bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Note on the Mode of Eruption of the Deccan Trap Lavas with Special Reference to Kutch
Authors: Biswas S. K. , Deshpande S. V. 
Published: November 2024

Abstract
On the basis of detailed field mapping and available gravity data, certain conclusions regarding the mode of eruption of Deccan trap lavas are drawn.
In Kutch, the Deccan trap formation outcrops along the western and southern periphery of the mainland. The trap flows which rest disconformably over the Mesozoic rocks, are also seen to cover the eroded Mesozoic structures. They thin out towards the central and northern hills of folded Mesozoic rocks. Whereas basic dykes and sills are concentrated in these fold zones, a number of plugs occur close to the Deccan trap outcrops. Igneous plugs, seem to be related more to the trap than the tectonism. The dykes and sills are probably syntectonic whereas the trap flows are post-tectonic with respect to the Mesozoic folding. Three volcanic cone-like structures have also been discovered at the fringe of the Deccan trap outcrop, near Jada and Wehar. It is therefore, concluded that the trap lavas in Kutch have mainly erupted from Hawaiian type shield volcanoes. The lavas erupted from such volcanic centres periodically and flowed to the south down the paleoslope towards the main volcanic field.
Positive gravity anomalies are noted around well known plugs of Saurashtra which have long been considered as the eruptive centres along tectonic lines. Similar anomalies which could also be interpreted as the subsurface volcanic plugs or cones, are seen within the major rift zones of Western India like Cambay and Narmada grabens and faulted west coast. Thus, the Deccan trap lavas of Peninsular India too might have erupted from Hawaiian type shield volcanoes situated along the major fracture zones.
A System of Classification and Nomenclature of Granitic Rocks
Authors: Viswanathan S. 
Published: November 2024

Abstract
The paper proposes a system of classification and comprehensive kinematic-descriptive-genetic nomenclature of granitic rocks based on results of detailed petrographic studies of samples from the southern margin of the Canadian shield. Unlike the schemes currently in use that emphasise only the relative proportions of quartz, potassium-feldspar and plagioclase, the proposed classification recognizes the significance of several additional parameters: (a) biotite/amphibole ratios, (b) non-opaque calcic trace mineral contents (e.g., sphene, apatite, epidote), and (c) plagioclase compositions. Using these parameters, a new modal Quartz-Alkali feldspar-Plagioclase ternary diagram is presented. An example of a comprehensive kinematic-descriptive-genetic nomenclature of granitic rocks, derived from the proposed system is: 'late-kinematic, pink, slightly porphyritic, weakly foliated, medium- to coarse-grained, chloritized, muscovite-biotite-albite (An6)-microcline leucogranitic anatexite', The proposed system should prove useful in mineral exploration programmes aimed at locating rare-mineralic granitic bodies, and in inter-continental petrographic comparisons.
Wrench-Faulting and its Relationship to the Structure of the Southern Margin of the Sub-Himalayan Belt Around Ramnagar, Uttar Pradesh
Authors: Rao Y. S. N. , Rahman A. A. , Rao D. P. 
Published: November 2024

Abstract
On the basis of detailed field studies. the authors postulate that there is a wrenchfault on either side of the Kosi River, and that both of them pass into thrusts along the southern margin of the Sub-Himalayan belt.
Copper Mineralisation in the Ultrabasic Complex of Nuggihalll, Hassan District, Mysore State
Authors: Radhakrishna B. P. , Achuta Pandit S. , Prabhakar K. T. 
Published: November 2024

Abstract
The paper records an interesting occurrence of chalcopyrite and other sulphide minerals associated with the ultrabasic complex of Nuggihalli. Exploratory work carried out in the area for copper is described. The need for a closer observation of ultramafic and related rocks as potential sources for copper in the country is stressed.
The Geomorphology of the Vindhyan Plateau, Central India
Authors: Choubey V. D. 
Published: November 2024

