bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross-Folding and En Echelon Folding in Precambrian Rocks of India and their Relation to Metallogenesis
Authors: Narayanaswami S. 
Published: November 2024

Abstract
Cross-folding in Precambrian rocks of India affects the earlier folds to varying degrees and has been classified into (a) cross-fold axes at right angles to earlier folds, (b) at an angle to earlier folds, (c) parallel to earlier folds, and (d) with reversals in plunge relations resulting in culminations and depressions. En echelon folding in Precambrian rocks of India is of simple type producing a zig-zag pattern in the interference of minor folds on the axial trend of major folds. Elliptical pattern of en echelon folding is uncommon in these rocks.
Various types and degree of cross-folds and en echelon folds are described drawing illustrations from (i) intensely folded and metamorphosed charnockitic regions of Madras, DharwaI' schist belts of Mysore, and Sausar-Gangpur-Iron-ore Series rocks of Madhya Pradesh, Bombay, Orissa, and Bihar, and also from (ii) less intensely folded and metamorphosed Cuddapah-Kurnool formations of Andhra. The plunge of cross-folds and en echelon folds have consistent relation to the differential shear couple.
Metalliferous ore deposits of both syngenetic and epigenetic origin in India show remarkable localization in regions of cross-folding and en echelon folding. The controls of these folds in localizing various types of ore deposits are described, including the plunge of folds and its relation to the pitch of ore bodies. Illustrations are drawn from (i) bedded and enriched iron and manganese-ore deposits of Bonai-Keonjhar, Bailadila, Mysore, Madhya Pradesh, Bombay and Andhra, (ii) magmatic chromite deposits of Mysore, (iii) gold-quartz veins of Kolar, Ramagiri and Gadag, (iv) copper deposits of Singhbhum, Kurnool and Guntur, and (v) pyrite deposits of Chitaldrug. The recognition and application of cross-fold and en echelon fold structures to evaluate structural control of ore deposits have great value in future mining exploration and development in India.
The Calc Zone of Pithoragarh, with Special Reference to the Occurrence of Stromatolites
Authors: Misra R. C. , Valdiya K. S. 
Published: November 2024

Abstract
The paper records the occurrence of stromatolitic structures, ascribed to the algal genus Collenia, from the dolomitic limestone of Pithoragarh, U. P. Overlying this limestone is an extensive band of magnesite. It is tentatively suggested that the magnesite deposit is the result of primary precipitation of magnesium carbonate, aided by the activity of algae.
The limestones, dolomitic limestones, shales and slates, including the stromatolite-lime. stone and magnesite beds constitute a distinct formation which may be designated as the Calc Zone of Pithoragarh. On the basis of lithology, stratigraphical position and the evidence of stromatolitic structure, this Calc Zone of Pithoragarh appears to be the equivalent of the Deoban limestone of the Chakrata area. It is not possible at this stage to state definitely, as to which specific geological period this zone belongs. It may, however, be stated with some confidence that it lies somewhere between Precambrian and early Ordovician.
Wollastonite Bearing Calc-Silicate Rocks of Tinnevelly District
Authors: Lakshmi Narayanaswami P. 
Published: November 2024

Abstract
The mineralogy and petrography of certain wollastonite bearing calc-silicate rocks from different localities in Tinnevelly district are described. These rocks occur as layers, lenses and stringers in gneisses. Wollastonite occurs as a general constituent of some of the calc-silicate bands and also near limestone and quartz vein contacts. Thin sections of these rocks displaying reaction textures indicate interaction between minerals and metasomatic changes during regional metamorphism. Detailed optical determinations of wollastonite and other calc-silicate minerals are presented. Wollastonite is abundant; the other minerals are clinopyroxene (Di90 He10), calcite, scapolite (Ma35 Me65), feldspar (chiefly micropertbite), garnet and sphene. Twinning parallel to elongation in wollastonite and zoning in pyroxene and scapolite are noteworthy. The formation of wollastonite may be attributed to high-grade regional metamorphism, and partly to reaction between limestones and intrusive quartz veins.
Ostracoda from the Early Tertiary Sediments of Pondicherry, South India
Authors: Rajagopalan N. 
Published: November 2024

