bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary Results of Some Gravity Surveys, in Singhbhum Area, Orissa
Authors: Qureshy M. N. , Bhatia S. C. , Subba Rao D. V. 
Published: November 2024

Abstract
The regional gravity survey in the area bounded by Lat. 21°N to 23°N and Long. 85°E to 87°E has brought out a broad gravity' low' over the granite batholith south of the Singhbhum thrust zone. The amplitude of gravity' low' is more in the southern portion (about 30 mgal near Keonjhargarh) than that in the northern portion of the granite batholith (about 20 mgal near Hatgamaria). This gravity 'low' in general suggests that the granite body may continue to a considerable depth.
A broad gravity 'high' has also been observed east of Singhbhum granite where one or two outcrops of basic rocks are observed. The areal distribution of this' high' would seem to suggest the existence of a substantial amount of basic rocks in this area which may represent the Simlipal and the Dhanjori basins filled with high density material as suggested by Iyengar and Alwar.
This correlation of gravity to surface geology can be advantageously used as an aid to structural mapping and in getting the third dimensional configuration of the major rock types.
Radioactive Limonite of Lata Pahar, Singhbhum District, Bihar
Authors: Subramanyan V. 
Published: November 2024

Abstract
Transported, radioactive (up to about 1,000 ppm of U) limonite occurs in Lota Pahar, which is shown to be the westernmost extension of uranium mineralization in the Singhbhum thrust belt. Limonite might have acquired the uranium content by the adsorption of uranyl ions on the colloidal ferric oxide hydrate. This radioactive limonite served as a prospecting aid in the discovery of uraniferous breccia in the Lota Pahar ridge and the environs.
Clay Mineral Distribution of Dharmsala Sediments in Northwest India
Authors: Bhattacharya N. , Raiverman V. 
Published: November 2024

Abstract
Clay mineral distribution in Dharmsala sediments over a region extending from Palampur to Mandi and Sarkaghat in northwest India was studied using standard X-ray diffractometer techniques. Lower Dharmsala sediments show uniform clay mineral distribution over the region and contain partially degraded illite and chlorite with minor amounts of kaolinite. Upper Dharmsala sediments seem to vary in clay mineralogy from one part of the region to another. They are characterized by the presence of illite, chlorite and vermiculite at Palampur-Baijnath. The clay minerals are mainly degraded illite, vermiculite and expandable mixed layers at Jogindernagar-Mandi and Rewalsar areas. Upper Dharmsala clays at Sarkaghat consist of montmorillonite, expandable mixed layers and minor amounts of highly degraded chlorite. Differences in clay mineral distribution over the region is explained here by variations in the characters of source rocks, weathering intensity, sediment transport, drainage and topography. The present findings are compatible with information obtained from paleocurrent investigalions.
Zircons from the Granitic Rocks Around Sagtala, Panchmahal District, Gujarat
Authors: Bhaskar Rao B. , Venkataraman G. 
Published: November 2024

Abstract
Zircon studies have been carried out on the granitic rocks occurring around Sagtala, Panchmahal district, Gujarat, The granitic rocks are coloured grey or pink and can be classified into three types: (1) Grey quartz-monzonite, (2) Grey granodiorite, (3) Pink granite. Elongation frequency diagrams drawn for the zircons of the different granitic rocks show maxima in the range 2 - 2.5. Positional as well as slope differences are observed in the reduced major axes of the zircons of quartz-monzonite, granodiorite and granite. On the basis of zircon studies, it is concluded that the Sagtala granite is a composite intrusive consisting of three distinct intrusive phases whose emplacements were separated in time.
Mineralogy and Genesis of Barytes Deposits East of Khammam, Andhra Pradesh
Authors: Reddy B. R. G. , Sriramadas A. 
Published: November 2024

Abstract
Deposits of barytes, east of Khammam, Andhra Pradesh, are associated with early and late Precambrian formations. The barytes in association with chert occurs in the form of irregular veins and lenses along and across the bedding and foliation planes and along axial plane traces of the folds, in several lithological units indicating structural controls. Optical, chemical, X-ray and spectrochemical studies of four different types of barytes have been made in detail. The mineralogical studies and the mode of occurrence indicate that the barytes mineralisation resulted from residual solutions.
The Subsurface Geology of the Indo-Gangetic Plains
Authors: Ramachandra Rao M. B. 
Published: November 2024

