bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of Beach Sand Ilmenite from Manavalakurichi, Tamil Nadu, India
Authors: Subrahmanyam N. P. , Rao N. K. , Narasimhan D. , Rao G. V. U. , Jaggi N. K. , Rao K. R. P. M. 
Published: November 2024

Abstract
The study shows that the alteration of ilmenite has taken place according to the two stage model proposed by Grey and Reid (1975). Identification of the intermediate altered compound, pseudorutile, was found difficult in earlier studies by optical and X-ray diffraction methods, because of the occurrence of this phase in altered ilmenite in very fine grain size (30 Å), its poor crystallinity and coincidence of many of the diffraction lines with those of other phases. The present study has shown that the Mossbauer technique is more suitable in the identification and estimation of this phase.
The relative amount of pseudorutile increases progressively in the magnetic fractions in the following order: 0.30 - 0.35 amps (5%), 0.25 - 0.30 amps (40%), 0-0.25 amps (75%) and 0.35 - 0.50amps (95%), indicating that the magnetic susceptibility of the grains is increasing initially with progressive pseudorutile formation, and decreasing in the later stages of alteration. Reflectivity and hardness are also increasing up to the stage of pseudorutile formation and decreasing in the later stages.
Radiometric Geochronology of the Himalaya
Authors: Saini Hari S. 
Published: November 2024

Abstract
The radiometric age data obtained by different dating methods have been interpreted in terms of possible orogenic activities prevailing in the Himalaya. In general, the age data confirm four main events, the Precambrian, the Late Precambrian-Cambrian Assyntian (Caledonian), the Late Palaeozoic-Hercynian and the Late Cretaceous-Tertiary Himalayan Orogeny. The mineral dates are particularly significant in delineating different phases of the last i.e. the Himalayan orogeny which indicates main activity of the young Himalayan metamorphism around 70 to 50 Ma and followed by a momentous phase of major uplift during 25 to 10 Ma, which was responsible for the rise of the deeper part of the Himalaya into great folds and thrust slices and the formation of nappe structures.
Petrology of a Scapolite-Bearing Rock From Karera, District Bhilwara, Rajasthan
Authors: Sharma Ram S. 
Published: November 2024

Abstract
The scapolite-garnet-epidote-hornblende-pyroxene-calcite ± plagioclase rock of the Aravalli Group (Early Precambrian) is found as thin bands within the high-grade paragneisses of the underlying Banded Gneissic Complex around Karera in northwest peninsular India. The mineralogy and chemical composition of the rock imply that it is derived from impure calcareous sediments. Significant amounts of chlorine are present in both scapolite and hornblende. In epidote and garnet ferric iron is an important component and its presence together with hematite indicates high fo2 during recrystallization of the rock. The partitioning data of Na/(Na+Ca) between scapolite (Me71.3) and the coexisting plagioclase (An85-90) and its reference to the experimentally based diagram yield recrystallization temperature of 650°-700° C, conforming to those computed from other mineral equilibria of the enclosing paragneisses. The scapolite is considered to develop as a result of extreme diminution of PH20, presumably by incoming of chlorine from an evaporite component.
Sivaganga Formation, its Sedimentology, Micropalaeontology and Sedimentation History
Authors: Banerji Ranjit K. 
Published: November 2024

Abstract
The textural study of the sand grains of Sivaganga Formation indicates that sedimentation commenced in a fluvial environment passing through the lacustrine-marsh conditions and ending with the influence of tidal estuary. The clayey sediments in the upper part have yielded an arenaceous foraminiferal assemblage having a low dominance and diversity value belonging to the Neocomian-Aptian (Early Cretaceous) age. The sedimentary basin was formed as a result of downwarping of the crystalline basement along the prominent Eastern Ghat trend during Late Jurassic and Early Cretaceous. The basin established its fragmentary connections with the open sea situated at some distance towards the east and southeast.
Living and Dead Foraminiferida in the Araniar River Estuary, Chingleput District, Tamil Nadu State
Authors: Reddy A. N. , Reddy K. R. , Jagadiswara Rao R. 
Published: November 2024

