bluuebunny/crossref_metadata_2025_split huggingface dataset:
Planktic Foraminiferal Biostratigraphy and Biochronology of the Post-Miogypsina Neogene of Bombay Offshore Basin
Authors: Dave Alok 
Published: November 2024

Abstract
Neogene planktic foraminiferal events and biostratigraphy of four deep well sections viz. D1-A-1, SS-1, R-13-1 and D-4-1 in the Bombay Offshore Basin have been established. A pronounced and regiona lunconformity separates the post-Miogypsina (post Zone N10 or N12, Middle Miocene) clay/claystone succession from the underlying carbonates. In most of the studied wells the hiatus covers a time span of 6.5 Ma (or 9.7 Ma) involving part of Middle Miocene and entire Late Miocene except in well D-4-1 where its span is greatly reduced. Three planktic foraminiferal datums viz. LAD of Globigerina nepenthes (3.78 Ma), LAD of Dentoglobigerina altispira (2.6 Ma) and LAD of Globigerinoides fistulosus (1.6 Ma) have been demarcated in the Pliocene. A comparison of these biochronologic datums with those recorded from the DSDP sites in northern Indian Ocean is made. The delayed Last Occurrence of Globoquadrina dehiscens in Bombay Offshore is attributed to its reworking in Pliocene.
Stratigraphy and Palichnology of Nimar Sandstone, Bagh Beds of Jobat Area, Jhabua District, Madhya Pradesh
Authors: Kundal P. , Sanganwar B. N. 
Published: November 2024

Abstract
Medium to fine grained Nimar Sandstone has yielded abundant ichnofossils comprising sixteen ichnospecies shared among eleven ichnogenera. These are: Annetuba chapdiensis, Cylindrichnus sp., Granularia yelamensis, Gyrochorte comosa, Imponoglyphus kevadiensis, Keckia annulata, Laevicyclus mongraensis, Palaeophycus heberti, P. intermediatus, P. tubularis, Planolites annularis, P. beverleyensis, P. montanus, Rosselia socialis, Thalassinoides paradoxicus and T. suevicus. Five species, namely, Planolites annularis. P. beverleyensis, Rosselia socialist Thalassinoides paradoxicus and T. suevicus are new additions to our knowledge of the ichnofauna of the Bagh Beds. Palaeophycus intermediatus is the solitary ichnospecies described herein as new.
Incipient Diapirism Coeval to Bhuban Sedimentation: A New Hydrocarbon Exploration Play in Cachar Fold Belt, Assam
Authors: Palakshi K. , Rao C. G. , Ramprasad B. P. , Subrahmanyam D. 
Published: November 2024

Abstract
Reflection seismic facies analysis pertaining to southern part of Katakhal syncline, Cachar Fold Belt, Assam, has brought out an anomalous zone of chaotic reflections bounded by high amplitude, continuous, correlatable reflection events. This anomalous zone displays an elliptical shape in plan view and is aligned with the associated folds. The genesis of this anomaly, developed along the eastern flank of the syncline, bracing the synclinal axis is assigned to the non piercement type of shale diapirism within Middle Bhuban Formation of Middle Miocene age. The geological model envisaged has further led to the delineation of supra and lateral diapiric traps in the overlying Upper Bhuban and Bokabil Formations of Mio-Pliocene age. The reconstruction of structural evolution has brought out a phase of inversion during Plio-Pleistocene where the anticlines within Miocene and Mia-Pliocene sequences turned into synclines. The delineated supra and lateral diapiric traps have not been obliterated during inversion episodes. The identified prospects are new type of plays to be tested in Cachar Fold Belt, and form a step forward in focusing the thrust areas of exploration on the gentler synclinal flanks
Record of Well Preserved Trilobites from the Cambrian of Zanskar
Authors: Kumar Ashok 
Published: November 2024

Abstract
Trilobites are important fossils ranging from Cambrian to Permian in age while they are stratigraphically significant in the Lower Palaeozoic. Well preserved trilobites discovered from the Kurgiakh area of the Kunzam La Formation of Zanskar Basin including Ptychoparia consocialis, P. pervulgata, Ptychoparia sp., Lyriaspis spitiensis, Lyriaspis sp., Anomocarella resseri, Anomocaraspis hundwarense. Anomocare sp., Hundwarella transversa, Hundwarella cf. convexa, Hundwarella personata, Hundwarella sp., Elrathia cf. chuwansis, Eymekops hermias. Lisania sp., Damesella sp., Lorenzella sp. Yuehsienszella sp. are reported.
Mudbank Dynamics: Physical Properties of Sediments
Authors: Manoj Kumar P. , Narayana A. C. , Tatavarti R. 
Published: November 2024

