 19.5 Ma. Comparison of radiolarian and planktonic foraminiferal assemblage in the Piu Bay section with Deep Sea Drilling Project data indicate an Early Miocene age of 18.5 to 19.5 Ma.
Studies of Depositional Environment of Therria Sandstone in the Sheelveta Area, Karbi Anglong District, Assam
Authors: Kataki T. 
Published: November 2024

Abstract
The Therria Sandstone of Eocene age includes sandstones, shale, carbonaceous shale, coal seam and clay. Petrographically Therria Sandstone is mainly a micaceous quartizite, whose constituents were derived from an igneous terrain. A slight admixture of clastic material transported from low rank metamorphic and older sedimentary rocks is found. The provenance area was not far from the depositional site. Environmental interpretation based on bivariate grain size parameter plottings is not an effective tool since conflicting results are obtained. The deposition took place mainly by tractive current possibly in fluvial channel, The clastic materials were cemented by calcite, iron and silica of which calcite dominates over the others.
Efficacy of Some Chemical Extractions in the Recognition of True and False Anomalies in Geochemical Exploration
Authors: Ramanamurthy M. V. 
Published: November 2024

Abstract
Various chemical extraction techniques are being employed in exploration geochemistry to identify true and false nature of soil anomalies. The efficacy of hydroxylamine hydrochloride, sodium dithonite and ammonium acetate selective extractions have been evaluated through model experiments on a series of Pb, Zn, Mn and Fe near pure mineral forms. The results obtained suggest that these extractions are not as specific as claimed in literature. Due to its complexing tendency, ammonium acetate extractant cannot be employed to extract ion-exchangeable trace metals either in the selective or sequential extractions. Selective and differential chemical quantities arc useful in designing an interpretative methodology for recognising true and false anomalies. Selective chemical quantities of Zn have provided greater insight into the distribution characteristics. Computation of background, anomalous and highly anomalous components has been accomplished from the Zn selective quantities, which are usable directly in exploration. Evaluation of this nature can assist in taking a decision. whether to carry out detailed exploration or not. Hence practicing of such an approach is strongly recommended.
The Position of Indian Tin Occurrences in the Tin-Belts of Gondwana
Authors: Schuiling R. D. 
Published: November 2024

Abstract
Tin deposits and occurrences show an inhomogeneous distribution in elongate belts on all the continents. When the continents are fitted together in pre-drift position, these belts form a coherent pattern. The delineation of tin-belts in Gondwana is difficult due to the inaccessibility of Antarctica and to the fact that most continents belonging to Gondwana seem to have a relatively deep average level of erosion. This may have caused the removal of pre-existing tin-deposits to a large extent. Still it appears that most of the Indian tin occurrences including the recently discovered tin province of Bastar, M.P., fall on a continuation of the tin-belt in Western Australia. The association of cassiterite with Nb-Ta minerals and with Li-minerals is a characteristic of most of the eastern Indian occurrences as well as of most of the Western Australian deposits.
Clay Mineralogy of the Siwalik Group of Simla Hills, Northwestern Himalaya
Authors: Chaudhri R. S. , Gill G. T. S. 
Published: November 2024

Abstract
Clay mineralogy of the Siwalik Group of Simla Hills was worked out by X-ray diffraction technique. The mineral assemblage comprises kaolinite, illite, chlorite, vermiculite, montmorillonite and mixed-layers. The source rocks bearing feldspars, micas and ferrornagnesian minerals suffered chemical decomposition and mechanical fragmentation in temperate climate. The sediments were deposited in rapidly subsiding fresh-water basins. Terrestrial and (or diagenetic origin has been assigned to the various clay minerals.
Comparative Petrology of Pedogenic Carbonates from Quaternary Deposits of Kashmir and Rajasthan
Authors: Sharma Rajiv , Tandon S. K. 
Published: November 2024

