bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trace and Rare Earth Elements Geochemistry of Alkaline Rocks of Sarnu-Dandali, Harmer, Rajasthan
Authors: Shastry Anant , Kumar Santosh 
Published: November 2024

Abstract
The alkaline rocks belonging to ijolite series and carbonatites constitute the Sarnu-Dandali igneous complex (68.5 Ma) associated with Precambrian acid volcanics. Trace elements including REE of ten selected Late Cretaceous rock-types viz. melteigite, melanephelinite, phonolite, carbonatite, basalt and Precambrian rhyolites of SDIC have been examined and discussed. The data of alkaline rocks suggest their derivation from an alkaline (ijolitic) magma formed by the partial melting of mantle source. Ba-Sr-REE enriched carbonatites possibly represent an immiscible split from nephelinite. The basalt (Hawaiite) represents a subalkaline magmatic pulse unrelated to alkaline suite. The associated Precambrian rhyolites have formed by a combination of magmatic processes such as partial melting, fractional crystallization and/or magma-mixing.
Geochemistry and Petrogenesis of Hanuman Tibba Granite of Kullu Valley, Himachal Himalaya
Authors: Islam R. , Bist K. S. , Chaudhuri B. K. , Rawat B. S. , Purohit K. K. 
Published: November 2024

Abstract
A maiden attempt has been made to study the far-flung Hanuman Tibba Granites of Kullu valley, Himachal Pradesh. The granite has intruded the low grade Haimanta (-Lahaul) Formation which tectonically overlies the Rohtang Gneissic Complex. Integrated field, petrographic and geochemical studies have revealed that it is peraluminous S- type granite derived from sedimentary protolith. Compositional difference in terms of depletion of Fe, Mg, Ti, Ca, Sr, Zr and enhancement of Sit K and Rb from margin to core of the granite body is consistent with fractional crystallization process.
The emplacement of Hanuman Tibba Granite on the same tectonic level as Jispa and Ratilaman granite (500±ma) in adjacent Lahaul-Spiti region suggests a Cambro-Ordovician age for the Hanuman Tibba Granite.
Fault Segmentation and Earthquake Hazard Zones in Deccan Trap Region: Gravity Evidence
Authors: Ramachandran C. , Kesavamani M. 
Published: November 2024

Abstract
Detailed structural interpretation of the regional gravity map over the Deccan traps has brought out a number of major structural discontinuities (fault/fractures), particularly the E-W features whlch were not delineated by earlier investigators. The most significant among them is the major E-W fault from west coast to east coast along Bombay-Latur-Hyderabad-Bhadrachalam-Visakhapatnam (BLHV fault). Several features of the BLHV fault suggest it to be a major reactivated strike slip fault. The structural scenario presented in this paper will have great implications in earthquake studies in Deccan trap area. Based on some aspects of fault segmentation technique for earthquake hazard and from the structural interpretation of the regional gravity map over Deccan traps, several zones are identified which could be termed as earthquake hazard zones. These hazard zones are typically located at: (1) the segment boundaries or fault steps of BLHV and other major E-W faults, (2) in many cases are associated with gravity low nosings which possibly reflect buried granite intrusions (regarded as asperities or barriers in the context of seismicity), and (3) intersection of major E-W faults with other transverse structural trends (fault/fractures). The areas where the major E-W faults terminated against the west coast fault system can also be important in terms of future seismicity. The recent seismicity in the Deccan trap, area is inferred to be due to the reactivation of the major E-W faults due to the still continuing convergence of India with Asia.
The present work, for the first time, demonstrates the importance and application of fault segmentation technique in earthquake hazard studies in Deccan trap area, and also the full potential of gravity interpretation in such studies.
Spinifex Textured Peridotitic Komatiite from Nuggihalli and R.N. Pur Schist Belts, Karnataka
Authors: Jafri S. H. , Subba Rao D. V. , Ahmad S. M. , Mathur Ramavati 
Published: November 2024

Abstract
Spinifex textured ultramafic rocks occur at Bhaktarahalli in Nuggihalli schist belt and as an enclave within the Peninsular Gneiss near Dodda Gudda, Holenarasipur belt in Hassan District. They have Komatiitic chemistry pointing to ultramafic volcanism in the Dharwar Craton during the Archaean Era.
Glacial Erratics in the Higher Himalayan Region of Lahaul, Himachal Pradesh: Their Geomorphological Significance
Authors: Prashra K. C. 
Published: November 2024

