bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micropalaeontology of Marine Miocene Subsurface Sequence of Galsi Area, Bengal Basin
Authors: Banerji Ranjit K. , Baruah R. M. , Gupta S. C. 
Published: November 2024

Abstract
The exploration for hydrocarbons in the Bengal Basin has revealed the development of nearly 100m of a highly fossiliferous subsurface sequence near Galsi in West Bengal. This sequence has yielded a large number of planktonic and benthonic foraminiferal species. In all, twenty-two species belonging to seven genera and three families of planktonic foraminifera are identified and described. Based on their stratigraphical distribution, four assemblage Zones are distinguished which range in age from Zone N.4 to N.14 (Aquitanian to Langhian, Early to Middle Miocene). The microfaunal study suggests an oscillatory nature of the depositional basin varying from coastal marginal facies to short intervals of open marine inter-tongues within overall shallow marginal basin.
Geochemistry of Anorthositic Dyke from Nuggihalu Schist Belt of Dharwar Craton, Karnataka, India
Authors: Jafri S. H. , Saxena Ramavati 
Published: November 2024

Abstract
Geochemical data is presented of an anorthosite dyke from Nuggihalli made of calcic plagioclase (An70-80), amphibole, pyroxene and accessories like magnetite, sphene and apatite. The chemical data shows high Mg/Mg+Fe++ ratio (Avg.=0.48) and CaO/Na2O ratio (Avg.=8.70) with, &lt;5 ppm Rb and 56-90 ppm Sr., indicating a substantial fractionation of ferromagnesium phase from a highly calcic ultrabasic parent magma.
Determination of Weathered Granite Resistivity from Electrical Resistivity Profiling Data using Empirical Relations
Authors: Srisailanath A. , Patangay N. S. , Bhimasankaram V. L. S. 
Published: November 2024

Abstract
Methodology of groundwater prospecting in granitic terrains using electrical resistivity method sequentially consists of conducting profiling survey, selection of low apparent resistivity zones indicative of probable saturated regions, and estimating the resistivity and thickness of the weathered layer to determine its hydrogeological characteristics employing VES method.
In Musi Ayacut region, where a detailed survey was carried out for groundwater, one of the current electrodes (AB/2) separation used for profiling survey was 10 m. The apparent resistivity values obtained using the above separation were found to be indicative of the hydrogeological nature of the weathered granite layer in the area. It was observed that the apparent resistivity values obtained by the above separation ?a (AB/2= 10m) are linearly related to the true resistivity (?2) value of the weathered granite.
Using the above obtained statistical empirical relations, the weathered granite layer resistivity can be estimated from the profiling survey results even without conducting a large number of vertical electrical soundings in the area.
Minor Element Geochemistry of Pyrite and Sphalerite in the Polymetallic Sulphide Deposit of Deri, Sirohi District, Rajasthan - A Preliminary Study
Authors: Aggarwal Pradeep K. , Nair N. G. K. 
Published: November 2024

Abstract
Data on the distribution of Cd, Mn, Cu, Ag, Ni and Co in four monomineralic fractions each of sphalerite and pyrite from five ore samples of the Precambrian stratiform zinc-lead-copper deposit of Deri, Rajasthan are presented. The minor element geochemistry of the sulphides suggests possible volcanic exhalative origin.
Geological Effects of Storm Associated Tidal Wave on the Krishna Delta Area, East Coast of India
Authors: Durga Prasada Rao N. V. N. 
Published: November 2024

Abstract
The effect of storm associated tidal wave, that struck the Andhra Coast, on the sediments of the Krishna Delta is investigated. Granulometric analysis of the pre- and post-tidal wave estuanne sediments of the Krishna River revealed a remarkable increase in the silt content of the post-tidal wave sediments. Enormous quantity of silt was transported from the shelf and deposited io the estuarine environment by the tidal wave. A slight difference is noticed in the chemical composition of the pre- and post-tidal wave estuarine sediments. Deposition of silt-sized sediments is also observed in the interdistributary area during the field survey. Stabilisation of coastal dunes with proper vegetation is suggested to minimise the effects of tidal waves and storm surges on the coastal region.
Coexisting Humite-Chondrodite-Spinel-Magnesian Calcite Assemblage from the Calc-Silicate Rocks of Ambasamudram, Tamil Nadu, India
Authors: Krishnanath R. 
Published: November 2024

