bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controls of Asbestos Mineralisation in the Roro Ultramafics, Singhbhum District, Bihar
Authors: Ballurkar Ashok , Pal P. C. 
Published: November 2024

Abstract
The ultramafics of Roro are layered bodies comprising two major lithological units-serpentinised pyroxenites (SPX) and serpentinised saxonites (SSX). Ribbon zones of chrysotile mineralisation are found localised in thin granular serpentinite (SR) horizons at the contacts of 'the SPX and SSX layers in cross folded portions of these ultramafic bodies.
The SSX rock is typically a clot-bearing one, comprising poikilitic clots of saxonitic composition embedded in relatively olivine-rich and more serpentinised groundmass. Two controls for chrysotile localisation can be readily identified in the Roro ultramafics. The lithological control is provided by extensively serpentinised interfaces of the already partially serpentinisied pyroxenitic and saxonitic layers. These horizons of secondary serpentinisation (viz., the SR horizons) appear to have resulted from either a fusion of the SPX and SSX rocks at their contacts or, alternately, from the segregation of the SSX clots at the interfaces of these layers and their subsequent serpentinisation. The composition of the SSX rock therefore appears to have been a vital factor in fibre development in the SR horizons. The structural control is considered to have been provided by the superposition of structural deformations due to Singhbhum orogeny over those caused by the older Iron ore orogeny.
Fibre development is indicated to be a dynamothermal process in the structure-restricted zones of secondary serpentinisation in an already serpentinised ultramafic body.
Stylolitic Origin of Chrysotile Asbestos Near Pulivendla, Cuddapah District, Andhra Pradesh
Authors: Ramam P. K. , Ananta Iyer G. V. , Narayanan Kutty T. R. , Murthy M. V. N. 
Published: November 2024

Abstract
The field observation that chrysotile asbestos near Pulivendla is localised along stylolites in the Proterozoic carbonate sediments of the Vempalli Formation (Cuddapah Supergroup) proved crucial and paved the way for a re-thinking on the origin of Pulivendla asbestos. The length of the fibre, nowhere, transgresses the amplitude of the stylolite. Further, the lateral termination of the chrysotile seams invariably coincides with that of the enclosing stylolite. The stylolite development and fibre growth appear to be a sequel to directional pressure. X-ray and infra-red studies of the massive serpentinous zones revealed dioctahedral dewelyite to be the main serpentine mineral. It is suggested that the chemical pre-requisites (e.g. magnesia, silica and hydroxyl molecules) necessary for serpentinisation and pari passu chrysotilisation, were present in the carbonate sediment itself at the loci of stylolitisation and that the intrusive dolerite merely provided the desired thermal energy. The emplacement took place, possibly, when the carbonate sediment was in a semi-consolidated stage. Stylolitisation and chrysotilisation appear to have ceased with the complete consolidation of the enclosing sediment.
U-Pb Isotopic Ages of Uraninites from Kulu, Himachal Pradesh and Berinag, Uttar Pradesh
Authors: Bhalla N. S. , Gupta J. N. 
Published: November 2024

Abstract
U-Pb Isotopic ages of a eight uranmites, occurring as veins and disseminations in quartzite in Kulu district of Himachal Pradesh and Berinag (Pithoragarh district) of Uttar Pradesh are reported. The ages are discordant and show the general pattern (207Pb/206Pb) age &gt; (207Pb/235U) age &gt; (206Pb/238U) age. An attempt has been made to find a convergent age related perhaps to the actual time of mineralizanon and to explain the discordancy in terms of episodic loss of lead/gain of uranium, Uraninites occurring as disseminations in quartzite in Kulu are estimated to have been formed at 1232±120 my., whereas those occuring as veins and fracture fillings appear to be younger Both the mineralizations show the effect of a recent episodic event (55 my.).
Gravity Surveys for Barytes Around Mangampeta, Cuddapah District, Andhra Pradesh
Authors: Bose R. N. , Vaidyanathan N. C. 
Published: November 2024

Abstract
The barytes deposit of Mangampeta (14°01'15" : 79°19'15") may now be classed as the largest single barytes deposit in the world. Though the occurrence of barytes in Mangampeta was known since mid-sixties, a multi-disciplinary approach including gravity surveys carried out during 1971-73 revealed the immense potentialities of the deposit. Exploratory drilling at the recommended points over the gravity' high' struck thick zones of barytes. As many as 61 boreholes have so far been drilled over the main gravity: anomaly zone, of which 53 intersected barytes ranging in thickness from 5 to 44 metres, indicating a reserve of about 60 million tonnes.
Observations on the Geomorphology of Goa
Authors: Sriram K. , Prasad K. N. 
Published: November 2024