Abstract
The paper presents a comprehensive account of the results of the geophysical surveys and well data available in respect of the sub-surface geology of the Indo-Gangetic Plains, pointing out the major divisions of this gigantic depression. The geological relation of this depression with the Peninsular shield on the one hand and the Extra-Peninsular region on the other has been briefly discussed, pointing out the need for further investigations to obtain a complete solution to the problem posed by this major unit in the geology of the Indian subcontinent. A few remarks are also added on the petroleum prospects in these plains.
Petrology and Geochemistry of Hornblendic Rocks from Kanigiri-Gogulapalle Area, Andhra Pradesh
Authors: Rama Rao P. , Narasinga Rao A. 
Published: November 2024

Abstract
Hornblendic rocks (hornblende schists, amphibolites, and hornblendites) occur in intimate association with metasedimentary schists and granitic rocks in the Kanigiri Gogulapalle area of Andhra Pradesh, India. Field studies indicate that a majority of these rocks are possibly concordant intrusives, some of them being metasedimentary. Petrographic study shows that most of them consist of hornblende and plagioclase as essential minerals, whereas some are characterized by tremolite and plagioclase with accessory calcic minerals. Absence of detrital minerals and pyroxenic cores in the amphiboles characterize all the rocks.
Geochemical studies reveal that the rocks are most probably magmatic intrusives judged from the low Niggli k and high TiO2 values and the presence of high Sr, Cr, V, and Ni amongst the trace elements.
Tectonic Uplift of the Nellore Mica Belt, India, as Revealed by Fission Track Dating Technique
Authors: Parshad Rajinder , Lal Nand , Nagpaul K. K. 
Published: November 2024

Abstract
Fission track ages of two cogenetic minerals viz., garnet and apatite collected from the pegmatites of Nellore Mica. Belt of India, emplaced during the closing stages of the Eastern Ghats Orogeny (1500-1600 Ma) are found to be 1065 Ma and 440 Ma respectively. The data has been interpreted in terms of tectonic uplift of the pegmatites. The average rate of uplift for this region has been calculated as 0.04 mm/year.
Geochronological and Geological Studies on a Granite of Higher Himalaya, Northeast of Manikaran, Himachal Pradesh
Authors: Bhanot V. B. , Bhandari A. K. , Singh V. P. , Kansal Ashok K. 
Published: November 2024

Abstract
Rb-Sr whole-rock data is presented for a biotite-granite of Central Crystallines. The whole-rock isochron age is found to be 467±45 m.y. This should represent the time of intrusion of the granite. A brief account of the geology and petrography is also presented. The age of the biotite is found to be 8.8±2.0 m.y., which is the youngest Rb-Sr age reported so far for a mineral from the Himalaya. This fixes the period when the rocks of this area, after being heated and uplifted, cooled to a temperature of about 300°C.
Geology and Geochronology of Early Precambrian of the Ukrainian Shield
Authors: Shcherbak N. P. 
Published: November 2024

Abstract
The Early Precambrian of the Ukrainian shield is represented by geological formations older than 2.6 b.y. The Archean formations are established in three big regions of the Ukrainian shield. These regions are tectonic blocks. Each block is characterized by specific petrological and geological features. In each block the grade of metamorphism of the rock is different.
The metamorphic rocks are represented by three series and the granites are represented by three complexes.
In the lower parts of the section of the series, effusive rocks predominate and in its upper parts metamorphosed sedimentary rocks are predominant. The effusive rocks of acidic and medium composition are characterized by dominating quantities of sodium. Genetically acidic and medium rocks are the products of differentiation of tholeiite-basalt magma.
Geochronologically the complexes of granites are characterized in detail. These data were obtained on accessory minerals and correspond to 2.8 b.y. ± 100 m.y. Dates of about 3.0 b.y. were obtained on zircon from metamorphosed effusive rocks by means of U-Th-Pb isotope methods. The data obtained on micas of metamorphosed rocks reflect superimposed processes.
Study of Lead Isotopes for Investigating the Origin of Endogenic Deposits with Special Reference to Some Ore Deposits from India
Authors: Chernyshev I. V. , Safonov Yu. G. , Radhakrishna B. P. , Krishna Rao B. , Vasudev V. N. , Deb M. 
Published: November 2024

