bluuebunny/crossref_metadata_2025_split huggingface dataset:
Petrography, Geochemistry and Origin of the Carbonatite Veins of Mer Pluton, Mundwara Igneous Complex, Rajasthan
Authors: Subrahmanyam N. P. , Rao G. V. D. 
Published: November 2024

Abstract
Alvikite veins, genetically related to Mer alkali pluton arc located in the peripheral Erinpura granites of Mundwara Igneous Complex. These veins vary in length from 7 to 70 metres and are lenticular with discontinuous lenses arranged en echelon., Fluidal, pegmatitic, porphyritic, vesicular and frothy textures, chilled marginal effects, fenitization and carbonatization are observed. Their mineralogy and textures indicate that they are pneumatolytic hydrothermal veins.
Trace element content (in ppm) is Y-53, La-163, Ce-74, Sc-18, Rb-4, Ta-5, Th-5, U-3, Sr-997, Ba-684, Pb-36, V-26. Cr-15, Co-6 and Cu-4. The mean values and the range of trace element content (in %) of pure calcites of these veins are, Sr-0.605(0.71-0.41); Ba-0.059 (0.07-0.03); Ce-O.038 (0.047-0.033); La-0.029 (0.034-0.021); Y-0.0069 (0,0081-0.005); Mn-O.4 (0.47-0.32); Mg-0.05 (0.14-nil); P-0.05 (0.19-nil) ; Sr, Ba, Mn and Mg contents are well within the range of values reported for other carbonatites, though they are on the lower side of the average values. Lower values may be due to the hydrothermal nature of these veins.
Mer Pluton occupying a small 2 Sq. Km. area, presents a complete suite of differentiated rock series, pyroxenite, banded gabbro, mela gabbro, theralite, essexite, nepheline syenite, sodalite syenite and the parent chilled basalt, basanite. High oxygen fugacity conditions of formation of this rock suite are indicated by the crystallization of magnetite in considerable quantities from the earliest formed pyroxenite, conversion of titanomagnetite to titanohematite, ilmenite to titanohematite and rutile in the chilled basalt, and extensive maghemitization of magnetite in almost all other rock types. Petrochemical studies indicate that the carbonated basanitic magma, following the calc-alkaline trend of fractional crystallization, has given rise to the miascitic suite of Mer pluton. It is inferred that the carbonatites are formed from tile residual carbothermal liquids. Na, Fe-rich vapour phase, in equilibrium with other phases in carbothermal solutions has fenitized the surrounding rocks.
Biostratigraphy and Evolution of the Cauvery Basin, India
Authors: Sastri V. V. , Raju A. T. R. , Sinha R. N. , Venkatachala B. S. , Banerji R. K. 
Published: November 2024

Abstract
Outcrops ranging in age from Late Jurassic to Recent are located nearer the western margin of the basin. The eastern parts of the basin are covered by alluvium and contain a relatively thicker and more complete sedimentary sequence. The exposed and subsurface sedimentary sequence are adequately fossiliferous and several faunal as well as palynological zones are established.
The basin was formed during Late Jurassic by sagging of a part of the Indian shield, mainly along the dominant NE-SW Eastern Ghat trend. The basin was well differentiated into depressions and ridges formed owing to taphrogenic fragmentation and block faulting along the dominant basement trends during the onset of Late Jurassic. Initial sedimentation was under non-marine environment. The first marine transgression occurred during the close of Late Jurassic. Marine environment of sedimentation continued till Cretaceous, although through a series of minor transgressions and regressions. The depocentres were mainly due west.
A major regression occurred during the close of Cretaceous. The basin underwent an easterly tilt and the depocentres shifted due east prior to marine transgression during the beginning of Tertiary. The differentiation of the basin into depressions and ridges was almost lost during Eocene. Sedimentation during the Tertiary period was marked by repeated transgressions and regressions as is evidenced by biofacies, isopachs, and several sedimentation breaks which are relatively more pronounced in the western parts of the basin.
Plant Fossils from the East Coast Gondwana Beds of Tamil Nadu with a Note on their Age
Authors: Ayyasami K. , Gururaja M. N. 
Published: November 2024