Abstract
The living and dead foraminiferida in the substrate samples collected from 14 Stations in the Araniar River estuary along the east coast of India from June 1978 to May 1979 have been studied quantitatively. The average salinity ranges from 23.5 to 38.5% and it is considered to be the principal controlling ecologic factor that limits the distribution and abundance of foraminiferida. The pattern of distribution of foraminiferida is also explained in terms of deposition of fluviatile sediments in the estuary. The abundance and living/dead ratios of foraminiferida tests have been compared with those recorded in the nearby Dugarazupatnam and Pennar estuaries.
Compaction in Limestones: A Reappraisal
Authors: Chanda S. K. , Bhattacharyya Ajit , Sarkar Soumen 
Published: November 2024

Abstract
An important outcome of recent research on carbonate diagenesis has been the increasing realization that compaction may be as important as cementation in the lithification of carbonate sediments. Absence of compaction-deformation features should no longer be relied upon as unique evidence against compaction in limestones. The paucity of such features arises from the fact that the load-bearing capacity of allochems (grains) is hardly exceeded in the normal course of lithification of carbonate sediments. Their load-bearing capacity seems to have been exceeded only in the presence of rigid bodies (nodules) or surfaces (hardgrounds or ernersion surfaces). Wherever this prerequisite is met, compaction-deformation may be set into motion in the adjacent sediments, irrespective of their environments of deposition.
So far as the mud-supported carbonate sediments are concerned, they may undergo autolithification entirely through solution-reprecipitation without the benefit of subaerial exposure. In the case of grain-supported carbonates too, there are indications that an appreciable amount of their cement may be derived from elsewhere in adjacent rocks undergoing deeper burial diagenesis within the same basin. While burial diagenesis seems normal, subaerial diagenesis is exceptional for carbonate sediments, other than those of the nearshore areas.
Evolution of Pre-Siwalik Tertiary Basin of Himachal Himalaya
Authors: Srivastava V. K. , Casshyap S. M. 
Published: November 2024

Abstract
The Subathu, Dagshai and Kasauli rocks of Himachal sub Himalaya have been classically interpreted as of marine brackish or lagoonal origin. In this study, the pre-Siwalik Tertiary rocks of southern Himachal Pradesh are grouped into five distinct lithofacies, which collectively represent a consanguineous association of sediments deposited in related geomorphic environments: 1. Fossiliferous green shale, locally red, with lenses of limestone interpreted as tidally influenced shelf deposits; 2. Clean white sandstone interpreted as coastal barrier bars; 3. Red mudstone locally green, and lenses of grey sandstone with channel lag interpreted as lagoonal and tidal flat deposits; 4. Grey sandstone with channel lag and red mudstone and siltstone inferred to have accumulated in distributary channel and inter-distributary plains of fluvio-delta complex; 5. Grey, white sandstone and mudstone interpreted as a mixed assemblage of fluvio-delta and coastal barrier facies.
Two systems of currents operated during the deposition of these rocks: one, across the delta plain complex was directed towards south and southwest following the prevailing regional paleoslope; and the other representing longshore currents in adjacent coastal areas operating parallel to shoreline, was directed towards west-northwest.
Distribution of Alkali and Alkaline Earth Elements in Bauxites-Laterites of Paduvari Plateau (South Kanara District, Karnataka State)
Authors: Devaraju T. C. , Khanadali S. D. 
Published: November 2024

Abstract
Analysis of 34 bauxite-laterite and 11 precursor granitic gneiss samples, from Paduvari plateau, fer alkali and alkaline earth elements has revealed: (1) the strong depletion of laterites/bauxites in Ca, Na, K, Sr, Li and Rb, with a reduction in Ca by 124 times, Na and K by 55 times, Sr by 38 times, Li and Rb by 7½-8 times, (2) low mobility of Mg and Be to result in a depletion of only 2½ times, (3) the lack of significant or systematic variation in the content of these elements in the laterite-bauxite profile and (4) the retention of Na: K and Li : Rb ratios of the precursor gneiss in the laterite/ bauxite. The study substantiates the general observation that alkali and alkaline earth elements with their low ionic potential (except Be) are thoroughly leached during lateritization.
Superposed Deformation in Delhi Rocks near Patan, Sikar District, Rajasthan
Authors: Ray J. N. 
Published: November 2024

