bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foraminiferal Biostratigraphy of Meso-Cenozoic Sequence of the 'Cauvery Basin, South India
Authors: Banerji Ranjit K. , Mohan Radha 
Published: November 2024

Abstract
In this paper, an unified regional foraminiferal biostratigraphic zonation scheme for the Albian to Burdigalian sequence of the Cauvery Basin is presented. In all twenty-six zones and a number of sub-zones are delineated. Their typical sections, geographic extensions, important foraminifera and geologic age are described in detail. A number of faunal datum lines are also recognised. This type of zonation will serve as the basis of reference for the stratigraphic section, outcrop or sub-crop, of the entire Cauvery Basin as well as other sedimentary basins of India in terms of its precise and relative time-stratigraphic level.
Some Non-Diastrophic Structures in the Lower Siwalik of the Haldwani-Tanakpur Area, Uttar Pradesh
Authors: Rao Y. S. N. , Rao D. P. , Rahman A. A. 
Published: November 2024

Abstract
Some structures of non-diastrophic origin - are described from the Lower Siwalik (Nahan) strata of the Haldwani-Tanakpur area. Some are epigenetic and the others are syngenetic or penecontemporaneous. The epigenetic structures simulate structures formed due to the penecontemporaneous slumping of sediments; but the presence of cross-bedding passing undisturbed through them negates this mode of origin. They are considered to be due to 'Liesegang banding'.
Among the syngenetic or penecontemporaneous structures are groove casts which are uncommon in Siwaliks. It is suggested that though there might have been occasionally grooving, the grooves were rarely preserved because of the turbulence of the environment. The other structures described comprise those due to slump deformation and intrusion of soft sediments, and those due to organic activities.
Some Orthopyroxene-Bearing Rocks Constituting an Integral Part of High-Grade Metapelites of Satnur-Halaguru Area, Mysore State
Authors: Devaraju T. C. , Sadashivaiah M. S. 
Published: November 2024

Abstract
Orthopyroxene-bearing rocks viz., quartz-norite, cordierite-biotite-hypersthene granulite, leptynite and hypersthene-biotite quartzite containing minerals like hypersthene (aluminous), diopside, brown hornblende, biotite, garnet, cordierite, plagioclase and quartz, occur constituting an integral part of the high-grade metapelites of the area. The field and petrological observations suggest that these orthopyroxene-bearing rocks are variants of the metapelites, derived by the metamorphism of appropriate sediments and have no connection with the associated charnockites of the area.
An Edge Notched Card System for Marine Geological Data
Authors: Karunakaran C. , Siddlquie H. N. 
Published: November 2024

Abstract
The note describes a simple data processing and retrieval system designed for marine geological data. The data for each station are recorded on a single card (18 cm × 14 cm) with mainly a single row of 101 holes; about 97 different data can be coded on a single card. The system has already been put into operation; and to begin with, data for about 140 stations have been coded on the cards, and more are being coded as the information becomes available.
Precambrian Carbonatites of Tamil Nadu, South India
Authors: Borodin L. S. , Gopal V. , Moralev V. M. , Subramanian V. , Ponikarov V. 
Published: November 2024

Abstract
The newly discovered carbonatites of Tamil Nadu are Upper Precambrian in age. They are associated with alkali syenite massifs in Tirupattur area, where the fault system directed NE-SW, very likely represents an ancient deeply eroded trough or rift valley. The carbonatites are mostly beforsitic (para-ankeritic); and pyrochlore mineralization found here is unique in the world, as in general pyrochlore is not reported from beforsitic carbonatites. Both geological setting and petrological features support the view that the Tamil Nadu carbonatite province differs in many respects from Narmada Valley province in India as well as from other carbonatite provinces all the world over.
Thrust Faulting and Related Structures in the Bannikoppa-Bagewadi Conglomerates of Gadag Schist Belt
Authors: Gokhale N. W. , Gothe N. N. , Koppad V. B. 
Published: November 2024

