bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation Parameters of the Lower Eocene Rocks in Qatar
Authors: El-Sayed A. A. 
Published: November 2024

Abstract
The study of some carbonate rock samples collected from four different locations in Qatar and attributed to the Rus Formation (Lower Eocene) reveals that these rocks are mainly heterogeneous in their petrophysical characteristics. This is indicated not only by study of pore space geometry but also by a skewed distribution of porosity, permeability and hydraulic conductivity data.
These parameters help in reservoir evaluation and description. Useful empirical relations have been derived by which both the storage capacity and the gas-permeability of the studied rocks can be estimated. Study of SEM-micrographs have shown the influence of post-depositional processes on both porosity and gas-permeability in varying degress.
Magnetic Polarity Stratigraphy and Vertebrate Palaeontology of the Upper Siwalik Subgroup of Jammu Hills, India
Authors: Ranga Rao A. , Agarwal R. P. , Sharma U. N. , Bhalla M. S. , Nanda A. C. 
Published: November 2024

Abstract
Magnetic polarity stratigraphy of Upper Siwalik Subgroup, Jammu Hills was worked out based on partially demagnetized data from 208 sites in three sections: Parmandal-Utterbeni, Nagrota-Jammu and Balli. One/two bentonitized tuff horizons occur close to the base of a long reversed polarity zone associated with Pinjor age fossils. Fisson track dates of 2.8±0.56 m.y. and 2.31±0.54 m.y. have been obtained on the zircon phenocrysts from these tuffs. These data permit correlation of our magnetic stratigraphy with the standard magnetic polarity time scale. The longest sampled section spans the interval from 4.92 to 0.22 m.y. This dating places the lower part of Upper Siwalik in the early Pliocene.
In the sampled parts of the sections, the magnetic polarity zonation establishes 16 magnetozones in Parmandal-Utterbeni, 13 in Nagrota and one in Balli. Individual magnetic transitions can be correlated over a lateral distance of 62 km and these provide time lines for correlation of lithology from one section to the other.
Estimated rates of sedimentation indicate rates varying from 0-45 m to 0.71 m/l000 years for Gilbert and Gauss epochs, while a decreased rate varying from 0.21 m to 0.37 m/l000 years is indicated during the Matuyama epoch.
The ]ast folding event of Suruin-Mastgarh anticline is not older than 0.22 m.y. However, the decrease in the rate of sedimentation during post Gauss time could possibly be due to an earlier period of deformation.
A significant change in fauna near the Gauss-Matuyama boundary is observed by the appearance of Equus and cervids with antlers and by the absence of Hipparion. We correlate this boundary with the Tatrot-Pinjor faunal boundary, No change either in lithology or in the vertebrate fauna is observed at the Pliocene-Pleistocene boundary if it is to be placed at the top of the Olduvai Normal Subchron.
Secondary Geochemical Dispersion in the Lateritic Tracts Over Two Copper Sulphide Deposits in Orissa, India
Authors: Banerji P. K. , Mohanty A. K. , Mahakud S. P. 
Published: November 2024

Abstract
Host rocks are kyanite-quartzite at Kesarpur and uralitised garnet-diopside granulite (± scapolite) at Adash. Primary sulphides include chalcopyrite, pyrite and pyrrhotite with small but variable amounts of bornite. The ore bodies are lenticular and carry variable trace constituents of Ag. Au, Ni and Co. Supergene minerals occur only in thin stretches and include covellite, marcasite and violarite. No discrete zone of supergene enrichment is noted in the boreholes. Oxidised zones at the top are 15-45m. thick and analyse in Adash up to 2.27% Cu plus 0.4% Zn over 3-4 m width. Goethite, haematite, malachite, azurite and chrysocolla are the constituent minerals.
Feeble to strong anomalies are present in pedogenetic laterites over orc bodies. but spurious anomalies locally with 1 % Mn are common. Laterites in Adash are polycyclic and anomaly values are locally erratic. Over groundwater laterites of Kesarpur. very feeble secondary anomalies are confined to only 100 m from the ore zone.
Stream sediment signals are confined to first order seasonal drainge courses and are traceable for only 2-3 km from the source down stream. Such limited anomaly dispersion is due to differential block movements in this area.
Landforms developing under this dynamic system have not given rise to widespread and strong stream sediment dispersion patterns of chalcophile elements. Systematic search for small ore bodies in such tracts has, therefore, to be hased only on sampling the sediments of first order drainage courses.
A Study of Proterozoic Phosphorite from Chelima-Pachcherla Area, Kurnool District, Andhra Pradesh, India
Authors: Banerjee D. M. , Saigal Neeta 
Published: November 2024