Abstract
The isotope composition of leads from ore deposits in general reflects the age of ore mineralisation and its genetical features. Two examples have been given to illustrate a direct connection of ore lead isotope composition with the source ore. Calculations of the model age from lead isotope data form the basis for genetic reconstructions of Precambrian deposits. Radical improvement in the accuracy of mass spectrometric isotope lead analysis has made possible the employment of two-stage and in some cases more complicated models for genetic reconstructions. The Penehanga Bay lead-zinc deposit and gold-silver deposits of South Dakota have been studied using high accuracy mass spectrometer. Both the deposits show that ore formation took place one to two billion years after craton formation, and lead present in ores originated at least from two different Sources.
Keeping this background of experience, fifteen galena samples from five sulphide and gold-sulphide deposits of the Indian Shield have been selected and determination of lead isotope composition has been carried out by the Soviet authors in the USSR using recently developed M.I.1320 Mass Spectrometer. The isotopic ratios of galena from Ingaldhal copper deposit are the most primitive among the analysed ores of the Indian Shield. The results of lead isotopic determination have been interpreted in terms of the general theory of 'plumbotectonics '.
Gravity Field, Structure and Tectonics of the Raniganj Coalfield - Three Dimensional Model
Authors: Verma R. K. , Bandyopadhyay T. K. , Mukhopadhyay Manol 
Published: November 2024

Abstract
A residual Bouguer gravity anomaly map of the Raniganj Coalfield, West Bengal, India, has been prepared using graphical method of regional and residual separation. The gravity anomaly map reveals a minimum residual gravity of the order of -27 mgal in the central part of the coalfield. The residual gravity field over the basin has been interpreted in terms of the Gondwana sediments overlying the crystalline metamorphic rocks, using a three dimensional model with the help of computer programme given by Strange and Woollard (1969). A density contrast of -0.37 gm/cm3 between Gondwana sediments and metamorphic rocks has been used for calculations. The maximum thickness of sediments filling the basin is estimated to be 2.9 km in the central part of the basin. The basement depths obtained by three dimensional analysis are correlated with available borehole data in the coalfield and are found to give a good indication of the reliability of the model constructed.
Alluvial Fan Model for the Himalayan Piedmont Deposits
Authors: Roy Subimal Sinha 
Published: November 2024

Abstract
The Ganga-Brahmaputra fluvial plains are separated from the Himalayan foothills by the extensive piedmont belt. Four longitudinal large-scale terraces that have sequentially developed are recognised ill the interfluvial region of the Tista and the Jaldhaka rivers. These terraces are composed primarily of Boulder Beds and Gravel Beds, and of subordinate Sand Beds, and show rapid facies variations. These deposits are dissected by streams into cut and fill type transverse small-scale terraces. The evolution of the Himalayan piedmont tJelt is consistent with a dynamic alluvial fan model in which the sediments are considered to have been derived through upliftdependent episodic debris-flows and rrtass emplacement. The vertical and lateral accretion of the fans is in consequence to shifting of the mountain front, and to flattening of the stream gradient in the mountains. The hinge-lines of the fans migrated toward south with time, while the transitional zones between the fanglomeratic and the floodplain facies, toward north. Several empirical relationships in the magnitude-frequency matrix between uplifting, terracing and fan-formation are suggested.
Development of Flexural Slip Folds, Overlapping Boudins and Extension Faults in Multilayered Materials: Field Evidence and Experimental Model
Authors: Dubey A. K. , Behzadi H. 
Published: November 2024

Abstract
Structural features of natural chevron folds were studied in north Cornwall, England and an experiment was performed to simulate these structures. The study reveals that the amount of interstitial flow (Biot, 1965) varies along the fold limb and this variation is attributed to the formation of, (1) limb thinning and hinge thickening, (2) variation in the intensity of development of extension faults along the fold limb, and (3) development of overlapping boudins.
Structures in the Tethys Himalayas and their Tectonic Significance
Authors: Kanungo D. N. , Murthy D. S. N. 
Published: November 2024

Abstract
Structural studies of Tethys sediments between Malari and Lapthal show development of many minor structures e.g. - 'cleavages, tension and shear fractures' - which have been utilised to deduce the stress fields responsible for the deformation of these rocks. The primary sedimentary structures such as bedding, current bedding suggest shallow deposition conditions. The shape of folds, the fracture cleavages, quartz and calcite filled tension gashes and other fractures, and the thrusts are all taken as evidence for 'shallow-level' deformation of these rocks in which 'brittle deformation' was dominant.
The study suggests that major compressive stress responsible for the deformation of these rocks was always directed northeast-southwest and was lying sub-parallel to the earth's surface, the P-intermediate was directed NW-SE and was also horizontal, while the P-minimum was always invariably perpendic:ular to the earth's surface. Hence, it is concluded that these rocks have been deformed by horizontal compression and it appears that the major push was from the SW in this part of the ranges.
Sulphur Isotope Abundance Variations in Sulphides of the Dharwar Craton-Part I: Kalyadi
Authors: Menon A. G. , Venkatasubramanian V. S. , Ananta Iyer G. V. 
Published: November 2024

