bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gravity Surveys for Lignite in Parts of Soutb Arcot and Tiruchchirappalli Districts, Tamil Nadu
Authors: Vajdyanathan N. C. , Appa Rao M. , Balakrishna Rao N. , Subrahmanyam S. 
Published: November 2024

Abstract
Lignite occurs within the Cuddalore sandstones of the Tertiary Group. The Bouguer gravity map has demarcated the basin with the axis extending from north to south passing close to Andirnatam, with steep gradients towards east and south. The residual gravity map has revealed three broad negative zones, comprising several gravity closures with magnitudes varying from -0.2 to as much as -1.7 milligals. Only a fraction of the anomaly could have been caused by the lignite body. It is likely that these zones indicate possible local depressions forming troughs or sub-basins where lignite deposits are likely to be confined. The boundaries of the lignite-bearing zones are fairly well marked. Drilling in two zones has proved the presence of lignite seams of 3 to 14 metres thickness at depths varying from 67 to 135 metres. The surveys have proved that the gravity method could advantageously be employed for delineating zones favourable for lignite deposits in similar environs.
Geochemistry of Trondhjemites from Sigegudda, Hassan District, Karnataka
Authors: Rama Rao P. , Naqvi S. M. , Govil P. K. , Balaram V. 
Published: November 2024

Abstract
The Sigegudda trondhjemites contain moderate Zr, high Ni and Cr and therefore appear to have formed by partial melting and/or fractional crystallization of Ni- and Cr-rich rocks like amphibolites. Lack of fractionation of Y, Zr and TiO2 and comparatively lower LREE/HREE ratio in these rocks perhaps indicate that garnet was not present in the magma source. The trondhjcmites were probably emplaced during the stabilization of the western Dharwar craton around 3.0 b.y. ago.
Central Indian Shear Zone: A Major Pre-Cambrian Crustal Boundary
Authors: Jain S. C. , Yedekar D. B. , Nair K. K. K. 
Published: November 2024

Abstract
The paper records the occurrence of mylonites along a major ductile shear zone in Nagpur-Bhandara- Balaghat-Bilaspur-Korba region of Central India, now named as Central Indian Shear/Suture zone (C.I.S.). The main shear zone extends from SSE of Nagpur to south of Korba over a distance of 500 km with a sinuous E-W trend and subvertical to steep northerly dips. Its northern branch extending in ENE direction from Amarkantak to north of Nagai has been named as the Tan Shear. The CIS separates the high-grade Sausar metasediments with a zone of granulites to its north from the dominant low-grade volcanogenic sequences to its south.
Bouguer gravity trends over Central India suggest that the CIS probably extends eastwards into the Singhbhum shear zone of Bihar-Orissa and westwards, into the Delhi-Aravalli shear zone in Rajasthan.
Geomorphic History and Lithostratigraphy of a part of Eastern Gangetic Plain, Uttar Pradesh
Authors: Joshi D. D. , Bhartiya S. P. 
Published: November 2024

Abstract
The Quaternary deposits of the area are classified into three lithounits, viz., Varanasi Older Alluvium, Chhoti Sarju Older Flood Plain Deposits and Chhoti Sarju Recent Flood Plain Deposits. The facies organisation of the Varanasi Older Alluvium (+300 m thick), indicates a braided to meandering river environment for the lower sandy facies and meandering river to local lacustrine conditions for the upper silt clay facies. Presence of a regionally persistent shell-bearing silty-clay horizon (at a depth of about 1 m to 2 m below ground level) indicates commencement of lacustrine conditions towards the waning phase of sedimentation of Varanasi Older Alluvium. The Chhoti Sarju Older Flood Plain Deposits rest over the eroded surface of Varanasi Older Alluvium. This deposit is about 10 m thick with fining upwards sandy facies deposited in a meandering river regime. The Chhoti Sarju Recent Flood Plain Deposits are confined within a very narrow zone (approx. 250 m wide) in the bed portion and flood plain of the river. In this regime, the sedimentation is still going on in the form of point bars, channel bars and side bars. At places, lacustrine conditions (oxbow lakes) are also present.
The Quaternary history of the area indicates at least two prominent episodes of base-level (sea-level) rise during the Late Pleistocene-Holocene period.
Compositional Variations in Mackinawites from the Chandmari Mine of Khetri Copper Belt, Rajasthan
Authors: Mukherjee Ananda Deb , Sen Partha Pratim 
Published: November 2024

