bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sediments of the Western Continental Shelf of India-Environmental Significance
Authors: Shankaranarayana Guptha M. V. 
Published: November 2024

Abstract
The degree of fragmentation and colour of the skeletal fragments, colouration in benthic foraminifers have been studied in surficial sediment samples collected from forty stations from the continental shelf region between Ratnagiri in the south and Indus canyon in the north. The abundance peaks of fragmented shells correspond to the terrace depths of -65, -75, -85 and -92 m in the outer shelf region off Ratnagiri which indicate the different phases of eustatic sea levels. It is inferred from the occurrence of abundance peaks at similar depths in the other regions of the continental shelf that they must correspond to the presence of lowered strands. The disposition of the black shells in a linear fashion parallel to the coast line at the depths mentioned above also supports the proposition.
Metamorphic History of the Sandur Schist Belt, Karnataka
Authors: Roy Abhinaba , Biswas S. K. 
Published: November 2024

Abstract
The Sandur schist belt is predominantly characterised by greenschist facies of regional metamorphism, which increases to amphibolite facies near the periphery of the schist belt. The higher facies rocks are marked by the appearance of metamorphic index minerals like garnet, andalusite, staurolite and cordierite. Study of the 'Si - Se' tectonites suggests that metamorphism is progressive, where chlorite and micas grow 'synkinematically' and garnet, andalusite, staurolite and cordierite grow post-kinematically with reference to first phase of folding (F1). Static growth of garnet, andalusite, staurolite etc., following the first phase of folding (F1), and their subsequent rotation with reference to second phase of folding (F2) clearly indicates a time gap between F1 and F2. Formation of assemblages of higher grade metamorphic minerals along the border region of the schist belt, is possibly due to influx of additional heat from some source (? intrusi ve granite) at a late tectonic stage.
Superposed Folding in the Lower Vindhyans of Dala-Gurma Area, Mirzapur District
Authors: Sharma R. P. 
Published: November 2024

Abstract
The Semri and Kaimur Series in the Son valley region have undergone two phases of deformation. The first phase structures are penetrative recumbent folds, minor puckers and kinks. The second phase structures are open folds of varying wave lengths. The deformation is a post-Kaimur event. Markundi fault seems to have existed before folding.
Crustal Structure Along Kavali-Udipi Profile in the Indian Peninsular Shield from Deep Seismic Sounding
Authors: Kaila K. L. , Roy Chowdhury K. , Reddy P. R. , Krishna V. G. , Narain Hari , Subbotin S. I. , Sollogub V. B. , Chekunov A. V. , Kharetchko G. E. , Lazarenko M. A. , Ilchenko T. V. 
Published: November 2024

Abstract
Deep Seismic Sounding (DSS) studies were initiated for the first time in India under a 3-year Indo-Soviet collaboration agreement starting 1972, along a 600km long roughly ENE-WSW profile which lies near 14°N latitude, extending from Kavali on the east coast of India to Udipi on the west coast.
A crustal section is depicted along the Kavali-Udipi profile, showing a large number of reflectors from about 2 km to about 50 km depth. The 600 km long section consists of 17 major blocks, besides a few smaller ones. It is cut up by 15 major deep faults and two major low angle thrusts. In addition there are 5 faults/thrusts extending to intermediate depths. The geological evolution of this part of the shield probably began in Early Proterozoic with the formation of the Dharwar geosyncline between Parnapalle and Agumbe, This was divided into two parts by the uplift of the block where Closepet granites are now exposed. The Dharwars in the eastern part are now almost completely eroded, exposing their basement. The Moho here is at an average depth of 35-36 km, going down to 38 km below Dharmavaram. In the western part, where there is a large thickness of Dharwars still present, Moho is more or less flat at a depth of 38 km, going down to 41 km below Holalkere and rising about 36 km below Chennagiri, The basement of the schist belt here varies from 4 to 7 km in depth.
The Cuddapahs must have been deposited starting near Parnapalle eastward due to en-echelon type faulting. Moho goes down from 34km below Parnapalle to 40 km below Duttaluru. The block between Maidukuru and Malepadu subsided later to create a fresh depression in which the Kurnools were deposited. In general, the basement of the Cuddapahs is at a depth of 8-10 km. The Cuddapahs, on their eastern margin, have been subjected to a major low angle thrust.
Geochemistry of Archaean Granites of the Indian Shield: A Review
Authors: Saha A. K. 
Published: November 2024

