bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Geometry of the Dharwar Rocks near Chitradurga
Authors: Mukhopadhyay Dhruba , Baral Mohan C. 
Published: November 2024

Abstract
The major structure south of Chitradurga is a southerly closing, very steeply plunging, nearly vertical fold (Chitradurga Fold) defined by the BIF horizons. This is a second generation structure and the dominant schistosity with NNW-SSE strike is parallel to the axial plane of this fold. The first generation structures are represented by minor folds only. They have variably oriented axes and their axial planes are bent by the major Chitradurga Fold. The strike of the third generation axial planes varies from NNE-SSW to ESE-WNW, and the axes are generally steeply plunging.
During the second deformation, folds formed at different stages and their geometry was modified by rotation in the subsequent stages of progressive deformation. The axes of the minor folds show a wider range in orientation than the direction of maximum elongation in the rocks, and there is often an angle between the two.
The distribution of the bedding plane poles in the projection diagrams of most of the sectors indicate steeply plunging ß (F2). The major Chitradurga Fold shows a conical geometry with a subvertical cone axis and very small apical angle.
Copper metallogeny in the Jogimardi Volcanics, Chitradurga Greenstone Belt
Authors: Anantha Iyer G. V. , Vasudev V. N. 
Published: November 2024

Abstract
Massive volcanic-hosted sulphide deposits, within the Jogimardi volcanic suite (JVS) are Cu-rich with minor Zn and Pb and form an important early phase in the evolution of the late Archaean Chitradurga belt. The deposits are concordant stratabound lenses in the bedded mafic tuffs emplaced as submarine volcaniclastites. The JVS is an integral part of the Chitradurga antiform flanked by synclines on either side. The stratiform massive and vein-type sulphide deposits of the JVS are confined to the eastern limb of the antiform.
The volcanic rock succession in the JVS consists of 85% tholeiitic basa1ts; 12% low silica variolitic andesites and 3% of rhyolites. The basalts are quartz-normative tholeiites, not known to occur in MORB environment. Unlike those of MORB, in their major, minor and REE geochemistry, the basalts related to massive sulphide deposits are almost identical to back-arc basalts generated in an ensialic marginal basin environment.
The thermal and chemical environment of ore formation are determined based on fluid inclusions data and d34S pyrite values of individual sulphide phases. These data indicatce that the ores were deposited under anoxic chemical environment at a temperature of 350°C within a pH range of 5 to 7 corresponding to proximal facies conditions. The stratiform sulphide ore body in the area is located in the vicioity of a fracture controlled stringer/stock-work ore zone - 'a hydrothermal discharge vent' in the pillowed basalts of tholeiitic composition which confirms the proximal nature of the deposit.
Uranogenic and thorogenic lead isotope studies on the galenas of Ingladhal stratiform sulphide bodies indicate that they are not of mantle origin but derived from the basement gneisses, dated at 3 b.y.
Geologic setting, preservation of quench plagioclase textures in the pillowed basalts and volcanogenic synsedimentary nature of the stratiform sulphide deposits indicate that the sulphides were deposited initially in the JVS prior to folding and regional greenschist facies metamorphism.
Identification of Titanomagnetites by Simple Magnetic Techniques and Application to Basalt Studies
Authors: Radhakrishnamurty C. 
Published: November 2024

Abstract
Some members of the titanomagnctite solid solution series, xFe2TiO4 (1-x) Fe3O4, have specific magnetic properties by which their presence in basalts could be inferred from one or two simple measurements. The titanomagnetite with x = 0.56 shows a characteristic constricted hysteresis loop in a low-field (10 Oe) at room temperature, while pure magnetite has a sharp peak in susceptibility at about 120 K. The presence of even other members, when occurring with one unique composition in basalts, could be identified by observing the change in either susceptibility or coercive force between 77 and 300 K. For x = 0.1, the susceptibility of the mineral at 77 K will be 1.3 times the value at 300 K. The coercive force for x = 0.7 is 50 Oe at 300 K and it attains a value of 1800 Oe at 77 K. Howewr, often a basalt sample contains more than one type of magnetic grains which will be revealed by a superposition of the individual characteristic features in some cases.
The techniques used for the study of the magnetie grains in basalts are described briefly. Results obtained using these techniques on samples from different volcanic provinces like East African Rift, Columbia River basalts, Deccan traps, Rajmahal traps and some Precambrian basalts, indicate that while titanomagnetite with up to x = 0.6 is fairly common and pure magnetite is rare in the younger basalts, the converse is the case in the older basalts. Some implications of such results are pointed out.
Crystal Growth of Zircons in Puttetti Syenite: Nature of Fluids and Implications on CO2 Activity
Authors: Santosh M. 
Published: November 2024