Abstract
The Delhi Supergroup of rocks exposed around Patan (27°48'N, 75°58'E), Sikar district, Rajasthan, was subjected to three successive phases of deformation. First phase folds have variably oriented axial planes with moderate to steep plunge towards ssw while second phase folds have, in general, N-S to NNE-SSW trending sub-vertical axial planes and steep south-southwesterly plunging fold axes. Most of the major folds and associated flexures of the area were produced during this phase of folding. The first and second phase folds are generally co-axial. Expression of last phase of folding is mild and extremely localised.
Trace Fossils from the Ordo-Silurian Rocks of Kinnaur, Himachal Himalaya
Authors: Bhargava O. N. , Bassi U. K. , Chopra Suresh 
Published: November 2024

Abstract
Ichnofossils Teichichnus, Phycodes aff. palmatum, Planolites, Ichnogenus indet. A and B, and Phycodes circinatum, P. aff. palmatum, Skolithos, Rouaultia and Planolites are being reported respectively from the basal and middle parts of the Yamrang La Formation of Ordovician age. Arthrophycus, Chondrites, Planolites, Rusophycus, Skolithos and Ichnogenus indet, C occur in the basal part of the Manchap Formation of silurian age. Phycodes circinatum Magdefrau 1934 mainly know from Lower Ordovician probably represents an Upper Ordovician age in this area.
2900 M. Y. Old Stromatolite from Sandur Greenstone Belt of Karnataka Craton, India
Authors: Murthy P. S. N. , Krishna Reddy K. 
Published: November 2024

Abstract
Confirmed stromatolites from a limestone band from Sandur greenstone belt of Karnataka Craton are reported for the first time. The stromatolites are oval to elliptical in shape in gently dipping bedding plane and conical in cross section. Indirect radiometric age data indicates the rocks in which the structures occur are 2900 m.y. old. The discovery of stromatolites demonstrates that biological processes were operative in the early Archaean basins of the Karnataka Craton.
Petrology of the Precambrian Banded Iron Formation of Gandhamardan Hill, West of Keonjhargarh, Orissa
Authors: Pandey N. , Chatterjee B. K. 
Published: November 2024

Abstract
The Precambrian Banded Iron Formation of Gandhamardan hill, Keonjhar district, Orissa, belongs to Noamundi Group. It is restricted largely to oxide facies of Lake Superior type. The sulphide facies in association with black chert is present in small amount. It is almost unmetamorphosed and exhibits many depositional and penecontemporaneous deformation sedimentary structures. A preliminary field and petrographic examination reveals that iron formation was initially deposited at least in major part as hematite-magnetite-chert rock in a near-shore epicontinental environment partially restricted from free-circulation of sea water. Iron and silica were precipitated almost contemporaneously largely due to physico-chemical changes in sea water. The presence of siliceous stromatolitic laminations and alga-like spheroid Archaeospheroides barbertonis similar to that of Fig Tree cherts, however, suggests biogenic activity during the deposition of the Banded Iron Formation.
The Study of Dinosaurian Eggs from Infratrappean Limestone in Kheda District, Gujarat
Authors: Mohabey D. M. 
Published: November 2024

Abstract
Well-preserved dinosaurian eggs from the infratrappean limestone of Kheda district, Gujarat are described. The mode of occurrence of these eggs and their distribution pattern suggest them to be autochthonous egg clutches. The distribution of these egg clutches indicates that dinosaurs probably nested in colonies.
Ostracoda from Vestfold Hill Lake Terraces, Antarctica
Authors: Anantha Padmanabha Setty M. G. 
Published: November 2024

