bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gondwana Palynostratigraphy from Drill-Core Studies in Coastal Tamil Nadu and Pondicherry
Authors: Tiwari R. S. , Vijaya  , Tripathi Archana 
Published: November 2024

Abstract
The palynoflora of subsurface coal-bearing sequence in cores from boreholes TC-1 and TC-2 in Kandmanglam and Marakkanam area, Tamil Nadu and Pondicherry Union Territory has been found to be rich in pteridophytic spores. The palyno-assemblage is assignable to the Coptosporo cauveriana Zone of Aptian age. The findings add to our knowledge of Gondwana coal deposits along the east coast of India.
Occurrence of Fluorapatite in Granitic Veins from the Kerala Khondalite Belt, Southern India
Authors: Braun I. , Raith M. 
Published: November 2024

Abstract
This paper presents the first description of fluorapatite in rocks of the Kerala Khondalite Belt in southern India. The fluorapatites occur either dispersed or aggregated in granitic and pegmatitic veins which intruded into high-grade metamorphic gamet-biotite gneisses. Microtextures indicate an exclusively magmatic origin for the fluorapatites and the strong zoning of F and OH points to a change in fluid/melt composition during apatite crystallization. The P-T conditions of melt crystallization are estimated to be in the range of 750-800°C and =5 kbar. The origin of the fluorapatite bearing melts is poorly known. It is suggested that they formed either through fluid-absent incongruent melting of a F-rich biotite or during a late stage of fractional crystallization of a granitic parent magma. Additionally, we report a single occurrence of a monazite-rich quartzmonzodiorite vein. Field observations indicate an emplacement subsequent to the fluorapatite bearing granites and pegmatites. The occurrence of magmatic andalusite and cordierite in this rock points to a crystallization at low pressures (P = 3 kbar).
Fluorapatite from Alkaline Pegmatites of the Kerala Khondalite Belt: A Petrologic and Fluid Inclusion Study
Authors: Rajesh H. M. , Santosh M. 
Published: November 2024

Abstract
We report the occurrence of primary apatite crystals in association with graphite within alkaline pegmatite dykes in the Kerala Khondalite Belt (KKB). Petrologic and X-ray diffraction studies identify the mineral to be fluorapatite. Fluid inclusion studies show that the fluorapatites contain abundant CO2-rich inclusions with densities in the range of 0.85-0.72 gcm-3. A subsequent generation of trail-bound CO2-HP inclusions with low salinity were entrapped along hydraulic cracks. The abundance of CO2-rich inclusions, and the intimate association of fluorapatite with fluid-precipitated graphite suggest that the pegmatite dykes hosting fluorapatite were rich in CO2-dominated fluids. We identify that among the magmatic conduits proposed for the transfer of CO2-rich fluids in granulite processes in the KKB. the fluorapatite and graphite bearing pegmatites reported in this study form important examples.
Geophysical Discovery of Archaeological Sites at Nelakondapally in Andhra Pradesh, India
Authors: Atchuta Rao D. , Ram Babu H. V. , Rao Ch. Rama 
Published: November 2024

Abstract
The discovery of a hemispherical shaped Maha Stupa, the largest known in South India belonging to the 2nd to 6th century A.D., Buddhist monastic order at Nelakondapally (Khammam district, Andhra Pradesh), has marked the area for further exploration for cultural sites and objects. The Department of Archaeology and Museums, Government of A.P., has been actively pursuing exploration in this area using conventional methods and brought to light some important archaeological findings indicating the importance of the area for elucidating the full structural details of the dwelling complexes and other cultural objects. With a view towards creating awareness among the archaeologists on the use of geophysics in archaeology, an experimental geophysical survey has been carried out using magnetic, electrical and electromagnetic methods, in an area near Nelakondapally. These surveys have brought out geophysical anomalies resulting in the discovery of sites and objects of archaeological interest. This paper describes the survey and the results which led to the discoveries.
Petrology and Geochemistry of Kimberlite Pipe 11 of Chigicherla Area, Anantapur District, Andhra Pradesh, South India
Authors: Murthy D. S. N. , Dayal A. M. , Natarajan R. , Balram V. , Govil P. K. 
Published: November 2024

