bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Tantalite Pegmatite from Bihar, India
Authors: Babruvahan Rao K. 
Published: November 2024

Abstract
In the vicinity of Khairidih village-near Koderma is a tantalite pegmatite with a prominent quartz core trending in N35°w-s35°E direction. Presence of successive zones of contrasting composition and absence of successive replacements suggests that this pegmatite has formed by fractional crystallisation in a closed system. Along the strike from NW to SE direction the order of sequence of accessory minerals biotite, tourmaline, beryl, tantalite and monazite is observed with a little overlapping. This appears to be due to the combined effect of gravitational rise of pegmatite fluids along up dip direction during the formation of pegmatite.
Structural Framework in Delhi Group of Rocks with Special Reference to Interference Patterns: A Study Around Kushalgarh, North-Eastern Rajasthan
Authors: Gangopadhyay P. K. , Sen R. 
Published: November 2024

Abstract
The Precambrian Delhi Group of rocks, which extend along a northeast-southwest belt in Rajasthan, disclose the presence of superimposed folds. A limited area around Kushalgarh in north eastern Rajasthan has been structurally studied in detail to establish the relative influence of the successive generations of folds which control the distribution of different units of the Delhi Group.
At Kushalgarh area a special interest is the study of superimposition of a late generation of fold on an earlier one. The structural pattern of the Delhi Group of rocks is shown to be dependent on the manner of such superimposition.
Gravity Survey Over Bankura Anorthosite Complex, West Bengal
Authors: Verma R. K. , Ghosh D. , Roy S. K. , Ghosh A. 
Published: November 2024

Abstract
Results of Gravity surveys conducted over Bankura anorthosite complex lying between latitude 23°28.5' to 23°33'N and longitude 86°50' to 87°15'E are discussed. The area is characterised by a gravity high of the order of 20 mgals in the eastern part and decreases to 4-5 mgals in the western part. The gravity high is found to be unrelated to the anorthosite and extends beyond the outcrop of this exposure. It is attributed to the presence of a gabbroic body underlying the anorthosite and its adjacent areas. The thickness of anorthosite layer is found to be less than 200 meters. Assuming a density contrast of +0.23 gm/cc between the underlying gabbro and the surrounding Bengal gneisses, the maximum thickness of the gabbro is found to be 5.0 km in the eastern part near Rajarampur (23°29.7'N, 87°11'E). The causative body is found to be elongated along the strike of the anorthosite exposure. It appears to be faulted underneath the Damodar river along the northern as well as the northeastern sides.
The Origin of the Meta-Anorthositic Gabbros and Garnetiferous Granulites of the Sittampundi Complex, Madras, India
Authors: Janardhanan A. S. , Leake B. E. 
Published: November 2024

Abstract
The petrochemistry of the highly metamorphosed complex is discussed using new chemical analyses for major and trace elements of 21 meta-anorthositic hornblende gabbros, 9 mafic rocks, mostly garnetiferous granulites, and 15 country rocks and xenoliths. The igneous origin of the complex is confirmed, contrary to some earlier views that the anorthite-rich rocks were of metasedimentary calc-silicate origin. The granulites and meta-anorthositic rocks give congruent, and therefore consanguineous igneous trends of variation, suggesting that they crystallized from one magma being the mafic and felsic portions separated by variable crystal settling. The metamagmatic country rocks, especially the amphibolites, are not part of the same suite.
The importance of 'normalising' critical trace element contents (e.g, Cr, Ni, Sr) to constant mafic or felsic mineral percentage to allow for the widely differing abundances obtained from felsic-rich and mafic-rich rocks is demonstrated. The procedure allows igneous trends of variation to be much more critically appraised, and, in the present rocks, leads to the suggestion that some of the Cr in the meta-anorthositic rocks was originally present as chromite, a view in accordance with the occurrence of chromite-rich layers in the intrusion.
The hornblende in the meta-anorthositic rocks, which are pyroxene-free, is metamorphic in crystallization from the texture and the hornblende composition. Whether it is recrystallized primary igneous hornblende or was derived by metamorphism of pyroxene, olivine and plagioclase is uncertain. Some chemical criteria that might enable the crystallization of primary igneous hornblende, even when metamorphically recrystallized, to be recognised are suggested and although their application to the present intrusion does not lead to an unequivocal conclusion, they may be useful elsewhere.
Geomorphic Patterns and Processes in the Terminal Triangular Tract of Inland Streams in Sutlej-Yamuna Plain
Authors: Mukerji A. B. 
Published: November 2024