Abstract
Stromatolitic and pelletal phosphorite deposits, belonging to Cumbum Subgroup of Nallamalai Group have recently been reported from Chelima-Pachcherla areas of Kurnool district in Andhra Pradesh. Most phosphorites of these areas are linked to the carbonate stromatolites like other Proterozoic phosphorite deposits of India. However, there are many variants which occur amidst quartzose rocks, assuming pel1etal forms, showing well marked neomorphic grain-growths and marked enrichment of elements like F, K2O, Ba, Co, Mn, V, Y and Pb. Based on mineralogy, petrology, and geochemistry of these phosphorites, a protected-isolated supratidal lagoon type of environment has been visualised for the precipitation and diagenetic alteration of the Cumbum phosphorite.
Tectonic Significance of Ultramafic and Associated Rocks Near Tal in the Bijawar Belt, Sidhi District, Madhya Pradesh
Authors: Roy Abhinaba , Bandyopadhyay B. K. 
Published: November 2024

Abstract
Serpentinised ultramafic bodies of peridotite-dunite composition occur as solid state intrusions in the Bijawar volcano-sedimentary sequence around Tal in Sidhi district, Madhya Pradesh. The associated basic volcanics and gabbros are predominantly tholeiitic in composition, although a slight enrichment in Na is recognised locally. However, apart from their juxtaposition, there is no petrological or chemical evidence to suggest that the uhramafic and gabbroic rocks were derived from a common magma. The ultramafics represent olivine-pyroxene cumulates, crystallised at depth and subsequently emplaced as crystalline mush (? diapiric intrusion) during the pre- to early-kinematic stage of basin development. This suggests the possible role of a mantle-derived magma to initiate basin depression. Near the cratonic margin of the basin, shelf sediments (orthoquartzite, carbonate-pelletal chert etc.) were deposited over the gneissic basement while the distal facies was mainly a turbidite. The rocks underwent polyphase deformation and low-grade greenschist facies metamorphism. The closing stage of Bijawar was marked by the emplacement of post-tectonic granite and occasional gabbroic diorite near the peripheral zones of the belt.
Triassic Microfauna of the Lilang Group with Special Reference to Scythian-Anisian Conodonts, Spiti Valley, Himachal Himalaya
Authors: Bhargava O. N. , Gadhoke S. K. 
Published: November 2024

Abstract
The Triassic microfauna from the type section of the Lilang Group recorded here includes conodonts (58 taxa), foraminifera (17 taxa), ostracoda (5 taxa) and radiolaria (one taxon).
Except for one form in the Carnian Sanglung Formatiqn, the conodonts are exclusive to the Scythian-Anisian Mikin Formation. The foraminifers come mainly from the Mikin, Norian Hangrang and Rhaetian-Dogger Kioto Formations. In the former two, they are rare, while in the last one common. The ostracodes chiefly occur in the Mikin Formation. The radiolarians are common in the Carnian Chomule Formation and sporadic in the Mikin Formation.
Based on microfacies analysis, the Mikin, Chomule and Sanglung Formations are interpreted to represent clear basin margin, Hangrang back-reef to fores]ope and Kioto restricted platform to edge-sand and lagoon environments. The varying abundance of the microfauna in different formations is possibly environmentally controlled. The conodonts, and radiolaria preferred basin margin, and foraminifers restricted platform to edge-sand and lagoon environments.
Zoning in Plagioclase (Normal and Oscillatory) in the Feldspar Porphyries of Karsog Area, Lesser Himalaya, Himachal Pradesh, India
Authors: Gupta L. N. , Marwaha S. 
Published: November 2024

Abstract
Growth of plagioclase crystals accompanied by rapid cooling and contemporaneous crystallisation with falling temperature is considered to cause disequilibrium due to incomplete reaction between the growing crystal and the residual sodic melt. This causes the formation of normal zoning. Regular oscillatory zoning has been explained mainly due to the process of diffusion of An-molecules towards the crystal face of growing plagiolcase in a magma. Growth of zoned plagioclase was accompanied by fractional crystallisation and accumulation of magma of trondhjernitic composition. During this process, zoned plagioclases came in contact with one another and resulted in synneusis. Partial resorption resulted in truncated zones followed by crystallisation of a more calcic rim.
Structural Analysis of Shear Zones in Basement Granite and their Relationship with Folding, Shearing and Faulting in the Cover Sediments Near Hirapur, District Sagar, Central India
Authors: Roday Prakash P. , Chourasia L. P. , Chaudhari Shailendra 
Published: November 2024

