bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mineralogy and Petrography of the Subsurface Alluvium Samples from Mahanagar Borehole, Lucknow (U.P.)
Authors: Singh Indra Bir 
Published: November 2024

Abstract
Mineralogical and petrographical studies of the samples from the subsurface alluvium near Lucknow, from a depth of 253 to 485 m, are presented. The sediments are marked by poor sorting, high content of subangular rock fragments and clay matrix. Both plagioclase and alkali felspar are present in the sand as well as silt fractions. Petrographically the sediments are lithic graywackes. Clay minerals present are montmorillonite, kaolinite, and illite. Quartz grain surface textures are dominantly glacial, along with some fluvial features. Heavy mineral assemblage is marked by the dominance of extremely fresh grains of very unstable minerals, e.g. garnet, epidote, hornblende, kyanite, tremolite. Tourmaline, apatite, zircon, and chlorite are also present.
It is suggested that the sediments were deposited by the high-gradient, rapidly flowing rivers coming from the Himalayas. Sediments were supplied from a glacial affected terrain, made up mainly of low to high grade metamorphics, and some granitic rocks. Deposition was rapid in the quickly sinking fluvial basin.
A Study of Cyclic Erosion Surfaces and Sedimentary Unconformities in the Cauvery Basin-South India
Authors: Babu P. V. L. P. 
Published: November 2024

Abstract
Geomorphological studies south of 13th parallel in peninsular India have indicated four base levels of erosion at elevations of 900, 600, 300 and 150 metres above mean sea level. Adopting' comparative' dating method they represent the last stages of Mesozoic, Early Tertiary, Late Tertiary and Pleistocene cycles of denudation. These are correlated with the sediments deposited in the adjoining basin.
A Statistical Approach to the Study of Uranium Mineralisation at Jaduguda, District Singhbhum (Bihar)
Authors: Venkataraman K. , Vajpai C. V. L. 
Published: November 2024

Abstract
The tenor of uranium ore in the mineralised field of Jaduguda has been statistically analysed. Distribution, the variations of the tenor in different directions and the continuity of mineralisation in the different directions (using the geo-statistical parameter, variogram) have been studied and it has been found that the distribution of the metal in Jaduguda is log-normal and the variations of tenor in the different directions are unique parameters in the mineralised tract. The variograms for tenor in Jaduguda are found to be of the 'transitive' type. The frequency histogram of the tenor of the ore across the strike, brings out the possibility of the mix-up of two populations, in the central portion of the deposit, probably by post mineralisation structural deformations like strike-slip faults.
Controls of Tungsten Mineralization at Chhendapathar, District Bankura, West Bengal
Authors: Singh V. K. , Varma O. P. 
Published: November 2024

Abstract
The paper, describes the structure and tectonic environments of the tungsten mineralization at Chhendapathar, India's largest tungsten mining district. The main structural configuration of the district developed as a result of early, cross and later fold movements during the Singhbhum Orogeny (2000-850 m.y.). The early folding generated axial plane schistosity, whereas cross fold movements produced asymmetrical folds, and the later folding gave rise to a broad zone of culmination, that was the site of an intrusion-the source of tungsten-bearing solutions, responsible for the ore deposits. Ore controlling structures like shear-slips, shear-fractures and fault-fractures were primarily formed during the period of cross folding. On mineralization, they developed into vein patterns trending: (i) N70°E, (ii) N50°w, (iii) N70°w, (iv) N50°E, and (v) N10°E. Post-ore faults have dislocated the veins, sometimes rotating their strike by about 25°.
Multiple Deformation in the Precambrian Rocks to the Southeast of Ajmer, Rajasthan, India
Authors: Sharma R. S. , Upadhyay T. P. 
Published: November 2024

Abstract
The paper describes two phases of deformation, excluding thrusting, in the Precambrian metamorphites of the Delhi System and the underlying Banded Gneissic Complex. The first deformation, DI, produced major folds, mainly overturned isoclinal and large antiforms and synforms, with NE trending northwesterly dipping axial surfaces and plunges at low angles. The second deformation, DII, produced folds that were superimposed upon DI major folds. These are commonly asymmetrical and are better developed in the Delhi rocks than in the underlying Banded Gneissic Complex. They have N to NNW trending, nearly vertical axial planes and plunges at high angles towards the north. These phases of deformation are also recorded on microscopic scale rocks from both the stratigraphic units.
The' basement' Complex was deformed more or less concordantly with the supracrustal rocks of the Delhi System during the Delhi Orogeny. The structural data also suggest that there was one more kinematic phase in the area. During this phase the overlying Delhi rocks slid over the Banded Gneissic Complex along a high-angle reverse fault that runs along the plane of unconformity between the two rock groups.
Late Miocene-Early Pliocene Discoaster from Neill Island, South Andaman
Authors: Singh Pratap , Vimal K. P. 
Published: November 2024