Abstract
A humite-chondrodite-spinel-magnesian calcite assemblage occurs in the calcsilicate rocks of the Ambasamudram area and is associated with the high-grade metamorphic rocks of Peninsular India. This assemblage was stabilised under high-grade metamorphic conditions followed by partial reequilibration under dominant fluorine influence. A coexisting humite-chondrodite assemblage in textural equilibrium does not appear to have been reported from elsewhere.
Effect of Separation of Sri Lanka and India on High Level Landforms and Coastal Sedimentation
Authors: Subramanian K. S. , Gopalakrishnan L. S. 
Published: November 2024

Abstract
The high level plateau landforms characterised by lateritic bauxite cappings and traced at altitudes of about 2,000m in the Nilgiri and the Palni hills in the Western Ghats and in the Central Highlands of Sri Lanka, are correlatable.
The presence of Talchir sediments (Lower Gondwana) below Upper Gondwana sediments in the Palar Basin suggests that the initiation of NE-SW trending tectonic basins on the east coast was in Pre-Jurassic times. The Palar Basin evolved even before the break-up and fragmentation of the Gondwanaland, determining the configuration of the east coast of the Indian Peninsula. The Cauvery Basin, where the oldest sediments are of Upper Jurassic age, came into being in Jurassic times, consequent on the impetus provided by the rifting and fragmentation of Antarctica from the east coast of India.
Sedimentation and Deformation Analysis of Gurusiddapura Conglomerate, Chitradurga Schist Belt
Authors: Bhasker Appah Amrit , Fareeduddin  
Published: November 2024

Abstract
The Gurusiddapura and Hoskere conglomerates of Chitradurga schist belt belong to one continllolls stratigraphic unit. Deformational analysis indicates that the pebbles in both the conglomerates belong to one single population. Graded bedding and occurrence of pebbly and non-pebbly zones indicate turbidite environment of deposition in an unstable geosyncline. Since the conglomerates are interbedded with chlorite schist they do not mark any unconformity.
Surficial Sediments of the Continental Shelf off Karnataka
Authors: Hashimi N. H. , Nair R. R. 
Published: November 2024

Abstract
The continental shelf in this area is about 80 km wide and the edge of the shelf varies between 90 and 120m water depth. Geologically modern fine-grained clastic sediments occur between the water depths of 15 to 50m corresponding to a distance of about 40 km from the coast. Beyond 50 m to the shelf edge are calcareous sands. Noncarbonate components of these deep water sands are essentially quartz, many of which are heavily iron-stained and are attributed to the presence of rich iron formation on the land. The carbonate components in the outer shelf sediments are mainly foraminifers, pelecypods, gastropods, pteropods, and ooids, while ooids and pteropods are absent on the inner shelf. X-ray mineralogy of the silt fraction of the sediments shows the presence of quartz, calcite, aragonite and orthoclase as major minerals. Some of the sedimentary processes effecting the distribution of these sediments are discussed.
Groundwater Chemistry and Formation of Carbonate Concretions in Alluvial Soils
Authors: Chaturvedi A. K. , Raymahashay B. C. 
Published: November 2024

Abstract
Gangetic alluvial soils of Uttar Pradesh typically contain carbonate concretions (kankar) of different morphology at various depths. The concretion mineralogy has been correlated with local groundwater chemistry by calculating mineral solubility products from available thermodynamic data. It is concluded that carbonate minerals are precipitated from supersaturated groundwater in pore space leading to formation of concretions.
Fenitized Sandstones in Amba Dongar Carbonatites, Gujarat, India
Authors: Sukheswala R. N. , Viladkar S. G. 
Published: November 2024

Abstract
Potash fenitization of sandstones of Amba Dongar carbonatite-complex was described earlier by Deans et al. in 1972. The present work mainly deals with newly found soda-fenites in carbonatites, rich in aegirine-augite, aegirine, albite and orthoclase. The chemistry of potash fenites and soda fenites (new analyses) reveals two trends in Amba Dongar fenites; (i) 'normal fenitization' in which both soda and potash have been added and (ii) predominantly potash fenitization leading to the development of potash fenites. The fenitlzing solutions were supplied by the carbonatite magmas (both sovite and ankeritic carbonatite).
Geochemistry of Archaean Metavolcanic Rocks from the Kudremukh Area, Karnataka
Authors: Drury S. A. 
Published: November 2024