Abstract
The early Tertiary sediments of Pondicherry, South India, have yielded a new Ostracode fauna. A new genus, Neocytheridea (type species: Neocytheridea inflata Rajagopalan) and six new species are described: Hermanites pondicherriensis, Actinocythereis indica, Cythereis anastomosa, Cythereis tamulicus, Schizocythere? Levinsoni and Neocytheridea inflata.
Effect of Uplift and Structure on Drainage in the Southern Part of Cuddapah Basin
Authors: Vaidyanadhan R. 
Published: November 2024

Abstract
A study of the nature of the basal sediments of the Cuddapah System and their position in space with respect to the Archaeans has resulted in the understanding of the probable original extent of the Cuddapah sea in the south, and the uplift which the southern part of the basin might have experienced. It is suggested that the faults along the Archaean-Cuddapah boundary in the south and south-west, and some within the basin affecting the Lower Cuddapah rocks, are due to these gradual uplifts of the south-eastern part of the basin, which range in time from post-Lower Cuddapah to pre-Tertiary.
Evidences are adduced to show that the pattern of major river development in the southern part of the basin is not due to either transverse subsequent drainage, or progressive piracy or antecedence, but is due to superposition (or superimposition) on a structural plain of the Kurnools, about 3,000 feet above mean sea level, over the south-western part of the basin and gradual lowering of the rivers since Tertiary times. The effect on the rivers due to oscillations of sea level during the Pleistocene is also shown.
Coal - A Palyno-Petrographic Approach
Authors: Navale G. K. B. 
Published: November 2024

Abstract
As the very title of the paper indicates, the two aspects of Coal viz., palynology and petrography are necessary for a complete study. It is known that there exists an intimate genetic relationship between the microfossils and petrographic components of coal. No serious attempt however has so far been made for an integrated palynopetrographic study which can resolve the complex nature of coal. In this paper some methods for the study of microfossil and maceral components of coal, their association and utility from the point of view of the present approach are briefly described; and these help us in understanding the complex nature of coal.
Recognition and Correlation of Erosion Surfaces In and Around the Southern Part of Cuddapah Basin
Authors: Vaidyanadhan R. 
Published: November 2024

Abstract
A study of the morphological features in and around the southern part of the Cuddapah Basin brought to light for the first time the existence of erosion surfaces in this area. Two methods were adopted in an attempt to arrive at quantitative data on these, namely (i) collection of data on summit heights (about 1800 in number) over an area of about 8000 sq. miles and (ii) construction of a large scale laboratory model covering an area of about 13500 sq. miles showing 30 north-south profiles taken from 60 one-inch toposheets. As erosion surfaces usually extend across different geological horizons, the study was made to cover both the southern part of the Cuddapah Basin and the Archaeans to the west and south of it.
On the basis of the above studies substantiated by field observations, it is concluded that there are two major erosion surfaces, one around 3000-2700 feet and the other around 2000-1600 feet above mean sea level in this area both having a gentle inclination due north and north-east. The erosion surfaces seem to have been arched along an east-west axis south of the basin. The two surfaces are correlated with two others already suggested in the former Mysore State. The age of the higher surface is considered to be post-Miocene.
The Geomorphology of the Country around Sagar and Katangi, M. P: - An Example of Superimposed Drainage
Authors: West W. D. , Choubey V. D. 
Published: November 2024

Abstract
A study of the geomorphology of the country around Sagar and Katangi, M. P. has led to the conclusion that the present drainage, originating on a plateau of Deccan Trap lavas which once covered the whole area, has been superimposed on the underlying Vindhyan rocks. Around Sagar, with the partial removal of the Trap, a mature topography of hills and valleys carved out of horizontal Vindhyans has been resurrected. As a result the new drainage pattern bears little relation to this pre-Deccan Trap topography. The more powerful streams continued to erode in the courses they were following on the Deccan Trap, cutting gorges through Vindhyan hills; but the weaker streams appear to be adapting their courses to the old Vindhyan topography.
To the south-east of Sagar, along the south-eastern margin of the Vindhyan basin, the Vindhyan rocks have been considerably disturbed. A flat, elongated dome has been developed around Jabera, while further south-east sharp folding and faulting have produced long, steeply dipping ridges of Vindhyan, adjacent to the older Bijawar massif. Here also the Deccan Trap drainage is now seen superimposed on the Vindhyans, but there has also been a tendency to develop a radial drainage in the area of the dome, which has been carved into a basin.
The origin of typical Deccan Trap scenery, with its horizontal platforms and retreating scarp slopes, is discussed, as also the origin of the waterfall at Rahatgarh.
The time of uplift of the Vindhyan rocks, and the period of their folding and denudation in the Jabera-Katangi region, are also briefly alluded to.
Palaeogene Ostracoda of the Family Cytherellidae from Subsurface Samples of Cambay, Gujarat State Western India
Authors: Guha D. K. 
Published: November 2024

