bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extensional Strain using Pull-Apart Pyrite Grains from the Chamba Syncline, Himachal Himalaya
Authors: Singh Keser 
Published: November 2024

Abstract
Strain reversal technique is applied to the pull-apart pyrite grains collected from the Chamba Formation of the Chamba Syncline. The computed ratio values of the extensional strain for X:Z section of the strain ellipsoid varies from 2.3 to 2.7 for the pyrite grains. The X direction of the strain ellipsoid coincides with the stretching lineation direction indicating minimum amount of strain values required for its development on the cleavage plane.
Landscape Evaluation of Humboldt and Adjacent Areas, Wohlthat Mountains, East Antarctica
Authors: Ravindra R. , Pant N. C. , 'souza M. J. 
Published: November 2024

Abstract
The Humboldt region of the Wohlthat Mountains in East Antarctica, depicts both polar and alpine type of morphological set-up. While the former is represented by vast stretch of antarctic ice sheet with hills and nunataks, the latter is marked by glacially fretted uplands with cirques, aretes, horns and moraines. These and other landforms associated with denudation and depositional processes have been used to evaluate the regional landscape of Humboldt area, which conforms with the composite erosional landscape of Sugden and John (1976).
The glacial geomorphological features are largely, due to Somovken and Humboldt glaciers flowing on either side of the Humboldt fiat. The interference of the movement between the two glaciers is reflected in the depositional pattern of moraines. The polar ice evidently covered much greater portions of the area in the past with ice level covering the ridges at 1900 m - 2000 m above sea level.
Indian KimberIites and Lamprophyres: Mineralogical and Chemical Aspects
Authors: Paul D. K. 
Published: November 2024

Abstract
Mineralogical, chemical and isotopic age and abundance data on Indian kimberlites and lamprophyres are discussed to show critical differences. The available K-Ar ages indicate that the kimberlites (840-1120 Ma) are much older than the lamprophyres (56.7-113 Ma). New whole-rock chemical analyses of the Majhgawan diatreme, the only producing diamond mine in India, suggest that fractionation of olivine and spinel has been important during its evolution. In general, the lamprophyres of the Gondwana coalfield bear geochemical similarity with the kimberlites. The source region for both rock types need to be enriched in incompatible elements but the lamprophyres are likely to have formed at shallower depth compared to the kimberlites.
Densities of High Grade Metamorphic Rocks from South Indian Granulite Terrain
Authors: Ramachandran C. , Bosu Lili Rani 
Published: November 2024

Abstract
2.67 gm/cc is the normally assumed density value for the upper crystalline crust, in gravity data reductions. The densities measured in 210 metamorphic rocks, spread over a traverse distance of 2500 km from the granulite terrain of South India, gave a mean density of 2.77 gm/cc. The results show that 2.67 gm/cc is too Iow a value and 2.76 ± 0.01 gm/cc would be an appropriate choice for the mean density of the upper crystalline crust in South Indian granulite terrain.
Though in some of the charnockites the magnetic susceptibility is considerably reduced due to retrograde metamorphism, the effect is not perceptible on the density. The areas with high paleopressures have the maximum mean densities.
An Exhumed Channel Sandstone body of Suraideval Formation (Lower Cretaceous), Saurashtra Basin, Gujarat: A Possible Example of Delta Distributary and Nearshore Deposit
Authors: Casshyap S. M. , Aslam M. 
Published: November 2024

Abstract
An earthy brown, cross-bedded, channel sandstone body overlying a thinly bedded sequence of white sandstone and red shale of the Surajdeval Formation (Iower-Cretaceous) stands out as a low-lying flat-topped escarpment, about 3-4 m high and 30-60 m wide, alongside the village Dhaduka near Chotila on the Surendranagar-Rajkot highway. Plane ta ble survey brings out a sinuous pattern of the channel sandstone body longitudinally in the north-south direction all along the escarpment.
Integrated evidence from geometry, lithofacies and paleocurrents suggest that the Dhaduka sequence is an example of exhumed channel bar of delta distributary, in association with thinly-bedded coastal plain (1ongshore/tidal current) deposits.
Source Mechanism of the Cachar Earthquake of December 30, 1984, NE India from the Synthesis of Body Waves
Authors: Singh D. D. 
Published: November 2024