Abstract
The purpose of this study is to compare pedogenic carbonates which have accumulated in varying climatic conditions in Quaternary deposits of North India. The pedogenic horizons sampled for the purpose are from the dunal/interdunal tract of parts of Rajasthan and from the Upper Karewa sub-Group of Kashmir valley. These pedogenic carbonates reveal an overall preponderance of micrite in both the situations. Similarity in the form of presence of voids and floating textures is also observed. The pedogenic carbonates of the Upper Karewa SUb-Group show a greater degree of corrosion and replacement indicating a more reactive microchemical environment. The presence of ferroan calcite in the pedogenic carbonates of Kashmir and its absence in those of Rajasthan further bears out the reducing character of the palaeoenvironment of the carbonate layer underlying the loess in the Kashmir valley.
Mineral Chemistry and P-T Conditions of Formation of A Basic Scapolite-Garnet-Pyroxene Granulite from Doddakanya, Mysore District
Authors: Devaraju T. C. , Coolen J. J. M. M. M. 
Published: November 2024

Abstract
Electron microprobe analyses of coexisting phases in a basic scapolite-garnet-hornblende-two-pyroxene granulite from a Sargur supracrustal enclave near Doddakanya are presented. The results of various mineral geothermometers and geobarometers indicate temperature and pressure conditions of 810±20°C and 9.5 ± 0.5 kbar during metamorphic reequilibration. A comparison with other data from granulites of southern India shows that granulite-facies metamorphism of relatively high pressure is a common feature of the granulite region of the Archaean shield.
Petrochemistry and Tectonic Significance of the Peralimala Alkali Granite, Cannanore District, Kerala
Authors: Nair N. G. K. , Santosh M. 
Published: November 2024

Abstract
The E-W elongated pluton of Peralimala, Cannanore district, Kerala, which is classified here as an alkali granite, occurs along the Bavali lineament, spatially associated with the late Proterozoic anorthosite-gabbro-granite-granophyre suite of the Ezhimala Igneous Complex. Perthitic K-feldspar, plagioclase of albite-oligoclase composition, quartz alkali amphibole, aegirine and sphene constitute the main mineralogy of the alkali granite. Chemically, the rock shows high content of alkalies with K2O values ranging up to 10.96 wt. percent. The extremely high levels of K, AI, Ba and Ba/Sr suggest the existence of a phlogopite-rich pocket in the mantle beneath the Bavali lineament from where the melt equilibrated. As peralkaline plutonism is a keynote of pre-rift tectonics, the occurrence of the alkali granite along the Bavali lineament is a manifestation of rift-related alkaline magmatism in this part of the western continental margin of India.
Structure and Metamorphic Characteristics of Cordierite-Bearing Gneiss of South Kerala
Authors: Sinha-Roy S. , Mathai John , Narayanaswamy  
Published: November 2024

Abstract
Cordierite-bearing gneiss of the Quilon district, Kerala, occurs in a 8-10km wide zone within quartzo-feldspathic gneiss, being bordered on the north by a charnockite massif. These gneisses are deformed and are polymetamorphic in character. The cordierite-forming metamorphism is the second in metamorphic chronology. The reaction producing the bulk of cordierite was: biotite + sillimanite + quartz ? cordierite + garnet + K-fetdspar + H2O. The KD (Mg-Fe) values of coexisting garnet-cordierite and garnet-biotite pairs indicate that the PT conditions of metamorphism (~ 7 kb, ~ 720°C) were those of granulite facies. Under these conditions cordierite was produced from Fe-Mg enriched melt restite, being trapped at the fringe of the charnockite massif.
Heavy Mineral Zones in the Fluvial Environment - Ghaggar River, Haryana
Authors: Chaudhri R. S. , Gill G. T. S. 
Published: November 2024

Abstract
The heavy mineral assemblage of modern sediments of the Ghaggar River comprises such nonopaque minerals like zircon, tourmaline, rutile, garnet, epidote, chloritoid/chlorite, biotite, staurolite, kyanite and sillimanite. Opaque minerals include ilmenite, magnetite, hematite and limonite. Percentage frequency of the various minerals in channel, levee and flood-plain microenvironments has been worked out. It is concluded that the distribution and size of the minerals are functions of the physical conditions prevailing in the microenvironments and the heavy mineral assemblage can safely be used to decipher the provenance and evironments of sedimentation of older deposits.
A Computer Based Factor Model to Elucidate Secondary Trace-Element Distribution Patterns around the Sargipalli Lead-Zinc Sulphide Deposit, Sundergarh District, Orissa (India)
Authors: Roy A. 
Published: November 2024