Abstract
The paper is based on field observation, analysis of aerial photographs, and interpretation of large-scale topographical sheets of the triangular tract located at the terminus of, and drained by the distributaries of the Markanda River in the state of Haryana. The size of the terminal triangular tract is shown to be directly correlated with size and discharge of the stream, the angle of divergence, frequency of divergence, and the number of lower-order distributaries.
Fluid Inclusion Geothermometric Studies of Some Indian Fluorites Using a Fabricated Heating Stage
Authors: Balasubramaniam K. S. , Panchapakesan V. , Sahu K. C. 
Published: November 2024

Abstract
The homogenisation studies of gas-liquid fluid inclusions in fluorites from Handev Dongar-Ambadongar (Gujarat) and Kahela-Mandokipal (Rajasthan) carried out with a fabricated heating stage corroborates the earlier view that both the deposits are typically of a low hydrothermal origin.
Strain History of the Pangin Synform of Siang District of NEFA Himalaya, As Deduced from Deformed Pebbles
Authors: Thakur V. C. , Jain A. K. 
Published: November 2024

Abstract
The deformed shapes of pebbles indicate that both the limbs of the Pangin Synform have suffered flattening-type deformation - the normal limb has undergone greater magnitude of flattening than the inverted limb. The longest axes of the pebbles, representing maximum elongation direction Of the tectonic strain ellipsoid, lie parallel and subparallel to the axial direction of the fold.
Sone Valley Talchir Glacial Deposits Madhya Pradesh, India
Authors: Ahmad N. 
Published: November 2024

Abstract
Glacial origin of Talchir deposits of India has long been accepted but along with this all the tillites have also been regarded as the lower most Talchir bed. The author has found that in Sone valley this is not true and the tillites are Upper Talchir in age. Beds older than Talchir tillite deposited under the floating ice shelf were met with in Johilla river and other sections.
The ice movement direction in Sone valley is indicated by the two striated pavements as from southeast to northwest. There is no evidence to support the conclusion drawn by some earlier workers that the ice may have come from Vindhyan Plateau in the north.
The Gonditic Rocks of Manbazar, Purulia District West Bengal
Authors: Mukherjee S. , Bandyopadhyay B. K. 
Published: November 2024

Abstract
The presence of a Gonditic rock unit is reported from Manbazar, Purulia district, West Bengal. It occurs as a distinct band cofolded with the associated metapelites into an isoclinal antiform followed to the west by a complimentary synform with granitic rocks occupying the antiformal core. The metasediments including the gonditic unit were metamorphosed under Upper Greenschist Facies conditions of regional metamorphism. Mineralogically it is composed mainly of quartz, spessartite, piedmontite, braunite, magnetite, specularite and ilmenite. The minerology and textural relationships indicate moderately high temperature and high oxygen fugacity under which the original sediments were metamorphosed.
Geochemistry of Amphiboles from the Precambrian of Karnataka
Authors: Anantha Iyer G. V. , Narayanan Kutty T. R. 
Published: November 2024

Abstract
Amphiboles from the Precambrian of Karnataka were analysed for major elements by wet chemical methods. Their cell edges were determined by X-ray powder diffraction technique, using Cr K a radiation. The chemical composition of the amphibole is correlatable with the grade of regional metamorphism. Chemical compositions of the Ca-amphiboles from the northern parts show low alkali and Al+ characteristic of tremolite-actinolite group corresponding to greenschist facies. The amphiboles of the middle region are common hornblendes with higher alkali and Al+, characteristic of amphibolite facies. Amphiboles from the southern parts are aluminous and alkali-rich with higher titanium and Fe3+/Fe2+ ratios. They coexist with ortho-or clinopyroxenes, suggesting their formation under granulite facies conditions. The restricted occurrence of sodic amphiboles in the Bababudans, and of cummingtonite-grunerite series in Kudurcmukh iron formations is due to their narrow P-T fields of stability and compositional fields. Anthophyllites from certain horizons of the Precambrian may be regarded as products of metasomatism.
Tectonics of the 'Marble Rocks' of Jabalpur, Madhya Pradesh
Authors: Agrawal V. N. 
Published: November 2024