Abstract
The Bagewadi and the Bannikoppa conglomerates occupy a significant position in the Gadag belt. A detailed investigation of these conglomerates has revealed many important features regarding their origin and structure. The earlier workers reported the occurrence of a band of greywacke to the east of Bagewadi conglomerate. The present investigation bas shown that this is a micro-breccia and not a greywacke, and was formed due to the intensive brecciation of the eastern portion of the Bagewadi conglomerate. This brecciation was caused by a thrust fault. The Bannikoppa conglomerate constitutes the 'Klippe' structure.
Tectonic Framework and Subsurface Stratigraphy of the Ganga Basin
Authors: Sastri V. V. , Bhandari L. L. , Raju A. T. R. , Datta A. K. 
Published: November 2024

Abstract
Significant data on the structure, tectonics and stratigraphy of Ganga basin have been obtained from aeromagnetic, ground magnetic, gravity and seismic surveys and the deep drilling conducted in the basin during the last fifteen years, Based on these data, the Ganga basin has been defined as a major platform depression and classified into seven tectonic zones, viz., Monghyr-Saharsa ridge, East Uttar Pradesh shelf, Gandak depression, Faizabad ridge, West Uttar Pradesh shelf, Sarda depression and Delhi-Hardwar ridge. This classification is based on the continuation of major tectonic trends from the Peninsular shield into the Ganga basin, the variations in the total thickness of the sedimentary cover, and the basement configuration as deduced from different surveys.
The sedimentary cover over most part of the Ganga basin is essentially composed of two main stratigraphic cum structural sequences representing the two main sedimentary stages in the geological evolution of the basin. The oldest, probably corresponding to the Vindhyans, is represented by stable to unstable shelf sediments composed of quartz-arenite-limestone-shale alternations. The younger sequence, unconformably overlying the Vindhyans, corresponds to the Neogene terrigenous clastics (Siwaliks). The structural and stratigraphic data of these sediments have been discussed. The presence of a profound unconformity between these two groups of sediments representing a considerable time gap ranging from (?) late Palaeozoic to Paleogene is an important factor in deciphering the tectonic evolution of the Himalaya. However, towards the northernmost depressed parts of the Ganga Basin, the age of the additional thickness of sediments intervening between the two above mentioned groups remains uncertain.
Petrology of the Alkalic Suite of Sivamalai, Coimbatore, Tamil Nadu
Authors: Bose Mihir K. 
Published: November 2024

Abstract
The 'Sivamalai Series' of Holland comprise ferrosyenite, perthite syenite and a group of nepheline syenites. The main intrusion of Sivamalai forms a thick lensoid body tilted to the northeast. The ferrosyenite is characterised by abundant mesoperthite whereas the mafic phases, olivine and clinopyroxene, are appreciably rich in ferrous iron. The clinopyroxene, a hypersolvus ferroaugite, unmixed during subsolidus cooling. The major petrographic types in Sivamalai intrusion are (1) hornblende nepheline syenite (2) biotite hastingsite nepheline syenite (3) perthite syenite (perthosite) (4) leucocratic nepheline syenite and pegmatite with clots of iron-titanium oxides. Alkali feldspar, unmixed to mesoperthite or antiperthite, is the dominant constituent of these hypersolvus alkali syenites. Chemical and X-ray data indicate the primary feldspar to be a sodium rich monoclinic phase. The nepheline in leucocratic syenite and pegmatite shows deviation from the ideal composition with respect to Si and K contents. With progressive fractional crystallisation, both amphibole and biotite show relative enrichment in iron, the latter particularly in ferric iron. The coexisting iron-titanium oxides indicate a low temperature of crystallisation for the late syenitic liquid.
Differentiation index of the Sivamalai series increases progressively from ferrosyenite to leucocratic syenite, the composition of the magma descends down from near the feldspar join towards the temperature minimum in the undersaturated part of Petrogeny's residua system. The index of agpaicity in these rocks is normally below unity except for the locally developed peralkalic facies. The trend of evolution of syenitic magma in Sivamalai series has been compared with that in adjoining alkalic complexes.
Early Tertiary Stratigraphy of the Area around Garampani, Mikir-North Cachar Hills, Assam
Authors: Samanta Bimal K. 
Published: November 2024