Abstract
Archaean granites and granite gneisses are known to occur in (a) the Iron Ore Province of Singhbhum-Orissa region in eastern India, (b) the Granite-Greenstone Belt of Karnataka and Andhra Pradesh, (c) the Granulite Belts of Tamil Nadu and Kerala and (d) the Bundelkhand-Rajasthan Precambrian province.
In the Iron Ore Province of Singhbhum region, the Older Metamorphic tonalite-gneiss (OMTG-c. 3200 Ma) has strong geochemical resemblance with the 'Ancient tonalite-gneiss' of Barberton. South Africa. The low initial 87Sr/86Sr ratios (0.7018-703) for the total-rock Rb-Sr isochrons indicate derivation of the tonalitic melt from the mantle perhaps in a two-stage process. The magmatic units of the composite batholith of Singhbhum Granite (2900-3000 Ma) show distinctive trends of fractional crystallisation for the three successive but closely related phases. Multivariate analysis of variance of the trace-element data indicates statistically significant differences among the phases while Rsmode Factor analysis suggests operation of significantly different processes of trace-element distribution in the three phases. The geochemical relationship as well as the high initial 87Sr/86Sr ratio of 0.711 ± .009 suggest that the three magmatic phases were derived by partial melting successively in the same source region of the crust. The Bahalda metasomatic unit of Singhbhum Granite shows certain abnormal trends of trace-element variations in the sequence: hornblende schist?hornblende diorite?shornblende (-epidote) granodiorite. These have been explained by assuming that during progressive granitisation, (a) ionic charge and electronegativity have been relatively ineffective and (b) certain trace-elements are preferentially incorporated in some preexisting minerals.
The Peninsular Gneiss and associated Archaean granitic bodies in the Granite Greenstone Belt of South India show wide compositional variations ranging from migmatitic and tonalitic gneiss through granodiorite to K-rich adamellite. These rocks show clusters of Rb-Sr isochrons at 3200-3300Ma, 2900-3000Ma and around 2600Ma. Enrichment of nickel and chromium in parts of these gneisses has been reported. Although a metasomatic origin of the Peninsular Gneiss has been suggested, the low initial 87Sr/86Sr ratios (0.701-0.704) do not support this view and instead indicate direct or multi-stage derivation of the granitic melt from the mantle. Occurrence of several abnormal U-Th enriched granite bodies within Peninsular Gneiss is of special interest.
The Bundelkhand Granite is a composite body of several granitic and gneissic units and appears to be dominantly adamellitic - monzonitic in composition (2555 ± 55 Ma), but has numerous xenoliths and rafts of migmatite and gneiss, mostly of granodiorite and tonalite composition.
It appears that in the Indian shield, the oldest gneisses and granites (&gt; 3000 Ma) are dominantly tonalites while adamellitic granites become more and more abundant in the younger assemblages.
Some Studies on Hydrologic Parameters of Groundwater Recharge in Andhra Pradesh
Authors: Karanth K. R. , Srinivasa Prasad P. 
Published: November 2024

Abstract
Broad correlation is recognized between infiltration characteristics and basin yields. Rainfall infiltration factor has been estimated by different methods for different soil groups and topographic characteristics, as ranging from 5 per cent in predominantly hilly catchments to as much as 40 per cent in plain sandy catchments. Infiltration from applied irrigation also constitutes one of the major sources of groundwater recharge, and is found to vary from 30 per cent to over 80 per cent depending on depth of water table and soil characteristics. A linear relationship between the paddy field infiltration ratio and the logarithm of uniformity coefficient of soil is inferred from the studies. The infiltration from tanks is estimated to range from 2 to 114 mm per day.
Geochemistry of the Archaean Metavolcanic Rocks of Kolar and Hutti Gold Fields, Karnataka, India
Authors: Ananta Iyer G. V. , Vasudev V. N. 
Published: November 2024