Abstract
Wave forms modelling of P and S wave data is done to study the seismic source parameters of a moderate earthquake of December 30, 1984 (mb = 5.6), which occurred in NE India. A combination of thrust and strike slip faulting is determined with fault plane striking N 12° E, dipping 50° west, slip 32° and focal depth of 20 km. The total source time duration is found to vary from 5 to 6 seconds. Average value of seismic-moment, fault radius, stress-drop, apparent stress, dislocation, strain energy and strain drop are 2.25 x 1025 dyne-cm; 8.1 km; 23 bars; 16 bars; 14 cm; 1.45 x 1020 ergs and 0.24 x 10-4 respectively. The axis of maximum compression (pressure axis) is acting a1most horizontal in southeast-northwest direction and axis of minimum compression (tension axis) in northeast-southwest direction. This earthquake possibly resulted from the westward overtbrusting of Burmese arc and the simultaneous counter-clockwise motion of NE Indian wedge, driven by the general plate motion of the Indian subcontinent.
A New Metabasic Reference Sample (MB-H) from Himalayan Orogenic Belt
Authors: Saini N. K. , Purohit K. K. , Rathi M. S. , Khanna P. P. , Mukherjee Pulok Kr. , Rai Hakim 
Published: November 2024

Abstract
An attempt has been made to produce an international metabasic rock standard from the Rudraprayag Fonnation of Himalayan orogenic belt. The bulk sample collected has been processed and subjected to homogeneity test (F test). The salient petrographic features. proximate analysls and the F-ratio of the different fractions are presented in this paper.
Strain Analysis of Deformed Pebbly Horizon from the Garhwal Group, Pharsaun, District Chamoli, U. P.
Authors: Gairola V. K. , Hatwal Deepak 
Published: November 2024

Abstract
A deformed pebbly horizon has been observed in the quartzitic phyllite member of the Garhwal Group rocks exposed along a ENE-WSW striking fault, south of village Pharsaun, District Chamoli, U. P. The directions and ratios of the principal strain axes of tbe finite strain ellipsoids have been determined. The strain data have been plotted on Flinn triangular and polar graphs, respectively. The strain analysis reveals tbat the mean shape of the pebbles prior to deformation was flattening type and with progressive deformation, the shape of the pebbles changed to constriction type, then to flattening type, and finally to constriction type. The deformation of the pebbles bas been related to the first tectonic movement. Shearing along the fault of later generation was responsible for the rotation and reorientation of the principal axes of tbe deformed pebbles.
Cycles of Advance and Retreat of the Chbota Shigri Glacier, LahauI District, H.P.
Authors: Chaujar Ravinder Kumar 
Published: November 2024

Abstract
In the present paper an attempt has been made to study different cycles of advance and retreat of the Chhota Shigri Glacier, located in Lahaul district of Himachal Pradesht on the basis of various loops of lateral and terminal moraines in the Inactive Zone. From the shape and size of five morainic loops it would appear that the first three stages of glacial activity in the region were quite prominent and stable as compared to the last two. The energy of transportation and deposition of material was maximum during stage I of the glacier advance, as indicated by the presence of the rest of the morainic loops within the lateral and terminal moraines, and on the ground moraines of the loop of stage I of the glacier advance. After the development of these loops no major glacial activity has occurred.
Late Miocene (N eillian) Planktonic Foraminifera from Baratang Island, Andaman Sea
Authors: Mazumdar Debashis , Sharma V. 
Published: November 2024

Abstract
Neogene sequences exposed on the southwestern part of the Baratang Island have been assigned Early to Middle Miocene (?) and Late Miocene age. Biostratigraphically, the Late Miocene sequence is referable to Globorotalia (Globorotalia) plesiotumida Zone. A predominantly warm-water assemblage of planktonic foraminifera contains some cold-water species. Presence of these cold-water forms is linked with the Late Miocene climatic cooling.
A Preliminary Conceptual Model of Nubra Valley Geothermal System, Ladakh, J & k, India
Authors: Absar Ahsan , Prakash Gyan , Aggarwal R. K. 
Published: November 2024