Abstract
The morphology of ductile shear zones in the granitic basement of Bijawar rocks is described. The dextral shear zones are more ubiquitous than their sinistral counterparts and the obtuse angle between the two sets faces the direction of maximum shortening in rocks, the exact value of the angle presumably controlled by the mean stress. The maximum displacement vector of shear zones is generally subhorizontal. The negative dilatation in some shear zones has caused the overall defoi marion in them to be of the flattening type. The orientations of the principal stresses are calculated. The cleavage trajectories do not sometimes exactly bisect the acute angle between the conjugate zones, presumably due to rotation of principal strains with progressive shear or to the more accentuated development of one set of zones.
The sinusoidal and conjugate folds of monochnic or triclinic symmetry (D-1) in the Bijawar rocks are shown to be related genetically and from the point of view of orientation of principal compressive stresses to the ductile shear zone development in basement granite. The brittle-ductile shear zones in the basal carbonate unit associated at places with pressure solution or tectonic stylolitic structures whose formation was accompanied by about 14 to 24 per cent volume reduction formed at the same time.
There was a renewed activity during post-Vindhyan time along pre-existing shear zones in the older rocks but in the opposite sense under very Jow P-T conditions which produced ductile D-2 structures in Bijawar rocks, culminating in small or moderate scale strike-slip faults. The youngest movements along these faults were, however, with a vertical component under a subvertically oriented maximum principal compression. It appears that most shear zones have an minal period of strain softening, followed by rather sudden strain hardening or loss of material contmuity which causes either the termination of such zones or their passing into model ate scale wrench faults.
On the Occurrence of Upper Gondwana Plant Beds near Chintalapudi, West Godavari District, Andhra Pradesh
Authors: Lakshminarayana G. , Gururaja M. N. , Kutumba Rao N. 
Published: November 2024

Abstract
Variegated clay-clast-bearing sandstones and purple claystones containing upper Gondwana plant fossils viz. Cladophlebis cf. denticulata, Ptilophyllum sp., Pterophyllum sp., Elatocladus conferta and Elatocladus cf. plana are recorded for the first time near Chintalapudi from the upper part of the 'Chintalapudi Sandstone' hitherto believed to be of lower Gondwana age. The present study has established that the newly identified upper Gondwana rock units belong to the Kota Formation overlying the 'Chintalapudi Sandstone' (= Karnthi Formation) with an unconformable contact.
Planktonic Foraminifera from a Quaternary Deep Sea Core from the Southern Arabian Sea
Authors: Divakar Naidu P. , Rao P. S. , Pattan J. N. 
Published: November 2024

Abstract
An investigation on planktonic foraminifera and calcium carbonate content of a box core collected at a depth of 2556 m from the southern part of the Arabian sea indicates faunal changes depicting Quaternary climatic fluctuations. Based on the study the Last Glacial Maxima (LGM) boundary is placed at 65 cm and below LGM. Three warm and two cold episodes are identified.
Age of Manganiferous Laterite of Uttara Kannada District, Karnataka
Authors: Krishna Rao B. , Ahmed Mohamed Muzamil , Janardhana M. R. 
Published: November 2024

Abstract
Palynological studies on the lateritoid manganese ore revealed the presence of angiosperm, bryophyta, pteridophyta, fungi and algae. Among these Polyporina sp., Polypodiaceaesporites haardti, Palmaepollenites communis, Sapotaceoidaepollenites africanus, Pediastrum simplex var.duodenarium, Pediastrum boryanum var. undulatum and Plumbaginacipitesneyvelii have been identified. They indicate that the lateritic weathering of the Precambrian manganiferous formation of the area took place during Neogene.
Geochemistry of the Continental Margin Sediments of the Central West Coast of India
Authors: Rao CH. M. , Murty P. S. N. 
Published: November 2024

Abstract
The modern sediments accumulating on the western continental margin of India between 17° and 13° latitude are composed predominantly of terrigenous material in the inner shelf with moderate organic carbon content (&lt; 3%), carbonate sediments in the outer shelf with low organic carbon content (&lt; 1%) and organic carbon rich (upto 12%) carbonate sediments in the slope region. The bulk and partition geochemistry of the surface sediments reflect the complex intermixture of several sedimentary components (lithogenic, authigenic and biogenic) and enable the identification of geochemical processes that are responsible for the incorporation of elements into the sediments. The elemental concentrations are found to be related to the distribution of three major components i.e, terrigenous debris (Si, Al,Ti, Fe, Mn, Cu), authigenic Calcium Carbonate (Sr, P) and organic carbon (P, Ni, Zn).
Silver Mineralisation in Early Proterozoic Rocks of Bharak Area, Near Baghera, District Bhilwara, Rajasthan
Authors: Goyal R. S. 
Published: November 2024

