bluuebunny/crossref_metadata_2025_split huggingface dataset:
Step-Like Delta from Talchir Rocks Around Village Simlipal, Orissa
Authors: Sen D. P. , Pradhan S. N. 
Published: November 2024

Abstract
Within the Talchir Group of rocks of the Talchir Gondwana basin occurs a step-like delta around village Simlipal. The older of the two delta sequences is characterised by interference of topset and foreset beds, sleep foreset slope (10° - 26°) and imperceptible delta slope break. Irregular shifting of lake level during the growth of the older delta, possibly controlled by weather variation from abnormally high temperature condition to cold, cloudy and dry conditions resulted in the formation of step-like delta. Delta front collapsed due to decay of stagnant buried ice which formed part of the basement over which delta grew and gave rise to small scale fold, fault and stump features. Younger delta with a prominent well developed foreset forming a Gilbert type delta developed over the older delta under a stable lake level condition. Two delta sequences together fanned the complete sequence of step-like delta.
Geochemistry and Petrogenesis of Lamprophyres and Associated Dykes from Elchuru, Andhra Pradesh, India
Authors: Madhavan V. , Mallikharjuna Rao J. , Balaram V. , Kumar Ramesh 
Published: November 2024

Abstract
Late stage intrusives, dominantly represented by lamprophyres, form a dyke swann in the Elchuru alkaline pluton of Andhra Pradesh; the other dykes of the swann which are non-lamprophyric include microshonkinite, nepheline syenite porphyry, basanite and olivine dolerite. The Elchuru lamprophyres and their plutonic equivalents, shonkinite and foidolite, consist of clinopyroxene, biotite. alkali feldspar and nepheline. Due to variation in the amount of nepheline, these lamprophyres, cover a wide range of rock types like minette, sannaite and tjosite. A plagioclase- bearing lamprophyre, camptonite, is also present though not abundantly.
The hallmark of the Elchuru lamprophyres is their transitional geochemical character-ranging between alkaline lamprophyres(AL) and calc-alkaline lamprophyres (CAL). From the present study it is surmised that these lamprophyres have crystallised from an LILE and LREE enriched, hydrous basic alkaline (mildly potassic) magma of a deep-seated (mantle?) origin. A petrogenetic scheme is presented covering the evolution of various rock units of the Elchuru alkaline pluton in general and the late stage intrusives (lamprophyres and other associated dykes) in particular.
Pebble Count (Modal) Analysis of Four Outcrops of the Upper Siwalik Conglomerates of the Jammu Region, Northwest India and their Textural Implications
Authors: Mohan Chander , Gundu Rao C. 
Published: November 2024

Abstract
The pebble count data from the four outcrops of the Upper Siwalik Conglomerates of the Jammu region, northwest India are compared with the results expected from appropriate theoretical models of constant probability of occurrence from point to point. The resulting degree of fit is applied to characterise the textural arrangement of each constituent.
The experiment shows that within an outcrop for Jarger pebble counts the Positive Binomial and for lower counts Poisson are the appropriate theoretical models. For the combined data over the four outcrops, the proper models are Lexian and Lexian Poisson. This would suggest at anyone outcrop, 5, 10, or 100 pebble counts obtained from anywhere in the outcrop would yield unbiased sample estimate of the outcrop population parameter. Over many outcrops, however, the results are inconsistent. Combined distributions for the four outcrops indicate heterogeneity in the distribution of the variates. Therefore, it is suggested that no one outcrop or one sample from an outcrop represents the entire target population (Upper Siwalik Conglomerates of the Jammu region). The population has to be sampled regionally over several outcrops preferably over an orthogonal grid spread over the target population. The results also suggest that at anyone outcrop the process responsible for the deposition of the conglomerates is uniform but has varied from place to place thus suggesting more than one episode in the deposition of the conglomerates. One has to explain this multi-episodic deposition by a sedimentation model that would explain adequately the quantitative variability present in the data.
Multivariate Statistical Analyses of Polyphase Igneous Rocks of the Malani Igneous Province with Special Reference to Sarno - Dandali Area, Western Rajasthan
Authors: Chandrasekaran V. , Srivastava R. k. 
Published: November 2024