Abstract
A recent search for plant fossils from the East Coast Gondwana sediments of Tamil Nadu has revealed a number of new occurrences. They include Taeniopteris cf. lata, Sphenopteris sp., from the Terani beds from Terani, Tiruchirapally district and Pterophyllum sp., Ptilophyllum acutifolium, Cladophlebis indica, Gingkoites cf. rajmahalensis, Actinopteris sp., from the Sivaganga formations of Ramnad district.
The age of the East Coast Gondwana is reviewed in the light of the recent K-Ar dating of the Rajmahal traps assigning an Aptian age to the lower part of the Rajmahal traps. There is no contradiction in the ages assignable to the coastal Gondwana on the basis of plant and animal fossils.
A Note on a Fossiliferous Shale in Coastal Sedimentaries, North of Madras
Authors: Subramanian S. , Ramanujam C. G. K. , Patil R. S. 
Published: November 2024

Abstract
This paper highlights the geomorphic and palynological significance of the carbonaceous shale horizon subcropping 3 m below surface in the pits dug in the Korttalaiyar river section near Kondakarai, north of Madras. The carbonaceous shale underlies recent alluvial sand and appears to overlie Cuddalore Sandstones which are exposed to the west.
The palynological assemblage recovered consists of fungal spores, pteridophytic spores and angiospermic pollen grains. The pteridophytic spores are referable to Polypodiaceae, Cyatheaceae, Dicksoniaceae and Parkeriaceae, of which the Polypodiaceae represents the predominant taxon. The angiospermic pollen grains are referable to monocotyledonous and dicotyledonous taxa. The pollen grains of the following families have been recognised., viz., Palmae, Rhizophoraceae, Verbenaceae, Chenopodiaceae, Lecythidaceae, Caryophyllaceae and Leguminosae. Of these, the pollen grains of Rhizophoraceae and Verbenaceae are the most abundant. The spore and pollen assemblage indicates a Neogene-Quaternary age and points towards the presence of brackish water mangrove vegetation.
Boudinage in the Delhi Rocks Between Bhim and Todgarh, Rajasthan
Authors: Pahuja R. P. S. , Murty T. V. V. G. R. K. 
Published: November 2024

Abstract
Pegmatite veins of variable thickness occur in biotite schists and calc schists belonging to Delhi System between Bhim and Todgarh. Rectangular, barrel shaped, lozenge shaped, rotated and folded boudins have been observed in the pegmatite veins. The degree of competency contrast, the degree of strain and the direction of stresses seem to be the controlling factors in the development of boudinage. The thickness of the rock unit behaving homogeneously as a competent band in relation to degree of strain seems significant. Rotated and folded boudins have been attributed to later deformation. The development of boudinage has been shown to be a late feature of the deformation that resulted in F2 folds of this area.
The Carbonatite of Hogenakal, Tamil Nadu, South India
Authors: Srinivasan V. 
Published: November 2024

Abstract
The carbonatite complex (pyroxenite-syenite-carbonatite) of Hogenakal area of Tamil Nadu and adjoining parts of Karnataka were emplaced along NNE - ssw fracture zones within the Precambrian gneissic complex. The carbonatite is Sovite in composition and its characteristics are (1) occurrence as fracture filling dykes, (2) presence of agglomeratic and flow structures and (3) absence of dolomitic carbonatite or beforsite, true fenite and major rare earth mineralization. The carbonatite of Hogenakal belongs to the high temperature and deep level intrusion of sub-volcanic origin. It has certain similarity with that of Strangways Range area of Central Australia and differs in certain respects from other carbonatite occurrences of Tamil Nadu.
Deformation and Metamorphism in the Precambrians of Rajasthan
Authors: Banerjee A. K. , Mitra S. K. 
Published: November 2024

Abstract
The varied lithological units of the Precambrian complex, represented by the Pre-Aravallis, Aravallis and Delhis, exhibit a set of complicated structural and metamorphic features that were the result of overprinting of at least four successive cycles of non-affine deformative movements, followed by later minor orogenic impulses spread over a long span of time. The Delhis are characterised by two sets of major folding movements giving rise to NNE-SSW (F3) and WNW-ESE (F4) structural trends, while the Aravallis are associated with two completely separate structural trends i.e. E-W (F1) and NW-SE (F2), which indicates that the tectonicity varied in space and also in time during the Delhi and Aravalli times. The fold-pattern in the Pre-Aravallis is the same as is noticed in the Aravallis.
The main metamorphic episodes in the Pre-Aravallis, Aravallis and Delhis, which were, sensu stricto, regional in nature, were coeval with the earlier phases of the major folding movements and were followed by dislocation and diaphthoresis in zones of shearing, thereby causing retrograde metamorphism in limited locales. The grade of regional metamorphism, in general, varies between lower greenschist facies to Upper amphibolite facies. The presence of granulites, at places, however, suggests higher temperature and pressure conditions prevailing at least locally. The thermal metamorphic effects in contact with basic and ultrabasic intrusives and with effusive acidic phases are very local.
Petrography and Petrochemistry of the Kimberlite and Associated Volcanic Rocks of the Jungel Valley, District Mirzapur, U.P., India
Authors: Chattopadhyay P. B. , Venkataraman K. 
Published: November 2024