Abstract
Surface sediment particle sizes, their spatial distribution and their geotechnical characteristics in the Ambalapuzha-Purakkad Mudbank were studied, based on field observations during pre-monsoon and monsoon seasons. The study revealed that sediments in the mudbank are clayey silts in both the seasons. The magnitude of the fine silt and clay contents blanketing the ocean bed were however, observed to be more in the pre-monsoon season indicating the possibility of fine silt and clay going into suspension during the monsoon season. Geotechnical properties of surface sediments revealed that they are highly plastic, with high liquid limits. Organic carbon, fine silt and clay minerals play an important role in the behaviour of mudbank sediments.
Petrography and Geochemistry of the Mesozoic Granite at Mashhad, Khorasan Province, Northeastern Part of Iran
Authors: Iranmanesh Jalil , Sethna S. F. 
Published: November 2024

Abstract
A petrographic and geochemical study of the Mashhad granite in the northeastern part of I.R. Iran reveals that it is of two main varieties - the major body of S-Type continental collisionlsyncollision biotite/muscovite granite and pegmatites; the other of I-Type, Mthin plate/post collision uplift - homblende-hedenbergite/green biotite granite with the latter intrusive into the former. The homblendehedenbergite-compared to the biotite-granite, shows appreciable enrichment in the high field strength (HFS) and rare earth elements. One peculiar character in these granites is the negative correlation of Si02 and distinct positive correlation of CaO against the HFS and RE elements, and the latter character is attributed to the presence of large amounts of sphene and apatite in the homblende-hedenbergite granite.
Airborne Magnetic Lineament, Groundwater Potentiality and Basement Structures in S-E Part of Vindhyan Basin
Authors: Mishra D. C. , Gupta S. B. , Prabhakar Rao M. R. K. 
Published: November 2024

Abstract
Airborne total intensity magnetic survey flown at a height of approximately 152 m in central India has delineated several linear magnetic anomalies of 200-400 nT aligned together to form a large magnetic lineament approximately 1 km wide and 100 km long. The nature of magnetic anomalies suggest the lineament to be a fracture zone with basic intrusives at places. Magnetic and resistivity surveys on ground provide large magnetic (600-800 nT) and low resistivity anomalies along this lineament suggesting a fracture zone with basic intrusive rocks at places and very good groundwater potentiality along it.. Existing wells close to the lineament yield good amount of water, while those away from it show poor yield. Water table contour map of the area shows contours parallel to the lineament indicating pumping of more water from this zone causing lateral flow of groundwater.
This lineament does not find reflection in the ground gravity survey; instead it delineated some second order small dome and basin structures around Damoh and Jabera which are not recorded in the airborne total intensity map referred to above. This suggests that while linear features are better reflected in the airborne magnetic surveys small-scale three-dimensional basement structures are better reflected in the ground gravity surveys. This indicates the need for an integrated airborne and ground exploration programme for delineating subsurface structures/tectonics and to quickly assess the groundwater resources of a region.
Electron Microprobe Dating of Monazite from Spinel Granulite in the Eastern Ghats Belt, India
Authors: Rao A. T. , Fonarev V. I. , Konilov A. N. , Romanenko M. 
Published: November 2024

Abstract
Electron microprobe dating method is same as chemical aging method of U-Th minerals used in geochronology. The Th-U-Pb concentrations obtained from a single electron probe analysis allow calculation of geologically meaningful age. Based on this method monazite from spinel granulite of Visakhapatnam in the Eastern Ghats Belt (EGB) gave ~1,000 Ma, corroborating the late Proterozoic metamorphism and charnockite emplacement, established in parts of the EGB and Antarctica. Microgeochronology of commonly occurring accessory mineral such as monazite in granulite variants is recommended for quick reconnaissance correlation in Gondwanian fragments in East Gondwanaland.
Estimation of Parameters of an Extensive Aquifer - A Case Study
Authors: Thangarajan M. , Singh V. S. 
Published: November 2024

Abstract
With the growing needs of water, particularly in developing countries, groundwater resources are being exploited indiscriminately. Evolution of pumping schemes for the development of groundwater resources has become an imperative need to minimise the environmental hazards. This, in turn, requires a reliable estimation of hydrogeological parameters and quantitative appraisal of interference between wells. Pumping tests using a distributed battery of wells may give a representative estimate of aquifer parameters valid over a large area.
One such study was carried out in the Neyveli basin, Tamil Nadu (India), using pumping test data on wells distributed over a total distance of about 2 km. The spread of observation wells was about 4 km. The pumping was continued till a steady state condition was achieved which was monitored through continuous recording of water levels in the observation wells. The drawdowns at any observation point due to pumping of a number of wells is calculated using the principle of superposition. Forward modelling has been employed for the estimation of aquifer parameters through comparison of computed and observed drawdowns. This approach, besides enabling estimation of hydrogeological parameters, can also provide a first-order basis to design an optimal spatial pattern of wells and pumping rate to achieve a specified drawdown in a certain area.
Freibergite from Polymetallic Sulphide Deposits of the Delhi-Aravalli Belt, Rajasthan
Authors: Mukherjee Ananda Deb , Sen R. , Mondal Arpita 
Published: November 2024