Abstract
Applying multivariate Linear Regression and Principal Component analyses, the petrogenetic aspects of the polyphase igneous rocks of the Malani Igneous Province, Western Rajasthan were dealt with and inferences arrived. The various rocks of the province belong to different magmatic activities unrelated to each other. Normal and peralkaline rhyolites of the province are not co-genetic. Siwana and Jalor granites are distinct and generated at different stages. The acid dykes represent the end phases of the Jalor granite activity, crystallising from the same melt. Fractional crystallisation has played a major role in the development of the mildly alkaline and hyperalkaline rock series. Pyroxene, iron oxide minerals, feldspathoid and alkali feldspar play a major role in the development of the alkaline rocks, whereas pyroxene, iron oxide minerals and plagioclase playa dominant role in the development of the mildly alkaline rocks. The rocks of different groups fall on different liquid lines of descent in the Latent vector variation diagrams.
A Reinterpretation of the So-Called Compressed Fold Zone of Western Manipur Hills
Authors: Husain R. , Sengupta A , Pratap V. 
Published: November 2024

Abstract
The area between the Jiri and Makru rivers in the Western Manipur hills. designated as the compressed fold zone by the geologists of the Assam Oil Company, remained inexplicable in the context of its relationship with the regional geological set-up. This prompted the authors to undertake detailed geological investigations in the area. The studies revealed that the compressed folds are illusory and the associated dip reversals are attributable to overturning of strata due to surface creep in both flanks of a single structure Kharkhublen Anticline.
Trace Fossils in Cores of Kopili, Barail and Tipam Sediments of Upper Assam Shelf
Authors: Reddy A. N. , Nayak K. K. , Gogoi Daijee , Satyanarayana K. 
Published: November 2024

Abstract
A survey of trace fossi1s in cores of Kopili. Barail and Tipam (TS-5 member) sequences from Upper Assam Shelf reveals that the burrow types occurring in the sediments, produced by suspension and deposit feeding animals, includes Skolithos, Thalassinoides, Planolites and ?Muensteria. These ichnogenera indicate Skolithos ichnofacies and suggest that cores of Kopili and Barail sequences represent deposits of moderate to high energy marine conditions.
Deep-Sea Benthic Foraminiferal Changes and Terminal Miocene Event at Tropical Indian Ocean DSDP Site 214
Authors: Gupta Anil K. , Srinivasan M. S. 
Published: November 2024

Abstract
Quantitative data of Late Miocene deep-sea benthic foraminifera from the tropical Indian Ocean DSDP Site 214 have been combined with oxygen and carbon isotope values to understand the history of deep thermohaline circutation in the Indian Ocean. The important faunal changes include a significant increase in Uvigerina proboscidea percentages at c. 8.S to 7.5 Ma and during 6.2 to 5.2 Mat reaching their maximum values at the Miocene/Pliocene boundary. The increase in U. proboscidea percentages are accompanied by decreasing abundances of Bulimina alazanensis. Obicides kullenbergi, and C. wuellerstorfi. and lower values of H (S) and E'. The d 180 values are, in general, higher during these intervals While d13C values show a decreasing trend. The interval between 7.5 and 6.2 Ma is marked by a major increase in B. alazanensis which coincides with slightly higher dl3C and lower d180 values. C. kullenbergi and C. wuellerstorfi. interestingly, reveal significant variations with higher values before Chroo - 6 Carbon Shift at about 6.2 Ma and a prominent peak immediately preceding the shift, but remain low and less variable following the shift during the remainder of the Late Miocene as do the d 13C va1ues. The well-known Late Miocene Chron - 6 negative carbon shift is marked by significantly higber U. proboscidea percentages, and lower C. ku/lenbergi, C. wuellerstorfi and B. alazanensis values. Out data support the hypothesis that the shift was caused by excess organic carbon input to the system. and higher rate of upwelling and ocean productivity. The Miocene/ Pliocene boundary marks a warming event and is typified by highest percentages of U. proboscidea and Osanguiaria culter, lighter d180 and lighterd13C values, and lowest values of H(S) and E'. The sediment accumulation rates were remarkably higher at the Miocene/Pliocene boundary. These events reflect high rates of surface productivity intensified by strong upwelling.
Geochemistry and Genesis of Banded Iron Formation from Kudremukh Schist Belt, Karnataka Nucleus, India
Authors: Khan R. M. k. , Govil P. K. , Naqvi S. M. 
Published: November 2024