Abstract
Rich silver mineralisation (up to 0.78% on the surface and O. 58% in borehole) has been discovered in siliceous dolomitic marble at the interface with stratigraphically underlying calc-silicate rocks of Bharak area (Rajpura-Dariba Group of Late Archaean/ Early Proterozoic age). The surface geochemistry over the region bas helped in delineating a 600 m x 200 m zone on the surface having sil vel' content of more than 10 ppm and ranging up to 7800 ppm. The subsurface data obtained by drilling has shown the extension of the mineralised zone beyond the limits of the surface geochemical anomaly, and the extension is caused by the continuation of folded strata below surface. Ore microscopic study has indicated that the main silver ore mineral is cerargyrite (AgCI) with minor relicts of argentite Ag2S).
The variation diagram of Ag-Cu-Pb-Zn in the stratigraphic layering at the contact zone of siliceous dolomitic marble and the calc-silicate rocks, depicts significant patterns showing syn-sedimentary stratiform silver precipitation in a particular stratigraphic section, at the bottom of the siliceous dolostone. Two pulses of chemogenic silver precipitation within the bottom part of the siliceous dolomitic marble associated with CuPb- Zn are identified, while the effects of remobilisation and supergene enrichment are predicated by certain aberrant peaks of silver with variable relationship of associated metals such as Cu, Pb and Zn.
Late Pleistocene Fluvial Response to Tectonics in Jammu, Jammu and Kashmir
Authors: Ganjoo R. K. 
Published: November 2024

Abstract
The Quaternary tectonics in the sub-Himalayan zone is postulated on the basis of the LANDSAT imagery study of the structural features in the area. These studies are corroborated by geomorphic evidences as well. The deposition of Katra fill at the foot of Trikuta hill, the entrenchment by river Tawi and deep gorge at the exit of river Tawi from Udhampur dun indicate neotectonism. The event resulted in the integration of fluvial system. This is evident from the presence of rock components of Inner Himalaya in the late Pleistocene deposits.
Clay Mineral Distributions in Dated Miliolites of the Late Quaternary from Saurashtra and Kutch, Gujarat
Authors: Baskaran M. , Somayajulu B. L. K. 
Published: November 2024

Abstract
Forty-three dated miliolites (ages ranging from 30-235 kyr) of the late Quaternary period, from Saurashtra and Kutch regions of Gujarat State have been analysed for their detrital contents as well as for the four clay minerals, smectite, illite, kaolinite, and chlorite in the less than 2 micron fraction.
Between 235 kyr and 140 kyr BP. there was less detrital material available in the regions of miliolite formation. Landward and seaward sources, notably from southeast and northwest directions contributed equally efficiently to the clay component of the detritus resulting in illite smectite ratio of 1.0. This situation prevailed during 70-50 kyr BP as well as at around 12 kyr BP except that the total detritus in miliolites increased by a factor of about three, during the two recent periods. However, during 95-115 kyr BP, despite the high detrital content of 24%, the illite/smectite ratio dropped to 0.3 indicating the expected dominance of the local and southeastern sources which are enriched in smectite in their clay fractions.
Stratigraphy of the Gondwana Formations in the Chintalapudi Sub-Basin, Godavari Valley, Andhra Pradesh
Authors: Lakshminarayana G. , Murti K. S. 
Published: November 2024

Abstract
The Chintalapudi sub-basin, in the southeastern part of the Pranhita-Godavari Valley, was hitherto believed to contain mainly the Kamthi Formation of the Lower Gondwana Group. Recent geological mapping has brought to light the existence of the upper Gondwana sequence consisting of Kota and Gangapur Formations and also the occurrence of new areas of Talchir and Barakar Formations. Revised stratigraphic succession shows, in ascending order, Talchir, Barakar, Kamthi (Lower Gondwana). Kota and Gangapur Formations (Upper Gondwana). The Gondwana sediments are disposed in a NW-SE trending' graben affected by longitudinal and transverse faults. The Barakar Formation is identified over an area of 130sq km in Ayyanapalem-Sattupalli-Pakalagudem area, Khammam district, Andhra Pradesh. Stratigraphic drilling near Sattupalli has established the presence of coal seams with in a depth of 325 m in this newly identified Barakar Formation. The preliminary study of coal seams indicates that the coal is of Class III to Class IV type. The present study has established a new coal belt around Sattupalli in Chintalapudi Subbasins and this find is expected to augment the coal resources of the Godavari Valley considerably.
Geothermal Model of the North-Eastern Region of India: Its Possibilities and Limitations
Authors: Cermak V. , Kubik J. , Saikia M. M. , Sitaram M. V. D. 
Published: November 2024