Abstract
Two levels of glacial erratics of granitic rocks located at about 280m and 1250m above the present river level have been identified in the Higher Himalayan region of Lahaul, Himachal Pradesh, which may possibly correspond to advancing and waning phases of the valley glacier. The erratics have been transported over a distance of about 4 km to 28 km from their respective provenances. The appreciable difference in altitude between the two levels of erratics and that of the present river course suggests a considerable uplift of this part of the Himalaya during the Quaternary period.
Geothermometry and Oxygen Barometry of Coexisting Iron-Titanium Oxides of Majhgawan Diamondiferous Pipe, Madhya Pradesh
Authors: Mukherjee Abhijeet , Rao K. S. , Bandyopadhyay D. , Roy Gautam , Chatterjee A. K. 
Published: November 2024

Abstract
Geothermometry of the coexisting magnetite-ilmenite (Mt-Ilm) pair from Majhgawan diamondiferous pipe indicates a temperature of 1150°C. The values of fO2 T and P fall in the equilibria field defined by iron-wustite (IW) and wustite magnetite (WM) indeating depth of sampling of about 155km and pressure of 46kbar.
Hydrogeological Conditions and Optimum well Discharges in Granitic Terrain in Parts of Nalgonda District, Andhra Pradesh, India
Authors: Narasimha Reddy T. , Raj Pradeep 
Published: November 2024

Abstract
Ground water in study area underlain by peninsular Gneissic complex occurs in unconfined conditions in weathered zones and semi-confined to confined conditions in fractured zones. Productive fractured zones define narrow linear tracts closely corresponding to surface drainage. Fluoride content of ground water is low mostly in topographic highs and to lesser extent in tank beds or tank commands and in areas where fractures are not connected with fluoride bearing granites. For potability, most wells were drilled in topographic highs and some around tanks.
The aquifer is highly complex (anisotropic and heterogeneous) needing critical analysis to assess performance of wells, as recently yields of a large number of borewells drilled in granitic terrains of Andhra Pradesh are reported to have declined. This is attributed mostly to direct interference with other wells, improper construction of wells leading to silting and general decline in water levels due to various reasons. But rarely, it is realised that these aquifers are laterally limited. In this study pumping tests for 500 to 1000 minutes i.e., 2 1/2 to 3 log cycles of time were carried out and the data was analysed using graphical methods of Cooper and Jacob and Theis recovery method. [n four cases the test data was analysed by a micro processor based simulation technique. Optimum discharges were calculated keeping in view the effects of 'no-flow' boundaries, effective available drawdown and other field parameters. This has indicated that the optimum discharges of the wells are in general between 60% to 80% of the yields recorded during drillng.
A New Occurrence of Sapphirine in the High-Grade Pelitic Gneisses of Usilampatti, Tamil Nadu
Authors: Subba Rao D. V. , Nirmal Charan S. , Moeen S. 
Published: November 2024

Abstract
Sapphirine is found in the pelitic gneisses of Kosavankovilpatti near Usilampatti in Tamil Nadu. It is intimately associated with melt products and the associated minerals are garnet, biotite, orthopyroxene, plagioclase, mesoperthite and K-feldspars. The sapphirine-bearing rock is characterised by (i) enrichment of MgO, depletion of SiO2 (ii) absence of coronas and symplectites, (iii) presence ofmesoperthites (iv) high XMg values of the associated minerals and (v) high P-T conditions (855±20°C and 8.0±O.3 Kb) in contrast to the adjacent sapphiri ne absent rocks (750-800° and P of 6.5-7.5 Kb). This occurrence of prismatic sapphirines is in contrast with the reported sapphirine occurrences where it occurs as symplectites and coronas defining a decompression path (T= 700°C and p 5-7 Kb) in the adjacent Kodaikanal massif. It is suggested that the sapphirine being reported is of prograde origin.
R-Mode Factor Analysis, and Its Implications on the Geochemistry of Nishikhal Manganese Deposit, Raigada District, Orissa
Authors: Nayak B. K. , Mohanty Swati , Rajeev  , Sahoo R. K. 
Published: November 2024

Abstract
Normalised major and trace element data of manganese ores from Nishikhal are processed by using R-mode factor analysis of correlation matrix. Twenty major and trace elemental variables are expressed in terms of 3 common (rotated) factors to understand the mineralogical occurrences and the processes of formation of the manganese deposit. Varimax factor scores are used to classify in a finer detail the manganese ore types.
Marine Magnetic Anomalies as a Link Between the Granulite Belts of East Coast of India and Enderby Land of Antarctica
Authors: Murthy K. S. R. , Malleswara Rao M. M. , Venkateswarlu K. , Subrahmanyam A. S. , Lakshminarayana S. , Rao T. C. S. 
Published: November 2024