Abstract
The Banded Iron Fonnation is interbedded with 2.9 Ga old mafic and acid volcanics. It mainly consists of magnetite and quartz; calcite is also present in some mesobands. Thin silicate rich layers with abundant actinolite, cummingtonite, grunerite, biotite, riebeckite and aegirine occur between the quartz and magnetite rich rhythmites. Mixed oxide. silicate and carbonate facies (MOSCF) BIFs are found which arc prcmctamorphic cherty and shaly types. The distribution of Al2O3 , CaO, MgO, K2O, Na2O, Ni, Cr, Co, Rb, Sr, Zr, Cr/MgO and REEs indicate a combination of hydrothenna1, volcanogenic and continental sources. The relationship between Cr/Zr, Zr/Cr+Co+Ni, ZeN and Nd/Yb reflect that certain fine silicate-rich bands between the microbands arc made up of volcanic ash, whereas others are made up of shales of continental source or a mixture of both. LA enrichment, depletion in total REE, positive Eu anomalies, Nd/Yb, La/Lu and LREE/HREE ratios in Fe-rhythmites indicate that Fe, Si and REEs of the BIF were supplied by hydrothennal and fumarolic activity accompanying submarine volcanism. The enrichment in total REE and obliteration of La signature is probably a consequence of mixing of non-chemogenic component and ambient sea water with the chemical precipitates. Absence of negative Ce anomalies is consistent with most of the Archaean BIFs of other localities. Deposition of BIF appears to have taken place below wave base and photic zone of the shallow shelf region. It is inferred that oxygen was generated at some other place in the basin. Ocean circulation and upwelling brought FeO and 02 together resulting in precipitation of iron along with fine grained argillites.
The Volcano-Sedimentary Association of the Precambrian Hindoli Supracrustals in Southeast Rajasthan
Authors: Bose Utpal , Sharma A. K. 
Published: November 2024

Abstract
An arcuate belt of Precambrian vo1cano-sedimentaries, designated as the Hindoli Group, is sandwiched between the cratonic Archaean Banded Gneissic Complex terrain and the platformal Vindhyan sediments. Turbidites of mainly quartz wacke and petites with interlayered lava flows and tuffs of basalt, basaltic andesite and daciterhyodacite composition constitute the bulk of the Hindoli vo1cano~sedimentaries. These are interpreted to have been deposited in a continent-marginal basin with active participation of an arc system. Toward the end of the basin evolutioo; the continent-margin acted passively when quartzarenite and carbonates were deposited in a stable shelf regime.
Nature of Fluid Inclusions in the Antimony Mineralisation Near Barashigri Glacier, Lahul and Spiti, Himachal Pradesh
Authors: Nayak B. K. , Paul S. K. 
Published: November 2024

Abstract
Antimony mineralisation occurs in the form of Sb-Pb-Zn and Sb sulphide veins in the fractures of the granites present close to the Tethyan Thrust near Barashigri glacier of Himachal Pradesh. SimiJar strike and dip patterns of the Tethyan Thrust and the mineralised fractures indicate that the mineralisation may be either syn- or post-thrusting event. Two types of primary inclusions observed in the quartz intimately associated with the sulphides are, (i) liquid + vapour (15-40% by volume) and (ii) liquid + vapour + dark crystal, the latter being found only in Sb-Pb-Zn veins. Heating and freezing studies of the inclusions reveal that the mineralising fluid was epithermal in nature having low salinity and the final deposition of the sulphides was through a simple cooling phenomenon.
Primary Sedimentary Structures in Banded Ferruginous Quartzite of Sandur Schist Belt, Karnataka
Authors: Matini Abdul , Mukhopadhyay Dhruba 
Published: November 2024

Abstract
Banded ferruginous quartzite (BFQ) in the Sandur Schist Belt belongs to the Archaean Dharwar Supergroup of Karnataka and contains primary depositional and diagenetic features. These include banding of different types, ripple marks. syneresis cracks, scour-and-fill structures, globular and nodular structures and penecontemporaneous faults. The significance of these structures in terms of the environment of deposition of BFQ has been considered. The BFQ was deposited as chemical precipitates and passed through a hydroplastic stage of lithification. Shallow water environment of dcposition in a more or less quiet condition with intermittent local disturbances has been envisaged.
Ground Water Geochemistry of Recent Weathering at Panchpatmali Bauxite-Bearing Plateau, Koraput District, Orissa
Authors: Som S. K. , Bhattacharya A. K. 
Published: November 2024

Abstract
Recent weathering of Panchpatmali bauxite-bearing terrain, Koraput district, Orissa has been discussed in terms of groundwater geochemistry. pH and Eh are in favour of Fe (OHh development, whereas Na+ : Ca2+ vs. HCO3 : SiO2, HCO3 : SiO2 vs. ppm HCO) and pH -pNa, 2pH -pCa, pK-pH vs. -log [H4 Si04] are all in favour of kaolinite development with a minor amount of gibbsite. These observations have been confirmed by X.R.D., I.R., and S.E.M. of the recent weathered samples of the area. The condition of development of these mineral phases with respect to C02 has also been discussed.
Factors Affecting Optimum Development of Groundwaters in Crystalline Terrain of the Eastern Ghats, Visakhapatnam Area, Andbra Pradesh, India
Authors: Subba Rao N. 
Published: November 2024