Abstract
Six species of ostracodes are recorded from two transects of terraces of Deep Lake, Vestfold Hills, Antarctica. Two species (Xesteleberis sp. and Bradleya dictyon) range from Cretaceous to Recent, Poseidonamicus aff. P. major ranges from Oligocene to Recent, while Krithe tunnida ranges from Pliocene to Pleistocene to Recent. Paradoxostoma antarcticum and Loxoreticulatum fallax are reported from Antarctica and range from Pleistocene to Recent. Bradleya and Krithe were typical deep water (psychrospheric) forms during Paleocene to Oligocene as today but they were found in shallow (-45 to -37 m) depths here. Ostracodes are extremely rare as compared to the associated foraminiferal assemblage. Dissolution effect, loss of ornamentation, thinning and fragmentation of the fauna are considered to be mainly due to gradational external stress, and large scale physical environmental shifts such as high salinity, low temperature and high dissolved carbon dioxide content of the Deep Lake waters. Disparity in abundance is attributed to wind erosion, differential deposition after ablation of ice from ice sheets, physiographic variation of the region and high rate of dissolution of calcareous forms including foraminifera.
Geophysical Exploration for Uranium in Suryamalai Batholith, Salem District, Tamil Nadu, India
Authors: Anantharaman K. B. , Sethuram S. 
Published: November 2024

Abstract
Abnormally radioactive granitoids are targets of uranium exploration because they can be the source for uranium deposits as well as the hosts. Significant uranium mineralization is known to occur northwest of Suryamalai granite batholith at Kullampatti situated 40 km southwest of Salem. This paper embodies the geophysical exploration for uranium, using results of magnetic and radiometric methods. The investigations revealed that uranium mineralization is structurally controlled and such structures have magnetic expression. Incidentally, correlation of anomalous content of W with U is also brought to light.
Petrology of the Area East of Daltonganj, Palamau District, Bihar
Authors: Lahiri Gopal , Das Somnath 
Published: November 2024

Abstract
The Precambrian terrain to the east and south east of Daltonganj (84°04' : 24°02'), shows considerable variation in composition and mineral assemblage within the metamorphites comprising: paragneisses with local migmatitic variants, metapelites, calcgranolites and amphibolites. There are evidences of polyphase deformation in the metamorphics. Within the metamorphics is emplaced a post-kinematic leucogranite body forming an oval outcrop in the central part of the area. The present investigation reveals a calcalkaline suite post-dating metamorphism and comprising diorite, granodiorite and tonalite. The leucogranite appears to be the culminating phase of this calcalkaline magmatism.
Contemporaneous Intrabasinal Faulting in Gondawana Basin - The Jurabaga Fault of IB River Coalfield, a Type Example
Authors: Mukhopadhyay Abhijit , Chaudhuri P. N. , Banerji A. L. 
Published: November 2024

Abstract
An example of contemporaneous intrabasinal faulting in a Gondwana basin is described. The intrabasinal Jurabaga fault of Ib River Coalfield has been identified as contemporaneous fault on parameters followed in the Gulf Coast Province of U.S.A. namely, (a) abrupt increase in thickness of strata, and (b) increase of throw with depth on the downthrown side with respect to the upthrown side of the fault. The developmental history of Jurabaga fault in space and in time is reconstructed.
Geochemistry and Petrogenesis of the Peninsular Gneisses, Dharwar Craton, India
Authors: Jayaram S. , Venkatasubramanian V. S. , Rajagopalan P. T. 
Published: November 2024

Abstract
Systematic measurement of the abundances of major, trace and rare earth elements has been carried out on a number of samples of the Peninsular gneisses. The data suggests that the Peninsular gneisses could be broadly differentiated into Western tonalitic group and an Eastern granodioritic group. The dividing line roughly corresponds to the western margin of the Chitradurga greenstone belt. The Geochemical data also suggests that bulk of the Peninsular gneisses are magmatic. Critical differences in trace and rare earth element abundances are observed between the western tonalites and the eastern granodiorites.
Crustal Evolution and Metallogeny-Evidence from the Indian Shield: A Review
Authors: Radhakrishna B. P. 
Published: November 2024

