bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Dams in Central Himalaya in Context of Active Faults Seismicity and Societal Problems
Authors: Valdiya K. S. 
Published: November 2024

Abstract
India's two highest dams would be located close to the active faults that have been repeatedly reactivated in the Quaternary. These heavy structures are being built in the region of high seismicity where the probability of occurrence of major earthquakes appears to be very high. The probable high-magnitude earthquake will release quite a few hundred times more energy than the earthquakes for which the Tehri Dam is designed. The 50 percent failure probability accepted by the dam builders is at alarming variance with the globally accepted minimum standard of 16 percent (safety level of at least 84%). Impoundment of water in reservoirs upstream of the darns is likely to intensify and trigger landslides in the large reservoir areas particularly in the zones of active faults. Submergence of upstream lands in the most productive and populated valleys in Uttarakhand and western Nepal would cause great loss of forest and agricultural resources. In view of the horrifying implications of high dams it would be prudent to go in for a large number of smaller dams at much lower costs and risks, and which would confer greater benefits to all.
Stratigraphic Succession of Precambrian of Singhbhum: Evidence from Quartz Pebble Conglomerate
Authors: Sinha K. K. , Krishna Rao N. , Shah V. L. , Sunilkumar T. S. 
Published: November 2024

Abstract
Though the stratigraphic succession in the Precambrian of Singbhum-Orissa region of the Indian shield given by Saba et al. is widely accepted, there are several contentious issues whieh have been hotly debated over the years. The occurrence of uraninite and pyrite bearing quartz-pebble conglomerate at the base of Iron Ore Group (lOG) as well as the Dhanjori Group has indicated the necessity for a revision in the stratigraphic succession in view of the temporal significance of such conglomerate the world over.
The conglomerate contains a significant population of zircon, chromite and shows a typical minor and trace element composition. The zircon has morphometric properties similar to those found in several members of the Singhbhum Granite Complex. The presence of detrital chromite and high Cr content indicate the occurrence of older mafics/ultramafics in the provenance along with the Singhbhum Granite Complex. It is suggested that some mafic and ultramafic members presently grouped within the IOG may represent such "older greenstones". The IOG as well as the Dhanjori Group with basal QPC horizon lie over a basement of Singhbhum Granite-Greenstone Complex. From available evidences it is surmised that both IOG sensu stricto (the BIF sequence and associated ferruginous cherts. greywackes and acid-intennediate volcanics) and the Dhanjori Group represent late Archaean (2500-3000 Ma) supracrustals and hence are nearly coeval. The Singhbhum Group north of the shear zone represents early Proterozoic supracrustals.
Further Zircon U-Pb Age Data for the Daginkatte Formation, Dharwar Supergroup, Karnataka Craton
Authors: Trendall A. F. , de Laeter J. R , Nelson D. R. , Bhaskar Rao Y. J. 
Published: November 2024

Abstract
SHRIMP U-Pb analyses of zircons from a rhyolite sample collected from the Daginkatte Formation of the Chitradurga Group (Dharwar Supergroup), close to the type locality, give an age of 2601 ± 6 Ma (1s 23 of 24 analysed grains). This is within error of the 2614 ± 8 Ma (2s 11 grains) recently reported by A.P. Nutman and his colleagues in 1996 from a sample of acid volcanic schist of the same formation, about 25 km along strike. Combining Nutman et aI's (1996) published data with the new analyses reported here gives a pooled age of 2606 ± 6 Ma (n = 34, 1s, ?2 = 1.31), within error of both of the separately determined ages. Having regard to the reported uniform lithology of the Daginkatte Fonnation, the pooled age is probably that of a short magmatic event during which it was formed, and provides a firm constraint relevant to this stratigraphic level of the Chitradurga Group; however. it is now important to determine whether the rhyolitic rocks of the Daginkatte Formation are intrusive or extrusive.
A Precise Zircon U-Pb Age for the Base of the BIF of the Mulaingiri Formation, (Bababudan Group, Dharwar Supergroup) of the Karnataka Craton
Authors: Trendall A. F. , De Laeter J. R , Nelson D. R. , Mukhopadhyay D. 
Published: November 2024

Abstract
SHRIMP U-Pb analyses of zircon grains from two thin dark shales believed to be syndepositional ashfall tuffs close to the base of the banded iron-formation (BIF) within the Mulaingiri Formation of the Bababudan Group (Dharwar Supergroup) of the western Kamataka Craton provide a precise age for the onset of BIF deposition in the basin. Sample 120019C, from the exact base of the BIF, gave an age of 2720 ± 7 Ma, while sample 120018C, 14.5m above the base, gave an age of 2718 ± 6 Ma. The second sample contained younger grains which may have been affected by a late thermal event.
Ammonoid Stratigraphy of the Spiti Shale Formation in Spiti Himalaya, India
Authors: Pathak D. B. 
Published: November 2024