Abstract
The Eastern Coast Mudstone, exposed in Neill island, has yielded a rich assemblage of Late Miocene-Early Pliocene nannoplankton represented by the genera: Discoaster Tan Sin Hok, 1927 and Coccolithus Schwarz, 1894. The genus Discoaster constitutes about ninety-eight per cent of the assemblage and is represented by seventeen species including four new species and two new subspecies. A biostratigraphic zone named as Discoasterbrouweri-Discoaster variabilis Assemblage-zone is recognized and correlated.
Charnockitic Hypersthene-Quartz Diorite from Imala, Southwestern Nigeria
Authors: Kayode A. A. 
Published: November 2024

Abstract
The hypidiomorphic granular texture, greenish brown colour and mineralogy of the hypersthene-quartz diorite from near Imala in southwestern Nigeria suggest charnockitic affinities. The rock differs from typical 'intermediate members' of charnockitic rocks in two respects: (i) antiperthite is only scantily developed and (ii) the orthopyroxene crystals lack the strong pleochroism characteristic of charnockitic hypersthenes. Trace clement contents and ratios as well as the Niggli c versus mg plot suggest basic (basaltic) parentage. Marked depletion in the alkali elements Rb and K in the marginal sample of the rock is considered to have resulted from loss of volatile elements to the arnphibolitic country rock. Occurrence of the Imala rock in migmatised amphibolite facies environment accords with Cooray's proposed selting for intrusive charnockites.
Mineralisation Episodes in the Dharwar Craton of Peninsular India
Authors: Radhakrishna B. P. 
Published: November 2024

Abstract
Mineralisation episodes in the Dharwar craton are indicated to follow a recognisable pattern. Chromium, nickel, gold, copper, iron, vanadium and titanium mineralisation is characteristic of older lavas of Archaean age (&gt; 2700 m.y.). Mineralisation in Proterozoic is characterised by concentration of metals like gold, uranium and copper through sedimentary processes and to the influx of andesitic and spilitic lavas less primitive than the Archaean. Important accumulation of sedimentary manganese and iron ores mark the first appearance of primitive forms of life. The kimberlite pipe rocks and carbonatite complexes are intruded along deep main faults. Possible tin mineralisation in contact with granite batholiths is indicated. Crustal development in Peninsular India, as in other parts of the world is shown to be marked by specific mineral deposits characteristic of particular stages in its evolution. It is hoped that this new thinking will help identification of target areas for more intensive search for metals in favourable regions of Peninsular India.
Basement-Cover Relationships of Peninsular Gneiss With High Grade Schists and Greenstone Belts of Southern Karnataka
Authors: Ramakrishnan M. , Viswanatha M. N. , Swami Nath J. 
Published: November 2024

Abstract
The low grade Archaean terrain of southern Karnataka is composed of greenstone belts and high grade schists set in a sea of gneiss complex (Peninsular gneiss). Peninsular gneiss contains three major components which are inter-gradational, namely: (a) a trimodal macrolayered unit of amphibolites, ultramafites and granite gneiss (b) normal migmatites with characteristic megascopic structures and (c) nebulitic, schlieric and homophanous granitoids. On the whole it is a polymigmatite encompassing several episodes. The ubiquitous enclaves of mafic-ultramafic rocks within Peninsular gneiss probably represent residues of repeated reworking of the crustal rocks. The composition of the gneiss complex varies in the indestructible range of tonalite through granodiorite to granite. The high grade schists or supracrustals consist of shelf sediments, volcanics and ironstones with profuse emplacements of ultramafites. Their contacts with the gneiss complex are concordant due to intense deformation, high metamorphic grade and extensive migrnatisation. This high grade thermal event (Pantectogenesis) dated at 2900-3000 m.y. has acted as an effective smokescreen blurring earlier episodes. Subsequent to the pantectogenesis, greenstone belts were evolved on a basement of gneiss complex. Two types of greenstone belts of mutually exclusive geographic distribution are seen in the craton: (i) dominantly volcanic belts, lacking shelf facies rocks and ultramafics at the base, called the Keewatin type, which are broadly comparable to the Archaean greenstone belts and (ii) Platformal volcanic and protogeosynclinal belts of Dharwar type, which are similar to the early Proterozoic basins and geosynclines. The contacts of the Dharwar type greenstone belts with the gneiss complex are almost always unconformable, whereas in the case of Keewatin type of belts, the contacts are obscured either by soil cover or by massive invasion of later granites. This major granitic event possibly corresponds to the 2500-2600m.y. isochron in the gneiss complex. This evolutionary picture reconstructed mainly from newer field data is consistent with the available limited information on geochronology, geochemistry and mineralisation trends.
Chemistry of Blotites from Pelitic Schists and Granitic Rocks of McCluskieganj, District Palamau, Bihar
Authors: Ghose N. C. , Chakraborty S. K. 
Published: November 2024