Abstract
The occurrence and optical properties of mackinawites of different chemical, compositions from the Chandmari mine are described. The fact that mackinawites are clearly capable of accommodating a wide range of cations in their structures has been explained.
A Note on the Yttrium Mineral Potential of Granitic Soils in Parts of Andhra Pradesh, India
Authors: Singh Yamuna , Rai S. D. , Lakshminarayana Y. , Sankaran R. N. 
Published: November 2024

Abstract
Survey in parts of Karimnagar district, Andhra Pradesh, has brought to light the occurrence of colluvial placer deposits with appreciable concentration of REE and Y minerals in Dharmawaram-Yerabali area. The heavy minerals in the soil are thorite, zircon, xenotime, monazite, rutile, ilmenite, brookite, and magnetite. Panned concentrates (n=18) analysed 0.19 to 0.40% Y2O3 Dilute sulphuric acid leaching of the mineral concentrates solubilised 50% Y2O3.
On the Occurrence of Sargur Type Banded Iron-Formation in Banded Gneissic Complex of South Rajasthan
Authors: Sahoo K. C. , Mathur A. K. 
Published: November 2024

Abstract
The occurrence of BIF from a part of Banded Gneissic Complex of Rajasthan is reported. Older than 3.0 Ga granites, their field-setting and petrochemical characters are comparable to the BIF of older supracrustals of south India (Sargur Group).
A New Fluorite Deposit in the Palamau District, Bibar and the Associated Iron-Fluorine-Tungsten Skarns and Hornfelses
Authors: Soni S. , Mukherjee A. B. , Sengupta D. K. 
Published: November 2024

Abstract
Fluorite ore has been located at the Gore and Nawadih magnetite mines, about 20 km SW of Daltonganj. Palamau district, Bihar. The fluorite-bearing parageneses include amphibole-magnetite-quartz schists. mica schists and magnetite-quartz rocks-all occurring as discontinuous bands within the Chotanagpur granite gneiss. The amphiboles include hornblende, cummingtonite and anthophyllite. Scheelite occurs as an accessory mineral with fluorite', Pegmatitic granite and tonalitic gneiss occur as tongue-like intrusives within the schists. A calcite-clinohumite-periciase (brucite)-spinel-magnetite-sphalerite paragenesis is also reported from an adjoining area at Teliaband, 14 km east from the Gore-Nawadih mines. Thermal metamorphism of the hornblende hornfels facies accompanying a high temperature Fe-F-W pneumatolysis has apparently produced the fluorite-magnetite ore.
Origin of Miniature Pits in the Quartz-Arenites of the Badami Group (Younger Proterozoic), Umatar, Belgaum District, Karnataka
Authors: Ganesh A. , Sathyanarayan S. 
Published: November 2024

Abstract
A 50 metre thick horizontal to gently inclined sequence of granule conglomerate and Quartz arenite of the Badami Group (younger Proterozoic, ~1.6 Ga-1.0 Ga) is exposed at Umatar, Belgaum district, Karnataka. During the course of field mapping the presence of numerous miniature pits were noticed along the southern fringes of the outcrop, i.e., on the farther updip edge of the seaward slope inclined due north. Such structures have been commonly interpreted as products of weathering processes. But the morphology and anatomy of the miniature pits at Umatar points to their origin initially by wave splash action, later primary tilling by subsequently deposited sand, lithification and later modification by weathering leading to the removal of loose incoherent sand, filling the pits; finally, colesion, frost action and undercutting of the pits. The marginal updip concentration or the pits strongly supports their primary-origin.
Salinity in the Ground Water of the Purna Basin-Its Genesis
Authors: Muthuraman K. , Tiwari M. P. , Mukhopadhyay P. K. 
Published: November 2024

Abstract
Major element chemistry of the saline and the non-saline waters occurring between Popat-Khed and north of Akola indicate that the saline/fresh water contact is quite sharp and the saline waters are significantly restricted to the sandy aquifers inter-layered by clay beds, creating quasi-confined condition.
The ratios of major anions and cations of the saline waters are not comparable to those of sea-water. The plots of the major cations versus chloride are quite scattered and do not indicate any trend similar to their evaporite curves.
In view of the high 'Na/(Ca+Mg)' ratio, negative indices of base exchange and high SiO2-content of these waters, it is contended that these saline waters are nothing but diagenetically altered meteoric water having a long residence time.
Pegmatites: A Potential Source for Siting High Yielding Wells
Authors: Karanth K. R. , Jagannathan V. , Prakash V. S. , Saivasan V. 
Published: November 2024