Abstract
The area studied represents the coastal tract along the West Coast of Peninsular India. Remnants of planar surfaces showing deep lateritic weathering profiles are common in the northern part of Goa. The southern part, however, presents a rugged topography with hills ranging in altitude up to 600 m, especially near the coast. It is surmised that the present coast emerged during late Neogene and presumably before the onset of Pleistocene glaciation. Remnants of the emerged marine denudational surfaces are noticed at altitudes of 160m, inland near the ghats and at 60m along the coast. In general, most of the remnants are at 120 m above the present mean sea level. From the accordance of summit heights of hills and inselbergs rising above the remnants of planar surfaces, trace of the older erosional surface appears at 300 m above the mean sea level. This surface may be assigned to Mio-Pliocene. The remnants of the late Pliocene planar surface is marked by valley benches and terraces that are probably the result of oscillations of the sea level during Pleistocene. It is difficult to assess their specific relationship with the interglacials of the Quaternary period.
The Gariadih Rapakivi Granite of the Bihar Mica Belt Hazaribagh District, Bihar
Authors: Bhattacharya Udaybhanu 
Published: November 2024

Abstract
The rapakivi granite forms a large dyke-like body within a group of amphibolite facies Precambrian metamorphites and gneissose granite. The essential mineral constituents are orthoclase, microcline, plagioclase, quartz, biotite, hornblende (ferrohastingsite) and accessory minerals apatite and xenotime. Emplacement of a fresh surge of K-rich magma towards the closing stage of crystallisation of the gneissose granite body gave rise to the rapakivi granite.
Depositional History of Permo-Carboniferous Tillites and Associated Sediments in W. Bokaro Gondwana Basin, Bihar, India
Authors: Das S. N. , Sen D. P. 
Published: November 2024

Abstract
The Talchir Group of rocks in India form a very important stratigraphic horizon by their presence at the base of all the Gondwana basins. Talchirs have been recognised as glacial sediments. The present study suggests that the Talchir Group was deposited both as stratified drift and unstratified drift. The glaciers responsible for Talchir sedimentation in eastern India belong to piedmont glacier system. The number of times the glacial lobes advanced into different basins varies from basin to basin. In all the basins the bulk of the sediments was deposited during first deglaciation period as meltwater channel, esker, glaciolacustrine delta and lake deposits. The topography surrounding the basin during upper Talchir time provided infra-structure for Barakar sedimentation.
Mesozoic Sedimentary Model of Wagad Hills, Kutch, Western India
Authors: Deshpande S. V. , Merh S. S. 
Published: November 2024

Abstract
Wagad Hills in the eastern part of Kutch, Western India, mainly comprise of rocks ranging in age from middle Jurassic to lower Cretaceous encircled by a thin and narrow fringe of Tertiary sediments.
A sedimentary model of Wagad Hills is proposed comprising environments of deposition, basin geometry, lithic fill, lithic arrangement, directional structures and tectonic setting. The area experienced a prograding delta system with a gradual shift of strand line from east to west during the course of deposition.
Recent Foraminifera from the Pennar Estuary, Andhra Pradesh
Authors: Reddy K. R. , Jagadiswara Rao R. 
Published: November 2024

Abstract
45 foraminiferal species belonging to the suborders Textulariina, Miliolina and Rotaliina, identified from 180 bottom sediment samples from the Pennar estuary in the east coast of India are reported and illustrated.
Geochemistry of Spinifex-Textured Peridotitic Komatiites from Ghatti Hosahalli, Karnataka, Indi
Authors: Narayana B. L. , Naqvi S. M. 
Published: November 2024

Abstract
Spinifex-textured peridotitic komatiites (STPK) of Ghatti Hosahalli have low CaO/Al2O3 ratio (&lt; 1), low TiO2, K2O and high MgO. These STPK have comparable Ni and Co contents with those of the Australian and Canadian shields. These characters support the view that the spinifex-texture observed in these rocks is primary and not the result of later metamorphism. The Al2O3/TiO2 ratios are comparable to those of Chondrites indicating that the STPK are products of partial melting of the Archaean mantle. The STPK of Ghatti Hosahalli arc overlain by exhalative chemical precipitates and argillaceous metamorphosed sediments like bedded-barytes, fuchsite-quartzites and kyanite-mica schists. It is suggested that Ghatti Hosahalli band is a relic of an early Archaean greenstone belt.
Some Observanons on the Sedimentology of the Krol Succession of Mussoorie Area, Uttar Pradesh
Authors: Singh Indra Bir , Bhargava Ajai Kumar , Rai Vikram 
Published: November 2024