Abstract
In Central India, the rocks belong to two groups, Vindhyans of lower Palaeozoic or late Precambrian age and the Deccan Trap lava flows of Cretaceous-Eocene age. The study of the geomorphology has led to the conclusion that after the deposition of the Vindhyans in a shallow inland sea, the country was uplifted. peneplaned and subsequently greatly dissected by a later cycle of erosion. Much later, the old and mature Vindhyan topography was buried beneath the lava flows and the associated sediments.
As denudation proceeded, erosion removed the lavas and sediments in places, laying bare the old land surface beneath. Thus the former topography of mature hills and flat valleys has been resurrected. With the partial removal of the lava flows: the remnants of the Cretaceous peneplain exist at an elevation of about 1950ft. At a lower surface of 1450 ft.,-the lavas rest on a planation surface developed particularly on the weaker rocks in a much more widespread younger cycle. The subvolcanic surface is reconstructed in detail and shows that the current drainage is superimposed on the pre-Deccan trap topography; and after the removal of the lavas, the rivers are tending to revert to the pre-Deccan trap drainage system. The current valley cycle. where the basalts have been removed, is largely coincident with the lower erosion surface, but it is now coming under attack from a newer cycle working up from Narmada and Ganges rivers.
Mineralogy and Petrochemistry of the Differentiated Sill Around Gwalior City, Madhya Pradesh
Authors: Varadarajan S. , Verma V. K. 
Published: November 2024

Abstract
Mineralogical and petrochemical characteristics of the differentiated sill, occurring at the highest horizon of Morar Stage, Gwalior System (Cuddapah age), around the city of Gwalior, Madhya Pradesh, are detailed. Petrographically the sill, composed of dolerite which is sparsly porphyritic, tends to be quartz dolerite in higher levels. The occurrence of micropegmatitic texture is proportional to the amount of hornblende present in the rock. Chemical nature of the chilled margin reveals that the undifferentiated magma was tholeiitic. Differentiation in the sill is of limited extent and is considered to be the result of the combined processes of fractional crystallisation, crystal settling and mild convectional currents.
Mineralogical Studies on the Bauxites from Shevaroy Hills, Tamilnadu State
Authors: Krishna Rao G. , Borreswara Rao C. , Syam Sundar Y. 
Published: November 2024

Abstract
Bauxites of Shevaroy hills were analysed for their mineralogical composition adopting X-ray and differential thermal analyses, heavy mineral and microscopic studies. Gibbsite and goethite are the ubiquitous and major constituents while boehmite, hematite, lepidocrocite, kaolinite, halloysite and quartz are present in minor amounts in certain samples only. There is a variation in the abundance of these minerals with the grain size of the bauxite. Magnetite, ilmenite, zircon, rutile and garnets are the heavy minerals present.
Geology of Bhotang Sulphide Deposit, Rangpo, Sikkim
Authors: Mukherjee N. K. , Dhruva Rao B. K. 
Published: November 2024

Abstract
The Bhotang sulphide deposit, situated near the border town of Rangpo, Sikkim was explored in detail during 1957-59. The copper-lead-zinc lode is exposed in a hill scarp over a strike length of about 400 m. with a strike of N 50°E and a dip of 65°SE. The lode is folded into a sinistral drag fold plunging ENE and is faulted along the anti-clinal axis. The ore body shows pronounced zoning along strike and across the Width. It has a strong pitch of about 50° towards south. The pitch and zoning of the ore body and the faults in the area have a significant bearing on the planning of development and exploitation of the deposit.
The ore body has been proved over a vertical extent of 275 m and a strike length of 200 m in the lower levels; and because of erosion in upper horizons, the strike length is gradually reduced to 90 m. The ore body has an average width of 5 m. The drives in different mine development levels indicate a width of about 1.5 m with a total copper-lead-zinc content of 4.90%.
Dadikar Granite: A Study on a Precambrian Intrusive Body in Relation to Structural Environment in North-Eastern Rajasthan
Authors: Gangopadhyay P. K. , Das D. 
Published: November 2024

Abstract
The Precambrian Delhi group of rocks in north-eastern Rajasthan is associated with a few granite bodies. Among these the Dadikar granite near Alwar city is intrusive into the Delhi metasediments. Both the granite and the Delhi rocks are deformed and recrystallised under the common plan. The Dadikar granite had been emplaced within an overall domal structural framework of the Delhi rocks. Any radiogenic age determination of this granite must be interpreted in the light of the field relationships between the granite and country rock.
The Mode of Occurrence, Petrography, Metamorphism and Origin of Amphibolites of Devgad Baria Panchmahals District, Gujarat State
Authors: Narayana B. L. 
Published: November 2024