Abstract
Newly discovered kimberlite pipe 11 of Chigicherla area of Andhra Pradesh consists of two generations of olivine with phlogopite, spinel. perovskite, melilite etc., A comparative study of chemical characterstics of pipe 11 with those of pipe 1,2,3,4 and 5 of Wajrakarur- Lattavaram area and pipe 10 of Chighicherla indicate that Zr-Hf, Nb-Ta, Th-U have a high degree of correlation. The ratio of Ba/Nb( &lt;10), Z/Hf( -50) and Nb/Zr (&gt;0.5) are similar to the Group-I kimberlites. The chondri te normalised REE pattern of pipe 11 is similar to the other kimberlites and shows enrichment in LREE. Spider diagram of incompatible elements indicate similarity with those of many oceanic island alkalic basalts or other types of alkalic intraplate volcanics. They are highly enriched in incompatible elements. Major elements, Ce/Yb and La/Yb ratios suggest that the formation of kimberlite is due to low degree of partial melting of ultrabasic source along with an earlier subducted oceanic lithosphere.
Sedimentological Evidence for Cretaceous Reactivation of the Eastern Margin of the Cuddapah Basin
Authors: Lakshminarayana G. 
Published: November 2024

Abstract
The east coast Cretaceous Sedimentary basins namely the Krishna-Godavari Basin (K-G Basin) in north and the Palar Basin in south are located towards the tapering ends of the crescent shaped 'Cuddapah Basin'. Cretaceous stratigraphic succession in ascending order is Raghavapuram and Tirupati formations in the K-G Basin and Sriperambattur and Satyavedu formations in the Palar Basin. The Raghavapuram and Sriperambattur formations consist of mainly shale and siltstone deposited in prodelta/shallow marine environments. Sedimentological studies on sandstone and conglomerate revealed that in the Tirupati Formation coarse clastic detritus was derived from the Archaean crystallines and Proterozoic Cuddapah and Kurnool Groups of rocks by braided streams flowing towards east. Alluvial fans and the associated braided streams originated in the southern part of the 'Cuddapah Basin' were fed by mainly 'Nagri Quartzite' to deposit the bouldery conglomerate, conglomerate and sandstone sequence of the Satyavedu Formation. The Cretaceous sedimentary outcrops located east of 'Cuddapah Basin' i.e. Guntur, Ongole and Nellore areas show evidence for deposition in fluvial and fluviomarine settings. The Early Cretaceous tectonic disturbances coinciding with the break up of India from east Gondwanaland reactivated the eastern margin of the 'Cuddapah Basin' thereby enabling it to supply increased amount of detritus to the coastal sedimentary basins. However, the central part of the 'Cuddapah Basin' and the adjacent shield area located between Lat. 14° and 16° acted as a water divide to the Cretaceous drainage.
Magnesite Mineralisation Along the Chamba Thrust, Himachal Himalaya : Structural Control and Depositional Environment Using Fluid Inclusions
Authors: Singh Keser , Sharma Rajesh 
Published: November 2024

Abstract
The study reports magnesite mineralisation along the Chamba Thrust. The Tethyan rocks occurring south of the Higher Himalaya have translated along the Chamba-Thrust over the Higher Himalayan Crystallines and the Chail Thrust Sheet. Localized occurrences of magnesite along the Chamba Thrust are from Jiuni of Brahmour and Bindrabani of the Pangi valley areas. The fluid inclusion studies of magnesite and dolomite, indicate that the fluid involved in the genesis of magnesite was hot saline in nature at about 200°C to 275°C. The magnesite is formed from the reaction of this fluid with the limestone/dolomite during thrusting.
Geochemistry of Archaean Bimodal Volcanic Rocks of the Sandur Supracrustal Belt, Dharwar Craton, Southern India
Authors: Hanuma Prasad M. , Krishna Rao B. , Vasudev V. N. , Srinivasan R. , Balaram V. 
Published: November 2024