Abstract
Sulphur isotope abundance variations in chalcopyrite, pyrite and pyrrhotite samples from the sulphide deposits of Kalyadi have been measured with a double-collector mass spectrometer provided with digital ratio recording. The results fall into two groups - one with a near-zero per-mil value and another with a small positive value ~5‰. Data on coexisting sulphide minerals enable temperatures of deposition to be calculated, these being low ~250° C. The Ohmoto-procedure is adopted, and the range of d34S values of the minerals explained by assuming an initial total sulphur d34STS value and a range of pH and fO2 values that are plotted on an fS2 - fO2 diagram consistent with the stability fields of the minerals.
Hogbomite from Fe-Ti Deposits of Madangere, Ankola Taluk, Karnataka
Authors: Devaraju T. C. , Uttangi V. H. , Coolen J. J. M. M. M. 
Published: November 2024

Abstract
Hogbomite analysing 59.94% Al2O3, 6.01% TiO2, 0.21% V2O3, 21.02%, FeO, 0.14%, MnO, 9.66%, MgO and 1.06% ZnO occurs as a widely distributed mineral phase in the vanadiferrous Fe-Ti ore deposits of Madangere area. It occurs in well developed prismatic crystals, and small scales/rods/patches enclosed in magnetite ore grains, and locally as rims to spinel. While the coarse prisms of hogbomite bear characters of primary mineral phase, the small scales/rods/patches appear to represent exsolved phase and that forming rims to spinel is derived by the alteration of spinel. The mineral is reported for the first time from India.
Petrogenesis of Amphibolites in the Kolar Schist Belt, India-A Preliminary Report
Authors: Rajamani V. , Shivkumar K. , Hanson G. N. , Granath J. W. 
Published: November 2024

Abstract
The amphibolites in the Kolar schist belt include four textural types, schistoic, granular, massive and fibrous and occur in abundance in that order. The fibrous variety consists of two coexisting calcic amphiboles (A1 rich hornblende and A1 poor actinolite). The other three varieties contain hornblende and plagioclase (An40 to An85). The texture, mineralogy and mineral chemistry suggest metamorphism in the middle to upper amphibolite facies.
Major and Rare earth elements (REE) data indicate that (a) the fibrous amphibolite is somewhat similar to high-Mg basalts of Archean greenstone belts but with a strongly, heavy REE depleted pattern, (b) the other three varieties are similar to low-K oceanic tholeiites with slightly light REE depleted patterns and with strong positive Eu anomalies, and (c) the two groups do not represent primary melt compositions generated by the partial melting of a pyrolite mantle. It is concluded that the Kolar amphibolites must have been evolved from at least two separate parent magmas generated from different temperature and pressure (depth) conditions.
Geomorphic Evolution and its Significance in Exploration Planning of the East Coast Bauxite Deposits of India
Authors: Ramam P. K. 
Published: November 2024

Abstract
The East Coast Bauxite deposits top either the Khondalite or Charnockite Group of Archaean rocks that constitute the bulk of the Eastern Ghat physiographic province. Subsequent to the Eastern Ghat orogeny (1400-1600 m.y.), faulting in Mesozoic was the major tectonic event recorded in the Indian Peninsula.
The Eastern Ghat terrain was subjected to uninterrupted planation in the intervening period. The attainment of a clear macro-relief instead of a featureless plain (peneplain) is visualised as a consequence. This macro-relief, possibly modified to some extent due to Mesozoic faulting, after attaining stability and with the onset of monsoonal climate in upper Cretaceous promoted the process of residual chemical weathering. Chemical leaching was accentuated and optimised during Upper Tertiary-Quaternary period when there was copious rainfall with less of evapo-transpiration, resulting in thick bauxitic duricrusts. This view is at variance with the concept of an once extensive residuum formed at lower levels and what are now seen at high altitudes are their erosional relics, owing their elevation and discontinuous nature to post-residuum uplift followed by denudation. As the gibbsitic duricrusts formed insitu have not been disturbed later, an in-depth study of their geomorphic characteristics, especially the slope morphology, assumes added relevance as it aids geological prognosis of the behaviour of the pay zone in terms of grade and thickness fluctuations. Once the geomorphic evolution of the duricrusts has been logically reconstructed, a conceptual approach instead of a regular grid for exploration planning is considered more pragmatic not only for acquiring a geologic grip but also in minimising exploration costs.
Geochemistry and Significance of Mafic-Ultramafic Rocks from the Southern Part of the Holenarasipur Schist Belt, Karnataka
Authors: Hussain S. M. , Naqvi S. M. , Gnaneshwar Rao T. 
Published: November 2024