Abstract
Exploratory wells drilled in pegmatites in Karnataka, Kerala and Tamil Nadu have recorded high yields. The median specific capacity value is 80 1/min-m. A commonly observed phenomenon is that discharge of a borewell increases immediately after striking pegmatites. The detailed, long duration pump tests conducted also indicate their sustained high performance.
Intrabasinal Differential Subsidence and its Influence on Coal Thickness Configuration, Barakar Formation, Sohagpur Coalfield, Madhya Pradesh
Authors: Chakrabarti Utpal 
Published: November 2024

Abstract
Spatial and temporal variations in small scale subsidence pattern in a part of Sohagpur Coalfield have been identified and mapped using the method of graphic correlation. Subsidence was differential at the initial stage which later gave way to a tectonically stable condition of deposition. Lateral variations in thickness and continuity of mineable coal seams, however, cannot be satisfactorily explained in terms of relative rates of subsidence only. Geometric properties of the coal seams instead reveal a dominant control of depositional environment on seam morphology.
Geochemistry of the Sarnu-Dandali Carbonatites, District Barmer, Rajasthan, India
Authors: Chandrasekaran V. , Srivastava R. K. 
Published: November 2024

Abstract
The Sarnu-Dandali carbonatites of Western Rajasthan are some of the few occurrences of a typical carbonatit-nephelinite magmatic association known from India. They occur as dykes and dykelets of sovitic-alvikite and ferrocarbonatite showing distinct variation in their chemistry. The sovitic-alvikites have high contents of BaO (up to 3.42%) and SrO (up to 1 %). Fractionation trend is marked by decreasing concentration of SrO from sovitic-alvikite (1.00%) to ferrocarbonatite (0.06%). Trace element contents reveal pronounced preference of Ce and other rare earth elements for sovitic-alvikites. Their oxygen and carbon isotope values are that of typical primary igneous carbonatites. The chemical and isotopic data reveal that the Sarnu-Dandali carbonatites are magmatic, fractionated and have originated from a mantle-derived nephelinitic magma.
Volcanological Aspects of Jungel Metavolcanic Suite, Bijawar Greenstone Belt, Central India: Suspect Ancient Island-Arc Volcanism
Authors: Kumar Vinod 
Published: November 2024

Abstract
Spectacular array of volcanic structures shown by Jungel metavolcanics include pillow structures, pahoehoe flows and toes, groove lava and shark tooth projections. Some of these features are indicative of small volume phreato-magmatic eruptions under shallow water conditions. The style of igneous activity is inferred to be moderately explosive, fragmental and spasmodic, supported by substantial. amount of volatiles. Based on volcanological, geochemical and tectonic evidences it is suggested that the present volcanic rocks were erupted in island-arc environment and that the southern margin of the Bundelkhand protocontinent formed a zone of subduction.
Volcanic eruption of the Barren Island Volcano, Andaman Sea
Authors: Haldar D. , Laskar T. , Bandyopadhyay P. C. , Sarkar N. K. , Biswas J. K. 
Published: November 2024

Abstract
Geotectonically the Barren and Narcondum islands lie on the Neogene Inner volcanic are, which proceeds from the recent volcanoes of Central Burma in the North to the Miocene to Recent volcanoes of Indonesia in the SE and are believed to have evolved as a result of eastward subduction of the Indian Ocean lithosphere below the SE Asian plate. The Barren island volcano is characterised by resurgent volcanism; so far, three distinct volcanic episodes have been recorded. An initially submarine volcanism, possibly taking place in late to Post-Pleistocene time formed a giant volcanic cone representing the ancestral Barren island. This ancient volcanic cone was at times, blown out and a thick pile of pyroclastics got deposited over the surface of the relict cauldron. Historical records reveal that the volcano became active again in 1789 when the existing cone with a crater and three subsidiary vents were developed. The present eruption initially starting from the NE subsidiary vent, subsequently merged with the main crater. The intensity of volcanic eruption gradually gathered momentum and continued unabated with thundering explosions till the end of September, 1991. Since November it is lying dormant. There is no major disastrous effect.
The lava of the first phase was olivine basalt and that of the second pbase a high-alumina olivine basalt.
The Central Crystalline Precambrian Peraluminous Granites of the Western Part of Bhutan Himalaya
Authors: Sarvothaman H. 
Published: November 2024