Abstract
In the late Archaean Sandur supracrustal belt of the Dharwar craton, Southem India, bimodal (mafic-felsic) volcanic rocks are encountered in its eastern region (Copper Mountain region). The mafic volcanic rocks are represented by Al-depleted picritic basalt and tholeliitic basalt. Pieritic basalt has a HREE - depleted pattern. Tholeliitic basalt exhibits two types of REE patterns; (a) slightly depleted - to flat - LREE and unfractionated HREE patterns, and (b) LREE - enriched and HREEdepleted patterns. The felsic volcanic rocks are Na-Rhyolites, which show calc-alkaline affinity and LREE - enriched and HREE-depleted chondrite-normalised patterns. Geochemical signatures show that the picritic basalt owes its origin to melting of a mantle diapir at depths around 100 km. The LREE - depleted tholeiites are not genetically related to the picritic basalt. They were derived through high degree partial melting of a depleted shallow mantle source. The internal variations observed in the LREE - depleted tholeiitic suite are due to derivation of magma through different degrees of melting of the same mantle source. REE-based petrogenetic modelling shows that the LREE - depleted and LREE - enriched tholeiites are not related to a common parent magma. The LREE - enriched tholeiites were generated from a mantle source, which has been metasomatized by subduction related melt/fluid phase. REE chemistry shows that the mafic and felsic volcanic rocks, though spatially and temporally associated, are not genetically related. The HREE depleted rhyolites were derived by partial melting of a garnet - amphibole bearing source, possibly a subducting oceanic crust. Feild, geochemical and petrogenetic aspects suggest that the magmatic rocks of the study area evolved in an active plate margin environment.
Mineralogy, Geochemistry and Origin of the Late Archaean Norites from Kalyadi, Hassan District, Karnataka
Authors: Subba Rao D. V. , Charan S. N. 
Published: November 2024

Abstract
A lense shaped gabbro-norite pluton emplaced into the Archaean migmatitic Peninsular gneiss and intruded in turn by 2.6 Ga Banavar granite is exposed in the vicinity of Kalyadi, Hassan district, Karnataka. The norite is metamorphosed to upper greenschist-lower amphibolite facies. The parental magma of this suite is noritic (high Mg and Si rich) and may have been derived from an enriched mantIe source at higher degrees of partial melting.
Preliminary Geochemistry and Emplacement Mechanism of Mafic Dykes of Anantapur Area, Andhra Pradesh
Authors: Sarma K. J. 
Published: November 2024

Abstract
The granite - gneiss terrain of Dharwar Craton in Anantapur area of Andhra Pradesh is intruded by mafic dolerite dykes. These dykes are quartz or olivine-normative sub-alkalic tholeiites. Their Mg numbers range between 0.34 and 0.70 with low Ni (50-150 ppm), Cr(50-337 ppm) and Co( 41-70 ppm), indicating some degree of fractionation. The REE abundances show LREE - enriched patterns (La/YbN - 2.7 to 5.5). These dykes appear to be genetically related and were derived from a single magma.
Drainage of North Gujarat: Present and Past
Authors: Sridhar V. , Merh S. S. , Chamyal L. S. 
Published: November 2024