Abstract
Major and trace element data for metabasaits and metaperidotites from the littleknown Archaean volcanic-sedimentary belt at Kudremukh are presented. The dominant rocks are low K tholeiites showing evidence of partial melting from a Zr, Y and Nb enriched, P and Ta depleted mantle source, at depths where garnet was stable in peridotitic compositions. The action of olivine, pyroxene and possible spinel fractionation from a high MgO parent magma can account for many of the chemical variations within the suite. Clasts and matrix from an associated agglomerate prove to be the most evolved rocks of the suite and evidence strong plagioclase feldspar fractionation. No precise tectonic setting for the volcanics is attempted; this must await more information on age, structure and volcanic geochemistry for the rest of the Karnataka craton.
Petrology of the Carbonatites and Associated Alkaline Rocks of Siriwasan, Cahota Udaipur
Authors: Sethna S. F. , Borges S. M. 
Published: November 2024

Abstract
The upper portions of the Bagh sandstones of Siriwasan have been penetrated and soaked by a sill-like intrusive of carbonatite which has also penetrated the overlying Deccan Trap basalts at a few places. The carbonatite is intimately associated with tinguaite which shows the same form and occurs as discrete dykes as well. The carbonatite mainly forms the matrix of the brecciated sandstone but in places, where it collected as pools, large pockets of sovite are found. Pools of sovite are also found within tinguaite which shows brecciation at places. Thirty-four samples have been analysed for Sr, Rb, Zr, Nb, Zn, Mn, P, Ce, La, Y and Th. Thirteen of these have also been analysed for U. Analytical data show a consanguinity of the carbonatites and the tinguaites. Immiscible liquid fractions of a carbonatite-alkalic magma are considered to have produced the different rock types.
On the Genesis of Lapsa Buru Kyanite, Singhbhum District, Bihar
Authors: Banerji A. K. 
Published: November 2024

Abstract
A number of massive pegmatoid kyanite veins occur along shear planes at Lapsa Buru, in the western part of the Singhbhum shear zone, Bihar. The host rocks are Precambrian metatuff and metachert, now represented by muscovite-biotite-chlorite schist and quartzite, which have been affected by four phases of deformation and metamorphism. During the first two phases granitic rocks were emplaced within the shear zone at temperature between 650°-700°C and pressure around 2 Kbar. During the 3rd phase albite metasomatism took place within the shear zone under pressure of about 5 Kbar. At the same time, kyanite veins were emplaced along the northern boundary of the shear zone under slightly higher pressure ranging between 5-6 Kbar. A review of experimental data indicates that temperature around 450°-500°C prevailed during kyanite segregation. It has been suggested that under these P-T conditions alumina and silica were mobilised from the alumina rich volcanogenic rocks of the shear zone. Presence of tourmaline, topaz, and dumortierite in the kyanite veins indicates that boron and flourine may have aided the mobilisation process. The resulting kyanite was affected by minor shearing and local retrogressive metamorphism during the fourth phase of deformation in the region.
Large Scale Basin and Dome Structures in the High Grade Metamorphics, Near Visakhapatnam, South India
Authors: Natarajan V. , Nanda J. K. 
Published: November 2024

Abstract
Large scale basin and dome structures with intense buckling in some layers are recorded in the Archaean high grade metamorphic-migmatitc complex of the Eastern Ghats near Visakhapatnam, South India. Two major phases of deformation have been deciphered. The earlier phase was regionally continuous, and resulted in nonplunging, tight and isoclinal (overturned) folds, as well as gently plunging elongate structures. The axial trends of these folds vary from NE-SW to ENE-WSW. Gneissic layering of rocks, development of axial plane schistosity and tight isoclinal angular parasitic minor folds, and large scale shearing and faulting in the axial regions, are correlated to this event.
The later phase of deformation was discontinuous and variable in nature. Southerly/southeasterly plunging, open to tight, normal, similar folds belong to this event and they were superposed on the earlier structures. They modified the pattern and plunges of the latter, and also produced intense buckling or gentle warping locally at several places. Development of warp-like open minor folds, and groove and mineral lineations are correlated to this deformation.
On the basis of critical synthesis of the available structural data, the evolution of the Balacheruvu basin and Madhuravada dome has been attributed to a single deformation of the earlier phase of folding.
Bolaspidella from the Cambrian of Kashmir and its Stratigraphic Significance
Authors: Shah S. K. , Sudan C. S. 
Published: November 2024