Abstract
The' Marble Rocks' of the Narbada gorge, Jabalpur, Madhya Pradesh, appear to have a polyphase structural history. Of the three fold phases (F1 - F3) recognised in the metamorphic rocks of the Narbada section, west-southwest of Jabalpur town, only two are distinguishable in the Bhera ghat section-an early phase of tight folding on roughly easterly trending axes and a late phase of gentle folding on axes oriented transverse to the earlier fold trend. The early and late folds are, related to second (F2) and third (F3) fold phases respectively, in the region as a whole. Basic dykes cutting the marbles of Bhera ghat are shown to belong to two different ages-one highly metamorphosed and deformed and considered to be syntectonic with the early fold phase, and the other, practically unaltered and undeformed, of a post-tectonic, post-metamorphic age. Emplacement of quartz veins associated with the marbles is shown to have begun sometime during the early fold phase, continued through the late fold phase and outlasted it. Special features of the above rocks and those of the Sausar group are compared.
Konkanhundi Pluton: A New Layered Basic Intrusion from Karnataka
Authors: Ramakrishnan M. , Mallikarjuna C. 
Published: November 2024

Abstract
Konkanhundi pluton is the first recorded occurrence of a layered basic intrusion in Karnataka. It is an oval shaped mass having an area of 50km2 and is composed mainly of layered gabbro with cumulates of gabbro, norite and anorthosite, arranged concentrically. Non-layered norites are also conspicuous. Rhythmic layering is ubiquitous and cumulus textures are not uncommon. The pluton is emplaced into the gneissic complex of the Archaean high grade terrain. Subsequent to emplacement, it has been deformed and metamorphosed. It is considered to be a magmatic intrusion emplaced under plutonic conditions.
Thorium, Uranium and Lead Contents of Some Indian Zircons and Their Ages
Authors: Parthasarathy R. , Sankar Das M. 
Published: November 2024

Abstract
A number of zircon separates from-various localities of India were analysed for their uranium, thorium and lead contents. Uranium and thorium were analysed by neutron activation, and lead by anodic stripping methods respectively. Thorium, uranium and lead were found to vary between 60-250, 60-900, 8-90 ppm, respectively. The Th/U ratios are found to be in conformity with the accepted values for granitic or pegmatiticzircon. The elemental abundances have been used to calculate their chemical ages and the values compared with those reported in literature. The ages obtained in this study range from 400-800 m.y. These ages are comparable with the previous reported values.
Cadmium in Minerals from the Skaergaard Intrusion - A Further Study
Authors: Dissanayake C. B. 
Published: November 2024

Abstract
Cd has been determined in a suite of rocks and minerals from the Skaergaard intrusion, east Greenland by f1ameless atomic absorption spectrophotometry with the heated graphite atomizer. Cd is progressively enriched in the ultimate residual magmatic fractions. Among the minerals studied, Cd shows a distinct preference for ironrich pyroxene, olivine and titaniferous magnetite.
A study of the mode of entry of Cd into the minerals as discussed in terms of the number of Cd2+ ions per appropriate structural site reveals that despite the similarity of the ionic radius of Cd2+ and Ca2+ in octahedral co-ordination, Cd2+ ions appear to substitute more for Fe2+ in octahedral positions. It has been found that Cd enters octahedral sites in olivine, pyroxene and magnetite in approximately equal amounts. The poor entry of Cd2+ ions into the Fe2+ site of ilmenite is attributed to its highly distorted octahedral nature in addition to the presence of Fe2+ ions in the lattice.
Time-Space Relationship in the Metallogenetic Domains of Rajasthan
Authors: Jain R. S. 
Published: November 2024