Abstract
The area bound by the rivers Sabarmati and Luni forming a part of North Gujarat and Southwest Rajasthan alluvial plains has preserved in its sediments and landscape various changes which have occurred in the drainage systems during the Upper Quaternary times. The present day drainage mainly cuts across the material deposited by a set of older rivers which now stand disrupted. The present day rivers are observed to have been superimposed over older river channels and dominantly follow numerous tectonic lineaments and faults of a later date. The new channels reveal and have preserved relicts of the earlier fluvial system. Geomorphic and drainage studies reveal existence of two ancient major river systems, the remnants of which are now represented by the Banas and Rupen rivers. The Banas, along with its major tributary Sipu is the sole survivor of the older fluvial system. whereas Rupen has been partially destroyed.
Geology of a Tantalite Pegmatite from Belangi, Surguja District, Madhya Pradesh, India
Authors: Singh Yamuna , Sharma D. S. 
Published: November 2024

Abstract
The tantalite pegmatite from Belangi is zoned and comprises a quartz core, blocky microcline perthite, intermediate zone, wall and border zones of contrasting composition. Tantalite occurs as blocks, and in massive, radiating and finely fragmented forms. It is randomly distributed in pockets, mostly close to quartz core. The pegmatite is potassic. Presence of successive zones of contrasting composition and absence of mineral replacements, with a high value of triclinicity (0.95) for microcline perthite indicate that the pegmatite was fonned by fractional crystallisation in a closed system. Columbite-tantalite from the pegmatite has very low Nb/Ta ratio (0.38 - 0.52). The pegmatite has yielded beryl and ruby variety of muscovite of marketable grade, besides tantalite.
Sequence Stratigraphic Analysis of Pre-Tertiary Succession in Ganga Basin
Authors: Singh A. K. , Singh J. N. 
Published: November 2024

Abstract
The paper defines the Pre-Tertiary stratigraphy of the Ganga Basin which is concealed beneath the thick cover of Cenozoic sediments. The sub-surface structural configuration is characterised by development of four major depressions, separated by transverse uplifts. Ganga Basin represents two main stages of geological evolution: a pre-collisional (Pre-Tertiary) stage consisting mainly of Proterozoic and Gondwana sediments, and a post-collisional (Tertiary) stage representing the Siwalik molasse. The Pre-Tertiary succession is classified into four mega sequences; three of these representing Precambrian sediments, comprising of Aravalli, Bijawar, Delhi and Vindhyan systems and one megasequence corresponding to Gondwana system in the Pumea Depression.
A 2000-Year Palaeoflood Record from Sakarghat on Narmada, Central India
Authors: Kale Vishwas S. , Mishra Sheila , Baker Victor R. 
Published: November 2024

Abstract
A continuous record of the largest Narmada floods over the last 2000 years was obtained from Sakarghat, on the Narmada River from a study of slackwater flood deposits. Two sequences of extreme floods date between ca. 400 and 1000 AD and post-1900 AD. The period, 400-1000 AD representing a period of less frequent but more extreme floods, has been documented in the archaeological record as one of decline of human settlements.
Trace Fossil Assemblage in the Lower Siwalik Suhgroup of Jammu Region, J & K State
Authors: Singh B. P. , Sudan C. S. 
Published: November 2024

Abstract
Trace fossils are found in the lower Siwalik rocks at Mansar and Jhajjar Kotli. The trace fossils are identified as Thalassinoides and Imbrichnus. It is interpreted that these fossils were developed in flood plains.
Basement Configuration in Eastern part of Vindhyan Basin Derived from Aeromagnetics and its Significance in Oil Exploration
Authors: Atchuta Rao D. 
Published: November 2024

Abstract
The basement configuration of the eastern part of the Proterozoic Vindhyan basin has been deduced by re-processing of the aeromagnetic data. The depths to the magnetic basement vary from 2 to 6 km. The basement in this part appears to consist of basement 'highs' (culminations) and 'lows' (depressions) elongated in a general ENE-WSW to EW direction. This configuration has divided the eastern Vindhyan basin into sub-basins. The large thickness of sediments in the sub-basins may be of interest in exploration for oil industry.
Rb-Sr Ages of Lamprophyre Dykes from Schirmacher Oasis, Queen Maud Land, East Antarctica
Authors: Dayal A. M. , Hussain S. M. 
Published: November 2024