Abstract
The paper examines the results of computer based factor analysis performed on multi-element data from detailed soil geochemical survey over the lead-zinc mine at Sargipalli. Eleven elements (Pb. Cu, Zn, Ni, Co, So, Zr, Ag, Sr, Bi and Ga), measured on each of 216 soil samples by spectrographic and atomic absorption spectrophotometric methods were considered. The results from the factor analysis (R-mode) indicated that the multi-element soil geochemical distribution patterns around the Sargipalli deposit could be explained by a six-factor model. The proper evaluation of this model in relation to sound geological/geomorphological facts known from the area of study, would provide a significant insight into the probable nature of dominant underlying factors influencing the areal distribution of trace elements in soils around the ore body, and hence may serve as an indirect aid in locating further potential prospecting targets in the area.
Stromatolites from Middle-Riphean Gangolihat Dolomites (Deoban), Berinag-Gangolihat Area, Pithoragarh District, Kumaun Lesser Himalaya
Authors: Pant Charu C. 
Published: November 2024

Abstract
Gangolihat Dolomite (= Deoban) of eastern Kumaun Himalaya, predominantly made up of micrite, dolomicrite) pelmicrite, dolomitic limestone and talc-associated magnesite, has preserved a variety of stromatolites, of Colonnella group, in its uppermost horizons, best developed soulh of Berinag near Rain Agar, Bora Agar and near the township of Gangolihat. The paper describes four forms of stromatolites which are compared with similar forms described by earlier workers from different parts of Himalaya and the depositional environment has been deduced.
A middle Riphean age (1260 - 1000 m.y.) is assigned to these dolomites because of the presence of Colonnella and Baicalia baicalica. In the present structural superposition, the Gangolihat Dolomites are discordantly succeeded by quartzites and chlorite schist of Berinag Formation which have given a radiometric age of 725 m.y., thus confirming a structural break between the two formations.
Kinematics of the Transverse Lineaments, Regional Tectonics and Holocene Stress Field in the Garhwal Himalaya
Authors: Jain A. K. 
Published: November 2024

Abstract
Lineament and fracture trace analyses of the Indo-Gangetic Plain and different tectonic units of the Garhwal Himalaya reveal four important sets with strike-slip sense of movements. Horizontally-displaced lithologic and tectonic boundaries clearly depict the sense of displacement along certain lineaments, e.g. the Ganga and Yamuna. Also, small-scale straight fracture traces generally are associated with major fracture traces of lineaments in the sense of Riedel (R), Conjugate Riedel (R'). Displacement (D) and Thrust shears (P). L1 lineaments trend N5°-N10° and show dextral sense of displacement, while its conjugate sinistral set (L3) trends N50°. The other strike-slip fracture traces and lineaments trend N25° (L1) and N90° (L3) with a dextral and sinistral sense of displacement respectively. Kinematically. it seems that the orientation of maximum principal horizontal stressU 1. deduced from lineament and fracture trace analysis, has changed anticlockwise from N60° to N24° in space and time by an amount of 35°. Interplay of some important faults along some lineaments with the Krol Thrust in frontal parts of the Krol Thrust Sheet has produced the Dehradun Re-entrant as a lateral ramp unlike the other re-entrants in the Himalaya. Furthermore, present-day seismicity in the Garhwal Himalaya is controlled by certain transverse lineaments besides being associated with major thrusts.
Arculacythereis indoarabica, A New Species of Ostracoda from the Miani Creek, Saurashtra Coast
Authors: Khosla S. C. 
Published: November 2024

Abstract
A new species of the Ostracoda genus Arculacythereis is described and iIIustrated from the Miani Creek, in Saurashtra. The present record, thus, extends the geographic distribution of the genus from the east coast of Australia to the west coast of India.
Lithospheric Subduction Beneath the Arakan-Yoma Fold Belt: Quantitative Estimates Using Gravimetric and Seismic Data
Authors: Gupta Harsh K. , Fleitout Luce , Froidevaux Claude 
Published: November 2024