Abstract
Amphibolites occur towards south and south-east of Devgad Baria town in the Panchmahals district of Gujarat State, in the form of disconnected bands showing concordant relationship with the rocks of the Banded gneissic complex and passing into striped varieties, and also as caught-up patches in the granitic intrusive bodies. Mineralogically, the former type is a quartz and plagioclase bearing amphibolite, while the latter is only plagioclase-bearing.
The quartz-amphibolites are shown to be para-amphibolites on the basis of their intimate association with the impure calcareous metamorphosed sedimentary rocks, lack of relict igneous textures, absence of sphene and plagioclase, high modal percentage of quartz, and low weight percentage of TiO2 and Al2O3 showing a near concordance with the alumina content of marbles of the area. On the other hand, the plagioclase-amphibolites show, in addition to the disconnected sill-like form, relic sub-ophitic texture, high proportion of sphene and high weight percentage of TiO2 and Al2O3 indicating their primary igneous nature.
Mineralogy of the Fuller's Earth of Rajasthan, India
Authors: Singh Indra Bir 
Published: November 2024

Abstract
The paper incorporates the results of grain size and mineralogical investigations carried out on the clays of the Eocene Fuller's earth formation, collected from various localities in Rajasthan. The major clay mineral is palygorskite-attapulgite, The heavy mineral assemblage suggests a metamorphic provenance. The depositional environment of this Fuller's earth formation seems to be in alkaline, hypersaline coastal lagoons.
Detrital Radiolarian Cherts in the Subsurface Murree Formation of Suruin-Mastgarh Anticline, Jammu & Kashmir State
Authors: Khan K. N. , Raju A. T. R. 
Published: November 2024

Abstract
Detrital ferruginous chert rock fragments containing many radiolaria have been observed from one of the lithic arenite core sample of the Murree formation in a deep exploration well drilled on Suruin-Mastgarh anticline near Jammu. The age of these radiolarian cherts may range from Jurassic to Eocene. Presence of such reworked radiolaria in the Murree sediments indicates uplift of the main Himalaya providing partially material for the Murree sediments.
A Review of Geochemical Studies on Some Precambrian Plutonic Complexes of India
Authors: Sankaran A. V. 
Published: November 2024

Abstract
The important results of the application of trace element geochemistry to petrogenetic problems of the Indian Precambrian are reviewed. Such studies have gained importance only recently. Except for two major terrains comprising the Singhbhum granite in Eastern India and the Peninsular gneisses in Southern India, numerous rock complexes in other terrains have not been investigated in detail. The few available trace element data have provided insights into the emplacemental history of the Singhbhum and Soda granites and the associated mineralisation, and have also contributed to a better understanding of the nature of the Peninsular gneisses and some of the granites occurring within. The available data suggest a crustal heterogeneity in the Indian shield with respect to the granitophile elements.
Peninsular Gneissic Complex of the Dharwar Craton - A Suggested Model for its Evolution
Authors: Radhakrishna B. P. 
Published: November 2024

Abstract
The relationship between the gneisses and the greenstone belts of the Dharwar 'Craton is reviewed. Arguments for and against considering the gneisses as forming the basement, are presented and the evidences critically evaluated. Stages in the evolution of the craton are traced. The suggested model envisages the recognition of an older greenstone sequence, largely mafic and ultramafic in character followed by a major differentiation episode in the earth's upper mantle giving rise to a tonalite magma. The bulk of the gneisses forming the Peninsular gneissic complex is assigned to this major event which has not been repeated subsequently. The variations shown by the Peninsular gneisses are indicated to be the result of intimate mixing and interaction of the tonalite magma with the pre-existing mafic and ultramafic lavas and associated sediments. The banding and migmatitic character of the Peninsular gneisses is ascribed to plastic flow in response to relatively small directed stresses.
The suggestion is made that the greenstone belts of the Dharwar craton be split into two major stratigraphic units - an older, composed of mafic and ultramafic rocks of distinct chemical character, and a younger geosynclinal pile with a lower volcanic phase and an upper well-developed sedimentary phase. While the gneisses show an intrusive relationship with the older group, they form the basement for the younger group of lavas and sediments deposited in long linear basins. The suggested model explains a large number of related facts, reconciles the different views, and takes into account the prevailing conceptions of the evolution of the early crust in other parts of the world.
Geochemical Studies of the Precambrian of India: Suggestions for Future Research Work
Authors: Viswanathan S. , Radhakrishna B. P. 
Published: November 2024