Abstract
Ten species of Ostracoda of the family Cytherellidae are recorded and figured from Middle to Upper Eocene and Oligocene of the wells drilled on Cambay structure. Three species are described as new.
Rock Type Approach to the Problem of Correlation by Heavy Mineral Assemblages
Authors: Gundu Rao C. 
Published: November 2024

Abstract
Stratigraphic variability of sedimentary sequences is nothing but variation in the magnitude of development of sedimentary systems and their co-existing phases in space and time. An experiment, organized to investigate the differences in the proportion of heavy minerals between two co-existing phases of a system has shown that there are significant differences in the heavy mineral proportions between the two phases. Consequences of this, in accepted sampling plans for correlation by heavy minerals, are discussed.
'Pressure Shadows' in Daling Phyllite'
Authors: Karunakaran C. , Roy Subimal Sinha 
Published: November 2024

Abstract
'Pressure shadows' developed at the fringes of porphyroclasts of quartz, feldspar and rock fragments in gritty phyllite of Daling series, have been described in detail. Besides quartz, the 'pressure shadows' contain some secondary chlorite. They show a marked dimensional orientation and grain size variation vis-a-vis the distance from the controlling face. The mode of origin is suggested in the light of Riecke's principle.
On the Ostracoda from Neogene of Andaman Islands
Authors: Guha D. K. 
Published: November 2024

Abstract
An interesting assemblage of Ostracoda is recorded from the Archipelago series exposed in Interview island and Guitar island of Andamans. Thirty-two species belonging to twentyone genera are described of which one species Paracytherideaandamanensis is new. Most of the species were earlier recorded from Mia-Pliocene, Pleistocene and Recent of Manila (Phillipines), Malay, Sumatra, Java and New Zealand.
The Nomenclature and Classification of Granulites and Related Rocks of Mont Tremblant Park, Quebec, Canada
Authors: Katz Michael B. 
Published: November 2024

Abstract
The nomenclature of the granulites which are the characteristic rocks of many granulite facies terrains is reviewed. The granulites which are defined in the classical sense are found in two distinct geological settings. In the high-grade metamorphic terrains of the Precambrian shields, the granulites occur associated with large anorthosite bodies as in the case of Mont Tremblant Park, Quebec, Canada. Also granulites are found in cores of old orogens here associated with rocks of eclogitic affinities. A simple classification of granulites consists of two prinicipal groups; quartzo-feldspathic and hypersthene granulites.
Tectonic History of the Area East of Khammam, Andhra Pradesh
Authors: Janardan Rao Y. , Raju Ch. Sudarsana 
Published: November 2024

Abstract
East of Khammam town in Andhra Pradesh, the Precambrian rocks are classified into three distinct lithological groups as (a) Peninsular Granites (b) Pakhals and (c) Gncissic Complex. Detailed structural studies on foliation, lineation, joints, folds, trends of dykes, basic enclaves, pegmatite and quartz veins of these groups show that the Peninsular Granite area with its NNW trend is structurally quite distinct from the remaining area which shows NW as well as NE trends. Mineralogical variation diagrams drawn for acid granulites, as a part of the quantitative petrological studies, show that the emplacement of these granulites has been structurally controlled by NE trend. Petrological studies in the Gneissic Complex show increasing grade of metamorphism roughly from northwest to southeast. It is concluded that the area in general is affected by two phases of disturbance, one, Dharwarian and another, late' Eastern Ghat' orogeny. It is also suggested that the demarcation line between 'charnockitic region' and 'non-charnockitic region' of Fermor should pass through the contact between Peninsular Granites and Pakhals.
On the Krol Nappe Hypothesis
Authors: Ranga Rao A. 
Published: November 2024