Abstract
The polymetallic sulphide are deposits of Delhi-Aravalli orogenic belt exhibit occurrerce of freibergite (a mineral of fahlore group) as a major source for recovery of silver as an important byproduct. EPMA data on the chemistry offreibergite is presented. In order to obtain optimal recovery of Ag from the ores of these deposits, selective flotation of freibergite is suggested.
Compositional Study of Spinels from Wajrakarur Pipe-10 (Anumpalle), Ananthapur District and its Significance in Diamond Prospectivity
Authors: Mukherjee Abhijeet , Rao K. S. , Babu E. V. S. S. K. , Roy Gautam 
Published: November 2024

Abstract
Geological Survey of India had recently discovered Wajrakarur pipe-10 and spinels from this pipe were analysed. Q-cluster analysis of these spinels based on Cr2O3, Al2O3, TiO2 and MgO contents indicate the presence of S1, S3, S4, S5 and S10 groups. S1 group spinels are supposed to be cogenetic with diamond i.e., stable in the mantle within the P-T regime under which diamonds are known experimentally to form. The Cr/(Cr+Al) vs Fe/(Fe+Mg) plot also show that a few spinels are from the field of diamond inclusion chromites. This study suggests probable diamondiferous nature of the Anumpalle pipe.
Reaction Textures in Gneisses from Dallmannfjellet - Conrad Area, Orvin Range, Central Dronning Maud Land, East Antarctica : Implication for Metamorphic Evolution
Authors: Kundu Amitava , 'souza M. J. , Mohan Anand 
Published: November 2024

Abstract
Preliminary study of metamorphic reaction textures coupled with thermobarometry suggests that the metapelites. garnet-clinopyroxene gneisses. calc-silicate gneisses and orthopyroxene bearing quartzo-feldspathic gneisses exposed in Dallmannfjellet-Conrad area, central Dronning Maud Land, East Antarctica were metamorphosed to granulite grade. Peak metamorphic conditions evaluated from core thermobarometry are ~900 - 1050°C and pressure ~9 kbar. Sillimanite and garnet growth over spinel in metapelites suggests cooling of the rocks to 800°C, followed by a mild decompression inferred on the basis of orthopyroxene+plagioclase moats around garnet in metanorite pods within metapelite. The metanorite pods record P-T conditions of 7-10 kbar and 750-850°C. Late component of the P-T segments is represented by cooling stage and eventual exhumation of the terrain.
Sediment Mixing Pattern of the River Ajay with the Bhagirathi-Hooghly River System
Authors: Basumallick S. , Mukherjee P. C. 
Published: November 2024

Abstract
The sediment mixing pattern of the Ajay with the Bhagirathi-Hooghly river system has been worked out utilizing three different kinds of data viz. grain size, grain shape and heavy mineral composition. The near concurrence of the results of sediment mixing pattern worked out by three different techniques demonstrates the usefulness of each of the properties as tracer. The bed load contribution of the Ajay to the Bhagirathi during freshet appears to be 25% which can not be regarded as an insignificant contribution. Assuming the conventional bed load content of 5 to 15 percent of the total load, it can be presumed that the suspended load contribution of the Ajay to the Bhagirathi-Hooghly system couId also be quite significant and may be an important factor in the silting of the Hooghly in its lower reaches.
Archaean Komatiites from the Older Schist Belt of Kalyadi in Western Dharwar Craton, Karnataka
Authors: Subba Rao D. V. , Naqvi S. M. 
Published: November 2024

Abstract
The cluster of enclaves at Kalyadi, Hassan district includes ultramafic-mafic metavolcanic rocks and minor metasedimentary rocks such as chert, cherty quartzite and pelite. Occurrence of pillow and vesicular structures in the ultramafic rocks is being reported for the first time from this area. The average composition of the ultramafic rocks is : SiO2 46.05%, TiO2 0.18%, MgO 31.81%, K2O 0.15%. Cr 3409 ppm and Ni 1610 ppm with a CaO/Al2O3) ratio close tol. The composition, relict igneous structures and metasedimentary rock association are suggestive of a komatiitic affinity for these rocks, which possibly accumulated under subaqueous conditions.
Phurcalite: A Rare Secondary Calcium Uranium Phosphate Mineral from Putholi, Chittaurgarh District, Rajasthan
Authors: Singh Yamuna , Singh K. D. P. , Bhatt A. K. 
Published: November 2024