Abstract
Two metallogenetic domains are discernible in Rajasthan, a copper domain towards northeast of Ajmer and a predominantly lead-zinc domain to the southwest of Ajmer along the Aravalli-Delhi strike. The metallogenetic domains can be correlated with the tectonic zones of the Aravalli-Delhi geosynclinal system. The earlier phase of sulphide mineralisation consisting primarily of lead and zinc in the Aravallis, is associated with the eugeosyncline, characterised by the presence of turbidites and ophiolites; while the latter phase of dominantly copper mineralisation in the Delhis is in the miogeosyncline, typified by comparative shallow water deposition and preponderance of acid igneous activity of the late stage of geosynclinal evolution.
Syngenetic ore formation with possible biogenic processes has played dominant role in the lead-zinc mineralisation in the eugeosyncline. Hydrothermal activity related to post-Delhi acid intrusives has influenced the copper mineralisation in the miogeosyncline. Both the domains have borne the stresses of repeated orogeny, which have reoriented ore localisation.
Differentiation of the Deccan Trap Basalt Flow in Bombay Island
Authors: Sethna S. F. , Merchant Hemant 
Published: November 2024

Abstract
The basalt flow in the Malabar, Cumbala, Worli and Bandra Hills is the youngest lava flow in Bombay Island. It has been riddled by a network of thin veinlets which were in the past thought to be of secondary origin. A detailed examination has revealed that these veins are microaplitic and of an early hydrothermal phase being composed of alkali felspar, quartz and some hydrothermal crystallisation of quartz, zeolite, adularia and fluorite. The formation of these veins has been attributed to late stage differentiation of basaltic lava. This is perhaps a unique example of differentiation of basaltic magma after extrusion.
Occurrence of Rhyolytic Tuffs at Deep Sea Drilling Project Site 219 on the Laccadive Ridge
Authors: Siddiquie H. N. , Sukheswala R. N. 
Published: November 2024

Abstract
A study of thin sections from the lower and middle parts of Unit V (Paleocene) from Site 219shows that these largely consist of acidic or rhyolitic tuffs. The overlying limestones in Unit V (Paleocene) and Unit IV (Lower Eocene) also contain tuffaceous material in varying proportions. Albite/oligoclase forms the phenocrysts as also needles in the groundmass of these tuffs and tuffaceous material in limestones. The euhedral fresh felspars suggest that the source of activity was nearby and possibly most of the activity was subaqueous rather than subaerial. Similar acidic tuffs in the Deccan Traps have been reported particularly from the West Coast of India. The acidic tuffs at site 219 are of the same age as the Deccan Traps and may represent a late phase of Deccan Trap activity on the Laccadive Ridge before its subsidence and separation from peninsular India.
Ore Elements in the Metavolcanics of Ingaldhal Karnataka State, India, as Possible Guides in Ore Search
Authors: Hegde M. P. , Aswathanarayana U. 
Published: November 2024

Abstract
Sixteen samples of metavolcanics of Ingaldhal have been analysed for sulphur and for Cu, Co, Ni and Zn (in the hydrogen peroxide-ascorbic acid leach solution). There is no visible mineralisation where the S content in the metavolcanics is below 200 ppm. A sulphur content of more than 500 ppm and/or a copper content of more than 200 ppm in the hydrogen peroxide-ascorbic acid leach, may be indicative of economically important copper mineralisation in the Ingaldhal-type metavolcanics. Mineralised metavolcanics are apparently characterised by higher Cu/Ni (&gt; 90)& Cu/Co (&gt; 60) ratios and lower Co/S(&lt; 0.03) & Ni/S (&lt;0.02) ratios than barren metavolcanics.
Some Significant Palynomorphs from B Member of the Jutogh formation of Simla Hills
Authors: Sah S. C. D. , Maithy P. K. , Bhargava O. N. 
Published: November 2024

Abstract
The paper outlines the preliminary results of a palynological study of a carbonaceous phyllite sample from the B Member of the Jutogh Formation of Simla hills. Systematic descriptions are given for 5 genera and 6 species of acritarch assemblage recovered. Among the species described, five are new. Microfloral evidence favours a Lower Cambrian age for the bed.
Structural and Metamorphic Evolution of the Bengal Anorthosite and Associated Rocks
Authors: Roy Asit K. 
Published: November 2024