Abstract
The quartzo-feldspathic protoliths associated with the Central Crystalline gneisses of the western Bhutan-eastern Sikkim Himalayan segment are of peraluminous adamellite, granite (s.s.) and trondhjemite compositions. Peraluminous granite melt of first event is generated coeval to the kyanite or sillimanite grade metamorphism and it has syntectonically intruded a metapelite-quartzite sequence. These granites, along with the mctasedimentaries. have undergone partial melting under amphibolite facies conditions resulting in the generation of the peraluminous granite melt of second generation. which has syn- to late-tectonically intruded the pelitic sehist-quartzite-peraluminous gneiss assemblage. Approximately 20 Ma old post-tectonic peraluminous granites (s.s.) of the third event have intruded the Central Crystalline. The Central Crystalline adamellite-granite-trondhjemite suite is of 'non-minimum' melt compositions in contrast to the 'minimum melts' of the =20 Ma old leucogranites (such as the Manaslu granite of Nepal), which show unifonn granite (s.s.) compositions.
Sedimentological Evidence for a Palaeobeach off Mangalore, West Coast of India
Authors: Shankar R. , Karbassi A. R. 
Published: November 2024

Abstract
Sedimentological and SEM studies have been carried out on surface and sub-surface samples of outer shelf sands off Mangalore, west coast of India. The outer shelf sediments can be described as coarse sands, moderately sorted, nearly symmetrical to positively skewed and mesokurtic. Multi group discriminant analysis of the data shows that the sands were deposited in a beach environment during Pleistocene when the sea level was lower than at present. SEM studies reveal mechanically formed features like 'v' pits and curved grooves, which also corroborate the beach environment of deposition. The' v' pits and grooves have been smoothened due to chemical etching of the grains as the latter were in contact with sea water subsequent to the Pleistocene-Holocene transgression. Similar sand in cores obtained from east of the palaeobeach indicates its extension beneath Recent sediments. The thickness of palaeobeach sand increases landward. The cores studied have recorded tbe marsh Get black colour and abundance of vegetative matter), beach (coarse sands) and inner shelf (clayey silt) environments that prevailed at the core site as the sea transgressed. It is proposed that the outer shelf sands were not covered by Recent sediments because of the insufficient supply of sediments from the small, west-flowing rivers of Peninsular India, entrapment of sediments in estuaries, and onshore transport of sediments in the West coast region.
Deformational History and Shape Analysis of Folds in the Metamorphic Rocks of the Petermann Ranges, East Antarctica
Authors: Bejarniya B. R. , Joshi A. 
Published: November 2024

Abstract
Considered earlier to be very little defonned, the granulite facies rocks of the Petennann Ranges, East Antarctica, reveal three phases of folding and two episodes of ductile shearing. These metamorphic rocks preserve the F1 folds as small scale, rootless, intrafolial features with tight to isoclinal profiles, and F2 folds as mesoscopic features with close to tight profiles. F1 and F2 folds are coaxial and broadly coplanar having axial surfaces marked by pervasive NW-SE striking foliation. F3 folds are open, upright with N-S to NNW-SSE axial planes and impart local swings in the regional foliation. The early ductile shears produce a strong mylonitic fabric and are synchronous to F1, while occurring as thin wavy zones, the later shears are post F2.
Shape and geometric analyses of representative folds show that F1 folds belong to class 2 and 1C at low and high limb dips respectively and are fonned dominantly by flexural flow. F2 folds exhibit geometric features of class 1C at low as well as high limb dips and owe their origin to buckling with a flexural slip component and flattening.
Quartz Grain Surface Textures as Indicators of Depositional History of Beach and Strand Plain Sediments Along the North Kerala Coast
Authors: Samsuddin M. , Ramachandran K. K. , Dora Y. L. 
Published: November 2024

Abstract
SEM analysis of quartz grain surfaces from the strand plain show many of the characteristic textures that are produced under sub-aqueous environments with second generation features of wind action. It is inferred that the initial stage of deposition of the strand plain sediments was associated with a wave dominated environment. With emergence of this coast, the strand plain sediments were exposed to sub-aerial action, thus registering both sub-aqueous and sub-aerial action features.
Thermodynamic Data for Dolomite and Kutnahorite from the Experimental Decarbonation Curves
Authors: Tareen J. A. K. , Fazeli A. R. , Basavalingu B. , Bhandage G. T. 
Published: November 2024

Abstract
The P-T stability field of rhombohedral double carbonates, CaMg (CO3)2 (dolomite) and CaMn (CO3)2 (kutnahorite) has been studied up to 2 kb of PCO2. The dolomite decomposes to CaCO3 (ss)+MgO+CO2 and the kutnahorite to CaCO3 (ss)+MnO+CO2. The kutnahorite was considered to be completely disordered (R¯3C) near the decomposition temperature while the dolomite was found to be in ordered state at the decomposition temperature, though both were considered to stabilise with ordered structures at lower temperatures. The standard enthalpy and free energy data retrieved for the ordered dolomite is ; ?H0f = -2331.64±2.07 kJ/mol, ?G0f = -2168.59±2.07 kJ/mol., and for the disordered kutnaborite, is; ?H0f = -2093.46±3.77kJ/mol, ?G0f = -1944.80±3.77kJ/mol. The new data on dolomite are atIeast 7 kJ more negative than the earlier reported values. In the low temperature region the double carbonate field is preceded by a metastable two carbonate field of M'CO3 (ss) and M"CO3 (M' = Ca, M" = Mg, Mn) phases. This is considered to be the likely stage in the natural process of dolomite or kutnahorite formation.
Raoceras, A New Cretaceous Ammonoid Genus from Southern India and Some Observations on the Distribution of Pachydiscids in India
Authors: Ayyasami K. 
Published: November 2024