Abstract
Lamprophyre dykes intrude the late Proterozoic metamorphic terrain of Schimucher Oasis, Queen Maud Land, East Antarctica. Rb-Sr whole-rock/mineral isochron ages of two lamprophyre dykes are 455 ± 12 Ma (Sr1 = 0.70886 ± 5) and 458 ± 6 Ma (Sr1 = 0.71388 ± 98). This lamprophyre dyke activity of Schirmacher Oasis, may be interprete4 as a manifestation of post orogenic alkaline magmatism related to the Ross orogeny of the Transantarctic mountains.
Geochemical Characteristics of Post-Magmatic Alteration and Thngsten Mineralisation Associated with Balda Granite, District Sirohi, Rajasthan
Authors: Singh Santosh K. , Singh Satyendra 
Published: November 2024

Abstract
Balda leucogranite is characterised by high B, F, Li, Rb, W, Sn Nb content & Rb/Sr ratio and low Sr, Ba content & Ba/Rb ratio. In the case of altered and mineralised leucogranite geochemical data indicates variable B, F, Li, Rb, W, Sn, Nb contents and Rb/Sr & Ba/Rb ratios, differing significantly from those of fresh rocks. The Rb/Sr and Ba/Rb ratios as well as B, F, Li and Rb contents are the guiding characteristics of the granitic rocks which have undergone postmagmatic alteration and mineralisation. and they provide valuable clue for searching tungsten mineralisation in this area.
Occurrence of Gold and Silver in Khetri-Kolihan Copper Ores, Rajasthan, India
Authors: Krishna Rao N. , Sunilkumar T. S. , Narasimhan D. 
Published: November 2024

Abstract
Native gold, etectrum with a wide spectrum of compositional variations between gold and silver, and native silver are identified based on ore microscopic and scanning electron microscopic studies in the copper ores of Khetri-Kolihan, Rajasthan and probable mode of origin is discussed.
Depositional Framework of the Sandy Mid-Fan Complexes of the Proterozoic Chaibasa Formation, E.Singhbhum, Bihar
Authors: Das Subhasish 
Published: November 2024

Abstract
The Proterozoic Chaibasa Formation belonging to the Singhbhum Group was deposited in small overlapping submarine fans along the eastern cratonic margin of an unstable foreland trough during the early phase of the Singhbhum Orogeny. The following features suggest deposition within the mid-fan complex: (I) a relatively high proportion of coarse, massive psammitic layers with small proportion of pelitic layers and classic graded sandstones; (2) the presence of shallow sand-filled channels; (3) the frequent associations of olistostromes; (4) association of thick coarse sandstone with thin layers of fine sandstone separated by thick shale units; (5) the presence of both positive and negative cycles in the stratigraphic record.
Sandstone bodies characteristic of the unchanneled fan lobes, represent deposition associated with basinward progradation of the lobe complex. Accumulation of a thick siltstone on top of the coarse sandstone facies during the active progradational phase is related to a channel cutoff in the upfan region. In contrast, the sandstone bodies present in the channel show an overall graded nature, lack thick siltstone horizon, contain erosional structures, and a higher percentage of positive cycles. The development of the submarine fan was related to external and internal factors, that is, the flow velocity, the rate of sediment supply coupled with channel migration, frequency of major storms or earthquakes to initiate submarine gravity flows. This development of alternating graded sandstone units and siltstone blankets may be a more useful criterion (than sedimentary structures) for the recognition of ancient mid-fan lobe sequences.
Petrography and Depositional Environment of the U-Mineralised Phosphatic Siliceous Dolostone of Vempalle Formation in the Cuddapah Basin, India
Authors: Roy Minati , Dhana Raju R. 
Published: November 2024