Abstract
Geological mapping by the author in parts of Garhwal and Punjab Himalaya, in the areas between Nayar and Sutlej rivers in the south, and between Bhagirathi and Sutlej rivers in the north, revealed that the Krol belt rocks are autochthonous sediments deposited on a floor of Simla slate - Deoban group, and are not allochthonous as interpreted by Auden. The various field evidences in support of this view are cited.
On a New Species of Sivaplthecus from the Siwalik Rocks of India
Authors: Pandey J. , Sastri V. V. 
Published: November 2024

Abstract
A new species of Sivapithecus Pilgrim, designated as Sivapithecus lewisi, has been described. The species has been based on the study of a broken right ramus collected from the? Nagri horizon of the Siwaliks. This species is characterised by a very massive and deep mandible, exceptionally large teeth and by the presence of a better defined external cingulum in the first lower molar. The holotype is believed to be the second largest specimen of fossil anthropoids so far reported from India, next to Sivapithecus (Dryopithecus) giganteus (Pilgrim).
Stromatolites of the Lesser Himalayan Carbonate Formations and the Vindhyans
Authors: Valdiya K. S. 
Published: November 2024

Abstract
A number of carbonate formations of the Lesser Himalaya and the Vindhyachal have been found to display widespread and prolific development of stromatolites. These are confined to definite stratigraphic horizons and exhibit no influence of facies changes. Time-controlled changes are clearly expressed in their morphology and the 'regular sequence of different forms over extensive areas suggests their evolutionary variation.
The Fawn Limestone of the Semri Series of Southern Mirzapur exhibits bioherms of Conophyton cylindricus and Collenia columnaris with C. kusiensis, characteristic forms of the Lower Riphean formations (older than 1260 m.y.) of U. S. S. R. The Bhander Limestone of the Upper Vindhyan, the Gangolihat Dolomites of the Calc Zone of Pithoragarh, the Lower Deoban Limestone of Dehra Dun District, the Lower Shali Limestone of Mahasu District and the Tundapatthar Limestone of Ambala District are characterized by Collenia baicalica, with C. cotumnaris, C. symmetrica and C. buriatica. These forms constitute typical Middle Riphean (1260 to 1000 m.y.) stromatolite-complex of U. S. S. R. The Thalkedar Limestones of Pithoragarh, the Upper Deobans and the Upper Shali Limestone contain what look like Jurusania of the Upper Riphean formations of the southern Urals in U. S. S. R. Kakarhatti and Naldera stromatolites seem to be of a still younger age.
Some Contributions to the Stratigraphy of the Upper Gondwana Formations of the Pranhita-Godavari Valley, Central India
Authors: Kutty T. S. 
Published: November 2024

Abstract
The Gangapur beds, believed to be the basal beds of the Upper Gondwana Kota formulation, are here shown to overlie the latter unconformably. This discovery, based on detailed mapping, clears up a long standing confusion, i.e. of a flora from the Gangapur beds judged to be later in age than the Kota fauna, but successionally preceding it. The Gangapur beds are hence removed from the Kota formation and are called here the Gangapur formation.
The base of the Kota formation is redefined on the basis of faunal and lithological evidence. A new, late Upper Triassic, fauna has been discovered below the Kota beds, which is quite different from the typical, early Upper Triassic, Maleri fauna and also from the Lower Jurassic Kota fauna. On this faunal basis as well as on stratigraphic grounds the erection of a new formation (here called the Dharmaram formation) is suggested, and the boundary of the Maleri and Dharmaram formations is defined.
Petrological Studies of Coals from East Bokaro Coalfield, Bihar
Authors: Bhattacharyya Ajit , Mukherjee Bankim 
Published: November 2024

Abstract
Coals from two major seams viz., Karo and Bermo seams, East Bokaro Coalfield, Bihar were washed in the laboratory at different specific gravity medium. Chemical and petrological analyses of unwashed coals and the washed fractions from these were undertaken. Reflectance measurements (by Seyler's method) were made on the vitrinites for the unwashed coals and for different Iloat fractions after washing. The clean coals show an improved assemblage of macerals and reflecting components from the point of view of their physical and coking properties. It is also noticed that at 1.50 to 1.55 specific gravity cuts, the floats show a good reduction in ash content and a definite concentration of vitrinite and reflecting components, responsible for developing better coking characters. It is further observed that the coals from bottom section of the Bermo seam is more amenable to cleaning than the coal from the top section.
A Study of Pebble Deformation in the Precambrian Rocks of Singhbhum District, Bihar
Authors: Mukhopadhyay D. , Bhattacharya S. 
Published: November 2024