Abstract
Magnetic data of the eastern continental margin of India (ECMI) helped in demarcating the offshore extension of the granulite belts of east coast of India and their possible link to those of the East Antarctica. Short wavelength and high amplitude negative magnetic anomalies (200 to 1600 nT) are observed over the northern part of ECMI between Kakinada and Chilka lake and also off Madras shelf, the coastal regions of which are associated with granulite facies rocks . This part of the shelf is associated with structural lineaments with predominant NE-SW trends . In contrast, the offshore basins off Cauvery, Krishna - Godavari (K-G) and Mahanadi rivers are associated with subdued positive anomalies (less than 200 nT) indicating subsidence off these basins by heavy load of Phanerozoic/younger shelf sediments. Structural lineaments with NW-SE or W-E trends delineated over these basins are related to the offshore extension of these rift related Gondwana grabens. Similarity in the trends of the magnetic anomalies and the granulite facies on the east coast of India and their correlation with the granulite belt of Enderby Land of Antarctica supports the view that the entire region comprised of a single and stable block of granulite rocks prior to the fragmentation of the Gondwanaland. The study also suggests probable continuation of Mahanadi and Godavari grabens into East Antarctica.
Dune Associated Calcretes, Rhizoliths and Paleosols from the Western Continental Shelf of India
Authors: Purnachandra Rao V. , Thamban M. 
Published: November 2024

Abstract
The calcareous deposits on the western continental shelf of India, off Bhatkal (water depths 50 to 58 m) occur as crusts, sheets, cylinders and reddish brown mudstones. The outer layers of the crusts are micrite-dominated and beneath this layer detrital/carbonate sands with thin heavy mineral laminations are found. Textural studies indicate that the detrital sands are derived from dunes. Drusy calcite and neomorphic calcite cements are associated with the sands. Sheet deposits contain coarse calcareous component-dominated layer within micrite layers and abundant micrite cements. These are similar to dune associated calcretes.
Cylinders are rhizoliths and show different stages of root calcification. Circular bodies. about 0.15 mm to 0.70 mm diameter, interpreted as vascular cylinders of the root tissues are typical. Radial fibrous calcite and spar calcite with inclusions indicate neomorphic cements. Reddish brown mudstones contain calcified root-hair sheaths, micrite glaebules and reworked pollen suggesting that these are indurated soils. X-ray diffraction studies indicate the presence of ferroan calcite, quartz, pyrite and dolomite in rhizoliths and ferroan calcite, goethite and quartz in mudstones. Mudstones and some rhizoliths are Fe-rich and some other rhizoliths are Fe-poor but enriched with Mg and Mn. The particulate matter in the calcareous deposits were initially at the proximity of the coast and cemented by metastable calcites during the ultimate Pleistocene interglacial sea-level stands on the shelf. Pedogenic cementation processes overprinted and developed them into eolianites and paleosols during the subsequent Late Pleistocene sea-level regression. The compositional differences of these deposits were apparently controlled by type of sediments and associated sedimentary environments.
Variation of Crustal Velocity Structure in India as Determined from DSS Studies and their Implications on Regional Tectonics
Authors: Kaila K. L. , Sain Kalachand 
Published: November 2024

Abstract
The Indian subcontinent has been divided into six crustal velocity zones based on P-wave velocity structure obtained along 20 Deep Seismic Sounding (DSS) profiles, covered in India from 1972 to 1992. Zone - 1 consists of two parts: zone - 1.a comprises the Dharwar craton, Cuddapah basin, Godavari graben and the Koyna region, and zone- 1 .b consists of the western margin of the Bengal basin and the Singhbhum craton. Zone - 2 covers the West Bengal sedimentary basin and the Mahanadi coastal basin. Zone - 3 includes Bundelkhand craton and the Vindhyan basin. Zone - 4 covers Cambay basin north of the Narmada lineament and the Aravalli - Delhi fold belt. Zone - 5 lies south of the Nannada lineament covering the Tapti graben extending up to the west coast of India. Zone - 6 comprises the northwest Himalaya up to the Nangaparbat including Jammu and Srinagar sedimentary basins. Detailed crustal velocity structures in these six zones have been described with their bearing on regional tectonics. Velocity structure of the lower crust in some of these zones, suggests that crustal underplating has played a very important role in the evolution of the Indian continental crust and lithosphere. Some petrological inferences have also been drawn for the Indian crust from crustal velocity zonation.
Pattern of Seismicity in Shillong-Mikir Plateau and the Orientation of Compressional Axis
Authors: Baruah Saurabh , Duarah Ranju , Yadav Dilip K. 
Published: November 2024