Abstract
Fluid inclusion studies in a number of doubly polished plates of zircons showing interesting features are documented. The equilibrium balanced shapes of inclusions and their pattern of distribution are suggestive of slow growth rate, largely controlIed by stacking mechanism, resulting in completed layerites. Development of tensional fractures which eventually healed by dendritic growth and typical necking-down textures of long tabular inclusions are recorded. Thermometric studies show tbat the early fluids were of high density (0.90-0.85 g/cm3)CO2 type with probable traces of CH4 and/or N2, entrapped at a pressure of 4.5 Kb. The fluids evolved into pure CO2 (O.83 - 0.68 g/cm3) and to mixed CO2-H2O around 650°C and 3.7 Kb due to formation of vapour phase, while a fraction of the melt was sti!l present. The composition of fluids recorded suggests repeated CO2 activity in south India with a peak during Late Precambrian-Early Palaeozoic times, effecting the generation and emplacement of alkaline plutons.
Hydrometric Implications of Morphometry and Geology: A Study of Lower Ramganga Catchment
Authors: Jawat J. S. 
Published: November 2024

Abstract
Total stream length (ΣL) and relief ratio (Rr) are the most significant morphometric parameters, which have been used to define allometric change of hydrometric parameters i.e. stream discharge (Q) and silt delivery (S) as: Q = a+b (ΣL) and S = a b (Rr). The allometric models are largely controlled by bedrock lithologies. The lower Ramganga catchment in the central. U.P. Himalaya was employed as a natural laboratory for the above investigation.
A New Species of the Genus Physa from the Deccan Infra-Trappean Beds of Andhra Pradesh, India
Authors: Ayyasamy K. , Ganesan V , Narasimham C. V. L. 
Published: November 2024

Abstract
The paper records the find of a new species of the genus Physa, occurring in the infra-trappean beds of Andhra Pradesh, India. Discussions on the distribution, phylogenetic significance and the stratigraphic importance of this new find are presented.
Modelling of Trace Element Behaviour in Hydrothermal Brines
Authors: Menon A. G. , Anantha Iyer G. V. 
Published: November 2024

Abstract
Details of a new method to mode1 trace element distribution in hydrothermal ore deposits is outlined. The behaviour of Pb2+ at 100°, 200° and 300°C has been highlighted as a function of solution parameters fs2 fo2, and pH.
Stable Isotope Systematics in Tree Cellulose as Palaeoenvironmental Indicators - A Review
Authors: Ramesh R. , Bhattacharya S. K. , Gopalan K. 
Published: November 2024

Abstract
Stable isotope ratios of hydrogen, carbon and oxygen in tree cellulose have been recently demonstrated as potential indicators of past climate, However, a number of problems remain to be solved before isotope dendroclimatology can be used for routine reconstruction of palaeoclimate. Here we review the existing Literature, with a special reference to the Indian context and identify key problems that deserve immediate attention.
Wind-Sculpturing of the Vindhyan Sandstone in the Bhopal Region, M.P.
Authors: Mathur S. M. 
Published: November 2024

Abstract
Wind-sculpturing of the Karauli Quartzite (Rewa Group, Vindhyan Supergroup) at several localities in the Bhopal region has produced rock monuments like monad-rocks, inselbergs, etc., with tunnels boring through some of them. These monuments are found as isolated rock masses of various shapes and sizes standing above land surfaces that have reached base level of erosion. The highly jointed, horizontally bedded and fractured quartz-arenite rests over massive but softer sandstone which is first eroded causing overhang of the former. Eventual collapse of the overhanging rock masses and their ultimate removal leaves 1he soft but massive horizon underneath unprotected. Repetition of the process over eons of time has produced these natural monuments; the most remarkable group is seen at a locality known as Bhim Baithka. Several of these natural sculptures have developed tunnels and passages that pass right through them in the softer sandstone towards t he base. where the action of the sand- and particle-laden wind is most destructive.
Geochemistry of the Gabbro-Tonalite-Trondhjemite-Granite Suite of the Ezhimala Pluton, North Kerala
Authors: Sinha-Roy S. , Ravindra kumar G. R. 
Published: November 2024