Abstract
A new Cretaceous pachydiscid ammonoid genus Raoceras, with the type species AmmonitesKuluturensis Stoliczka, is proposed. The Genus is restricted to the Coniacian. Its affinity with other pachydiscid ammonoid genera, the associated fossils in the field and its stratigraphic status are given. The known pachydiscid species in various marine Cretaceous basins of India are listed and correlated.
Foraminiferal Events Across K/T Boundary and Age of Deccan Volcanism in Palakollu Area, Krishna-Godavari Basin, India
Authors: Jaiprakash B. C. , Singh Jagmohan , Raju D. S. N. 
Published: November 2024

Abstract
Temporal distribution of planktonic and benthonic foraminifera across the K/T boundary in the Palakollu deep well section of Krishna-Godavari (KG) Basin, India, suggests that the lower Deccan trap flows have erupted during Zone M-18 of the latest Maastrichtian (66.5-65.5 m.y.) to Danian and the upper flows in lower Zone P2 of the Early Paleocene (6 1.2-60.7 m.y.). The span of volcanism will be approximately 6 m.y.
Nepheline Syenite from Rairakhol, Sambalpur District, Orissa
Authors: Panda P. K. , Patra P. C. , Patra R. N. , Nanda J. K. 
Published: November 2024

Abstract
A newly identified body of nepheline syenite with associated non-feldspathoidal syenites from the Rairakhol area of Sambalpur district in the Eastern Ghat belt of Orissa sector adds to the present population of such complexes in this segment of Precambrian crust of Indian Peninsula. Recent researches have emphasized the significance of these bodies as a major Late-Proterozoic tectonothermal marker event in this belt.
The Rairakhol syenitc complex consists mainly of nepheline syenite, syenite and minor quartz syenite. Biotite and hornblende are the chief mafic constituents which occur as accessories in varying proportions. This body is emplaced within an interbanded sequence of quartzite, khondalite and charnockite. Syenitic rocks have a flow banding/foliation well-developed at many localities. A pink pegmatitic K-feldspar sycnite possibly represents a late-magmatic product. Occurrences of a few relatively smaller bodies of similar composition are also recorded.
Solubility of Gold and Silver in Oxygen-Saturated Fluids and the Formation of High Fineness Gold Grains in the Lateritic Profile
Authors: Jaireth Subhash 
Published: November 2024

Abstract
This short note reports calculated solubilities of gold and silver in low-temperature, moderately saline, oxygen-saturated fluids. Based on the solubilities of goId and silver it is argued that the quantity of gold transported by the fluids depends on the concentration of silver in the primary ores. In ores, where silver/gold ratio is high (&gt;1 to 10) the fluids become saturated in silver and cannot dissolve geologically significant concentrations of gold. In ores where the silverlgold ratio is low (&lt; 1), the fluids remain undersaturated with respect to silver and can dissolve geologically realistic concentrations of gold and silver. The oxidised fluids will start depositing gold and silver as they move downwards and are reduced by the Fe+2 bearing minerals of the primary ores. The formation of gold in the lateritic profiles can be explained by a prolonged process of interaction between the fluid and the primary ores.
Metamorphism and Structural Interpretation of the Zanskar Shear Zone, PJW Himalaya, India
Authors: Routh Joyanto 
Published: November 2024

Abstract
Herren in 1987, reported normal faults resulted in the telescoping of metamorphic isograds within a 200 meter zone between Sumche Topko to Mulung Topko in the Zanskar Shear Zone NW Himalaya. However petrographic study-of sections obtained from Mulung Topko and surrounding areas (pensila-padarn section) indicate that the rocks belong to the kyanite-sillimanite-starurolite grade only. Extension crenulation cleavage and other shear criteria show an initial NESW movement after which a layer parallel extension occurred and the shear zone developed. Minieralogical assemblage and mapping indicate that the isograds run paralleI to each other before they possibly truncate against the shear zone along the Pensila-Padam section. A probable model has been proposed to explain the features.