Abstract
Hydrogeological conditions in crystalline terrain of Visakhapatnam area of . the Eastern Ghats suggest that topography and fracturing are the predominant factors controlling well yields. This is supported by statistical analysis also. Incremental well yields for the wells are found to decrease with depth. Further. large diameter of the wens do not necessarily increase yielding capacity of wells. For groundwater development in the area. optimum depth and diameter of the wells are therefore recommended to be 25 -45 m and 10 cm respectively to reduce the capatilisation on them.
On the Occurrence of Planolites Nicholson from the Bbaduka Limestone of the Wadhwan Formation (Cretaceous), Kathiawar, Gujarat
Authors: Borkar V. D. , kulkarni K. G. 
Published: November 2024

Abstract
Planolites beverleyensis (Billings) Pemberton and Frey is being reported from the Bhaduka Limestone. Wadhwan Formation (Cretaceous) of Kathiawar, Gujarat, wherefrom only one trace fossil. viz., Feddenichnus feddeni Chiplonkar and Borkar was reported. Bryozoa from the Bhaduka Limestone ascribe a palaeoenvironment suitable to suspension feeders. However. Planolites along with Feddenichnus suggests palaeoenvironment congenial to infaunal deposit feeders.
Clay Mineralogy of the Carbonate Rocks of the Shali Series (Lower-Upper Proterozoic) of Larji and Shali Windons, Lesser Himalaya
Authors: Gundu Rao C. 
Published: November 2024

Abstract
XRD Study of carbonate and shale samples of Larji and Alsindi sections of the Shali Series (Lower-Upper Proterozoic) of Lesser Himalaya, has revealed that they essentially contain illite, degraded illite, kaolinite, random mixed layers of illite+montmorillonite and traces of vermiculite. The clay minerals in the Shali carbonates mostly appear to be detrital in origin. Corrensite and to some extent montmorillonite seem to suggest hypersaline conditions of carbonate deposition. Kaolinite suggests nearness to the then shoreline of the basin of deposition and illite is environmentally insensitive.
Evolution of Regional Transmissivity Pattern in Adila Basin : A Nested Squares Finite Difference Model
Authors: Narayanpethkar A. B. , Gurunadha Rao V. V. S. , Mallick K. 
Published: November 2024

Abstract
Aquifer parameters have been estimated through pump tests conducted on large diameter wells at 40 locations well distributed in the basin. The pre- and post-monsoon groundwater levels during 1988 and 1989 have been measured at 40 observation wells. (1) Total groundwater input of 23.8 MCM to aquifer system consists of 23.2 MCM of recharge due to rainfall and 0.6 MCM of seepage from canal network. (2) Total output stresses include groundwater draft of 14.6 MCM from about 1300 open wells and borewells, and groundwater effluence of 9.2 MCM to the Adila stream. (3) The regional transmissivity (T) values in the basin range from 10 to 235 m2/day.
Morphology of a Coral Bank, Western Continental Shelf of India : A Multibeam Study
Authors: Rao P. S. , Kodagali V. N. , Ramprasad T. , Nair R. R. 
Published: November 2024

Abstract
Morphology of a living coral bank (Gaveshani Bank) is described using multibeam swath bathyrnetric survey system Hydrosweep. The bank has a height of 42 m, length of 2 km and a maximum width of 1.66 km, with steep flanks and flat top. It has a north-souh orientation and occupies an arca of about 3 sq km. A 100% coverage obtaincd in the present study enables us to determine the exact morphology of the bank. A comparison with the single beam echosounding data reveals that the dimensions (length and breadth) and areal extension of the bank are much larger than previously known.
The Karimnagar Granulite Terrane-A New Sapphirine Bearing Granulite Province, South India
Authors: Rajesham T. , Bhaskar Rao Y. J. , Murti K. S. 
Published: November 2024

Abstract
A new terrane of granulite facies rocks-the Karimnagar granulite terrane (KGT) is identified. The KGT is ~ 150 km x 20 km extending along NW-SE in the Karimnagar, Warangal and Khammam districts of Andhra Pradesh along the southern flank of the Godavari graben which separates the Dharwar and Bastar Cratons. The KGT is interesting because of its location far outside the known charnockitic region of south India. The important rock types in the KGT include : hypersthene granite (charnockite), two pyroxene granulite, calc-granulite and sapphirine bearing pelitic rocks. The association of sapphirine with orthopyroxene and cordierite in the pelitic rocks indicates metamorphism at pressures of ~ 7 Kbar and temperatures of ~ 750°C.
It is suggested that the KGT is a remnant of an Archaean supracrustal-granite association which underwent granulite grade metamorphism at ~ 2.5 Ga ago. This ancient orogenic belt appears to have been exhumed during the early Proterozoic.
Petrography and Geochemistry of Jungel Metavolcanics, Bijawar Greenstone Belt, Central India : A Picritic Basalt Low K-Andesite Association
Authors: Kumar Vinod 
Published: November 2024