Abstract
X-ray powder diffraction data are presented for phurcalite [Ca2(UO2)3 (PO4)2 (OH4 4H2O], with orthorhombic symmetry, a very rare, yellow coloured, secondary uranium mineral, from Putholi (24°57'45":74"38'30"). The host rock is quartzite which contains fluorapatite, pyrite, goethite, hematite, magnetite, chlorite and mica as accessory minerals. Measured cell parameters of the phurcalite are: a0 = 17.3416 Å, b0 = 16.1138 Å and c0 = 13.5491 Å, with a cell volume of 3786.16 Å3.
Chronostratigraphic Implication of Carbon and Oxygen Isotopic Compositions of the Proterozoic Bhima Carbonates, Southern India
Authors: Kumar B. , Das Sharma S. , Shukla M. , Sharma M. 
Published: November 2024

Abstract
Carbon isotope records on carbonates from the Bhima basin are characterized by 13C enriched values (up to 4‰ PDB). These data are integrated with the available palaeontological records to suggest a Terminal Proterozoic (post - Varanger) age for the Bhima sediments. The carbon isotope compositions of Katamadevarhalli and Shahabad carbonates analysed in the present study exhibit two distinct trends. While the Katamadevarhalli carbonates show a positive trend, those from Shahabod display a negative trend from bottom to top, probably indicating long-term temporal trend of carbon isotope values.
Mineralogy and Geochemistry of Profiles Through Lateritic Nickel Deposits at Kansa, Sukinda, Orissa
Authors: Das S. K. , Sahoo R. K. , Muralidhar J. , Nayak B. K. 
Published: November 2024

Abstract
In the Sukinda ultramafic belt of Orissa, significant deposits of nickeliferous laterite have formed by weathering of large chromiferous dunite-peridotite suite of rocks. Two typical laterite profiles obtained by drilling (BH-1 = 50 m and BH-2 = 46 m) from Kansa sector of Sukinda belt were studied in order to establish petrochemical relationships between supergene Ni-laterites and the parent rock. In BH-1, ferruginous layers comprise the profile where goethite is intimately admixed with quartz, kaolinite and gibbsite at various depths. In BH-2, a complete laterite profile from bed rock (altered dunite) to top pisolitic laterite with transitional clay-serpentinite zone is encountered. The altered dunite is essentially composed of olivine (FO93.8 ? 35% vol.) and serpentine. The clay-serpentinite zone consists of varying proportions of smectite clay (nontronite) and antigorite with minor amount of chromite, goethite and quartz. This zone is enriched in Ni with a maximum value of 1.09% Ni. In the ochreous ferruginous zone overlying clay-serpentinite zone, serpentine and nontronite disappear completely and goethite constitutes the principal mineral with varying proportions of secondary quartz. This zone is rich in Fe, Ni, Co, Mn, Al and Cr and is formed by residual concentration of stable oxides. Mass-balance equation assuming Cr2O3 as constant chemical constituent reveals that nickel is strongly accumulated in the clay-serpentinite zone. A second maximum in nickel concentration is found in ochreous ferruginous zone with almost complete removal of magnesium. Normalised major and trace element data generated on the bore hole samples have been processed, by using R-mode factor analysis of correlation matrix to understand the natural process of weathering. Leaching studies of the samples suggest that nickel occurs in adsorbed state within amorphous hydrated iron oxide and in weakly bonded and lattice bound states within gaethite and secondary silicates.
Anatomy of a Porphyry Copper Deposit - Malanjkhand, Madhya Pradesh
Authors: Bhargava M. M. , Pal A. B. 
Published: November 2024