Abstract
Composition of biotites from the pelitic schists and granitic rocks of McCluskieganj indicate that the former is rich in magnesium and the latter in iron; their Mg-Fe content is controlled by the composition of the respective host rock. The study of biotite of granitic rocks suggests that oxygen fugacites which prevailed during crystallization closely followed the QFM buffer. Positive correlation of Na between the co-existing K-feldspar and biotite in the granitic rocks, indicates that equilibrium conditions had reached during crystallization of these minerals. Experimental results of a porphyritic granite show that the rock was formed at the 'minimum melt' condition (655°C at PH20 = 4 kb).
Microfossils from the Badami Group, Karnataka South India
Authors: Viswanathiah M. N. , Venkatachalapathy V. , Khadeer Amtul 
Published: November 2024

Abstract
Occurrence of a number of micro-organic remains belonging to Coccoidal nannofossils, Acritarchs and other forms is recorded from the quartz-arenites of Badami Group, Karnataka. The fossils consist of 22 taxa classifiable into the following 9 genera, besides organic plates and cells: Micrhystridium, Granomarginata, Baltisphaeridium, Lophosphaeridium, Protosphaeridium, Tasmanities, Gloeocapsamorpha, Protoleiosphaeridium and Polyedrosphaeridium.
The Stratigraphic Position of the Kioto Limestone of Himalaya
Authors: Gupta V. J. 
Published: November 2024

Abstract
The stratigraphic position of the Kioto Limestone succession is defined between middle Upper Noric and Lower Dogger on the basis of field studies and palaeontological investigations in parts of Kashmir, Ladakh, Spiti, Kumaun and Nepal Himalaya. The lower part of this succession lies conformably above the beds yielding Monotis salinaria of lower Upper Noric age. The boundary between the Triassic and Jurassic lies above the beds yielding Conchodon. The succession belonging to Rhaetic age is much smaller than had been believed earlier. The presence of 'Lithiotis' facies is recorded for the first time in the Kioto Limestone succession. The upper part of this limestone succession lies conformably below the reds containing Middle and Upper Dogger fossils.
On the Discovery of Conophyton and the Record of Oncolites from the Kumaon Himalaya
Authors: Bhattacharya A. R. 
Published: November 2024

Abstract
Stromatolite Conophyton, and oncolites have been recorded from the calc-argillaceous Kapkot formation of the Calc Zone of Tejam, Kumaon Himalaya. The typical cone-in-cone type, belongs to the form Conophyton cylindricus, typical of Lower and Middle Riphean. The age of the Kapkot formation of the Calc Zone of Tejam, is fixed at Lower to Upper Riphean. It can be correlated with the Jammu limestone, the Semri Series (Vindhyans) and the Bijawars of Peninsular India, which are the only rockunits of India from which this form has been reported.
The other forms recorded here, are the oncolites, known from Siberia and Japan only. Inview of their rarity, the present report from the Precambrian of Himalayas is significant.
Tectonic Framework of Sedimentation in the Western Part of the Palnad Basin, Andhra Pradesh
Authors: Vijayam B. E. , Reddy P. H. 
Published: November 2024