Abstract
Study of sedimentary structures indicate that Krol succession of Mussoorie area represents deposits of a shallow tidal sea: Krol A-deposits of open sea tidal flats in intertidal-subtidal zone. Krol B - deposits of protected embayment Or lagoon, Krol C - open tidal flats to intertidal zone of restricted tidal flat, Krol D - algal mat facies of inner intertidal to supratidal zone with increased salinity, Krol E - intertidal zone. The algal mat facies of Krol E shows dominantly Loferite, fenestral dolomite or bird's eye dolomite, showing different types of shrinkage cracks e.g. sheet cracks, irregular fenestral fabric, shrinkage pores. The supratidal facies is quite abundant, represented by vuggy dolomite and bird's eye pisolitic dolomite.
New Foraminifera from the Neogene of Little Andaman Island, Bay of Bengal
Authors: Srinivasan M. S. , Singh D. N. 
Published: November 2024

Abstract
The following five new species of benthic foraminifera are described and illustrated from the Neogene sequence of Little Andaman Island, Bay of Bengal: Bulimina andamanica* , Cibicides hochstetteri* , Pararotalia geei, Fursenkoina indica, Ehrenhergina schwageri. Observed stratigraphic ranges are given for each species. All the new species described occur associated with deepwater assemblages characteristic of lower to middle bathyal depths. Those marked with an asterisk have proved useful, as zonal markers in the Andaman Sea region.
Rare Minerals from Rajpura-Dariba, Rajasthan, India 1: Owyheeite
Authors: Basu Kanika , Bortnykov N. , Mookherjee A. , Mozgova N. 
Published: November 2024

Abstract
Owyheeite is reported for the first time from an Indian ore deposit. Optical properties, microhardness and X-ray powder diffraction data of the mineral are furnished. Microprobe analysis yields the formula Pb4.76(Ag1.59CU0.11)h0.70Sb6.54Sl5.32. Comparison with other available microprobe data of samples from different localities indicates nonstoichiometric composition of the mineral phase. A small amount of copper seems necessary to stabilize the mineral, since it could not be synthesized in the system PbS-Ag2S-Sb2S3. Curved nature of lamellar grains and existence of spindle-shaped deformation (?) twins imply pre- or syn-tectonic crystallization of the mineral.
Some Aspects of Diagenesis of the Broach Group of Tertiary Sediments Around Jhagadia, District Broach, Gujarat
Authors: Gadekar D. R. 
Published: November 2024

Abstract
The supra-Trappean Broach Group of Tertiary sediments show evidences of a variety of diagenetic changes. The arenaceous sediments of the Vagalkhod Formation contain proofs of recrystallisation of sparry and micrite cement indicating pore-filling and shallow depth of burial. The calcareous sediments of the Bhilod Formation (Nummulitics) show limonitisation suggesting low temperature metasomatism and precipitation in shallow waters. The argillaceous rocks of the Tarakeshwar Formation reveal authigenic sparite, also indicative of shallow burial. Silica cementation, authigenesis and limonitisation are some of the important diagenetic changes discernible in the overlying rudaceous Babaguru Formation. These changes suggest redoxomorphic stage, precipitation from gel and epidiagenesis. The calcareous sediments of the Kand Formation reveal recrystallisation of spa rite from micrite, which may suggest diagenetic transformation. The arenaceous sediments of the Jhagadia Formation bear evidence of the activity of carbonate cementation ~nd replacement, which may perhaps indicate locomorphic stage of diagenesis.
Petrochemical Studies on Chromites from Sinduvalli, Karnataka, India
Authors: Srikantappa C. , Friend C. R. L. , Janardhan A. S. 
Published: November 2024

Abstract
Mineralogical and chemical studies of chromite deposits of Sinduvalli ultramafic body, Mysore District, show definite evidence of layering and other crystal settling processes. Stretching of occluded olivines, chain structures in chromite and rotation of chromite layers indicate their participation in the deformational episodes which affected the area. Structure and chemistry of chromites classify the host ultramafics as belonging to stratiform type. Presence of gabbroic anorthosites confirms this and indicates that they represent layered complexes characterizing the Sargur high-grade terrain.
The presence of recrystallised orthopyroxenes and development of chrome amphibole indicate their formation under metamorphic conditions. Olivine-spinel geothermometry suggests re-equilibration at sub-solidus temperatures during high grade metamorphism. The formation of 'Ferritchromit' zones is connected to magnesite formation.
Geology of Part of Central Ladakh Himalaya with Particular Reference to Indus Tectonic Zone
Authors: Srikantia S. V. , Razdan M. L. 
Published: November 2024