Abstract
The Ezhimala pluton emplaced in possible Sargur-equivalent sequence in North Kerala is a differentiated suite showing a continuous compositional range from gabbro to granite through tonalite and trondhjemite. Geochemistry indicates that the suite is the product of diapiric emplacement of magma generated at shallow depth and of fractional crystallization in which the major participating phases were hornblende and plagioclase. Biotite and Fe-Ti oxides were minor fractionating minerals. There is an indication that this suite is one of the many igneous bodies of variable composition which are the products of important magmatic event in the Kerala region, in late Proterozoic and early Palaeozoic times.
Geology and Geochemistry of Tertiary Clay Deposits in South Kerala
Authors: Ghosh Swapan K. 
Published: November 2024

Abstract
The sedimentary clay deposits in south Kerala are the source of excellent quality kaolinite, formed due to weathering of arkosic sediments of Tertiary and crystalline Precambrian rocks. It has been possible to differentiate two such kaolinite beds in south Kerala based on mineralogy, chemistry and field relationship. At places, the two kaolinite beds are separated by sandstone-clay intercalations. The upper clay bed contains higher amount of impurities of quartz, goethite, hematite and gibbsite. The concentration of these impurities decrease at depth and vary horizontally having no consistent pattern. Study of sedimentary structures within the kaolinite beds, presence of kaolinite pseudomorph of feldspar still maintaining crystal faces, and lignite bed, support the hypothesis that the beds were deposited after a short and rapid transportation in a fluctuating flow regime. The lower elay bed, underlying the sandstone, is impoverished in both quartz and iron minerals. The source material for this clay deposit is the pre-Miocene weathered regolith extensively developed on Precambrian chalnockite- khondalite suites of rocks. After burial, ferric iron oxide from these beds was leached away in a reducing environment. The variation of mineral content and its chemistry in the kaolinite beds, have been related to spatial difference in micro-environment in the stratigraphic horizons in the geologic past and at present.
Uranium Mineralization in the Carbonate Rocks and Sandstones from the Subuk-Rishi Area of Sikkim Himalayas
Authors: Siddiqui A. S. , Dhana Raju R. 
Published: November 2024

Abstract
In a number of radioactive occurrences near the contact of Buxa and Gondwana rocks in the Subuk-Rishi area of Sikkim Himalayas. uranium mineralization, in the form of hydrothermal veins and disseminations of brannerite-davidite, is recorded in the carbonate rocks of the Buxa. Group (Older Palaeozoic) and quartz arenite of the Lower Gondwana Subgroup. The carbonate rocks are intermediate between a pure limestone and a pure dolonlite, and are phosphatic with P2O5 upto 17wt. %, reflected in essential apatite. Radioactivity is relatively more in carbonate rocks than in sandstone, and there is an apparent increase of U with P in both the rock types.
Regional Groundwater Flow Investigations in Visakhapatnam Basin, Andhra Pradesh
Authors: Jagannadha Sarma V. V. , Narayana Swamy A. 
Published: November 2024

Abstract
The study of regional groundwater flow in an area plays an important role in the exploration, exploitation and conservation of groundwater resources. This paper deals with the investigations of horizontal groundwater flow made in Visakhapatnam basin of Andhra Pradesh state using water table and hydraulic gradient as criteria. In general. it is observed that movement of groundwater follows the trend of surface drainage. An attempt is made to apply hydrochemical approach to the interpretation of groundwater movement in the unconfined conditions of the region.
Crocodilian Remains from the Miocene of Kachchh, India
Authors: Sabale A. B. , Vijayasarathi G. 
Published: November 2024

Abstract
Crocodilian fossil remains from the Miocene sediments of Kachchh including a well-preserved skull, mandible with few teeth intact, numerous vertebrae and a few scutes are described. This is the first record of fossil Gavialidae from the Miocene of Kachchh.
Strain Analysis in the Basal Unit of Delhi Supergroup in Kishangarh Area (Rajasthan): As Deduced from Deformed Pebbles
Authors: Srivastava H. B. , Gairola V. K. 
Published: November 2024

Abstract
The arkosic quartzites overlying the rocks of Aravalli Supergroup along an unconformity cum thrust contact, exhibit strong deformation resulting in preferred dimensional orientation of the pebbles. The three dimensional strain is of constriction type where the mean value of k varies from 1.33 to 6.52 from locality to locality. The shapes of the pebbles prior to deformation were mainly of constriction type. The path of pebble deformation has been traced. The strain in these pebbles is related to folding and later thrusting (gliding) during the first phase of deformation.
Stratigraphic Relations of the Precambrian Rocks in the Salumbar Area, Southeastern Rajasthan
Authors: Mohanty S. , Naha K. 
Published: November 2024