Abstract
New species of the trilobite genus Bolaspidella viz., B. himalayensis, B. costalus, B. magamensis and Bolaspidella sp. have been recorded from the top part of the Middle Cambrian of Kashmir. Bolaspidella bearing beds constitute a well marked zone which may be extending into the base of Upper Cambrian. This is the first record of Bolaspidella from Asia and the stratigraphic position of this genus corresponds exactly to that known from North America.
Mesozoic Ammonites from the Spong Valley, Zanskar, N. W. India
Authors: Brookfield M. E. , Westermann G. E. G. 
Published: November 2024

Abstract
A Callovian-Oxfordian sphaeroceratid, (?) Prograyiceras, proves for the first time, the presence of Jurassic flysch in the allochthonous Spongtang Klippe. A berriasellid, Kilianella, similarly proves the presence of probable Valanginian in the autochthonous shelf sequence of the Zanskar range, and supports the presence of the (upper) Spiti Shale hitherto recognized in the area on lithological grounds.
40Ar-39Ar Incremental Heating Studies on a Suite of 'Disturbed' Rocks from Cape Breton Island, Canada; Detection of a Deformational Episode
Authors: Baksi Ajoy K. 
Published: November 2024

Abstract
40Ar_39Ar incremental heating studies have been carried out on a set of Middle Cambrian (age) whole-rock samples, which, in an earlier study (Hayatsu and Carmichael, 1970), yielded a K-Ar isochron age of ~400 Ma and an initial 40Ar_39Ar ratio of ~500. Age spectrum plots reveal that almost all of the argon originates from fine-grained K-feldspar and plagioclase in these rocks; the argon clock in these minerals was almost totally reset by a deformational event (part of the Acadian Orogeny) which occurred ~400 Ma ago. Plotting the results on an Isochron diagram suggests that the high initial argon ratios noted earlier are not due to isotopic homogenisation on a grainsize scale. Since feldspars are known to be susceptible to argon loss at temperatures of &gt;250°C, mild deformation and/or metamorphism in suitable rocks can now be identified and dated by careful 40Ar_39Ar incremental heating work.
Mineralogy and Origin of Jammu Bauxite
Authors: Chadha S. K. 
Published: November 2024

Abstract
The bauxites of Jammu comprise extensive surface spreads of generally hard dense varieties with a typical knobby appearance. The bauxite unconformably overlies Upper Pre-Cambrian limestones and underlies the Nummulitic series of Eocene age. Thickness varies from 1.5 m to 9 m. Three distinct facies are recognised: pisolitic. semi-pisolitic and non-pisolitic.
The bauxites have been analysed for their mineralogical composition adopting X-ray, D.T.A., heavy mineral analyses and optical study. The pisolitic bauxites mostly contain diaspore (A12O3 H2O) and boehmite (AI2O3. 2H2O), the semi-pisolitic bauxites contain, boehmite, limonite, and quartz. The non-pisolitic varieties contain kaolinite. Heavy mineral studies have shown the presence of magnetite, limonite, anatase and corundum. The source rocks appear to be limestones which weathered mitially into clay. The desilicification of the clays under tropical and sub-tropical climatic conditions gave rise to bauxite.
Dehydroxylation and Dehydration as Parameters For Characterisation of Clays - Part II: Kaolinites, Pyrophyllite and Talc
Authors: Venugopal J. S. , Hirannaiah B. V. , Majumder S. K. 
Published: November 2024

Abstract
A sophisticated technique of modified TG, DTG has been described which can detect clay species of kandite, pyrophyllite and talc groups by employing a simple home-made TG Instrument. Many new parameters like half weight loss, differential phase lag and half weight loss temperature are obtained along with other thermal parameters and their rationale are discussed in relation to species level characterisation. The parameteral derivation and its relationship to surface morphology of clays has been described. This highly sensitive method has special application in developing countries and could be adopted in clay based industries for material quality control.
Grain Characteristics of Zircons of Beach Sands from Southwest Coast of India
Authors: Sinha-Roy S. 
Published: November 2024