Abstract
A set of consistent geophysical data show the presence of cold material at depth, east of the mountain chain, in the Arakan-Yoma fold belt region. There are intermediate focus earthquakes to a depth of 150 km or so and longitudinal seismic waves are faster under the chain than west of it. The pronounced gravity low, east of the chain, is well explained by cold high density material at depth in the seismic area, compensated by crustal thickening under the mountain chain and a sediment filled depression under the eastern basin. The gravity low flanking other collisional chains might also be due to compensation of cold material at depth rather than the usually invoked flexural effect.
Graphical Solution to the Drawdown Due to Pumping of the Limited Confined Aquifers in Unsteady State Flow
Authors: Mohapatra P. C. , Anjaneyulu B. 
Published: November 2024

Abstract
At the initial stage of pumping, the discharge-drawdown relationship in a limited confined aquifer is identical to that of an extensive aquifer followed by a transition-period during which the zero-drawdown contour moves from the nearest to the farthest boundary. After that the time-rate of increase in drawdown assumes a constant value. A graphical method is proposed in this paper to calculate the drawdown at a place due to unsteady flow in a limited confined aquifer.
Metamorphism and Magnetic Susceptibilities in South Indian Granulite Terrain
Authors: Ramachandran C. 
Published: November 2024

Abstract
The magnetic susceptibilities measured in 220 metamorphic rocks collected over a traverse distance of about 2500 km, from South Indian granulite terrain, varied over a wide range. The wide variation in the susceptibilities, 6-4420×10-6 emu/cc is explained in terms of changes in magnetic mineralogy during prograde and retrograde metamorphic processes.
Clay Mineralogy of the Soils of Indrayani River Basin, Western Maharashtra, India
Authors: Patil D. N. , Bhosale V. N. , Kulkarni A. V. 
Published: November 2024

Abstract
Clay mineralogy of the soils of Indrayani river basin of western Maharashtra, has been investigated with the help of DTA, XRD and IR spectroscopic techniques. On the basis of clay mineral assemblage of the soils, trends of chemical weathering of basalt and formation and evolution of the soils have been visualised. It has been observed that the chemical weathering of basalt of nearly uniform chemical and mineralogical composition, has led to the development of two contrasting soil types. Red to reddish-brown coloured lateritic to semi-lateritic soils of the western part of the basin are predominated by the presence of kaolinite group of clay minerals. Formation of these soils has been attributed to free drainage and high rainfall conditions. On the other hand, grayish-black coloured margalithic or black cotton soils showing predominance of the minerals of smectite group, have been formed under poor or restricted drainage and low rainfall conditions in the eastern part of the Indrayani river basin. An attempt has been made to discuss the formation and evolution of soils in the light of clay mineralogical data.
A Geochemical and Pb, Sr Isotopic Study of the Evolution of Granite-Gneisses from the Bastar Craton, Central India
Authors: Sarkari G. , Pauli D. K. , De Laeter J. R. , Mcnaughton N. J. , Misra V. P. 
Published: November 2024

Abstract
Preliminary Pb-Pb and Rb-Sr geochronology of granitic and gneissic rocks from the Sukma area of the Bastar craton, Central India, provides important constraints on crustal evolution, Much of the craton is made up of felsic orthogneisses and younger granitic intrusives, compositionally ranging from tonalite to granite. Pb-Pb isotopic data suggest the presence of ca. 3.0 Ga old gneisses. Younger granitic intrusives have been dated at ca. 2.6 Ga which represents a widespread resetting and/or emplacement event. Comparison of the Pb-Pb and Rb-Sr whole rock ages suggests that the latter were more perturbed after the gneiss-forming or emplacement events. All rock suites show significant geological scatter of isotopic data probably because of sampling on a regional scale, and reflect multi-stage isotopic evolution in a complex terrain.
The present isotopic data indicate the presence of Archaean rocks in the Bastar craton and suggest temporal similarity with the oldest crustal rocks in the Singhbhum and Dharwar cratons.
Geocbemistry and Magnetic Susceptibility of Surficial Sediments of the New Mangalore Port
Authors: Shankar R. , Karbassi A. R. 
Published: November 2024