Abstract
A critical evaluation of the scope, nature, and results of the geochemical researches so far conducted on the Precambrian of India, when viewed against the background of contemporary global trends, reveals that India lags very much behind countries like Canada, the U.S.A., South Africa, and Australia in this important discipline. To remedy, and even reverse this rather unfortunate situation, the paper proposes some major research projects aimed at elucidating (I) the geochronological evolution of the Indian Precambrian; (2) geochemical affinities and evolution of Early Precambrian volcanic-plutonic complexes; (3) nature of the Indian protocrust; (4) evolution of Iron formations and related chemical sedimentary rocks; (5) bio-geochemistry of the Indian Precambrian; (6) geochemical facies of granitic complexes; (7) Precambrian ore genesis and metallogeny in India; (8) evolution of Precambrian carbonatite complexes; (9) episodes of Precambrian volcanism and plutonism; (10) nature of 'cratonization' in Peninsular India; (11) core-mantle-crust differentiation in the Indian sub-continent; and (12) plate-tectonic regimes in the Precambrian of India, and related metallogenic provinces.
As fundamental geochemical researches on the Indian Precambrian are extremely relevant to India's planning for socio-economic uplift, because the results can be applied to projects aimed at locating new ore deposits, the paper emphasises that unless the Government of India sets up expeditiously a National Institute of Precambrian Geochemistry, it would be impossible for India to plan meaningful mineral exploration programmes in the future, and to catch up with the tremendous advances made in the western world. The structure of such an institute is outlined in Table I of the paper.
Rb-Sr Age Determinations for the Mount Abu Granite and Related Rocks of Gujarat
Authors: Crawford A. R. 
Published: November 2024

Abstract
The mount Abu Granite of south-western Rajasthan and related 'Erinpura type' granites in Gujarat give Rb-Sr total rock ages of about 735 m.y. They are therefore of the same age as the Malani Igneous Suite of western and south-western Rajasthan and not older as previously believed. Though possibly updated by re-heating related to emplacement of that Suite, it seems more probable that the two were emplaced at about the same time. This could have taken place in a tectonic environment created by sinistral shear of what are now northern and southern Peninsular India along the Narmada-Son lineament, with bending of the southern end of a rectilinear Aravalli orogenic belt by major fault drag.
A Petrological Study of Charnockites and Associated Rocks East of Chipurupalle, Srikakulam District, Andhra Pradesh
Authors: Perumal N. V. A. S. 
Published: November 2024

Abstract
Geological mapping of a 300 sq km area forming part of the Eastern Ghats, east of Chipurupalle, supplemented by modal analyses, optical petrographic data, and chemical analyses of seven whole-rock samples and a garnet, show that (1) basic charnockites of the area represent igneous rocks of noritic composition metamorphosed to granulite facies, and (2) some rocks of the area that resemble intermediate charnockites are metamorphosed hybrid rocks derived from assimilative reaction between basic magma and pelitic sedimentary rocks.
Lithostratigraphy of the Precambrian Rocks around Koira, Sundargarh District, Orissa
Authors: Murty V. N. , Acharya S. 
Published: November 2024

Abstract
A group of little metamorphosed volcanic and sedimentary rocks of Precambrian age belonging to the 'Iron Ore Series' of Jones (1934), comprising lavas, tuffs, banded iron formation, shales and quartzite-sandstone is preserved in a narrow, low, northplunging synclinorium with a well defined horse-shoe closure facing south in Bonai Subdivision, Sundargarh district, Orissa. Detailed mapping carried out by the authors in the southern part of the belt (in Bonai) has thrown new light on the stratigraphic relations of these rocks. The group is designated here the Koira Group, is subdivided, on lithological grounds, into five formations.
A Note on the Study of Movement of Beach Sand by Fluorescent Tracer at Paradip and Gopalpur, Orissa Coast, India
Authors: Shrivastava P. C. 
Published: November 2024

Abstract
The fluorescent tracer tests at Paradip and Gopalpur beaches on the Orissa Coast, India during June, 1971 indicate a north-easterly and shoreward movement of sediments. The direction of movement of sediments have been correlated with the wave approach, wind and currents in the area. The computed depletion rates for Paradip and Gopalpur were 9.9%, 4.7% and 2.4% per minute for the first 10, 20 and 40 minutes respectively. The computed average grain velocity was 5 m per minute.
Lithology and Age of the Tal Formation in Garhwal, and Implication on Stratigraphic Scheme of Krol Belt in Kumaun Himalaya
Authors: Valdiya K. S. 
Published: November 2024