Abstract
The early Tertiary rocks developed in and around Garampani, Mikir-North Cachar Hills, Assam, are made up of three formations, in ascending order, Mikir formation, Garampani limestone and Kopili formation. The sequence is apparently conformable. The Tertiary rocks rest unconformably over the Precambrian complex and are covered by soil and alluvium. The Mikir formation, essentially an arenaceous unit, is apparently devoid of faunal element. The Garampani limestone, a dominantly calcareous unit, and the Kopili formation, an argillaceous unit, are highly fossiliferous and contain abundant foraminifera. On the basis of the occurrence of the stratigraphically significant larger and planktonic foraminifera, the Garampani limestone and the Kopili formation are zoned and correlated. The former is dated as middle to upper middle Eocene and the latter as upper Eocene in age. The Mikir Formation is suggested to be lower to lower middle Eocene in age.
Geology of the Area around Kajlidongri, Jhabua District, Madhya Pradesh
Authors: Lahiri Dipankar 
Published: November 2024

Abstract
Manganese silicate rocks interbedded with manganese oxide ores occur enclosed in phyllites of the Precambrian Aravalli Group in and around Kajlidongri, Jhabua District, Madhya Pradesh. The phyllites are metamorphosed up to the biotite zone of regional metamorphism. The manganese oxide minerals in the bedded ore deposits are braunite and hematite of two generations, bixbyite and jacobsite associated with spessartite and alurgite. A granite body and a few small calcareous bodies present in the area are younger than the phyllites and the enclosed manganese deposits. Epigenetic veins cutting across all the formations are important in this area. Though the mineral composition of the veins are in general simple, being constituted by quartz and calcite, a number of minerals are present in them and the surrounding wall rocks where they intersect bedded manganese deposits. Their unusual mineral composition containing aegirine-augite, micaceous hematite, richterite, zoisite, cummingtonite, scapolite, barite, fluorite, hollandite, blanfordite, brown manganese pyroxene, winchite, tirodite, alurgite, piedmontite, manganophyllite, tilasite, pyrolusite and cryptomelane is explained from field and textural evidences as due to reconstitution of the sedimentary manganese by the effect of the epithermal veins.
An interesting feature of the phyllites is the presence of fluid inclusions in quartz which have a definite pattern of abundance in relation to the granite and the carbonate bodies. The petrographic characters of the carbonate bodies indicate their replacement origin apparently due to the activity of fluids derived from granite.
Superposed Folding in the Aravalli Rocks of the Type Area around Udaipur, Rajasthan
Authors: Roy A. B. , Paliwal B. S. , Goel O. P. 
Published: November 2024

Abstract
Around Udaipur, the Precambrian rocks belonging to the Aravalli System are represented by feldspathic greywacke grading to phyllite and mica schist, calc-arenite, and ferruginous and carbonaceous quartzites. The rocks display a high degree of structural complexity resulting from the impress of three distinct periods of folding (F1, F2 and F3). The earliest folding movement (F1) produced tight to isoclinal folds with drawn-out hinges. The F1 folds are accompanied by a set of very well developed axial plane schistosity. These folds are presumed to have been initially recumbent with E-W to NW-SE axial trend. The second fold movement (F2) refolded the F1 folds to upright, open to occasionally isoclinal folds. The F2 folds have variable plunge and an overall northerly axial trend. The third fold movement has resulted in the formation of tight to isoclinal folds (F3) of small and intermediate scales on the limbs of larger F2 folds. The F3 folds are characterized by a set of axial plane crenulation cleavages. The superposition of the three fold systems has resulted in complex interference patterns on different scales.
Aravallian Stromatolites from Udaipur, Rajasthan
Authors: Banerjee D. M. 
Published: November 2024

Abstract
At least five types of stromatolites have been reported from the Aravalli succession near Udaipur. Excepting Collenia columnaris all other forms are phosphatic. Association of these stromatolites with phosphorite deposits of economic importance has been clearly demonstrated. Age significance of these stromatolitic forms has also been discussed in detail.
Myrmekite from the Charnockite Series of Amaravathi, Guntur District, Andhra Pradesh
Authors: Ramaswamy A. , Murty M. S. 
Published: November 2024

Abstract
A detailed description of myrmekite is furnished and its origin discussed in the light of the existing theories. Myrmekite is believed to be formed by exsolution, deriving both the components - quartz and plagioclase, which are held in solid solution in the form of albite and CaAl2, Si6O16 in po:ash felspar. Myrmekite in norite is presumed to be formed due to the breakdown of anorthite molecule of the plagioclase releasing the required silica, thus making the plagioclase less basic than its parent. The granulite facies (charnockite environmental) conditions seem to be ideal for the formation of myrmekite by exsolution process.
Carbonatite Veins of Mundwara Igneous Complex, Rajasthan
Authors: Subrahmanyam N. P. , Rao G. V. U. 
Published: November 2024