Abstract
In the Central Ladakh Himalaya, the Ladakh Granitic Complex with Kharbu Group, the Indus Tectonic Zone and the Spiti-Zanskar and Kashmir Precambrian Phanerozoic belts constitute the chief geological units. The Ladakh Granitic Complex comprises a heterogeneous association of granitoids, gabbroids and basic rocks. The Spiti-Zanskar and Kashmir belts comprise Precambrian-Eocambrian crystallines and Late Palaeozoic-Mesozoic sediments.The Indus Tectonic Zone, a name adopted in preference to the Indus Suture Zone consists of two parallel and almost homotaxial sedimentary belts viz., the non-ophiolitic Indus Group in the north and the ophiolitic sedimentary volcanic belt of the Sangeluma Group in the south. The Indus Group unconformably overlies the Ladakh Granitic Complex, and the Sangeluma Group tectonically overlies the former. The Indus Group is divisible into the Skinding, the Kuksho, the Maklishun and the Karit Formations in the ascending order, and the Sangeluma into the Khalsi, the Dras Volcanic, the Nindam and the Shergol Formations with ophiolite association in all the formations excepting the Nindam.
The Indus Group cycle of sedimentation comprises, shallow diamictite, flyschoid, lagoonal and molassic stages, whereas the Sangeluma comprises the platform, submarine volcanic, flyschoid and unstable shelf type sedimentation.
Tectonically, the area can be divided into: Ladakh Granitic Complex-Indus Group autochthon, the Sangeluma parautochthon, the Kuling-Lilang schuppen belt, the parautochthon of Spiti-Zanskar and Kashmir Precambrian-Phaneroxoic belts and Shilakong ophiolite nappe.
The Indus Tectonic Zone was an original mega lineament which later became a site of opening of sea and sedimentation for the Indus and the Sangeluma. A sequence of stages of sea-floor spreading subduction and closing is envisaged.
The Occurrence of Heavy Mineral Sands along the Tanzanian Coast
Authors: Duyverman H. J. 
Published: November 2024

Abstract
Heavy mineral sands containing garnet, ilmenite, kyanite, zircon, rutile, magnetite and monazite occur along the eastern coastal belt of Tanzania. Concentrations of these heavy minerals vary along the coast from south to north, but the mineralogical assemblage is fairly constant, the average for the entire coast being garnet 39.2%, ilmenite 33.8%, kyanite+zircon 21.7%, rutile 3.8%, others 1.4%, total heavy minerals 23%.
The heavy mineral concentrations are restricted to the Mtoni Terrace, consisting of lagoons, swamps, raised coral reefs and beach ridges of Pleistocene to Recent age, the richer concentrations being found north of the mouths of the bigger rivers, e.g., the Msimbati Peninsula, north of the Ruvuma River. The source rocks are the Precambrian Basement rocks to the immediate west of the coastal belt and, to a lesser extent, the younger sedimentary rocks from Karroo to Recent in age.
A study of beach profiles and of heavy mineral concentrations at five selected localities along the coast has shown that higher concentrations occur during November to January and May to July, coinciding with the beginnings of the monsoonal periods, when the erosive action of the sea is greatest.
Cluster Analysis and Ecology of Living Benthonic Foraminiferids from Inner Shelf off Ratnagiri, West Coast, India
Authors: Nigam Rajiv , Sarupria J. S. 
Published: November 2024

Abstract
Q-mode cluster analysis explains the spatial distribution data of living benthonic foraminiferids from the inner shelf off Ratnagiri. Two main biotopes and two subbiotopes are recognised within the study area; biotope A, characterised by Trochammina inflata (Montagu), covers the inner shelf north of Ratnagiri and demarcates the influence of fresh-water from Shastri and Vashishti rivers. Biotope B characterised by Nonion and Ammonia covers the inner shelf south of Ratnagiri and represents less influence of fresh water from Rajapur and Vaghotan rivers. Two sub-biotopes in Bare represented by the additional occurrence of Ammobaculites agglutinans and Nonionella respectively. Relatively low and high rate of sedimentations were noted in areas of biotopes A and B respectively.
Some Recent Earthquakes in Peninsular India
Authors: Mohan Indra , Sitaram M. V. D. , Gupta Harsh K. 
Published: November 2024

Abstract
The Peninsular Shield of India, generally considered to be aseismic, has recently experienced significant activity al Koyna (1967), Bhadrachalam (1969) and Broach (1970). Besides, over two hundred tremors, with magnitudes ranging from 2 to 5, have also been identified mainly in Andhra Pradesh, Karnataka and Maharashtra during 1967 to 1977, and are catalogued. Low magnitude activity (M &lt; 4) is observed to be prevalent in the Peninsular Shield.
Sulphur Isotope Abundance Variations in Sulfides of the Dharwar Craton - Part II: Ingaldhal
Authors: Venkatasubramanian V. S. , Menon A. G. , Ananta Iyer G. V. 
Published: November 2024