Abstract
The lithologic character of sediments, geometry and sedimentary characters of the formations belonging to the Palnad Basin have been taken into consideration in interpreting the probable tectonic framework of sedimentation and tectono-environmental classification of sedimentary formations in the western part of the Palnad basin. The Banganpalli quartzites were deposited in the littoral to infra-littoral environment under stable shelf conditions. The Narji limestones were deposited in infra-littoral to neritic environment under stable shelf conditions. Due to uplift the environment changed to infra-littoral and quiet water environment, when the Auk shales were deposited. The Paniam quartzites were deposited in the littoral to infra-littoral environment under stable shelf conditions with minor tectonic instability in certain local areas where positive elements were active during the uplift of the basin. The Kundair limestones and shales were deposited in neritic zones under reducing environment on stable shelf.
Know Thy Mother's Face - A Plea for Geomorphological Studies in India
Authors: Mukherjee S. K. 
Published: November 2024

Abstract
This paper has been put together from a series of notes written by Sri S. K. Mukherjee, Additional Secretary, Ministry of Mines & Steel and circulated among the participants of the seminar on Himalayan Geology. Sri Mukherjee is not a geologist but is one who is greatly interested in geology, especially the study of the face of the Earth. He is Widely travelled and is well informed about the topographic peculiarities of the Indian sub continent. The present note is a fervent plea to Earth Scientisits in India to take to the study of geomorphology or, as he puts it, 'to know the Mother's face '. The thoughts embodied in this note deserve the earliest consideration by Earth Scientists in India.
Provenance and Sedimentation of Pakhals
Authors: Venkateswara Rao M. 
Published: November 2024

Abstract
Thc Pakhals (Cuddapahs) comprise basal conglomerates at the base, followed by coarse and fine clastics and non-clastics. They rest unconformably over the Peninsular granites and gneisses (Archaeans). The statistical parameters of size and shape analyses and the heavy mineral analysis were computed from the coarse clastic sediments (quartzites and ferruginous sandstones). The data so obtained suggest that the sediments were deposited in a littoral environment.
Model Galena Ages from Karnataka and Surrounding Areas
Authors: Venkatasubramanian V. S. , Radhakrishna B. P. , Jayaram S. 
Published: November 2024

Abstract
Lead isotope ratios have been measured for selected samples from the Chitradurga and Kolar schist belts, the high-grade gneisses E of Karnataka (in Tamil Nadu) and Agnigundala of Cuddapahs. Most of the isotope data approximately fit a single-stage model and yield model ages at 3000 m.y., 2500 m.y., 1400 m.y. and 1100 m.y. The relations with other available age data are discussed.
Airborne Geophysical Survey - A Case Study from Central India
Authors: Mishra D. C. , Narain Hari 
Published: November 2024

Abstract
The airborne magnetic case history from Central India presented here provides indications regarding following concealed geological structures: (i) a deep-seated structure oblique to Narmada-Son lineament at a depth of nearly 4800 feet (below Vindhyan sediments). (ii) a subsurface basic intrusion similar to volcanic plug located at a depth of nearly 4900 feet (below Vindhyan sediments). (iii) extension of Bijawar rocks underneath Vindhyan sediments.
X-Ray Studies on the Structural State, Orthoclase Content and Al-Distribution in Tetrahedra of Potassium Feldspars from Southern India
Authors: Krishna Rao J. S. R. , Dhana Raju R. 
Published: November 2024

Abstract
Potassium feldspars from the granitic and related rocks occurring in Hyderabad, Salem, Mysore and Waltair areas were subjected to X-ray diffraction studies, both in their natural state and after heating to 1050°C for 8 hrs. The triclinicity (?) value in the natural samples varies from 0.98 to 0.74, indicating more or less complete ordered Al/Si distribution, whereas in the heated samples it varies from 0.76 to 0.0, showing increasing disorder with heating. The % Or for these samples as well as for the K-feldspars of Chipurupalle-Razam area was estimated using d-¯201 following different methods. The % Or obtained from the equations of Wright (1968) very closely agrees with the value obtained from reliable chemical analysis.
Quantitative estimation of the Al contents in the four tetrahedral sites (T1O, T1m, T2O and T2m), following the method of Stewart and Ribbe (1969), shows that in orthoclase the Al content is equally distributed between T1O and T1m sites, whereas in intermediate and maximum microcline A1 is concentrated more in T1O site than in T1m site. Based on the triclinicity values, the K-feldspars from the Chipurupalle-Razam area belong to the high structural state followed by those from Salem, Waltair, Hyderabad, and Mysore areas with low structural states, and the differences in the structural state may be related to the differences in the P-T conditions prevaling at the time of K-feldspar formation in these areas.
Synthesis of Abiogenic Graphite under Precambrian Conditions
Authors: Karkhanis Suresh Narayan 
Published: November 2024