Abstract
Ammonoid biostratigraphy of the Spiti Shale Formation is being discussed in light of new data. Their systematics supported by stratigraphic details of the collected ammonoids have resulted in the organization of a set of 9 distinct successive ammonoid assemblages ranging in age from Oxfordian to Berriasian i.e. from 154 Ma to 130 Ma. The chronostratigraphically significant Jurassic/Cretaceous System and Kimmeridgian/Tithonian Stage boundaries have been identified. The ranges of species of Spiti Shale ammonoids are presented here for the first time.
The Talkad Sand Dunes in Mysore District of Karnataka - their Description, Evolution and Origin
Authors: Srikantia S. V. , Anantharamu T. R. 
Published: November 2024

Abstract
Situated along the left bank of the river Cauvery, Talakad represents a typical riverine sand dune. The point bar deposit along the left bank of the Cauvery is the main source of the sand. However, this stretch, in the upstream has a weir built some 400 years ago which diverted water from the Cauvery into the Madha vamantri canal, which resulted in the lowering of the level of water in the point bar deposit downstream thereby exposing its sand to monsoonic winds blowing from SW to NE towards Old Talkad. The settlements and also the NW to SE blowing cross wind in the valley acted as barriers for the sand laden monsoonic winds with the consequent development of sand dunes which on gradual migration buried temples and many old settlements.
Significance of Fossils from the Rajpipla Limestone, Cretaceous of Narmada Basin Gujarat
Authors: Rajshekhar C. 
Published: November 2024

Abstract
Mega fossil (fragments of Lame11ibranch shells, Gastropod, and Echionoid spines) in thin section and micro fossils (Benthic foraminifer Textularia sp.?) are being reported for the first time from the Rajpipla Limestone of Bagh Group.
Tungsten Mineralisation at Khobna, Maharashtra Fluid Inclusion Studies
Authors: Narasimhan D. , Krishna Rao N. , Panchapakesan V. , Sahu K. C. 
Published: November 2024

Abstract
Fluid inclusion study has indicated two distinct stages of mineralisation: one with higher TH and lower salinity (greisens) and the other with lower TH and slightly higher salinity (quartz vein) conditions. These mark the formation conditions of wolframite and scheelite respectively.
Rare Earth Element Geochemistry of a Sediment Core from the Lower Bengal Fan
Authors: Ramesh S. , Ramasamy S. 
Published: November 2024

Abstract
The Post Archaean Australian Shale (PAAS) normalised Rare Earth Element (REE) distribution pattern of a 4m box core from the Lower Bengal Fan clearly exhibits different types of patterns according to the climatic fluctuations of Late Quaternary period. Based on the vertical profiles of REEs, SLight REE/SHeavy REE ratio, Ce^ and SREE the climatic boundaries were further confirmed. The influence of continental sediments with a rugher rate of sedimentation are reflected in higher concentration of SREE in glacial periods. The above observations suggest the Late Pleistocene - Holocene boundary at 45-50 cm depth, the Last Glacial Maximum at 50-120cm depth and Glacial (I) stage at 150-290cm depth in the core studied. Warmer periods of Interglacial stages (II) and (I) correspond to 120-150cm and 290-400cm depths.
A Tidal Island Model for Carbonate Sedimentation: Karondia Limestone of Cretaceous Narmada Basin, India
Authors: Akhtar K. , Khan D. A. 
Published: November 2024

Abstract
The Cretaceous sedimentary sequence of Narmada basin comprise a lower clastic formation (Nimar Sandstone) and an upper carbonate sequence (Karondia Limestone). The depositional model of limestones was reconstructed by identifying 8 microfacies which were regrouped into 5 facies associations. The carbonate sequence of the study area was interpreted to be deposited on a ramp without a striking break in the slope of the ramp and where shelf margin was not developed. The vertical arrangement of facies of Karondia Limestone forms a shallowing upward sequence. It shows much lateral and vertical variation which can be attributed to deposition on a platform dotted by a mosaic of exposed banks or island separated by subtidal areas with the whole complex shifting both laterally and vertically in response to hydrodynamic conditions through time.
Petrogenesis of the Perinthatta Anorthosite, Northern Kerala, India
Authors: Nambiar C. G. , Soney K. P. , Radhakrishna M. 
Published: November 2024