Abstract
The deformed pebbles in the conglomerate show a large variation in the orientation of their longest axes as well as in the values of the axial ratios a' and b'. This has been interpreted as due to a nonspherical nature of the original pebbles. The effect of deformation has been separated from the effect of the original shape. It has been shown that a superficial analysis of the shape of deformed pebbles may give a wrong idea about the state of strain in the rocks, and the method by which the true amount of strain can be computed from dc:formed pebbles has been discussed.
Reconnaissance Rb-Sr Dating of the Precambrian Rocks of Southern Peninsular India
Authors: Crawford A. R. 
Published: November 2024

Abstract
Many new Rb-Sr age determination analyses are reported for the crystalline complex of southern Peninsular India. These are mostly total-rock ages, often isochrons.
Data are still insufficient for a reliable geochronology. Rocks of apparent ages ranging from over 3000 m.y. to 720 m.y. have been dated, and a lower Palaeozoic event reflected in mineral ages of about 500 m.y., known to have affected all Ceylon and much of the east coast of India, has been found as far north as Coimbatore.
The oldest rocks have been found in Kerala, the Nilgiri Hills and southern Mysore. One age of 2700 m.y. has been found in Kerala. The craton of Mysore-Hyderabad has an age of at least 2585 ± 40 m.y., which is the apparent age of the Peninsular Gneiss over a wide area. The age of the Dharwar System remains uncertain, although the lavas near Chitradurga give an isochron at 2345 ± 60 m.y. The Chitradurga Granite has an age between 2450 and 2400 m.y. The Closepet Granite presents difficulties arising from its poor definition, but contains components between 2400 and 2000 m.y. Rocks of about 2100 m.y. occur in Kerala and western Tamizhagam, and could be present in Mysore, where an event at this time is recorded by biotite. The Chamundi Hill Granite of Mysore city, and a granite from the Ramanathapuram District of Tamizhagam give 790 ± 60 and 720 m.y. respectively, suggesting the possibility of widespread if sporadic intrusion in the southern half of the region at about this time. There is no real evidence yet of any major reflection of the Vijayan retrogressive metamorphism of Ceylon at 1140 m.y., except possibly in the intrusion of the Sivamalai soda-syenite. However, the known mineral ages of about 1690, 1650 and 1150 m.y. along the west coast suggest repeated marginal mobility of the Mysore-Hyderabad craton otherwise stable since about 2000 m.y. though intruded repeatedly by several dyke suites not yet dated.
Much further sampling is needed, as well as the combination of several methods of dating. To facilitate this, modern geological and tectonic maps of medium scale are very desirable.
Microfossils from the Archaean Complex of Mysore
Authors: Sambe Gowda S. , Sreenivasa T. N. 
Published: November 2024

Abstract
The paper reports an assemblage of microfossils from the Guddadarangayanhalli Formation of the Chitaldrug Schist Belt. The organic fossils discovered are the oldest fossils from India and they are coming from an age group of 2000-1400 m.y. The assemblage consists of Sphaeromorphitae and Netromrophitae of the Group ACRITARCHA Evitt, and cuticular remains (Spongiophyton Kraeusel). Forms referable to Protoleiosphaeridium Timofeev, Leiosphaeridium Timofeev, Leiofusa Eisenack and Deunffia Downie and/or Bacisphaeridium Eisenack are identified. The scope for refining the stratigraphy of the Archaean Complex is pointed out.
Heavy Mineral Suites of the Jamkhandi Granites
Authors: Govinda Rajulu B. V. , Nagaraja H. R. 
Published: November 2024

Abstract
The heavy mineral assemblages of the Jamkhandi granites have been investigated, and their percentages and frequencies estimated. Based on these data, histograms and cumulative curves are prepared. Correlation between the Jamkhandi granites and the Cuddapah granites is also attempted. The heavy mineral suites indicate that the Jamkhandi granites have been contaminated, a conclusion confirmed otherwise by field studies.