Abstract
Lenticular veins of carbonatite are located in the pheripheral Erinpura granites E of Alkalic Mer pluton in Mundwara igneous complex, Sirohi District, Rajasthan. These veins vary in length from 20' to 200' and are composed of discontinuous lenses arranged en echelon. Calcite is the principal mineral of these veins and the associated accessory minerals are ankerite, hematite, magnetite, aegirine, apatite, feldspar, quartz and baryte. Frothy and fluidal textures as well as chilled marginal and fenitisation effects are observed in these veins. Martitised magnetite and chalcedony indicate low temperature of formation whereas the vesicular nature of these veins indicates low confining pressures (may be as low as I bar). These veins.are having high Sr, Ba and RE contents. The calcites from these are enriched in Sr, Ba, RE, Mo, Mg and P compared to their sedimentary counterparts. Thus, these veins are alvikites formed under pneumatolytic-hydrothermal conditions.
Lenticular veins are not reported by earlier workers and the Mundwara veins seem to be unique in this respect.
Petrology of the Basic Intrusive Rocks Around the Moulabhanja Hills in the Dhenkanal District of Orissa
Authors: Chakraborty K. L. , Mallik A. K. 
Published: November 2024

Abstract
The Moulabhanja hills and the adjoining areas are underlain by Precambrian granite gneiss which is intersected by a variety of gabbroic dykes and stocks. Mineral assemblages and textural relationships point recognition of four types of gabbroic rocks which also represent critical stages of fractional crystallization, e,g., (i) olivine gabbro with essential olivine, pigeonite augite and bytownite (ii) hypersthene gabbro with essential hypersthene, augite and labradorite (iii) doleritic gabbro with essential augite and labradorite, and (iv) normal gabbro with augite and less calcic labradorite.
The chemical and normative mineral composition of the basic magma is tholeiitic. The magma seemingly differentiated into different types of gabbroic rocks by fractional crystallization and gradual enrichment in iron. Two analyses of the olivine gabbro lie on the transitional zone between tholeiitic and calc-alkali suite. The closing temperature ofcrystallization of the basic magma and the corresponding oxygen fugacity are estimated to be 600°C and 18.4 (-Log10 FO2) respectively.
Petrography and Environmental Significance of Bhander Limestone (Upper Vindhyan) in Kota-Rawatbhata Area, Rajasthan
Authors: Bhardwaj B. D. 
Published: November 2024

Abstract
Field and petrographic characters of the Bhander limestone in the Kota-Rawatbhata area, Rajasthan, permit its division into three lithofacies: (1) interlaminated calcilutite-calcisiltite, (2) flat-pebble calcirudite breccia, and (3) flat-bedded limestone. The predominant red colour, microcrystalline texture, large quantity of insoluble clay residue, and presence of algal stromatolites in lithofacies (1) and (2) suggest their deposition in the supratidal environment. Lithofacies (3) is predominantly micritic, characterised by flat and continuous bedding and marked by the presence of stromatolites, and is interpreted as a product of sedimentation on a vast, shallow submerged shelf where wave energy was cut off by the extensiveness of the shelf.
The Structural State of K-Feldspars and Regional Metamorphism in the Precambrian of S-E Mysore
Authors: Anantha Iyer G. V. 
Published: November 2024

Abstract
The Precambrian of S-E Mysore belongs to the non-charnockitic province of Fermor and the amphibolite facies of Pichamuthu, and include the rock formations between the longitudes 77°E and 79°E. Along the southern and the eastern margins of the formations in the State are the transitional amphibolite-charnockite facies rocks.
Field features of the metamorphic rocks across the prevailing N-S regional trend of the formations suggest a correspondence between the K-feldspar structural state and metamorphism.
The structural state of K-feldspars determined both by X-ray and infrared absorption techniques reveals (i) partially disordered feldspars occur in the transitional facies zone and completely disordered feldspars in the charnockites of Halagur, (ii) a decrease in the intensity of metamorphism as the Closepet belt is approached from the south-west margin and (iii) ordered feldspars of high obliquity are characteristic of amphibolite facies of granitic complex between the Closepet belt in the west and the Kolar schist belt in the east.
Shape Analysis of Gondwana Sediments of a Part of Johilla Valley, Madhya Pradesh
Authors: Jhingran Vinaya 
Published: November 2024