Abstract
The anorthosite pluton has textural and trace element characteristics typical of a magmatic cumulate. A soda-rich intermediate magma is inferred to be the parent. Rare earth element based modelling shows that the anorthosite was derived from a parental melt having hundred times chondritic REE with a slightly fractionated pattern probably derived by the melting of granulitic or edogitic source.
Ooid Turbidites from the Western Margin of the Bengal Fan Sediments
Authors: Suresh N. , Bagati T. N. 
Published: November 2024

Abstract
Sedimentology, mineralogy and geochemistry of ooid sand beds in deep sea gravity cores (water depth &gt;2818 m) reveal that they were derived from continental shelf by turbidity currents. The presence of ooid turbidites at two different levels suggests two periods of turbidity current activity. The first activity probably took place during the Last Glacial Maximum in Late Pleistocene and the second activity prior to the stabilization of sea level in the Early Holocene.
Nabaviella acanthomorpha N. Sp, a Sponge Spicule from the Precambrian-Cambrian Boundary Interval in the Tethys Sequence of Northwestern Kashmir
Authors: Tiwari Meera 
Published: November 2024

Abstract
A new species of sponge spicule Nabaviella acanthomorpha is described here, which occurs in association with an assemblage of small shelly fossils (SSF) from the Precambrian-Cambrian boundary sequence, exposed in Pohru Valley of northwestern Kashmir, with an obvious biostratigraphic potential to understand the Precambrian-Cambrian boundary in the succession.
Diversity and Distribution of Recent Ostracoda in the Continental Shelf Sediments off Pentakota and Kalingapatnam, Central East Coast of India
Authors: Naidu T. Y. , Varma K. U. , Shyam Sunder V. V. 
Published: November 2024

Abstract
Twenty-nine species of Recent Ostracoda have been identified from the continental shelf sediments off Pentakota and Kalingapatnarn, Central East Coast of India. Of the twenty-nine species, five species are abundant, nine species are common and fifteen species are rare in occurrence. The distribution and diversity of the Ostracoda suggest that the inner and outer shelf environments are more favourable than the middle shelf of Pentakota whereas the inner shelf is more favourable than the middle and outer shelf environments off Kalingapatnam. On the whole, the Pentakota shelf environment is more favourable for the Ostracods to survive than Kalingapatnam shelf.
Mineral Replacement of Plant Roots in Fluvial Sediments of the Link Channel of Krishna River, Near Yedurwadi, Belgaum District, Karnataka
Authors: Achyuthan Hema , Ghate S. N. , Rajaguru S. N. 
Published: November 2024

Abstract
Micromorphology, XRD analyses and SEM studies of rhizoliths from Late Middle Pleistocene yellowish brown silty fluvial sediments of Yedurwadi reveal that calcium carbonate has a localized source. Silica and calcium carbonate are formed by the plant roots through their metabolic activity creating a favourable microenvironment for the processes of SiO2 and CaCO3 precipitation and replacement.
Petrology of Post -Archaean Magmatic Rocks in the Eastern Indian Craton
Authors: Sengupta S. , Ghosh Mitra , Gangopadhyay P. , Chattopadhyay A. 
Published: November 2024

Abstract
Minor rhyolite intrusives spatially associated with granophyric granites occur along the eastern and southwestern fringe of the Archaean Singhbhum Granite batholith in the eastern Indian Craton. Some minor trachyte dykes occur within the batholith and both are of post-Archaean age. On the basis of major and trace element studies it has been inferred that a process more complex than simple fractional crystallisation has controlled the observed chemical variation in both the rocks. However, the two are genetically unrelated and have been generated from different sources. All the rhyolites, which are scattered as small bodies over an extensive area, are produced from similar source compositions. The chemical variation among the rhyolites is the result of a difference in degree of melting and the samples enriched in LREE and other incompatible elements represent a lower degree of partial melt. Composition of the rhyolites suggests that neither muscovite nor aluminosilicates were present in the source. The likely source is therefore the trondhjemites and mafic-ultramafic rocks constituting the Archaean crust of the region. Similar source for rhyolites distributed over a large area indicates a homogeneous composition for the Archaean crust.
A S-Isotopic Study of the Baryte and Galena from Quartz-Baryte Veins at Rasimalai, North Arcot Ambedkar District, Tamil Nadu
Authors: Dhana Raju R. , Prasad R. N. , Pande D. D. , Panneer Selvam A. , Kumar Mary K. 
Published: November 2024