Abstract
A survey of the important metalliferous deposits of India has been attempted in the light of developing ideas about crustal evolution and metallogeny. Mantle dominated volcanic regime of the Archaean is indicated to be characterized by simple ores of gold, chromium, nickel and copper. A marked change is apparent at the end of the Archaean with the emergence of large areas of land and oxygenated atmosphere and hydrosphere. Near surface processes begin to play the dominant role. Proterozoic is thus marked by the first appearance of uranium-gold-bearing conglomerate, spectacular development of banded iron formations and sediment-hosted Pb-Zn-Cu deposits. High temperature albitization phenomena connected with younger plutons has led to concentration of beryllium, tantalum, niobium, zirconium and tin in granite pegmatites. A special type of barium-rich volcanism has given rise to a unique type of barite deposit within the Proterozoic Cuddapah Basin. Tensional tectonic regime of the Proterozoic has given place to plate tectonic regimes in the Phanerozoic, thereby enabling further recycling of crustal material and concentration of metals. The full metal potential of the Himalayan folded mountain belt is yet to be ascertained. Alluvium and palaeo-channels of major rivers, off-shore extensions of beach placers, and metals on the sea bed are promising fields where exploration effort has to be concentrated in the coming years.
Petrology of Sillimanite Gneisses from Garividi, Andhra Pradesh
Authors: Sivaprakash C. 
Published: November 2024

Abstract
Sillimanite+K feldspar+quartz±garnet±Fe-Ti oxide-beartng rocks occur associated wIth calc-silicate locks and manganese formations near Ganvidi in Vijayanagaram district of Andhra Pradesh The whole-rock chemistry shows varying rock oxidation ratios which are reflected in the mineralogical assemblages Almandine garnet is oxidized to mixtures of hematite, quartz and hydrous alummosilicates in oxidized rocks and is absent in highly oxidized rocks in the latter, ilmenite is oxidized to mixtures of rutile and hematite Such relatively high temperature alteration/oxidation effects could have occurred with the influx of water Garnet compositions, and the presence of sillimanite + K-feldspar associiation rather than muscovite+quartz, suggest minimum pressures of 6 Kb, temperatures around 700° and XH2O around 0 6 during metamorphism.
Cleavage in the Lesser Himalaya of Bhutan
Authors: Sengupta Subhasish 
Published: November 2024

Abstract
In the low grade rocks of Bhutan, a situation of multilayer anisotropy is preserved in the form of alternate argillaceous and arenaceous layers. Planar fabric parallel to the axial plane of F2 folds, varies in morphology from crenulation cleavage to slaty cleavage and one type grades into the other. The variation is controlled by the difference of the material in which the cleavage occurs and also by the position where it occurs with reference to F2 mesoscopic fold. In the short limb these are discrete laminae separating microlithons with crenulated S1 fabric (Type I). In the long limb it is a coarser slaty cleavage, defined by parallel alignment of phyllosilicate sheafs (Type II).
Mechanical rotation of grains plays an important role in producing both the cleavage types. It is suggested that deformation in the layered material starts as a crenulation process. Further, inhomogeneity is introduced in the material in the form of asymmetrical folds of competent bands. The long and short limbs of the asymmetrical buckles are differently oriented with respect to the principal axes of strain and respond differently during further deformation. In the short limb lying at small angle to the direction of compression, mechanical rotation ceases to be operative after a certain stage and chemical processes become dominant. The result is a discrete crenulation cleavage developed due to solution transfer. In the long limb lying in the zone of extension. mechanical rotation continues and produces a phyllosilicate preferred orientation defining the slaty cleavage fabric. Grain growth produces the coarsening of the fabric in this limb.
Nature of Aquifers and their Inter-Relationship in a Part of Sutlej Basin, Punjab
Authors: Jagannathan V. , Pandey D. S. 
Published: November 2024

Abstract
Results of a detailed hydrological test conducted with arrays of observation wells have been utilized in deciphering inter-relationship between aquifers in the SutIej basin. Drawdown values obtained at various distances from the pumped well are interpreted, and it is shown that the aquifers below the first clay layer are under leaky confined condition.
Banded Iron-Formation of Huliyar-Kudurekanve Area, Tumkur District, Karnataka State
Authors: Nadagouda D. B. , Hanagodimath R. S. , Devaraju T. C. 
Published: November 2024

Abstract
The banded Iron-formation, corresponding mostly to oxide facies, exposed in the south-western parts of Chitradurga belt has been studied with respect to their field, petrographic, mineralogical and petrochemical aspects. It is concluded that, these iron-formations are essentially the results of chemical precipitation of iron and silica derived from continental weathering of basic rocks under anaerobic, quiet, below-wave base marine conditions. The banding is attributed to cyclic changes in climatic conditions.