Abstract
The anorthosite is emplaced along the core of a doubly plunging (east-west) antiformal structure developed on the lithologic contacts of the associated metasediments and metanorites.
In the first phase of deformation (prior to the emplacement of anorthosite) the country rock together with numerous noritic sills was metamorphosed to pyroxene granulite facies. During the second phase of deformation a hydrous gabbroic anorthosite magma was synkinematically emplaced and slowly consolidated expelling considerable amount of water-rich volatiles which permeated the associated rocks. Metanorites (pyroxene granulites) and anorthosites were then metamorphosed to hornblende granulite facies followed by local diaphthoresis to greenschist-amphibolite transition facies. At the waning of deformation, palingenesis of the leptynites at places resulted in younger microcline-granites which brought about metasomatic changes in the anorthosite.
On Some Geochemical Aspects of the Sevattur Carbonatite Complex, North Arcot District, Tamil Nadu
Authors: Krishnamurthy P. 
Published: November 2024

Abstract
The major and trace element compositions of the Sevattur carbonatites are broadly comparable with the 'typical carbonatite abundance' values compiled by Gold (1966). The mean values for the Sevattur carbonatites are as follows (in weight per cent): SiO2-2.60, Al2O3-2.49, TiO2-0.46, Fe2O3 + FeO-9.64, MnO-0.52, MgO-10.14, CaO-32.84, Na2O-0.85, K2O-0.49, P2O5-3.48, CO2-36.15, H2O±0.32, with trace elements in parts per million as: Ba-1663, Sr-6427, Zr-763, Rb-2, La-271, Ce-641, Y -41, Nb-78, Ta-34, SC-16, Zn-69, Cu-78, Ni-18, Pb-27.
There is an enrichment of total iron, MgO, MnO, P2O5 and Na2O with successively younger phases within the main carbonatite body and such a feature is comparable with the liquid lines of descent, observed in synthetic carbonatite systems. Fenitisation of the country rocks (granitic gneisses) along the southern border of the carbonatite body is indicated from the enrichment of K2O, Na2O, Al2O3 and impoverishment in SiO2, total iron and MgO in the fenites when compared with the country rocks.
Sr (4109-9375 ppm, mean 6427) exceeds Ba (1000-2420 ppm, mean 1663) in all the types of carbonatites by a factor of 2 to 5. The lighter rare earths such as La and Ce are enriched in the calcitic types (La + Ce, 892-1351 ppm) when compared to the beforsites (647-920 ppm). In general, the beforsites are richer in Ba, Nb, Ta and Sc.
Among the carbonatitic minerals, early calcites are much enriched in Sr (5500-6200 ppm) in comparison with Ba (1230-1700) by a factor of 3 to 5. Sr with successively younger fractions of the carbonatite, seems to show a preference to the dolomites (3500-4000 ppm in the early phases and 9000-11000 ppm in the later phases) rather than to the apatites (6200 ppm). No systematic variation has been found in the Sr content of the different carbonatitic minerals within a particular carbonatite type.
The study emphasizes the importance of chemical data as one of the essential parameters in identifying carbonatite complexes from doubtful occurrences and also in elucidating their evolution. The study confirms the earlier observation that the carbonatites of Sevattur belong to the apatite-magnetite type.
Paleogeographic Evolution of a Part of the Indo-Gangetic Trough from the Late Tertiary to Recent
Authors: Parkash B. , Goel R. K. 
Published: November 2024

Abstract
Synthesis of the stratigraphy, paleocurrents and depositional environment of the Siwaliks and sediments suggests that Lower and Middle Siwaliks were deposited predominantly in the form of overlapping, mega alluvial cones of rivers emerging from the Himalaya and flowing southward. Forerunners of some of the modern rivers of great antiquity played an important role in their deposition. During the Upper Siwalik times the Himalaya attained great heights and several important rivers developed on the southern slopes of the central range and deposition continued as before with the difference that a wide piedmont deposit of coarse conglomerate formed near the foot hills. During Siwalik times, an easterly flowing river close to the southern boundary of the area of deposition drained the rivers emerging from the Himalaya.
The present geomorphic set up is essentially a continuation of the one developed during Siwalik times with only minor changes.