Abstract
This study shows d34S values for the study of co-existing baryte and galena, respectively, are in the ranges of +6.9 to 8.0% and -6.0 to - 9.8%0. Such narrow ranges make biogenic sedimentary source for sulphur less likely and suggest magmatic source. Sulphur isotope values indicate a hydrothermal system with a T of ~440°C, pH 5±1 and Log f02 of -34 to -37.
Early Proterozoic Rare Metal and Tin Pegmatites near Kawadgaon, Bastar, M.P.: An Example of Vertical Pegmatite Zonation
Authors: Singh Yamuna 
Published: November 2024

Abstract
The paper reports, for the first time, the occurrences of several almost non-metasomatized rare metal zoned pegmatites of small- to medium-dimensions near Kawadgaon in the Bastar. Columbite- tantalite and beryl occur mainly close to quartz core. Beryl is Ubiquitous. Replacement units are almost absent in the Be and Be-Nb-Ta pegmatites whereas, they are prominent in the cassiterite pegmatites.
Spatial distribution of rare metal and tin pegmatites of the study area suggests a distinct vertical zonation. At lower level, Be and Be-Nb-Ta-minetalization took place whereas, at higher level, albitization and Sn-mineralization are observed. Tin seems to have behaved as incompatible element at lower level, where high K/Na ratios and reducing conditions attended the crystallization. With the fractionation of substantial amounts of microcline perthite in the Nb-Ta pegmatites at lower level, Na and volatiles have increased and enriched Sn to form cassiterite in association with albite in the upper level pegmatites. Non-albitized pegmatites do not contain any tin mineralization, which is suggestive of Na-Sn geochemical affinity.
Systematic mining of pegmatites and their gravels will yield considerable quantities of cassiterite, besides columbite-tantalite and beryl.
Morphology of the Volcanic Ash from the Kukadi River Section, Pune District, Maharashtra
Authors: Karmalkar N. R. , Ghate S. N. , Mishra Shiella , Rajaguru S. N. 
Published: November 2024

Abstract
An ash bed varying in thickness from 20 cm to 2 m occurs within the lower part of 10 m thick yellowish-brown clay and calcareous silt unit that contains occasional lenses of calcrete, gravels and channel lag gravels both at the base and top of the sequence. The volcanic ash has yielded a K/Ar age of 1.4 Ma. The volcanic ash is highly siliceous in composition with SiO2 content varying between 72 to 78%. It is dominantly constituted of silt sized angular glass shards, and pumice fragments with sharp edges. Petrography, SEM and chemical composition of the glass shards helps in relating the ash morphology to magma composition and the type of eruption. On the basis of petrographic and morphological characters displayed by the volcanic ash, the formation of the glass shards is attributed to magmatic processes.
Calcrete and Gypsum Crusts of the Thar Desert, Rajasthan, their Geomorphic Locales and Use as Palaeoclimatic Indicators
Authors: Rakshit Prabal , Sundaram Raghavan Minakshi 
Published: November 2024

Abstract
Calcrete and gypsum crusts in Churu-Bikaner areas of the Thar desert, are presently found buried under a cover of aeolian sediments. Non-pedogenic and pedogenic calcrete types occur in various geomorphic locales like, channels, flood plains, pediments etc. Also, different non-pedogenic channel and lacustrine basin-fill gypsum crusts are noted. The occurrences of surface and near surface calcrete, gypsum crusts, their presence in representative sub-surface sequences of fluvio-aeolian sediments indicate climatic vicissitudes in the Late Quaternary from humid to arid and vice versa.
Point Bar Complex of an Exhumed Channel in Upland Interfluve of the Ganga Plain, India
Authors: Singh I. B. , Shukla U. K. , Srivastava P. 
Published: November 2024

Abstract
Facies architecture and evolutionary history of a point bar complex of exhumed channel on the upland interfluve surface of the Ganga Plain is presented. The point bar complex is made up of four distinctive sequences, each characterized by a specific lithofacies association and grain size, where successive sequence shows decrease in grain size and reduced channel width denoting reduction in the discharge of the channel. The top of each sequence represents a hiatus surface marked by dense bioturbation. The flow in the exhumed channel was towards south and southwest. At the end of the deposition of third sequence neotectonic activity caused uplift, tilting of the surface and disruption of the river channel. A facies model of such deposits is proposed.
A Note on Oxygen and Carbon Isotopes of Magnesite and Dolostone of Mesoproterozoic Gangolihat Dolomite (Formation), Pithoragarh District, Uttar Pradesh
Authors: Kumar S. 
Published: November 2024