Abstract
The hot spring areas in Nubra valley, Ladakh, J&K located at Changlung, Panamik and Pulthang lie in a 30 km long NNW-SSE trending stretch parallel to and on the left bank of the Nubra river. These hot springs are confined to the Karakoram Granite which is in tectonic contact with the overlying Shyok volcanics.
The local meteoric water, which is Ca-Mg-HCO3 type, alters to Na-HCO3, type before it emerges as hot springs. This chemical alteration of descending local meteoric water may largely be attributed to rock-water interaction and resultant ion-exchange. Application of chemical geothennometries indicates that the chemical mass transfer between rock and water could have taken place at temperatures approaching at the most 200°C.
An attempted conceptual model of the Nubra valley hot spring system suggests that the three thennal areas of Changlung, Panamik and Pulthang are fed from an 'outflow' aligned parallel to the Nubra valley and following the regional hydraulic gradient. The hot water 'outflow' lying at a depth of more than 2 km within the Shyok volcanics is characterised by a decrease in the temperature and dilution of the fluid in the direction of the flow.
The chemistry of the discharging fluid is apparently influenced more by the type of rock reacted (granite or volcanics) than by the residence time and reservoir temperature.
Kanisamys Sivalensis, a Late Miocene Rhizomyid Rodent from Siwalik of Garhwal Himalaya, India
Authors: Tiwari B. N. 
Published: November 2024

Abstract
Rodent molar recovered from the Kalagarh area has been identified as a 'rhizomyid Kanisamys sivalensis Wood, 1937. Utilizing the rhizomyid biochronology developed on the basis of large samples from Pakistan Siwalik, the Kalagarh faunal assemblage having K. sivalensis is assigned a Late Miocene age range of 9 to 7 Ma.
Clay Mineralogy of the Pelagic Sediments: Along a West-East Transect in the Indian Ocean
Authors: Roonwal G. S. , Srivastava S. K. 
Published: November 2024

Abstract
The clay fraction of the sediments contain illite, chlorite, kaolinite, montmorillonite and iron-smectite with minor amounts of goethite. The siliceous sediments contain both montmorillonite and iron-smectite, while the calcareous sediments show only montmorillonite. This suggests that montmorillonite is formed by the alterations of ridge basalts, palagonite and volcanic glass. Iron-smectite is probably formed during low temperature diagenesis by the chemical combination of iron and silicon. High biogenic sedimentation in the calcareous sediments inhibited the formation of iron-smectite.
Rb-Sr Chronology and Petrochemistry of Granitoids from the South-Eastern Part of the Singhbhum Craton, Orissa
Authors: Vohra C. P. , Dasgupta Sabyasachi , Paul D. K. , Bishui P. K. , Gupta S. N. , Guha S. 
Published: November 2024

Abstract
The tonalitic suite of Kaptipada is high-Al2O3 type with a highly fractionated REE pattern suggesting its derivation by partial melting of amphibolite with hornblende as a residual phase. The homblende/biotite-bearing granites of Nilgiri and Ramapahari areas also occurring along the southeastern fringe,are comparatively K-rich than the lonalite-granodiorite suite of Kaptipada. Based on whole rock Rb-Sr isotopic analyses, lhe Kaptipada tonalite-granodiorite suite yields an age of 3275 ± 81 Ma with initial Sr ratio of O.70130± 0.00045; ... the Nilgiri granite, an age of 2366 ± 126Ma with initial Sr ratio of 0.72526 ± 0.00832 and Ramapahari granite, an age of 1895 ± 46 Ma wilh initial Sr ratio of 0.76521 ± 0.00427.
The temporal evolution of the tonalitic rocks of Kaptipada is indistinguishable from the earlier phases of Singhbhum and Bonai granitoids of the Singhbhum Craton. It is concluded that an extensive growth of tonalitic crust took place around 3.3 Ga in the region.
Fluid Evolution in the Closepet Granite: A Magmatic Source for CO2 in Charnockite Formation at Kabbaldurga ?
Authors: Santosh M. , Jayananda M. , Mahabaleswar B. 
Published: November 2024

Abstract
Fluid inclusion studies in the Closepet granite reveal the common occurrence of trapped fluids which show melting temperatures and laser excited Raman spectral-characteristics close to those for pure CO2. The quartz-bound inclusions in this polyphase intrusive define two major genetic categories: an earlier CO2-rich fluid with only minor traces of water and a late mixed carbonic-aqueous fluid. Compelling evidence for fluid immiscibility is preserved by coexisting inclusions with widely varying filling ratios and similar filling temperatures. Salinities upto 10 wt per cent NaCl are estimated from microthermometry, which ascribe relatively higher temperatures for fluid immiscihility in the CO2-H2O system. Our results indicate that this late Archaean granite body which truncates regional metamorphic isograds has probably been a major carrier of CO2-rich volatiles, subsolidus exsolution and channelisation of which along structural locales caused incipient dehydration and the formation of Kabbaldurga-type arrested granulites in many adjacent localities. Our model seeks to associate advective transfer of both heat and volatiles required for dehydration with the Closepet magma.
Sediment Characteristics, Processes and Stability of the Beaches in the Northern Kerala Coast, India
Authors: Samsuddin M. , Ramachandran K. K. , Suchindan G. K. 
Published: November 2024