Abstract
Geochemical data on Archaean goldfields metavolcanics (2.7 b. yrs) have been plotted on major and minor element discriminant diagrams to define the magma type and to formulate the tectonic environment model for the origin of these ancient volcanic rocks. The meta basalts of Kolar and Hutti (Karnataka, South India), Norseman (Eastern Goldfields, Western Australia). Steynsdorp (Barberton, South Africa) and Yellowknife (Canada), plot within the field of mid-ocean ridge basalts (MORB). The marginal basin basalts (MBB) of South Sandwich Islands of Scotia Arc Region of Phanerozoic age also plot within the field of MORB. Unlike the depleted MORB, the MBB are enriched in certain large ion lithophile (LIL) elements with higher Rb/Sr, Ba/Sr and lower K/Ba ratios. Further, in contrast to MORB, they exhibit slightly enriched LREE patterns. The LIL element enriched goldfield volcanics of Kolar, Hutti, Norseman, Steynsdorp and Yellowknife, with their slightly enriched LREE patterns, compare more favourably with MBB than with MORB. Based on geochemical features and geological setting, marginal basin model is proposed as the most favourable tectonic environment for the generation of gold bearing Archaean greenstone belts of Kolar and Hutti.
Rb-Sr Chronology of the Khetri Copper Belt, Rajasthan
Authors: Gopalan K. , Trivedi J. R. , Balasubrahmanyan M. N. , Ray S. K. , Anjaneya Sastry C. 
Published: November 2024

Abstract
Rubidium and strontium determinations are reported for the Udaipur and Saladipura granites from the Khetri copper belt. The whole-rock data define a Rb-Sr isochron corresponding to an age of 1480 ± 40 m.y. and initial Sr ratio of 0.7131 ± 0.006. This age is older than previously believed, but consistent with the generally high age of post-Delhi intrusive rocks so far dated in the region. Biotites associated with these rocks give younger ages around 700 m.y, This indicates mobilisation of Sr isotopes in a later metamorphic event. It is significant that this secondary event is almost synchronous with the intrusion of granites to the west and south of the Aravalli mountains.
A New Stegosaurian Dinosaur from Upper Cretaceous Sediments of South India
Authors: Yadagiri P. , Ayyasami K. 
Published: November 2024

Abstract
The paper records the occurrence of a stegosaurian dinosaur with partial skull, tooth, sacrum, pelvic elements, armour plates and spike, from the marine Cretaceous rocks' of the Trichinopoly Group, Tamil Nadu. The bed yielding the dinosaurian fossils is assigned Coniacian age on the basis of rich ammonoid fauna which includes Kossmaticeras theobaldianum. The dinosaur is described as a new genus and species Dravidosaurus blanfordi. The stratigraphic and palaeontological significance of this report in indicating the survival of armoured dinosaurs till the close' of Mesozoic in the southern part of India is discussed.
Quantification of Foraminiferal Biofacies and Reconstruction of Palaeobiogeo-Graphy of the Cauvery Basin
Authors: Banerji Ranjit K. , Sastri V. V. 
Published: November 2024

Abstract
The paper deals with broad principles of quantified foraminiferal palaeoecology involved and their application in reconstructing the palaeoenvironments for different stratigraphic units (Upper Jurassic-Lower Palaeogene in age) exposed in the western part of the Cauvery Basin. The parameters used are the functions of structurally related characteristics and morphogenetic diversities of the foraminiferal fauna which are resultant of the environmental requirements, tolerance and preferences. The first sedimentary cycle started with fresh water deposits which soon gave way to brackish water and later continued under dominantly marine influence. The major transgressive phases during Neocomian-Albian, Senonian and Paleocene are better reflected in the quantitative bio-facies analysis. Along certain palaeomarginal highs, the environment favoured reef development where terrigenous influx was minimum. The strand-line progressively shifted since Lower Cretaceous times from west to east. The shift during Lower-Middle Eocene was more prominent and a delta front progressively started building with regression in the region bordering the western margin. The resultant sediments now cover a greater part of the exposed area and form the youngest exposed stratigraphic unit of this Basin.
Upward Regressing Energy Sequences in a Limestone Section from the French Jura
Authors: Dahanayake Kapila 
Published: November 2024

Abstract
Textural and compositional studies of a limestone section from the Upper Jurassic of the French Jura Mountains reveal a series of sequences of lithofacies, each sequence marking a progressive reduction of water turbulence (energy). The Limestones are oolitic, pelletiferous and oncolitic packstones, wackestones and mudstones.
Palaeobiology and Organic Geochemistry of Archean Helen Iron formation, Michipicoten Area
Authors: Karkhanis Suresh N. , Goodwin A. M. , Ponnamperuma Cyril 
Published: November 2024