Abstract
A geochemical study of surficial sediments of the New Mangalore Port has shown that there is no anthropogenic input of base metals (Cu, Zn, Pb, Mn and Fe). In comparison with the adjoining inner shelf sediments, Port sediments seem to have a higher proportion of detrital particles and hence relatively less organic matter. Manganese is found predominantly as adsorbed species. Other base metals are present in the lithogenous fraction. Organo-metallic association, reported by several workers for sediments, is not found in the Port sediments. Magnetic susceptibility of the sediments (Xm = 16.6 x 10-6 emu/g) is higher than that for shelf sediments. This is because of deposition of detrital particles of magnetic minerals in the nearshore area. The susceptibility values are not high enough to suggest any particulate pollution due to the Kudremukh iron ore loading operations at the New Mangalore Port.
Stratigraphy of the Upper Gondwana Sediments in the Krishna-Godavari Coastal Tract, Andhra Pradesh
Authors: Lakshminarayana G. , Murti K. S. , Rama Rao M. 
Published: November 2024

Abstract
The Raghavapuram Formation, as demarcated now, consists of shale and micaceous sandstone and contains Early Cretaceous (Neocomian-Aptian age) palynofossil assemblage-represented by Microcachryidites antarcticus, Contignisporites sp., Callialasporites sp, Lycopodiumsporites sp, Impardecispora sp, and Concavissimisporiles sp. The Tirupati Formation consists of conglomerate, ferruginous sandstone and sandstone. The hitherto considered 'Gollapalli sandstone' in Adamilli-Gopalapuram area of West Godavari district forms part of the continental Gondwana sequence (Kota Formation). Therefore, the present study has revealed that there is no stratigraphic unit called Gollapalli Formation in the Upper Gondwana of the Krishna-Godavari coastal tract and the revised stratigraphic succession consists of only two units, namely, the Raghavapuram and Tirupati Formations.
Origin of the Calcrete Deposits of Saswad-Nira Area, Western Maharashtra, India
Authors: Patil Dnyan N. , Surana Arati P. 
Published: November 2024

Abstract
Extensive development of calcrete deposits is observed in the Saswad-Nira area of western Maharashtra. Calcrete occurs in a variety of forms, the most common being powder, nodular, laminar, platy, tubular and hardpan calcretes. The DTA, XRD and IR spectroscopic studies show that the calcretes are composed chiefly of micrite - a microcrystalline calcite. Dolomite and opaline silica occur in subordinate amounts. The clay fraction of calcretes is dominated by attapulgite (palygorskite) and sepiolite, which along with other interlayer clay minerals like chlorite-montmorillonite and illite-montmorillonite, indicate extreme alkaline conditions for the precipitation of calcretes. The chemical data reveal that apart from calcium carbonate, silica and magnesium carbonate constitute an appreciable portion of some calcrete samples. From the textural, mineralogical and chemical characters of calcretes, it is evident that the precipitation of calcium carbonate in vadose zone and its progressive accumulation in the soils has ultimately resulted in the development of extensive calcrete deposits.
Petrographic and Geochemical Characteristics of the Kamthi and Lower Maleri Formations Adilabad and Karimnagar Dts (A.P.)
Authors: Sayyed M. R. G. , Patwardhan A. M. 
Published: November 2024

Abstract
Upper Kamthi sandstones are distinct being unimodal, less feldspathic, texturally more mature with a dominant ferruginous cement when compared with the Lower and Middle Kamthi sandstones which are bimodal, feldspathic with abundant carbonate cement. The bimodality and textural inversion in the latter is attributed to their derivation from both metasedimentary and plutonic sources. This is also reflected in the erratic distribution of Al2O3 total iron and Na2O contents. The Yerrapalli sandstones are petrographically not very different from the Lower and Middle Kamthi sandstones, but show finer grained feldspar, abundant carbonate cement and lime pellets. The Bhimaram sand'stones, however, show lesser carbonate content and are characterized by the presence of pyrite and ferruginous cement. In general, the Yerrapalli and Bhimaram sandstones show a greater mineralogical and textural maturity than the Lower and Middle Kamthi units. The distribution of CaO shows a maxima in. the middle portion of the Lower Maleri sequence, other major elements donot show any systematic variation.