Abstract
The empirical relationship between observed Pn (Sub-Moho) seismic velocities and the surface heat flow (including also the assessed crust-upper mantle temperatures) was used to improve the understanding of the regional geothermal activity of the North-Eastern Region of India. Vertical seismic velocity profile was further converted into radiogenic heat production and the knowledge of the crustal heat sources helped in both, to estimate deep temperature distribution within the crust and to evaluate the Moho heat flow. The most probable existing temperature at the crust-upper mantle boundary is between 800 and 900°C and the flow of heat from below the crust attains about 50% of observed surface heat flow, i.e, about 30mW. m-2.
Facies Analysis and Depositional Environment of Pokaran Saline Rann, District Jaisalmer, Rajasthan, India
Authors: Rai Vikram 
Published: November 2024

Abstract
Pokaran Rann occupies an area of 12.0 sq. km in Jaisalmer District of Rajasthan, resting over the basement rocks of Marwar Supergroup. Five distinct litho-facies are recognized in a basin developed along E-W-trending linear stretch of palaeo-course after calcification. The base of the sequence consists of inter-laminated clay /gypsite unit. This unit grades into carbonate-rich clay showing pede-calcic pedogenesis. After a break in sedimentation, highly bio-turbated clays were deposited probably during a prominent humid phase. This was followed by present day semi-arid climatic conditions which resulted in the formation of silt to silty-clay deposits.
Upper Barakar Lebensspuren from Hazaribagh, India
Authors: De Chirananda 
Published: November 2024

Abstract
A five metre thick silty-sandstone unit, below the topmost coal seam of the Barakar Formation, has been given a status of 'Burrrow Zone' owing to the presence of trace fossils in large numbers and variety. Six geometric forms have been described. The first two represent horizontal intrastratal burrow system (branching and nonbranching), and were produced by fresh water crickets. The fecal pellets (type 3) and the associated vertical tubular burrows (type 6) are correlated with one or both of beetles and crustaceans. Selective search for food from organic matter-rich sediments led to the formation of these fecal pellets. Type 4 and 5 structures represent trail marks of horsehair worms on the sediment-water interface.
Late Barakar basin experienced a very low energy condition of deposition which accelerated the luxuriant growth of plants and organic activities in all possible interfaces. Sudden change over to high energy condition prior to the start of Barren Measure sedimentation ceased all biogenic activities. This resulted in the formation of a burrow zone below the Barren Measure Formation.
Geoenvironmental Appraisal of the Proposed Site for Vidyadharnagar Township, Jaipur, Rajasthan
Authors: Das Sarma D. C. 
Published: November 2024

Abstract
The Amanisha river has shifted from west to east over the area and has left behind an array of abandoned channels and gullies under blown sand cover. This imparts considerable restraints on the urbanisation of the area. The potential environmental hazards include accentuated gully erosion, aggradation of the river leading to flash flood, underseepage in abandoned channels, sand mobilisation etc. The areas under potential hazards have been demarcated.
Petrogenesis of Metabasites from the Schist Belts of the Dharwar Craton: Implications to Archaean Mafic Magmatism
Authors: Rajamani V. 
Published: November 2024

Abstract
The supracrustal belts of the Dharwar Supergroup in the Dharwar Craton include variably metamorphosed komatiitic and tholeiitic volcanics. Komatiites in general occur only in minor amounts. Available geochemical data of these rocks from the Holenarasipur ? Kudremukh, Bababudan and the Kolar schist belts were quantitatively modelled to infer that (1) Komatiitic magmas originated from deeper mantle sources at depths &gt; 100 km., (2) tholeiitic magmas formed at depths &lt; 50 km from sources different from those of komatiites and with much higher Fe/Mg ratios compared to normal mantle, (3) the two magma types are not genetically related either to one common parental magma or to one common source, (4) Dharwar magmatism could be related to rift related volcanism perhaps associated with one or more mantle plumes. High quality geochemical, including isotopic, data on a large number of samples is required to test this model of Dharwar magmatism.