Abstract
Around Salumbar in the Udaipur district, Rajasthan, the Banded Gneissic Complex (BGC). the Aravalli metasedimentary rocks, the Dudar Gneiss and the Lakapa Granite Gneiss have been involved in the same style and sequence of muhiple deformation. The oldest rocks are the migmatites forming the BGC, which underlie the Aravalli metasediments with an unconformity marked by a conglomerate. Rare relict pre-Aravalli structures in the BGC, and the conglomerate containing gneissic pebbles provide incontrovertible evidence for a part of the BGC being the original basement. Identical structural style and sequence of the basement gneisses wilh those of the metasedimentary cover rocks, however, point to mobilization so that they could take part in the earliest deformation affecting the metasediments in a ductile manner. The Dudar Gneiss has formed by migmatization of the Aravalli rocks synkinematically with the first deformation, whereas the Lakapa Granite Gneiss has been emplaced as a syn-to late-tectonic intrusion.
Structure and Tectonics of Exposed Tertiary Rocks Between Narmada and Kim Rivers in South Gujarat
Authors: Agarwal C. G. 
Published: November 2024

Abstract
The Tertiary rocks of the area between Narmada and Tapti rivers have undergone folding, faulting and partial erosion, whereas those of the adjoining area of Cambay basin to the north lie undisturbed, technically, under the cover of Quaternary deposits. The exposed Tertiaries have been found to be folded into twelve linear anticlinal folds, plunging southwest and at times northeast as well, and invariably faulted along their southeast limbs. These faults are of reverse type and hade due northwest. The deformation was in all probability due to differential vertical basement fault-block movement caused by compressive forces related to the collision of the Indian Plate with the Asian Plate.
Geological Aspects of the Banded Iron-Formation of Bihar and Orissa
Authors: Chakraborty K. L. , Majumder Tapan 
Published: November 2024

Abstract
The metamorphic age (2.55-3.07 Ga) of BIF of Tomka-Daiteri belt has been established from Sm/Nd data which seemingly indicates that the sedimentation age of BIF is older than Singhbhum granite (3.12±0.OI Ga). Intrusive evidences of Singhbhum granite into BIF have been documented. An older age of the GorumahisaniBadampahar- Tomka Daiteri-Malayagiri BIF with respect to that of Jamda-Koira Valley is supported.
The BIF, consisting predominantly of magnetite-chert, magnetite-jasper (BMJ) hematite-jasper (BHJ) or martite-quartz (BMtQ}form part of a sedimentary succession, underlain by quartz-arenite or lithic wacke and interlayered with altered volcanic tuff (shale ?). Magnetite, hematite and chert were primary precipitates in the BIF. No primary carbonate, silicate or sulphide have been noticed to occur in these rocks excepting sporadic occurrence of carbonate pseudomorphs in the underlying quartz-arenite.
Primary sedimentary structures like current ripples, syneresis cracks, penecontemporaneous deformation structures (e.g. folds, faults, micro-brecciation, pods, etc.) and diagenetic recrystallization features are described.
Similar to other world deposits of Precambrian and Archaean age, the BIF of Bihar and Orissa are also deficient in major, trace (TE) and rare earth elements (REE). Mineralogical composition and geochemistry suggest that they belong to the oxide facies iron-formation, Low concentration of Al203, CaO, MgO. MnO and of Zr, Cr, Ti, V, Ni and Cu in the BIF with respect to their abundance in. the interlayered pyroclastics presumably suggests a non-volcanogenic source of iron and silica. Eu/Sm ratio (0.541.01) indicates an Archaean age for the BJF. A shallow water marine environment is predicted for the deposition of BIF.
Mechanisms of Charnockite Formation and Breakdown in Southern Kerala: Implications for the Origin of the Southern Indian Granulite Terrain
Authors: Ravindra Kumar G. R. , Chacko Thomas 
Published: November 2024

Abstract
Field studies in southern Kerala have been successful in locating a Dumber of quarries in which charnockite has partially replaced garnet-biotite gneiss. Four types of charnockite formation have been recognised. Three of these involve the dehydration of gneisses by the influx of CO2 - rich fluids. Types I and II show charnockite concentrated along shear and foliation planes. In type III, high CO2 pressures are required by the presence of interlayered, scapolite-bearing calc-silicates. In type IV, charnockite is restricted to the margins of granitic dykes. and formed as a result of the decompression reaction gar + qtz + Na-plag = opx + Ca-plag, rather than a dehydration reaction. The widespread occurrence of arrested charnockitisation in southern Kerala suggests that the process of carbonic metamorphism invoked at Kabbaldurga, Karnataka, was not a local phenomenon, but extended over the entire southern Indian granulite terrain. In contrast to these examples of charnockite in the making, three types of charnockite breakdown have also been recognised. These involve the influx of water-rich solutions by means of granite pegmatites, leucocratic magmas, and pink granites. Present geochronologic data are not sufficient to determine whether the various types of charnockite formation and breakdown were different phases of a single metamorphic event or the result of several distinct metamorphic episodes.
Rb-Sr Age of the Belka Pahar Granite, Sirohi District, Rajasthan
Authors: Chakranarayan A. B. , Powar K. B. , Pande K. , Gopalan K. 
Published: November 2024