Abstract
Jungel valley is known to have dominant magmatic rocks of basaltic affinity evolved on ancient oceanic crust. It consists of alkali picritic basalt (APB) - alkali olivine basalt (AOB) - low potassic andedsite (LKA) association besides those earlier reported lava flows, tuffs, agglomerates and lamprophyres. These rocks were emplaced along numerous fractures in the earth's crust caused by N-S compressional forces at the time of Satpura orogeny in a rifted back are tectonic setting.
Chemically the APB and AOBs are characterized by high MgO, mg values, CaO, TiO2 and P2O5 contents and depleted in SiO2, Al2O3 and K2O The APB is considered to be parental/primitive magma formed by varying degree of melting of garnet peridotite from the mantle. This source, however, was heterogeneous in respect of K, P and Rb contents similar to Sunda-Banda arc. The geochemical evolution of these rocks is shown to have analogy with some modem island arcs eg. Dunedian and Sunda-Banda arcs. Major elements, SiO2, Al2O3, Na2O, K2O, TiO2 and FeO1 show increase with increasing differentiation from APB to LKA while CaO and MgO have inverse relationship.
The basalts are enriched in both transitional and incompatible elements, whereas, andesite is depleted in these. Cu has followed silicate phase, while Pb and Zn have remained in residual liquids as in Dunedian arc rocks.
Bathymetric Study of the Neotectonic Naini Lake in Outer Kumaun Himalaya
Authors: Hashimi N. H. , Pathak M. C. , Jauhari P. , Nair R. R. , Sharma A. K. , Bhakuni S. S. , Bisht M. K. S. , Valdiya K. S. 
Published: November 2024

Abstract
The Naini lake is a product of rotational movernent on a NW-SE trending Nainital Fault, quite after the establishment of the drainage of a mature stream named Balia Nala. Detailed bathymetric study, permits division of this crescent-shaped lake into two subbasins separated by an approximately 100 m wide transverse underwater ridge, 7m to 20m below the lake surface. The southeastern and northwestern parts, 11 to 25 m and 4 to 27 m deep, respectively, are filled with unconsolidated sediments, 15 m thick on an average. The semiconsolidated sedimentary layers locally exhibit slumping an slopes and deformation in channel beds. These features together with thetransverse Central Ridge, the deep channel cutting through it, the small scarps and terraces or step-like features on the slopes of the narrow V-shaped undemater valley in the southeastern part and its thick filling in parts due to blockade resulting presumably from fault movements, and the existence of deformed and displaced acoustic reflectors are interpreted as indicating quite recent movements along the Nainital Fault. Hitherto unidentified pinnacle-like objects penetrating through or perched atop sediments, are suggestive of either tectonic displacement and squeezing or of the hazard of mass movements which have occurred. A number of small but rapidly growing deltas along shores indicate accelerated pace of sediment input, resulting from quickened erosion in the catchment area.
Evolution of Southern Part of Indian East Coast Basins
Authors: Prabhakar K. N. , Zutshi P. L. 
Published: November 2024

Abstract
Regional study of subsurface data of sedimentary basins on the East coast of India to the south of 18° North latitude has led to an appreciation of tectonic styles and sedimentation histories of Krishna-Godavari, Pennar Palar, and Cauvery basins. Tectonics and evolutionary history is understood through three distinct episodes of evolution viz. 'lnterier Fracture', 'Pull Apart' and 'Shelf Sag/Tilt'. These episodes being a part of structural development of passive margins are complicated by phase overlap and shear tcetonics associated with differential movements during the long flight of the Indian sub-plate. The block movements along the major planes of weakness has generated different sub-basins separated by ridges both in Krishna-Godavari and Cauvery basins.
These sedimentary basins have 3-8 kms, of sediments. Punctuated with major unconformities they range in age from Proterozoic to Recent. In the outcrops present on the western margin of the basins the stratigraphic record is less complete when compared with subsurface stratigraphic succession. The presence of subsurface Gondwana sediments has been confirmed into Krishna-Godavari basin. The metasediments present above basement both in Krishna-Godavariand the Pennar basins are suggested to be equivalents of Pakhals/Cuddapahs.