Abstract
Diamond Drill Core (D. D. H. U-2-647) samples of approximately 2.75 b.y. old Helen Iron Formation of Michipicoten area in the Superior Province of the Canadian Shield have been examined for morphological and molecular fossils. Evidence shows two types of bioforms - simple micron-sized filamentous microstructures resembling present day iron bacteria and laminated structures designated as cryptalgal mats.
Organic geochemical studies have shown that a variety of organic compounds is present. These include n alkanes, isoprenoid hydrocarbons pristane and phytane and fatty acids. The exact syngenetic nature of these compounds will be evaluated in the future by appropriate control experiments such as permeability measurements, diffusion studies, etc.
Presence of pristane and phytane is indicative of high photosynthetic activity. Predominance of n-C16 (palmitic) acid is significant in view of it being the major constituent of the cell membrane of an organism.
The morphological and molecular evidence and previously reported carbon and sulphur isotope data further substantiate the existence of autotrophic organisms and reducing bacteria in Archean times and they were operative during accumulation of these ancient Precambrian chemical sediments.
Textural Analysis of Red Sediments from Visakhapatnam District, Andhra Pradesh
Authors: Raman C. V. , Rao A. T. 
Published: November 2024

Abstract
The red sediments of Recent age confined to the slopes of hill ranges and along the coast of Visakhapatnam and Bhimunipatnam are classified into inland and coastal red sediments. The textural analysis reveals that the inland red sediments are poorly sorted with negative skewness, and the coastal red sediments are better sorted and positively skewed. Beach samples are well sorted Showing both positive and negative skewness. In the light of skewness patterns it is concluded that the coastal red sediments were laid down in a depositional environment, whereas inland red sediments belong to an erosional or non-depositional environment and further that these clastic red sediments are immature and have formed under a fluvial environment.
On Olivines and Pyroxenes of Amjori Sill, Similipal Complex, Mayurbhanj, Orissa
Authors: Chennakesavulu N. , Sahu K. C. 
Published: November 2024

Abstract
Olivine is found to have a short range of composition. Orthopyroxenes take up a significant amount of wollastonite molecule in the later stage. Clinopyroxenes show a large scatter in the endiopside-augite field. Fractionation of Fe and Mg among the minerals characterises crystallization from a slowly cooled layered intrusive. The trend of crystallization, of all the three minerals conform to a tholeiitic parentage.
Basement Slices within the Cover Sediments Near Hakegora and Jaikan, South of Tatanagar, Singhbhum District, Bihar
Authors: Mukhopadhyay Dhruba , Dasgupta Sabyasachi , Dhar Kunal 
Published: November 2024

Abstract
A sequence of metasediments with conglomerate at the base, unconformably overlies the Singhbhurn Granite. The direction of younging in the arkose-conglomerate is towards north, away from the granite border. Wedges of basement granite were emplaced as thrust slices within the metasediments at the earliest stage of deformation. The soda granite also occurs as a sheet like concordant body and is highly deformed and in places rnylonitized. The soda granite may also represent a tectonically emplaced slice of the basement.
Alkaline Magmatism in the Deccan Volcanic Province
Authors: Bose Mihir K. 
Published: November 2024

Abstract
Alkaline magmatism in the Deccan volcanic province is characterised by i) relative spatial restriction, being manifested in the western and northwestern parts of the province, ii) development of alkaline rock assemblages in plug like bodies and hypabyssal minor intrusions, iii) alignment of magmatic activities along three (or four) volcanotectonic belts meeting near the gulf of Cambay, iv) pronounced fractional crystallisation of parent alkali basaltic magma often leading to wide spectrum of rock composition and v) relative rarity of effusive alkaline rocks.
The ultimate derivative of fractionating alkaline basic magma is usually a hypersolvus foid syenite. Alkaline ultrabasic rocks (melteigite-ijolite) in association with carbonatites are developed in a few plugs. Alkaline minor intrusions of wide compositional variation, are largely associated with subvolcanic plugs and a few volcano tectonic belts. In comparison, effusive alkaline rocks are rare in the province. Manifestation of alkaline lavas together with picritic basalts and spilite in western India reflect unique structural setting of this terrain.
Available petrological, geomorphological and geophysical data all point to a plume activity in the present Cambay region and this appears to be the major controlling mechanism for alkaline magmatism.
Inverted Metamorphism in the Sikkim-Darjeellng, Himalaya, India
Authors: Banerji P. K. , Guha P. K. , Dhiman L. C. 
Published: November 2024