Abstract
Nine samples of sparry magnesite and five samples of dolostone of the Mesoproterozoic Gangolihat Dolomite (Formation) of the Chandak area, Pithoragarh are analysed for stable isotopes of carbon and oxygen. d18O for dolostone varies from -10.8‰ to -9.0‰ (SMOW) with mean as -10.1‰ (SMOW) and for magnesite it varies from -16.8‰ to -11.8‰ (SMOW) with mean as -14.0‰ (SMOW). d13C for dolostone varies from -1.6‰ to 0.6‰ (PDB) with mean as -0.0‰ (PDB) and for magnesite it varies from -2.2‰ (PDB) to 0.1‰ (PDB) with mean as -1.0‰ (PDB). Thus, magnesite and dolostone show distinctly different isotopic signatures and hence magnesite must have formed from isotopically different fluids than those which produced dolostones. Magnesite is not syndepositionally produced but must have formed at some later stage by hydrothermal solutions.
Importance of Recharging Depleted Aquifers: State of the Art of Artificial Recharge in India
Authors: Raju K. C. B. 
Published: November 2024

Abstract
Though India is blessed with good rainfall, large amount of it is lost through runoff and it cannot be impounded on the surface for want of suitable sites for storage. The varied hydrogeologic conditions prevalent prevent rapid infiltration into groundwater reservoirs. 'There is thus an imbalance between recharge and groundwater development in many parts of the country. The over-extraction of groundwater resources has affected the agricultural economy and has caused serious shortage of water for drinking. It is imperative that runoff which is going waste should be harvested and utilised for recharging depleted aquifers.
Realising this many artificial recharge projects have been taken up by the Central and State Groundwater Departments. There are other agencies who have come up with methods for recharging depleted aquifers. Results obtained are impressive.
X-ray Diffraction Studies on Graphites from Dharwar Craton
Authors: Sharma S. R. , Parthasarathy G. , Kumar B. 
Published: November 2024

Abstract
We report here., the results of powder x-ray diffraction studies on six graphite samples from the Archaean metasedimentary rocks of Dharwar craton, with the motivation of correlating the graphitization process of carbonaceous matter during metamorphism with metamorphic grade. Our studies show that interplanar spacing d(002) and crystallinity Lc(002) for all the studied samples are very close to that of well crystallized graphite.
The observed decrease in full width at half maximum (FWHM) of the (002) diffraction peak from 0.20 to 0.102 Å. increase in crystallite size, Lc(002) from 408 to 800 Å and graphitizing degree from 86 to 362 indicate different metamorphic grades. Our results indicate that the rocks from Hampapura are of low metamorphic grade and those from Arjun Bettahalli are highly metamorphosed. The peak metamorphic temperatures of metasedimentary rocks are estimated to be around 600±50°C. The temperature estimates based on graphite crystallinity studies and the temperatures estimated by silicate mineral geothermometry studies of the coexisting mineral assemblages were found to be consistent.
Light Rare Earth Elements (LREE) in Perovskite from Kimberlites of Andhra Pradesh, India
Authors: Chalapathi Rao N. V. 
Published: November 2024

Abstract
Electron microprobe analyses of ground mass perovskites from kimberlites of Andhra Pradesh, India, reveal that their LREE oxide contents range from 0.88 to 1.97 wt% in case of the Mahbubnagar kimberlites and 2.57 to 5.37 wt% in the Anantapur kimberlites, with Ce being the most abundant in every case followed by Nd and La. Chondrite-nonnalized REE distribution patterns of perovskites show good correlation with the respective whole-rock REE distributions thereby displaying the dominant role played by perovskite in controlling the kimberlite REE distribution patterns. Results of this study also show that the perovskites from Indian kimberlites, compared to those in Group 11 kimberlites (Orangeites) of South Africa, have relatively impoverished LREE.
Channel Sandstone Bodies in Fluvial Permian - Triassic Gondwana Succession of Peninsular India
Authors: Tewari R. C. 
Published: November 2024

Abstract
Two types (I and II) of channel sandstone bodies are recognised in the fluvial Permian - Triassic Gondwana succession of peninsular India on the basis of geometry, associations and sedimentary structures. Irrespective of geometry and associations, these channels are oriented towards northwest, comparable with the Permian - Triassic paleoslope. The geometry, hierarchy of sedimentary structures and association of these channel bodies suggest channel aggradation, and lateral accretion in crevasse channels, respectively for the deposition of Type-I and Type-II channel sandstone bodies.