Abstract
The study of eleven years (1982-1993) of seismicity (focal depths&lt;60km) in the Shillong-Mikir massif of N.E.R., India (25°-27°N) clearly delineates the pattern of activity within this region. The most important feature is a concentration of events in the depth range of 20 to 40 km where 70% of the activity took place. Minor seismicity prevails in the other ranges. The results from the focal mechanism solutions of 12 events of magnitude &gt;5.0 ascertain thrust and strike slip type mechanisms within the depth range of &lt;40km while dip-slip and normal type solutions are occurring in the range &gt;40km. The compressional axis of most of the events is oriented along north-northwesterly direction.
Pyroclastics in the Late Proterozoic Formations of the Simla Himalaya
Authors: Bose U. , Nagal S. C. , Sharma N. L. , Prashra K. C. , Sharma V. K. , Bassi U. K. 
Published: November 2024

Abstract
Pyroclastics are found in all the late Proterozoic clastic formations of the Outer Krol Belt in the Simla Himalaya. The field and petrographic characters leading to identification of the pyroclastics are described here.
Turbidite to Storm Transition Sedimentation during Early Carboniferous, Kashmir Himalaya
Authors: Bhat G. M. , Singh Rajinder , Pandita S. K. 
Published: November 2024

Abstract
This work, based on sedimentological data collected from two stratigraphic sections at Lambar and Malvat (Banihal area), reports the turbidite to storm influenced sedimentation of "Syringothyris Limestone" sequence, Kashmir Himalaya. An upward progresssion of the sequence reflects the depositional record of fine grained turbidite to storm - and wave - influenced sedimentation. Sedimentary structures like short wave length symmetrical ripples. flat lamination, thin graded bedding and structures in muddy siltstones suggest deposition in low energy, wave influenced settings, The storm influenced sediments display hummocky, cross stratification. skolithos ichinofacies, granule/shelly lags, mega ripples, low angle cross lamination and convolute lamination. The whole sequence is interpreted to represent episodic storm influenced sedimentation in a shallow basin, largely controlled by tectonic activity, The Markov Chain models structured for this sequence also suggest episodic sedimentation and do not show any cyclicity,
Geochemistry of Rajapur and Puttur Thermal Springs of the West Coast, India
Authors: Ramanathan A. , Chandrasekharam D. 
Published: November 2024

Abstract
Thennal springs of Rajapur and Puttur (Irde and Banduru) are of low-temperature and low-flow type. Though they are located at two different geological set up, they fall in Na-HCO3 facies . The imprints of basalt - thermal water interaction at Rajapur and local equilibration of doleritic dyke with the thermal water of Irde is deduced. The reservoir of the Rajapur thermal spring is likely to be located in the Precambrian formations, as that of Puttur thermal springs and hence the chemical processes undergoing in these systems are similar. The reservoir temperatures estimated using chemical geothermometers are about 200°C and &gt;120°C for the Puttur and Rajapur thermal springs respectively. Illite, K-mica. chlorite. kaolinite. Ca-montmorillonite and philipsite are the expected secondary minerals in the system.
Grain Size Studies on the Nearshore Sediments of Jaigad, Ambwah and Varvada Bays, Maharashtra
Authors: Rajamanickam G. V. , Gujar A. R. 
Published: November 2024

Abstract
Bivariate plots of the textural parameter data suggest overlapping environments. Such as river/beach to JB, beach/dune/river to AB and dune/beach to VB sediments.
Internally Consistent Geothermobarometers in the System FeO-MgO-Al2O3-SiO2-H2O Involving Garnet, Cordierite, Aluminosilicate and Quartz and their Application to Metapeiites
Authors: Dwivedi S. B. , Mohan A. , Lal R. K. 
Published: November 2024

Abstract
Reactions involving garnet, cordierite, aluminosilicate and quartz in FMASH system are calibrated as geothermobarometers, namely 1/2 Fe-crd + 1/3 Pyrope = 1/2 Mg-crd + 1/3 Almandine (1); 2 Almandine + 4 sillimanite/andalusite + 5 quartz = 3 Fe-crd (2 and 4); and 2 Pyrope + 4 sillimanite/andalusite + 5 quartz = 3 Mg-crd (3 and 5).
T = [6170+O.031(P-1)-400(XFe-XMg)Crd-A]/(RlnKD+2.812+B) (1)
A= 166 X2Mg-506 X2Fe+680 XFeXMg+336 (XCa+XMa) (XMg-XFe)-
XCa - 358 XMn and B = 1.5 XCa
For Fe and Mg end-member reactions involving sillimanite, the following geobarometric formulation is obtained:
PFe=1+[{(24.02-6RlnKFe)T-17369}/4.003] (2)
PMg=1+[{(7.238-6RlnKMg)T+19640}/3.82] (3)
Similarly for reactions involving and alusite, PFe and PMg expressions are : PFe=1+[{(26.04-6RlnKFe)T-19471}/3.86] (4)
PMg = 1+[{(9.25-6RlnKMg)T+17536}/3.68) (5)
A Genetic Re-Iinterpretation of the Shore Parallel Sand Ridges on the Balasore-contai Floodplain, W. Bengal and Orissa
Authors: Banerjee P. K. , Goswami S. , Chatterjee S. 
Published: November 2024