Abstract
At Belka Pahar, in the Sirohi district of Rajasthan, metasediments of the Delhi Super Group are associated with a medium-grained, leucocratic, alkali granite. Whole rock isotopic data for this granite define a Rb-Sr isochron corresponding to an age of 860±25 Ma and an initial 87Sr/86Sr ratio of 0.7059 ±0.0032.
Fluorite Mineralization in Garampani Thermal Spring Area, Palamau District, Bihar
Authors: Mukherjee A. L. 
Published: November 2024

Abstract
Fluorite mineralization in the form of salt (grains &lt; 0.5mm diam, crystalline white) and veins (grains 1-6mm diam crystalline, in shades of blue and voilet) is a conspicuous associate of Garampani thermal spring, Palamau District, Bihar, that belongs to an ENE-WSW trending belt of thermal springs in the northeastern Peninsular India. The springs of the belt are chemivally similar, characteristicallt enriched in F-, and are associated with Post-Gondwana faulting.
The Gararnpani spring (67.5°C) which emerges along a silicified shear zone in Barakar sandstone (L. Gondwana), is of Na-Cl-HCO3 type with near neutral pH (7.52 at 25°C), moderate specific conductance (352 mmhos/cm at 25°C), and is relatively enriched in F- (9.1 ppm) and SiO2 (67.2 ppm). Shallow groundwaters of the region are Ca-Na-HCO3 (within Gondwanas) to Na-HCO3-Cl types (within Archaean crystallines) with near neutral pH (7.1-7.6 at 25°C), low specific conductance (132-207 mmhos/cm at 25°C) and have low F- (0.5-1.2 ppm) and SiO2(12.3-24.0 ppm) content. Minor variations in the physicochemical properties of the thermal spring water in different periods, indicate slight mixing of shallow water.
From the estimated activity products of [Ca++] [F-]2, it is apparent that the spring water and shallow non-thermal groundwaters are respectively oversaturated and undersaturated with respect to APFluorite values at respective on-site temperatures of the samples. Both are, however, undersaturated with respect to calcite solubility. Physically contrasted spring-salt fluorite and the adjoining vein fluorite are co-ceived as precipitates from spring water and mixed stream water respectively. In the latter case, however, precipitation appears as episodic in nature. It is further envisaged that near saturation values of the springs of the belt with respect to APFluorite could be related to subsurface fluorite mineralization.
Role of Microstructures in the Spontaneous Combustion of Raniganj Coals: A SEM Study
Authors: Singh Mahendra P. , Chandra D. , Prasad Y. V. S. 
Published: November 2024

Abstract
The Scanning Electron Micrography of bulk coal samples from Dishergarh, Sirpur and Kajora areas of Raniganj Coalfield has been attempted with a view to find out the role of microstructures in promoting the spontaneous combustion of these coals. Microanalysis of vitrain and c1arain has shown that these bands of R-VIII seam are highly porous as compared to the overlying and underlying seams. Further, finely dispersed pyrite has also been observed filling these micropores. It is concluded that the occurrence of ubiquitous micropores could be a prevalent factor responsible for the spontaneous combustion property of these coals in different ways.
Dynamic and Gravitational Groundwater Levels-A Two-Layered Groundwater Model
Authors: Morner Nils-Axel 
Published: November 2024

Abstract
The equipotential sulfate of the rotational and gravitational potentials corresponding to the density of water is known as 'geoid'. A continental geoid surface of water called the hydro-geoid separating two distinct masses of groundwater is proposed. The flow pattern, potential water outflow and water mass balance markedly differ between the groundwater above and below the hydro-geoid level. A two-layered groundwater model with clear distinction between the actual, 'dynamic', groundwater level and the 'gravitational' (hydro-geoid) groundwater level is advocated. The hydro-geoid level is deformed by the tides and, in the long-term range also, by all other factors affecting the gravitational and rotational potentials.