Abstract
It has long been known that graphite can be formed by the carbonization of organic matter at temperatures greater than 2000°C. These experiments show that carbon from inorganic precursors-carbonate minerals-can form ordered layers at relatively low temperature of only 600°C at 1 Kb pressure. This relatively low temperature of graphitization might be due to other minerals acting as catalysts. The ordered layering of carbon at low temperature and pressure should have an important consideration in the study of ancient carbonaceous sediments.
'Peninsular Gneiss' in the Northern Parts of Andhra Pradesh
Authors: Perraju P. , Natarajan V. 
Published: November 2024

Abstract
The' Peninsular Gneiss' in the northern parts of Andhra Pradesh can be described briefly as a group of composite gneisses, mostly banded or layered, formed as a result of migmatisation of the older meta-pelites (predominantly biotite-schists), metapsammites, and meta-basics (predominantly amphibolites and hornblende schists), by a grey quartzo-feldspathic injection. The resultant migmatitic gneisses enclose inclusions of all shapes and sizes of the older rocks and exhibit different degrees of interaction and assimilation of them. This complex was later intruded by a 'Pink Granite' the effect of which is also seen as a ' second period of migmatisation '. The two major injections appear to be fairly well separated in time.
These two granitic injections and their corresponding migmatisation effects on the older group of diverse rocks has produced a heterogeneous complex of rock types which show wide variations in composition as well as in texture over the region. Both granites have their own groups of aplite, pegmatite and quartz veins. The white quartz and pegmatite veins traversing the grey porphyroblastic biotite gneisses in Karimnagar district carry molybdenite and sulphide mineralisation. All the rocks were later injected by quartz, epidote and at places by fluorite veins. Fluorite is also found as a component mineral of the' pink granites' in Karimnagar district. Dolerite dykes which cut across all the above, mark the last phase of igneous activity.
Charnockites from Hullahalli, Mysore District, Karnataka State
Authors: Janardhan A. S. , Ramachandra H. M. 
Published: November 2024

Abstract
Charnockites have been noticed in the canal sections near Hullahalli, south of Mysore city. From their field, petrographic and chemical character, it is argued that they were formed as a result of granulite grade metamorphism and migmatization of pelites and intercalated earlier basic igneous rocks and pelites of the Sargur schist complex.
Radioactive Carbonatites of Pakkanadu and Mulakkadu, Salem District, Tamil Nadu
Authors: Suryanarayana Rao C. , Narayan Das G. R. , Krishnaiah Setty B. , Perumal N. V. A. S. 
Published: November 2024

Abstract
Precambrian carbonatites associated with pyroxenites occur as discontinuous lenticular bodies intruding the syenites west of Pakkanadu (11°40'15'': 77°50'1'') and Mulakkadu (11°44'3'' : 77°50'2''). They strike northeast to southwest with easterly dips and have been emplaced along a major northeasterly trending deep crustal fault zone. Large outcrops of serpentinised dunites carrying accessory chromite, cut by asbestos and magnesite veins are also found along the same fault zone to the east and northeast of Pakkanadu.
The carbonatites are of the pure calcite-rich sovite type, with biotitic and ankeritic variants. Apatite, magnetite, allanite, barite, monazite, zircon and cerianite, are the accessory minerals.
Spectrographic analysis has revealed Ba, Sr, Ce and La in major amounts (more than 10,000 ppm) and Th, Nb, P, Zr, Y and Sc in minor amounts (&lt; 10,000 ppm). Spectrographic data suggest that the carbonatite-pyroxenite complex is Ce-La rich.
Niobium is not found in economic concentrations. The general radioactivity recorded by the carbonatite-pyroxenites ranges from 5 to 20 x BG. Representative whole rock samples assay from 0.02% to 0.054% eU3O8 (Carbonatites) and 0.02% to 0.06% eU3O8 (pyroxenites). Allanites assay from 0.35% to 0.4% eU3O8 with chemical U3O8 values from 0.007% to 0.034%, thereby indicating the predominance of thorium over uranium. Monazite is mostly concentrated in the biotite-rich portions of the carbonatites to the west of Pakkanadu, whereas allanites predominate in the pyroxenites west of Mulakkadu.