Abstract
The kimberlite plugs and the associated volcanics of the Jungel valley occur within the Bijawar Group. The Jungel ultramafics occur in the form of plugs. Serpentinization and calcitization are common. The rock has 53% serpentine, 17% calcite, 14% opaque minerals, 5% pseudomorphs of olivine and pyroxene, 6% tremolite-actinolite and 5% chlorite and glass. The rock is porphyritic in texture and agglomeratic in nature.
Percentage of oxides and oxide ratios of the Jungel samples are comparable to those of the known kimberlites of the world. The normative composition of 17 samples analysed has brought out the special feature of the kimberlite, viz., its unusually high apatite and ilmenite and the general lack of clinopyroxene in the rock. The oxide relationship in the form of ternary plots falls within the kimberlite field and the electron microprobe analyses confirm the kimberlitic nature of the plug rock.
Geometry of Superposed Deformations in Hesadi-Tebo Area, Western Singhbhum, Bihar
Authors: Sarkar A. N. , Bhattacharyya D. S. 
Published: November 2024

Abstract
The study reveals three generations of deformation which have produced two splanes and a host of linear structures with complex geometric relations. All the three fold systems are, however, not equally developed all over the area and the associated structures also regionally vary in orientation and angular relation; this has resulted in diverse geometric patterns in different subareas.
The first deformation produced subhorizontal folds (F1) on bedding (S1) with strongly developed axial plane schistosity (S2). These folds are refolded, along with S2, about a set of steeply plunging axes (F2) at high angles with the F1 axes (60° to 90°). The main structural closures defined by Hesadi antiform and Kamrora synform are caused by the second folds (F2). On these structures are superposed a subhorizontal E-W trending set of folds (F3) with northerly dipping axial planes, resulting in dispersal of all the earlier lineations. The F3 folding was also accompanied by shearing in several tracts producing shear cleavage (S3) with downdip striation and groove lineations. The F3 folds show somewhat regular plunge reversals on macroscopic scale forming highly elongated domes and basins.
An attempt has been made to restore the original attitudes of the fold systems.
An Analysis of Chevron Folds from the Delhi Rocks Around Biliawas, Central Rajasthan
Authors: Roday Prakash P. 
Published: November 2024

Abstract
An analysis based on measurements made on the profile sections of several chevron folds developed in the biotitic limestone and calc gneiss units of the Delhi system of rocks around Biliawas in Central Rajasthan reveals that while folds in calc gneisses locked up after no great shortening across the layers had been accomplished and limbs had attained only moderate dips, those in biotitic limestones underwent considerable shortening normal to axial surfaces and locked up at much smaller interlimb angles. Estimates made of the ratios of viscosities between two sets of layers in each lithology indicate that the contrast between properties of two sets of layers is greater in biotitic limestones. The greater shortening in biotitic limestones than in calc gneisses is envisaged rather as a widely differing behaviour of different multilayer complexes than any likely finite strain variability across the area.
Diagenesis of Larger Foraminifera (Lepidocyclina, Sp.) and its Effect on Porosity in the Limestone Reservoir Rocks of Bombay Offshore Area
Authors: Gundu Rao C. 
Published: November 2024

Abstract
The tests of the larger benthonic foraminifera (Iepidocyclina, sp.) in the limestone reservoir rocks of Bombay Offshore area show various progressive stages of diagenetic alteration, starting from the initial stage of the pillars and septae of the test being clarified to aggregates of microfibrous calcite enclosing polygonal areas suggestive of original chambers, to tests completely rendered to aggregates of fibrous calcite proceeding as parallel brush like rays from the axial plane of the test, with the total destruction of its original Skeletal morphology. Evidence is put forward to show that the sheaf like bundles of radiating fibrous spar are of pore filling and syntaxial overgrowth origin than one of aggradational neomorphism. In calcarenitic rocks of such foraminiferal assemblages excessive overgrowth cementation may remove original intergranular porosity, thus reducing considerably the oil and gas reservoir capacity of the rocks.
Tectonic Evolution of the Archaean Granulite Facies Belt of Sri Lanka - South India
Authors: Katz M. B. 
Published: November 2024