Abstract
A study on the shape analysis of Gondwana sediments in Pali-Parsora region of Madhya Pradesh reveals that the sediments in general are subsequant to equant, and subangular to subrounded. The results have been calculated both by graphical and moment methods. The grains are comparatively better rounded in the coarser grade, and they show no linear relationship between sphericity and roundness. This shape study suggests that the sediments have a moderate transportation history.
Geological Setting, Petrography, and Petrochemistry of the Darla Trap, and its Comparative Study with Mandl and Panjal Traps
Authors: Pareek H. S. 
Published: November 2024

Abstract
Studies on the Darla trap have not been made previously. The Darla trap is overlain by the rocks of Basantpur Formation, and underlain by those of the Sundernagar Formation. It forms the core of an antiform, and its northern extremity is in thrust contact with the Shalis, the volcanics trending along this contact as a thinned outcrop south-easterly to Tattapani and beyond.
Microscopically, the Darla trap comprises saussuritised plagioclase felspar microlites and laths, altered clinopyroxene of diopsidic-augite range, pseudomorphs of olivine, granular and massive or skeletal iron ores, glass, palagonite, chlorite, epidote, apatite, and spinel. The amygdaloidal variety is the most common, and includes arnygdules of quartz, chalcedony, zeolite, chlorite, and quartz being surrounded by a thick rim of pink chalcedony. The other common variety has porphyritic chlorite in ophitic texture with plagioclase felspar. The chief rock types are basalt, palagonite-basalt, diabase, spilite, actionlitic-ferrunginous schistose rock, and rhyolite, the volcanic outpourings being thus of essentially basic rocks.
Chemically, the Darla trap shows gradation between tholeiitic and alkali basalts. The analytical data has been plotted on alkali-silica, Or-Ab-An, Fe+-(Na+K)-Mg, DI-Oxides, SI-Oxides variation diagrams.
The Mandi trap forms part of the Darla-Mandi volcanics, and these traps are considered to be represented by the Panjal trap in the Simla area by Heron. Comparative studies have been made between the Darla, Mandi, and Panjal traps, and inferences drawn.
The Clans of Igneous Rocks and Their Associated Economic Minerals-A Critical Review
Authors: Orajaka S. 
Published: November 2024

Abstract
A classification of igneous rocks based on the clan concept is critically reviewed in this paper. The various rock clans have been correlated, as far as possible, with their tectonic environments, associations and sedimentation characteristics, if any. The mineralisations associated with each clan have been discussed and their economic significance stressed and outlined.
On the Banded Iron Formations of Precambrian Age in India
Authors: Pichamuthu C. S. 
Published: November 2024

Abstract
Banded iron formations, as elsewhere in the world, are characteristic of the Precambrian schistose rocks in India. In this paper an attempt has been made to bring together most of the information available on these interesting rocks which have contributed largely to the iron ore resources of India. They occur chiefly in the States of Bihar, Orissa, Madhya Pradesh, and Karnataka (former Mysore State).
Though the iron formations are fairly constant in lithology and chemical composition, there are variations in their structure, texture, and mineralogy, the metamorphism undergone by these rocks being an important factor in bringing about the changes.
It is now known that there are banded iron formations of different ages in the Precambrian of India and while there are no reliable radiometric age data available, stratigraphically they can be assigned to different horizons.
Though mineralogically the rock is fairly simple, there is great difference of opinion regarding the mineral paragenesis. In particular, the origin of the iron ore minerals has given rise to considerable speculation especially as to whether hematite or magnetite was primary. The silicate minerals appear to have generally formed by metamorphism.
The source of the iron and silica, the environmental conditions (both depositional and atmospheric) which produced the banded iron formations, and the mode of origin of the banding, are all matters on which there has been wide difference of opinion. A brief account of the various views on these questions has been given which points to the conclusion that many of these important problems have not yet been solved.