Abstract
The ultramafic rocks of Holenarasipur schist belt show micro-spinifex texture, deformed pillow lava-like structures and contain interbedded fuchsite-quartzite. Compositionally the mafic-ultramafic rocks are similar to peridotitic, pyroxenitic and basaltic komatiites. Available data exhibit a gap between 20 and 30% MgO content, which suggests discontinuity in their composition. A two stage melting model is projected to explain this compositional gap. The abundance of komatiitic mafic-ultramafic rocks supports the view that the Holenarasipur schist belt is a true greenstone belt.
Geophysical Investigations for Barite at Gopalpur, Khammam District, Andhra Pradesh (India)
Authors: Varaprasada Rao S. M. , Bhimasankaram V. L. S. 
Published: November 2024

Abstract
Barite deposits are known to occur in the Shernavala outlier near Khammam Town and are found associated with Pakhal sediments of Upper Proterozoic age. The results of electrical resistivity profiling were significant in tracing a shear zone consisting of vein quartz. The gravity method was useful in demarcating the barite body from the associated quartz, and the ore reserves were estimated to be 86,000 tonnes.
Angular Unconformity Between Sargur and Dharwar Supracrustals in Sigegudda, Karnataka Craton, South India
Authors: Viswanatha M. N. , Ramakrishnan M. , Swami Nath J. 
Published: November 2024

Abstract
The major angular unconformity between the Peninsular Gneiss and Dharwar Supergroup in Sigegudda belt, Karnataka, is now 'discovered' to separate the Sargur from Dharwar Supracrustals. It is the most critical area known so far in the craton to exemplify the Sargur-Dharwar relationship. In conformity with modern stratigraphic practice, the unconformity marked by supermature conglomerates incontrovertibly separates two major rock sequences in early Precambrian geological record of Karnataka Craton.
Borings on Belemnoid Rostra from Utatur Group of Upper Cretaceous Rocks of Trichinopoly District, Tamil Nadu
Authors: Ghare M. A. 
Published: November 2024

Abstract
The activity of algae, fungi, sponges, bryozoa and barnacles on the belemnoid rostra from clays of the Utatur Group in the form of micro borings are described. The sponge and bryozoan borings are represented by Clionoides Fenton & Fenton and Talpina Hagenow respectively; while, barnacle borings are represented by ichnogenus Brachyzapfes Codez and De Saint-Seine. The algal borings are assigned to ichnogenus Calcideletrix Haentzschel. Ichnogenera Nygmites Haentzschel and Radiarites ichnogen. nov. are the borings of fungi. Ichnogenus Cylindrocavites Ichnogen nov. is erected to accommodate circular borings of unknown affinities.
The present study shows that the borers and the belemnoids belonged to the same biocoenose and indicate littoral to shallow sublittoral depths of well aerated, slightly turbulent but clear marine waters.
Glacial and Periglacial Morphology of the Jorya and Adjoining Glaciers, Kinnaur District, Himachal Pradesh
Authors: Ameta S. S. , Swain P. K. 
Published: November 2024

Abstract
The glacial and periglacial region of the Jorya, Janapa, Naradu and Tumur glaciers shows Alpine sculptures like horn, cirques, 'U' troughs, serrated ridges, hanging glaciers, moraines, crevasses and glacial tables. 1 to 3km recession and 150m to 120m vertical shrinkage are noticed in these glaciers. Floor of cirques lies between 4800 and 4900m height a.s.1. suggesting active orographic firn line at a height of 5000m a.s.1. at the time of formation of the cirques. Evolution of the landforms took place in three stages: i) advent of the glacial climate, ii) advancement of the glaciers and iii) active deglaciation period.