Abstract
The Archaean granulite facies belts of Sri Lanka - South India contain abundant metasediments consisting of quartzites, garnet sillimanite gneisses, marbles, diopside scapolite calciphyres with subsidiary iron formations, along with other quartzofeldspathic gneisses, amphibolites and hypersthene 'charnockitic' gneisses of dubious origins. In these ensialic linear belts lithologies can be traced for hundreds of kilometres along the strike and the belts appear to be bounded by major tectonic lineaments.
The quartzites - garnet sillimanite gneiss - marble - calciphyre assemblages were derived from a sandstone- shale - limestone - evaporite sequence, which implies shallow water sedimentation in a shelf or intracratonic basin or trough. The sediments indicate a relatively stable cratonic source, which in Archaean times may have been a component of the earliest crust or protocrust. As these belts are fault-bounded, ensialic, linear zones within an older migmatitic basement they may represent intercratonic aulacogenes, The structural, metamorphic and igneous events indicated for these belts also point to tectonic controls that consist of at least two phases.
1) Tensional tectonic stage which led to the aulacogenes (&gt; 3000 m.y.)
2) Transform tectonic stage which converted the aulacogenes into mobile belts (~2800 m.y.)
Movement and displacement along these crustal transform mobile belts caused high angle-orthogonal external rifting. Thus the transform mobile belts are now acting as small circles of rotation initiating external rifting and spreading in the craton along great circles, as expressed in Eulers Theorem. The thin cratonic crust separated to form narrow basins floored by oceanic crust, the precursors of the greenstone belts. Thus the high grade mobile belt and the low grade greenstone belt are complimentary being formed at the same time and at the same crustal level.
On the Relation of Gravity Anomalies to Geotectonics of the Precambrian Terrains of the South Indian Shield
Authors: Subrahmanyam C. 
Published: November 2024

Abstract
Geological implications of the Bouguer gravity anomalies over the various structural provinces and their boundaries in the South Indian shield are discussed. The widely distributed greenstone belts and granites of Karnataka and Bastar craton show belts of positive and negative anomalies respectively, and control in a significant manner the Bouguer anomaly contour pattern over these low-grade terrains. The high grade Eastern Ghat terrain is divisible into two sectors whose geological and geophysical characteristics differ, as also their relationships with the adjacent low-grade terrains. While both represent deep crustal level root zones, the Tamil Nadu-Kerala granulite terrain appears to be exposed due to crustal tilting and continues northward underneath the Archean Karnataka craton. On the other hand, the Coastal granulite terrain is in faulted contact with the adjoining cratons. A strong negative anomaly flanking the western margin of this terrain is caused by downfiexuring of the crust along the cratonic margin.
Arkasani Granophyres from the Singhbhum Shear Zone, Bihar
Authors: Banerji A. K. , Bhattacharyya N. C. , Chattopadhyaya B. 
Published: November 2024

Abstract
The granophyre bodies have massive monzo- to syenogranitic core and gneissose to schistose borders where the composition varies from granodioritic to tonalitic. These bodies appear to have crystallised from granitoid melts generated within the shear zone during an earlier phase and were replaced by albitic liquids, around their borders, during a later phase. The evolution of these rocks seems to be related to the tectonic history of the shear zone which represents the boundary between a southerngranitic platform and a northern mobile belt and evolved as the platform progressively underthrust below the mobile belt during the course of four successive phases of deformation. It is suggested that the granitoid melt was derived through the partial melting of the metapelitic rocks of the shear zone during the first phase under pressure of about 2 Kbar while the albitic liquid was derived during a later phase when pressure exceeded 5 Kbar. Temperature, well above 650°C, required for such melting could have been provided by the higher geothermal gradient along the shear zone, which primarily represents a zone of deep seated fracture, possibly extending up to the upper mantle; frictional heat generated during thrusting and shearing, rise of isogeotherms on either side and within the shear zone during concomitant regional metamorphism, and radioactive heat as indicated by the occurrence of uraniferous minerals along this zone.
Granitic Gneisses of Lansdowne (District Pauri-Garhwal, U.P.)
Authors: Shah A. N. , Patel P. P. 
Published: November 2024