Abstract
The phosphatic siliceous dolostone (PSD) predominantly comprises ferroan dolomite that occurs as (a) micritic mosaic within the groundmass, intraclasts, peloids and ooids; (b) fibrous dolomite coating (a); and (c) clear dolomite filling cavities, and is secondary in nature formed due to dolomitisation of precursor high-Mg calcite. Stratigraphic position, sedimentary structures, structures of dolomite, process of dolomitisation and association with collophane and silicate clasts indicate a shallow marine intertidal depositional environment for PSD.
A New Method of Estimating Denudation Rates of the High Himalaya Based on Metamorrphic Index Minerals in the Siwalik Molasse
Authors: Sorkhabi Rasoul B. , Arita Kazunori 
Published: November 2024

Abstract
The erosion record of the high-grade metamorphic complex of the Himalaya is preserved in the Siwalik foreland molasse. Here we propose a new method for estimation of average denudation rates in the High Himalaya during the Miocene based on the first appearance of kyanite in the Middle Siwaliks (beginning at ~11 Ma) and of sillimanite in the Upper Siwaliks (at ~5 Ma) and from ahe fact that these metamorphic index minerals were formed at depths of 21-24 km(thermobarometric data) during the main Himalayan metamorphic event at ~23 Ma (geochronologic data).
Mineralogical and Petrochemical Studies of the Lamprophyres around Chhaktalao Area, Madhya Pradesh
Authors: Hari K. R. 
Published: November 2024

Abstract
Three lamprophyre dykes with E-W trend which cut across alkali olivine basaltic rocks and their differentiates are noticeable in the vicinity of Chhaktalao area. Clinopyroxene and olivine phenocrysts are set in a matrix of clinopyroxene, plagioclase, biotite, apatite, spinel, magnetite/ titanomagnetite, ilmenite and calcite. On the basis of Na2O and K2O percentages, these rocks are classified as alkaline lamprophyre (camptonite) and calc-alkaline lamprophyre (kersantite). Clinopyroxene phenocrysts in both the lamprophyres are of augitic composition; whereas few grains and bleb like structure in the groundmass are of salite composition. Fo% of olivine varies from 83.4 to 88.3. Both the rocks are nepheline normative. The camptonite have lower normative orthoclase, Na2O+ K2O, K2O/Na2O, S REE and Ce/Yb values than that of kersantite. These rocks do not carry any primary magma signature as they have low Mg' [Mg/(Mg + 0.9Fe) atomic], Ni, Cr, and Ni/MgO values. High alkali, REE, Ba, Sr contents in these lamprophyres indicate that source region got metasomatically enriched in these elements.
Recent Benthic Foraminiferal Genera from Pulicat Lake, East Coast of India: An Apprisal Using Factor Analysis
Authors: Jayaraju N. , Srinivas K. , Reddi K. R. , Suryakumar I. 
Published: November 2024

Abstract
A total variance explaining 86% of the matrix is consituted by six factors where Florilus-Asterorotalia assemblage (46%) emerged significant. Asterorotalia-Florilus assemblage is more abundant (37%) in monsoon. These faunal assemblages were related to environmental ingredients Viz., texture of sediment substrate, the amount of locked-up organic matter content and bottom water salinity. The cross plot of first two factors for both seasons revealed the common genera found to occur in descending order i.e., Asterorotalia, Florilus, Elphidium and Ammobaculites which are confined especially in normal marine action of sea oscillations are noticed.
Lohawat Meteorite-A Howardite
Authors: Chattopadhyay B. , Rajawat R. S. , Mathur K. N. , Gajanand  , Dwivedi G. L. 
Published: November 2024

Abstract
Lohawat Meteorite is a differentiated silicate rich aerolite of the high calcium howardite type. Unquestionable magmatic signature is stamped by ophitic, intersertal and spinifex texture, corona and vesicular structures, as seen in lithic fragment clasts. The simple mineralogy has been discussed in terms of the system olivine-clinopyroxene-plagioclase-silica. Varietal texture and compositional features suggest that the meteorite has sampled terrains of distinctly different genetic history.