Abstract
The cyclicity in the erosional and accretional pattern is monsoon controlled. The erosion during monsoon (May-August) and accretion during pre-monsoon (January-April) and post-monsoon (September-December) are well defined. The transport trends derived from the progressive changes in the grain-size characteristics show relatively better correlation with the measured trends where they are not influenced by the input of sediments from multiple sources. The obliquely approaching swell waves which generate intense northerly longshore currents during non-monsoon season favour accretion of the beaches. The foreshore in the accreted zones are gentler and are characterized by finer and negatively skewed sediments. This zone exhibits a higher period for the breaking waves. The converse is true in the beaches where erosion is prevalent during the monsoon season.
Foraminifera from the Nodular Limestone, Bagh Beds, Madhya Pradesh, India
Authors: Rajshekhar C. 
Published: November 2024

Abstract
The occurrence of twenty six benthic foraminiferal species belonging to the family Saccamminidae, Hormosinidae, Rzehakinidae, Haplophragmoididae, Lituolidae, Haplophragmiidae, Spiroplectamminidae, Tritaxiidae, Spiroloculinidae, Hauerinidae, Nodosariidae, Vaginulinidae, Turrilinidae, Bolivinidae, Siphogenerinoididae, Discorbidae and Nonionid ae from the Nodular limestone of the Bagh Beds, Madhya Pradesh is reported. The occurrence of mixed foraminiferal assemblage suggests normal and shallow marine conditions for the deposition of Nodular Limestone. In comparison to the underlying Nimar Sandstone, the Nodular Limestone shows high frequency of foraminifera, suggesting continued transgressive marine conditions.
Anomalies in Foraminiferal Distribution in Some Parts of Bay of Bengal
Authors: Madabhushi Srinivas 
Published: November 2024

Abstract
Three anomalous zones of (i) Low planktonic foraminifera; (ii) High agglutinated foraminifera and (iii) Low-Globorotalia (Menardella) menardii and no-Bathysiphon filiormis are identified in the Exclusive Economic Zone off Godavari delta to Puri. The deviation from Wright-van Marle model of zone (i) can most probably be due to the non-production of Neogloboquadrina dutertrei and Globigerinoides ruber in the top water layers owing to a higher salinity zone probably created by the current patterns. The counter currents of low salinity are probably responsible for the Bathysiphon filiformis dominant zone, (ii) The path of the low salinity under water currents is probably marked by the no- Bathysiphon filiformis, low-Globorotalia (Menardella) menardii zone.
Petrography and Chemistry of Basalts from the Carlsberg Ridge
Authors: Banerjee R. , Iyer S. D. 
Published: November 2024

Abstract
The petrography of the basalts collected in dredge hauls from the Carlsberg Ridge (3° 37' N and 64° 07' E) show systematic variations in their textural and mineralogical assemblages, from an outennost vitreous glassy to a holocrystalline interior through a variolitic zone. The silica-alkalies relation show these basalts to be of sub-alkaline nature. Variable normative compositions and Mg number, increase in alkali index, differences in Al2O3/CaO and FeO*/MgO ratios, variable trace element concentrations, together with variable relations of P2O5 TiO2 , Ni and Cr with MgO indicate a process of fractional crystallisation of a primary magma. Chemically and mineralogically these rocks have a closer affinity to those of the other parts of the Mid-Indian Ocean Ridge.
Core Journals in Earth Science - A Comparative Study
Authors: Parvathamma N. , Gunjal S. R. , Nijagunappa R. 
Published: November 2024

Abstract
A ranking list of 26 journals most frequently cited by Indian earth Scientists during 1983-88 has been drawn using the absolute number of citations received by each journal in the baseline journal, 'Journal of the Geological Society of India'. Comparison of the present ranking list of the core journals with other national ranking lists prepared from the utility point of view of Indian earth scientists shows that the 'Journal of the Geological Society of India' occupies the first place in all the lists indicating the national bias in citing references. Further, the five journals, namely, (i) Nature, (ii) Geological Society of America Bulletin, (iii) journal of Sedimentary Petrology, (iv) American Journal of Science, and (v) Journal of Geophysical Research, appear in all the national and international core lists under study. These five journals are considered as the 'Prime Core Journals' in the discipline of earth science.
Geochemistry and Petrology of the Cumulophyric Layered Suite of Rocks from the Toa Pluton of the Mundwara Alkali Igneous Complex, Rajasthan
Authors: Subrahmanyam N. P. , Leelanandam C. 
Published: November 2024