Abstract
The granitic gneisses of Lansdowne area form a part of the Amri unit of Garhwal nappe, formed before the main Himalayan orogeny. Field and petrological observations indicate that they have been thrust along with the crystalline rocks of Amri unit and there is no separate thrust contact between them. Chemical analysis and Petrography of the samples of gneisses from the margin to the centre show a progressive increase in feldspar-content which suggests a metasomatic origin for these granitic gneisses.
A. V. A. Technique in Microfabric Analysis: Examples from Delhi Group at Lalsot in Northeastern Rajasthan
Authors: Gangopadhyay P. K. , Pyne T. K. 
Published: November 2024

Abstract
Selected specimens of quartzite belonging to the Precambrian Delhi Group, which bear evidence of one main phase of deformation and related recrystallisation, have been studied by the A. V. A. technique. The c-axes of quartz show preferred orientation patterns which are controlled by the spatial distribution of direction groups of quartz. Recognition of the direction groups and the manner of their distribution help to predict the inherently inhomogeneous nature of the microfabric and the likely pattern of symmetry.
Radium Content of Some River Waters of India
Authors: Chatterjee S. D. , Banerji Partha 
Published: November 2024

Abstract
The radium content of river waters collected from eighteen different Indian rivers has been measured. The river water can usually be classified into two categories: limpid and turbid. The radium content of limpid waters has been found to be lower (~10-16g/ml) than that of its turbid Partner (~10-15g/ml). In the latter case, the radium contents both of the filtered component and the sediment have been separately measured. The sediment invariably exhibits a higher value.
Theralite-Melteigite-Carbonatite Association in Mer Ring of Mundwara Suite, Sirohi District, Rajasthan
Authors: Chakraborti Manas K. , Bose Mihir K. 
Published: November 2024

Abstract
The theralite-melteigite-carbonatite association is being reported from Mundwara alkaline suite in the Sirohi district, Rajasthan. The assemblage occurs in an arcuate ring around the central plug of Mer. Theralite (composed mainly of plagioclase, pyroxene, and nepheline) and melteigite (composed mainly of pyroxene and nepheline) are feldspathoid bearing basic and ultrabasic rocks, having high colour index and are closely associated with fine to coarse grained carbonatites in the south eastern part of the ring.
Acanthoceras from the Upper Cretaceous Rocks of South India
Authors: Chiplonkar G. W. , Phansalkar V. G. 
Published: November 2024

Abstract
Five species of Acanthoceras Neumayr are described here of which two species are new. Aeanthoeeras rhotomagense represented by two varieties-sussexiense (Mantell) and confusum (Gueranger), and Acanthoceras sanetorum Matsumoto are being reported for the first time.
Lithostratigraphic Classification of the Blaini, Infra Krol, Krol and Tal Formations-A Review
Authors: Bhargava O. N. 
Published: November 2024

Abstract
The Blaini, Infra Krol, Krol and Tal Formations constitute one conformable sequence. The palaeontological data pertaining to these Formations when screened collectively form an orderly pattern which suggests that the Blaini represents an Upper Carboniferous-Lower Permian; Infra Krol, Upper Permian-Lower Triassic; Krol, Upper Triassic-Uppermost Jurassic/Lowermost Cretaceous and Tal, Lower to Upper Cretaceous/Lower Palaeocene ages respectively. In this pattern the odd one out is the Permian fauna from the 'Tal '. It is surmised that the Permian fossils are not from the Tal but in all probability from the Boulder Slate Sequence (Bijni Unit) which rests as a klippe over the Tal-Nummulitic seccession.
Trace Fossils and Environment of Deposition of the Sedimentary Succession of Jabalpur, Madhya Pradesh
Authors: Kumar S. , Tandon K. K. 
Published: November 2024

Abstract
Well preserved Ichnogenus Ophiomorpha Lundgren and Thalassinoides Ehrenberg are recorded from the Mottled Nodular Sandstone Member of the Lameta Formation. The Thalassinoides type burrows are also quite common in the Upper Limestone Member and Upper Sandstone Member. On the basis of the presence of trace fossils and primary sedimentary structures it is concluded that the Jabalpur Formation and Green Sandstone Member of the Lameta Formation are fluvial deposits.