Abstract
Inverted metamorphic sequences from chlorite zone phyllites grading progressively upwards into staurolitc/kyanite zone schists and gneisses with associated granitic bodies occur intermittently in the Lower Himalaya from Kumaon to Sikkim. In Sikkim-Darjeeling area, this progressive metamorphism is broadly late-kinematic with respect to the polyphase fabric elements in the metasedimentaries and is broadly coeval with the emplacement of metasomatic/anatectic granitic masses, which occur as low to moderately dipping sheets within both greenschist and amphibolite facies metasediments and carry I-type enclaves. Locally, strong, gravity induced polarity has concentrated metasomatic transformations along the hanging wall sections of the granite.
This 'inverted' metamorphism, as well as positive gravity anomaly gradients and shallow focus seismicity in this sector, are correlative with differential vertical displacements, which have exposed the naturally inverted metamorphic sequences along footwall sections of moderately dipping intrusive masses. LANDSAT and air photo interpretations of various types of linears and lineaments with supporting indications from the location of hot springs, lakes, water falls, abrupt changes in river gradient, truncation of marker bands and erraticity in terrace distribution, suggest that the area has been witnessing differential uplift along a number of regional and local sub-vertical fault surfaces including a number of geofaults, some of which are transverse to the axis of the range in a crypto-aulacogen style. This tectonic regime appears to be an integral part of postorogenic processes in Sikkim-Kumaon Himalaya possibly extending eastwards up to Arunachal Pradesh.
Diagenetic Features in Sulphides of Dariba-Rajpura Deposit, Udaipur District, Rajasthan
Authors: Pandya M. K. , Solanki S. L. , Pandya T. K. 
Published: November 2024

Abstract
Mineralisation is mainly confined to kyanite-graphite-quartz-mica schist, meta chert (chert and its recrystallised form) at places interbanded with quartzite, calc silicate rock, and impure marble. Sulphide ores reveal a variety of diagenetic structures: diagenetic dykes, diagenetic fracture filling, stylolite seams in sulphide-cherty rock and cementation of silicate minerals by sulphide grains.
Uranium Mineralisation in Sikar District, Rajasthan
Authors: Narayan Das G. R. , Sharma D. K. , Singh Govind , Singh Rajendra 
Published: November 2024

Abstract
Uranium mineralisation of segregated type consisting mostly of uraninite and less commonly of brannerite has been noted in the pink quartzo-feldspathic or aplitic emplacements along shear zones in Rohil-Ghateshwar-Khandela-Diara and Saladipura area in Sikar district of Rajasthan. Ilmenite, molybdenite, pyrrhotite, chalcopyrite and pyrite are noted along with uraninite.
Mineralisation is controlled by structure and generally occurs along linear shears that are parallel to the main tectonic lineament. In Ghateshwar area, the mineralised quartzo-feldspathic emplacements have undergone refolding along with the rest of the formations. Uranium mineralisation is near to the main tectonic lineament that passes through the axis of the Ajabgarh synclinorium. Integrated radiometric and hydrogeochemical surveys have indicated continuity of the uranium bearing quartzo-feldspatbic emplacements along a 16 km belt.
The Salwari fluorite occurrence 10 km NE of Khandela is a post feldspathic emplacement and probably formed during the final phases of mineralisation.
Pebble Strain Analysis in the Raghunathpalli Conglomerate of Gangpur Group, Orissa, India
Authors: Chaudhuri A. K. , Pal A. B. 
Published: November 2024

Abstract
Shape analysis of a large number of pebbles from a 60 km stretch of the basal Raghunathpalli conglomerate in the Gangpur Group in eastern India, indicates that a flattening strain on originally constricted pebbles during the earliest folding episode gave rise to the present shape of the pebbles. The longest and the intermediate axes of pebbles lie invariably on the schistosity developed parallel to the axial planes of the earliest isoclinal folds. Though the Gangpur Group shows a remarkable multideformation plan, the pebbles show mainly the effects of the earliest deformation.
Depositional Environments of the Binge Bay Near Karwar, West Coast of India
Authors: Kumar Surendar 
Published: November 2024

Abstract
A large part of the area of the Binge Bay is floored by well sorted, medium to fine sand. The mean size of the sediments generally decreases with increasing depth and distance from the land. Variation in skewness from the Anjidiv Island to the middle of the Bay can be related to the mixing of two or more grain size populations in various proportions. An overall decrease in the weight per cent of total heavy mineral contents also is observed from the beach to the middle of the Bay. Fine muddy sediments are found in the regions of the main bathymetric low. Such variations occur as a result of decrease in velocity of the transporting tidal currents. The sign of the skewness is sensitive to the environment.