Abstract
The mineral beach sands of the southwest coast of India, particularly of Chavara and Manavalakurichi areas, contain 4-6% zircon. Although the general setting of the zircon-bearing sands in these two areas is similar, the zircon grain characteristics show some differences. The Manavalakurichi zircon is coarser than the Chavara zircon and in the former, the grain-size has in general a positive correlation with the aspect ratio, whilst in the latter, the correlation is not straightforward. Zoning is more prominent in the Chavara zircon than in the Manavalakurichi zircon. In contrast to the Chavara zircon, the Manavalakurichi zircon shows statistically significant preferred association of idiomorphic grains with microfractures. The level of inclusions (ilmenite, rutile, monazite, quartz, apatite and fluid), either in single phase or in polyphase, is higher in the Manavalakurichi zircon than in the Chavara zircon. The source rock (s) of these zircons may not have been much dissimilar.
Aspects of the Syntectonic Extension and Shear Veins from the Barwaha Region, Dhar forest, Central India
Authors: Roday Prakash P. 
Published: November 2024

Abstract
Extension veins with sigmoidal crystal fibres affected by post-crystallization deformation and synkinematic with the F2 deformational event are developed in the metamorphic rocks east of Barwaha in western Madhya Pradesh. Though the original vein textures have been modified by the effects of post-crystallization deformation such as bending, rupture and shearing, they are sufficiently well-preserved to conclude that the growth process was essentially of the' stretched crystal' or 'crack-seal' type.
The vein origin can be ascribed to a period of low grade metamorphism and associated deformation. Post-vein modifications in the matrix are not associated with any retrogressive metamorphic assemblages, suggesting that the modification process occurred under more or less the same conditions which prevailed during vein growth but under the greater influence of ductile deformation within the veins.
The veins cross-cut the regional schistosity or a statically recrystallised hornfelsic fabric and therefore they postdate the F1 movement and the post F1 dyke, but predate the end of regional ductile deformation F2. Extension veins are themselves cross-cut by shear veins or the shearing is restricted to the walls of extension veins suggesting significant change in orientation of the maximum principal compressive stress towards the late stages of vein dilation. The drusy fabrics of quartz crystals in nontectonic veins developed in the Lameta sandstones are also deformed, as are those of secondary calcite in basalt flow cavities in the area to the east of Sanavad, presumably related to the rifting and volcanism of late Mesozoic-early Cenozoic period. The effect of this later tectonic activity was found in the older syntectonic veins, this being the infilling of zeolite in the late' saddle-reef' type dilation sites between the bent crystal fibres.
Age Of Basic Magmatism in Kerala
Authors: Sinha-Roy S. 
Published: November 2024

Abstract
The Kerala basic dykes that cross-cut the crystalline rocks are quartz or olivinenormative tholeiites. In Trivandrum district. south Kerala, two of these dykes have yielded K-Ar whole-rock dates of 127±2 m.y. and 104±5m.y., whilst the third, 476± 11 m.y. The 104-127 m.y. group age dates the thermal response of the western continental margin distension, and it relates also to the early phase of the Deccan Trap volcanism. The 476 m.y. date is either obtained via crustal contamination or more likely, it represents an older and unrelated thermal event. This event has analog in South Africa, including Madagascar.
Trace Fossils from the Cambrian of Kashmir and their Stratigraphic Significance
Authors: Shah S. K. , Sudan C. S. 
Published: November 2024

Abstract
Trace fossil assemblages studied from the known stratigraphic horizons of Cambrian with a view to establishing their ranges in Himalayan succession have indicated that trilobite tracks and trails are stratigraphically significant. These include the ichnogenera Monomorphichnus, Rusophycus and a new genus and species, Kupwaria fusiformis, together with varieties of claw scratchings. As against this, the various species of ichnogenus Phycodes have stratigraphic ranges which do not exactly, correspond to their reported distribution from other parts of the world. A range chart based on associated trilobite fossils has been built for stratigraphically significant ichnofossil assemblages.
Metamorphism and Development of Morphometric Parameters: An Illustration from Bino Basin-Almora Crystalline
Authors: Joshi S. C. , Rawat J. S. 
Published: November 2024

Abstract
Composition of drainage net in the Almora crystalline is considerably controlled by tectonics. The open synformal structure of Almora Nappe 1, composed of highly puckered granetiferous mica schist with stretched quartz lenses of High Grade Metamorphic rocks are demarcated by relatively higher values of drainage density (1.81 km/km2), stream frequency (6.22 channels/km2) and ruggedness number (1.26); and lower values of the length of first (2.05 krn), second (.85 km) and third (0.51 km) order streams, basin area (2.24 km), basin perimeter (6.68) and basin length (1.63 km) than that of the Low Grade Metamorphic rocks of the Almora Nappe II, composed of quartzite. phyllite, orthogneiss, granite, schist and amphibolite.