Abstract
The Toa layered suite ranges from feldspalhic peridotites to gabbros and gabbroic anorthosites. This suite differs from the Mer and MusaIa plutons in having coarse-grained cumulophyric rocks (with ubiquitous olivine) and scanty feldspathoidal dikes.
Observed features are traceable to the high H2O content and high H2O/CO2 ratio of the parental liquid. High H2O content has reduced the viscosity of the magma by many orders of magnitude and facilitated rapid crystallization and settling of crystals leading to the formation of coarse-grained cumulophyric suite of rocks. With its selective reactivity to Si-O-Si bridges, H2O has depressed the activities of the saturated components (ab, or and qz) in the magma and led to the crystallization of considerable amounts of olivine from the silica-undersaturated components and consequently of feldspars (instead of feldspathoids). The depression of the liquidus of albite has facilitated the crystallization of more calcic feldspars leading to the formation of gabbroic anorthosites. A model of pulsed emplacement of magma is proposed to account (1) for the differing H2O and CO2 contents of the parental liquids of the Musala, Mer and Toa plutons, and (2) for the three different trends of differentiation in the three plutons which gave rise to an amazing variety of rock types in the Mundwara Complex.
The Stratigraphy and Structure of the Dharwar Supergroup Adjacent to the Honnali Dome: Implications for Late Archaean Basin Development and Regional Structure in the Western Part of Karnataka
Authors: Chadwick B. , Vasudev V. N. , Krishna Rao B. , Hegde G. V. 
Published: November 2024

Abstract
The Dharwar sedimentary and volcanic rocks adjacent to their basement granodiorites and gneisses in the Honnali dome can be interpreted in terms of three principal lithostratigraphic units. Each unit represents a distinct stage of basin development. The lowest unit is formed by the mainly shallow marine metabasite-orthoquartzite association of the Bababudan Group. It marks an early extensional phase of basin development. The group in the Honnali area has been subdivided into the Kudrekonda and Kalva Rangan Durga Formations. The second unit comprises mainly shallow marine sedimentary rocks, including polymict conglomerates and limestones, with intercalations of basic to acid volcanic rocks. The lithological association indicates unstable depositional and volcanic conditions with variable uplift and subsidence during the second stage of basin development. The unit is equivalent to the lower part of the Chitradurga Group and it has heen subdivided into the Musinhal, Adrihalli, Aleshpur, Medur and Daginkatte Formations. The acid volcanic rocks forming the Daginkatte Formation were formerly regarded as rhyolitic flows, but they are reinterpreted as ash flow deposits on the grounds of their textures. The third unit corresponds to the upper part of the Chitradurga Group. It begins with the thin, but persistent Basavapatna Formation of banded ferruginous cherts and interbedded carbonaceous phyllites. This formation is overlain by the re-defined Ranibennur Formation of greywackes and local volcanic intercalations. Whilst a marine setting with initial widespread quiescent conditions is indicated by the third unit, its significance is uncertain because of the lack of data from the large, but poorly exposed tract of greywackes.
The Dharwar rocks are dominated by ductile structures in the form of south or southwesterly verging inclined folds with superimposed, steep north-trending folds. In contrast, the basement rocks in the Honnali dome deformed cataclastically on myriad fractures and retrograde shear zones. The dome has a faulted southern boundary, whilst a steepened unconfonnity forms the remaining parts of the boundary. The contrasting structures in the cover and the basement may be modelled in terms of crustal shortening propagating from the north ornortheast on listric faults dipping northeast through the basement into a deep detachment. Later strike-slip displacements on steep NS faults and shear zones modified the south-verging structures. Alternatively, the structure may be interpreted in terms of jostling of basement blocks within a zone of transpression related to sub-horizontal displacements on NS faults and shear zones.
Microfossils from the Non-Stromatolitic Middle Proterozoic Vindhyan Chert, Chitrakut Area, Uttar Pradesh
Authors: Kumar S. , Srivastava Purnima 
Published: November 2024

Abstract
The black bedded-chert at the base of the Lower Vindhyan succession in Chitrakut area, exposed at the southern face of Sangrampur Hill shows good preservation of microorganisms in the petrographic thin sections. The chert is not associated with stromatolites. Unusually large coccoid Trachysphaeridium sp. Timofeev and filamentous forms showing branching are recorded.