Abstract
Linear mounds of sands, spread over 400 km2 in the Balasore-Contai floodplain and aligned parallel as well as close to the shoreline are not past strandline markers. It is suggested that these are compound products of fluviatile deposits capped by aeolian accumulations during late Holocene, albeit undated, arid intervals. The mounds were stabilished by soil and vegetation cover and are presently under anthropogenic attack.
Sulphur Isotopic Study on the Vein-Type Baryte from Vemula in the Vempalle Formation of Cuddapah Basin, Andhra Pradesh
Authors: Dhana Raju R. , Prasad R. N. , Pandey D. D. , Jeyagopal A. V. , Deshmukh R. D. 
Published: November 2024

Abstract
Baryte at Vemula near to the southwestern margin of Cudapah Basin occurs as a vein-type deposit discordant to both the carbonate rocks of Vempalle formation and its intrusive dolerite. S-isotopic data on the baryte have a range of d34SCDT between +16.2‰ and +23.3‰ whereas the coexisting chalcopyrite has a restricted range between +10.9‰ and +11.4‰. The average value of d34S of Vemula baryte (+20.8‰) differs much from that of magmatic rocks (0‰ to +2.5‰), metamorphic rocks (+3‰) and sediments of continental margins, platform areas and geosynclines (-12.5‰ -17,1‰), but is similar to that of sea water (+20‰) which appears to be the source for sulphur. The narrow range of d34S of baryte and chalcopyrite points to a uniform source with their sulphur possibly derived from sea water sulphate by bacteriogenic reduction.
Distribution of Organic Matter and Calcium Carbonate in the Shelf Sediments off Penner River, East Coast of India
Authors: Seetharamaiah J. , Swamy A. S. R. 
Published: November 2024

Abstract
Organic matter and calcium carbonate in the shelf sediments off Penner river are mainly controlled by the texture of the sediments. The outer shelf (30-50 m depth) sediments of the southern and northern parts have a higher content of organic matter (1.2 to 2.22%). The sharp differences in organic matter content (varies from 0.8-1.6%) and fine nature of the sediments at the river mouth reveals detrital contribution. A calcium carbonate rich zone (30-40%) associated with coarse sands occurs opposite to Penner river mouth (20-50 m depth). The source for high concentration of calcium carbonate in the coarse sands (relict) are molluscan shells, shell fragments and foraminifera indicative of the in situ origin . It is inferred that the calcium carbonate supports that the coarse sands are stillstand deposits admixtured with present conditions.
Petrogenesis of the Mandi Gabbroic Rocks, Lesser Himalaya, India
Authors: Chaudhri Naveen , Gupta L. N. 
Published: November 2024

Abstract
The gabbroic rocks of Mandi area occur as an oval-shaped, 500 m thick intrusive body within the Mandi granite. The central zone of the body is made up of fresh gabbro and it grades into metagabbro and epidiorite towards the margins. The relatively high abundances of Ti, AI, Ca and Mg in clinopyroxenes of the central part as compared to the clinopyroxenes of the marginal part suggest different rates of cooling within the Mandi gabbroic body. The zoned plagioclases have calcic-rich cores and calcic-poor rims. The Al - (Fe+Ti) - Mg values and incompatible trace element ratios of the rocks indicate tholeiitic nature of the body. The discrimination diagrams based on major elements as well as immobile minor and trace elements suggest that these rocks are of MORB type. However, the chemical characteristics like negative Nb, Ti and P anomalies in the primordial mantle-normalised spiderdiagram together with low TiN and ZrN ratios testify that the Mandi gabbroic rocks are akin to low-Ti continental flood basalts. [Mg]-[Fe] modelling, incompatible versus compatible trace element data and lower Ni abundances for the given Mg contents suggest 10-15 % fractional crystallisation of olivine after the rocks were generated by partial melting under pressure conditions ranging between 25 and 40 kb. The intrusive appears to have formed by low degree of partial melting of a non-pyrolitic metasomatised mantle source that was heterogeneous with respect of Zr and Fe/Mg ratios.