Abstract
The Tal Formation, containing datable fossil assemblages in the Lansdowne hills in Garhwal, occupies a crucial position at the top of the 6100-metre thick succession of predominantly unfossiliferous sediments constituting the Krol Nappe. The lithostratigraphic unit comprising of (i) Lower Permian fossil-bearing black shale (often phosphatic), mudstone, conglomeratic greywacke and mudstone, (ii) a variety of sandstone of varied colour and (iii) sandy, oolitic and shelly limestone, lithologically indistinguishable and tectonically inseparable from the formation recognized as the Tal, the limestone of the upper horizon of which has yielded Upper Permian fossils. The lower member of the Tal progressively thins out southward until finally disappearing so that the considerably attenuated middle member and the upper limestone member rest directly on the Krol, thus exhibiting transgressive overlap.
The Permian Tal is unconformably capped by the Subathu of Eocene age, implying that the whole of Mesozoic group is missing in the Lesser Himalaya. The Krol which conformably underlies the Tal is not Permo-Triassic as commonly believed and the Blaini that rests upon the Nagthat cannot be equated with the Upper Carboniferous Talchir formation of Peninsular India. The occurrence of Lower Palaeozoic bryozoan remains in the slate and calcareous beds resting on the Nagthat quartzite in the Nandhaur valley, southeast of Nainital, corroborates the Lower Palaeozoic age assigned to the Blaini.
Depositional Environment of Oil Bearing Eocene Sands in Anklesvar Field, Cambay Basin, India
Authors: Raju A. T. R. , Rao M. R. 
Published: November 2024

Abstract
The depositional environments of Eocene oil and gas productive sands in Anklesvar field, which are referred to as middle and upper sands, have been studied from three main Jines of investigation, namely litho-associations, petrography and textural attributes. The middle and upper sands show subtle differences in their associational characters, petrographic features and size distributions. The middle sands, appear to have been deposited along distributory channels, over inter channel tidal flats and along tidal inlets in a tidal estuary. The upper sands, belonging to Upper Eocene, were probably deposited along a barrier beach in a transgressive open marine environment.
A Complexometric Method for the Rapid Analysis of Chalcopyrites and Copper Ore Concentrates
Authors: Ananthasubramanyam C. R. , Satyanarayana Rao H. S. , Vasudeva Murthy A. R. 
Published: November 2024

Abstract
A rapid volumetric method has been standardized for the estimation of copper, iron, lead and zinc with the help of EDTA. The method can be employed for the analysis of chalcopyrites and copper ore concentrates.
Microorganisms from the Kaladgi Basin, South India and Their Stratigraphic Significance
Authors: Viswanathiah M. N. , Venkatachalapathy V. , Mahalakshmamma A. P. 
Published: November 2024

Abstract
Studies of several clastic and non-clastic sedimentary samples collected from the' Kaladgi basin have yielded 19 species classifiable into 15 genera, besides a few organic plates: Microtaennia sp., Menneria roblotae, Costatosphaerina angustata, Concentrites muricatus, Protoleiosphaeridium problematicum, Spumiosa alara, Leiosphaeridia aglutinata, L. dhakshinii, L. insigna, Protoleiosphaeridium sp., Granomarginata sp., Vavosphaeridium reticulatum, Trachysphaeridium sp. Leiovalia oblonga, Schismatosphaeridium sp. The results of investigation of these Precambrian palynofossils facilitate assignment of Precambrian-Cambrian age to the Kaladgi sediments investigated. Based on the microfossils data intertidal shallow marine depositional environment is envisaged.
The Origin of Deogarh Amphibolites Udaipur District, Rajasthan, India
Authors: Somayajulu P. V. 
Published: November 2024

Abstract
Chemical and modal analyses of ten amphibolites from Deogarh area together with mineralogical data are presented. Using petrochemical plots based on Niggli values, the trends of variation suggest that the progenitors for these amphibolites were probably extrusive basic igneous rocks.
Microfacies and Depositional History of Strand-Line Carbonates of the Semri Series, Lower Vindhyan System, Banda District, Uttar Pradesh
Authors: Safaya H. L. 
Published: November 2024

Abstract
An analysis of microfacies and microsequence of the rocks of the Semri Series (Lower Vindhyan System), in the southeast of Banda, Uttar Pradesh, is presented. The analysis reveals that these rocks were deposited contemporaneously in three laterally juxtaposed environmental belts, namely, the supratidal, the intertidal and the subtidal. The vertical sequence, now representing the Semri Series, developed as a result of the seaward progradation of the environmental belts in response to a general regressive phase of the depositional basin.