Abstract
In this sequel to the previous note, we describe the results of d34S measurements on sulphides of the Ingaldhal deposit. A component with near-zero permit values is superposed on a possibly larger component with positive d34S values ~+10‰. The spread can be explained in terms of change in the solution parameters (T, pH and fO2) of the source-fluid, these being represented by fs2-fO2 diagrams. An area on this diagram, sets constraints on the solution parameters during deposition, as indicated.
A Statistical Study on Reliability of Different Scale of Cross-Beds as Paleocurrent Indicator in the Late Paleozoic Fluviatile Rocks of Jharia Basin, India
Authors: Khan Zahid A. , Casshyap Satyendra M. 
Published: November 2024

Abstract
Three scales of cross-beds were recognised and investigated for the Barakar strata of the Jharia basin, attributed to deposition largely by streams of low to moderate channel Sinuosity. Following the recent modifications in statistical methods of crossbedding azimuthal data, sample resultant instead of mean was compared between three scales of cross beds. Sample resultant so computed was tested for 16 sample pairs in 6 sectors and 3 sample, pairs at formation level by applying a modified 'P' statistics. Results are found to be non-significant at 95% level of confidence in 16 out of 19 sample pairs.
Synthesis of paleocurrent data reveals With high degree of probability that all scales of cross beds in fluviatile deposits may be regarded as reliable indicators, provided a proper interpretation is made in respect of the environment of deposition of the host bed form and associated sediments.
Rapakivi Granite of Ezhimala Complex and its Significance
Authors: Nair M. M. , Vidyadharan K. T. 
Published: November 2024

Abstract
The field characters, chemistry and the spatial association of the 678 m.y. old Rapakivi granite with gabbros and anorthosites suggest that these litho-units have developed through bimodal magmatic processes whereby heat derived from basic magma parental to the anorthositic rocks caused partial melting at or near the base of the crust to produce granitic magma with Rapakivi characteristics.
A Plate Tectonic Model for the Geologic Evolution of Sri Lanka
Authors: Munasinghe Tissa , Dissanayake C. B. 
Published: November 2024

Abstract
A new model is put forward to explain the geologic evolution of Sri Lanka. The Highland Group is a highly metamorphosed assemblage of a marine deposited volcanic, volcano-clastic and sedimentary rocks. The origin of the Highland Group dates back to 3000 Ma during a permobile phase in the evolution of the earths crust. Archaean tectonics suggest a downfolding of a thin crust forming the Highland Basin and subsequent filling with marine sediments and volcanics. The tectonic characteristics of the Archean suggest that its evolution possibly passed through a transitional phase (during which the crust thickened) to a plate tectonic phase. Plate tectonic processes analogous to those of the present were active from 2000 Ma. The material in the Highland Basin was metamorphosed and deformed repeatedly, in a collisional tectonic environment, to form the present configuration in the Precambrian of Sri Lanka.
A Note on the 'Volcanic Conglomerate'/Pyroclast Horizon near Palkanmaradi in the Hutti Schist Belt, Karnataka
Authors: Roy Abhinaba , Biswas S. K. 
Published: November 2024

Abstract
Palkanmaradi 'Conglomerate' occurs as a conformable bed within the volcano-sedimentary sequence of the Hutti schist belt. Well-rounded pebbles of granodiorite/tonalite gneiss, microgranite/acid volcanic rock, angular to subangular fragments of amphibolite, are found embedded in a matrix having unusual chemistry representing probably an admixture of volcanic and sedimentary material. Along with the other rocks tbe conglomerate bed has suffered from three distinct phases of deformation and attained amphibolite facies of metamorphism.
Deformation Structures in the Delhi Group of Rocks around Nibhor, Rajasthan
Authors: Bhola A. M. , Saberwal K. K. 
Published: November 2024

Abstract
The metamorphic rocks occurring around Nibhor, northwestern part of the Alwar district, Rajasthan, bear evidence of three phases of folding and one period of regional metamorphism of green-schist facies. The first deformation phase, F1 produced the principal, foliation S1 and the later deformation phases, F2 and F3, produced crenulation cleavages, S2 and S3 respectively. Kinking by the rotation mechanism emerges as the dominant structure supported by kinks with tabular dilatant zones between parted laminae. Some kinks may also have developed by simple shear mechanism.