Abstract
The Malanjkhand ore body consists of rnineralised quartz veins, mainly of two generations, emplaced in altered and silicified granitoids. Hypogene wall rock alteration includes silicification, potassic alteration, chloritisation and biotitisation, Sassuritisation and sericitisation of plagioclase are common. Hydrothermal alteration has modified the composition of granitoids. Oxidation and supergene enrichment have resulted in distinct supergene mineral zoning. Leached zone, supergene oxide zone and supergene sulphide zone have been identified. Supergene enrichment has increased &gt;22% copper in the supergene sulphide zone. Localisation of copper in the deposit is related to intensity of fracturing in Stage-II veins as well as volumetric proportion of the silicified granitoid patches. The ore body contains &gt;2000 ppm Mo on the northern side. Mo mineralisation is independent of copper concentration. Gold and silver show positive correlation with copper. The mode of occurrence of sulphide mineralisation suggests its genesis under variable hydrothermal conditions. The localisation of quartz veins in long and narrow zones as well as limited hydrothermal alteration suggests that fluids must have followed permeable zones provided by the sheared and fractured granitoids.
Petrology Geochemistry of the Late Archaean Siliceous High-Magnesian Basalts (SHMB) from Kaklur, Southern Bastar Craton, Central India
Authors: Srivastava Rajesh K. , Singh R. K. 
Published: November 2024

Abstract
Greenschist facies rnetabasalts showing relict spinifex texture, associated with the Late Archaean Bengpal Group, are well exposed in the Kaklur area, Bastar craton. They are classified as siliceous high-magnesian basalts (SHMB) on the basis of its distinct chemistry, such as high SiO2 (52.83-54.52 wt%), high MgO (11.40-18.35 wt%), high Cr, Ni, enriched Rb and K, depleted Nb and Ti, and enriched-LREE patterns, as well as the presence of spinifex texture. Low Al2O3/TiO2 and Sc/Y ratios, high Ti/Zr and Sr/Nd ratios less than chondrite corroborate SHMB nature of these basalts and clearly distinguishes them from komatiites/lcomatiitic basalts and boninites. They show close geochemical similarities, particularly in high field strength and rare earth element concentrations, with other well studied Western Australian SHMB. Such SHMB are reported in literature to be derived either from komatiitic magma by crustal contamination though assimilation-fractional crystallization (AFC) processes or from magma generated from the refractory continental lithosphere.
Palaeomagnetic and Low-Field AMS Studies of Proterozoic Dykes and their Basement Rocks Around Harohalli, South India
Authors: Prasad J. N. , Satyanarayana K. V. V. , Gawali P. B. 
Published: November 2024

Abstract
Palaeomagnetic and Low-field Anisotropy of Magnetic Susceptibility (AMS) results are reported from 8 unmetamorphosed dolerite dykes, and from one site each of the Closepet Granite (CG), the Peninsular Gneiss (PG) and the Charnockite (Ch) in the Harohalli area of the Dharwar craton. The AMS results exhibit "normal" magnetic fabrics for three dykes. Rest of the dykes exhibit either "inverse" or "anomalous" magnetic fabrics, indicating the dominance of single domain (SD) uniaxial magnetite grains and a complex mixture of SD and multi-domain (MD) grains respectively. Almost similar AMS fabrics are exhibited by the Peninsular Gneiss, Closepet Granite and Charnockite. This magnetic fabric is in close conformity with the structural features of the terrain and indicates E-W compressional stress. Two dykes have yielded a mean characteristic remanent magnetization (ChRM) direction (D = 130°, I = -88°, a95 =33°; N=2) which is similar to a previous result from the same dyke swarm and the Tiruvannamalai dykes in the adjacent South Indian Granulite Terrain (SIGT). Thus we support the earlier suggestion (Radhakrishna and Joseph, 1993) that no relative motion took place between the granite-greenstone terrain (GGT) and the SIGT, at least since the emplacement of Tiruvannamalai dykes ca. 1600 Ma ago. The palaeomagnetic directions from the PG (D = 285°, I = 43°), CG (D = 300°, I = 43°), and Ch (D = 300°, I = 43°) are statistically indistinguishable and the corresponding pole positions fall close to those reported for 1100-1000 Ma old rocks. Thus partial remagnetization/streaking in these sites occurred probably during the Eastern Ghats orogeny. It appears that the Eastern Ghats orogeny has penetrated selectively into the adjacent Dharwar craton.
Geochemistry and Tectonic Setting of the Amritpur Granite Series, Kumaun Lesser Himalaya, India
Authors: Pandey Prabha , Rawat R. S. 
Published: November 2024

Abstract
Pre-Himalayan granites are important in the study of evolution of Himalaya. Amritpur Granite Series (AGS) in the Kumaun Lesser Himalaya is one such Pre-Himalayan, Precambrian granite and is of three types, viz. Porphyritic Amritpur Granite (PAG), Equigranular Amritpur Granite (EAG) and Amritpur Porphyry (AP). The field, mineralogical and geochemical characteristics of AGS are consistent with those of S-type granites. The AGS is peraluminous with A/CNK (&gt;1.1) and high normative corundum. besides high (87Sr/86Sr) ratio of 0.7117+0.0044. Major and trace element geochemistry of AGS indicates a syn-collisional regime and anatexis associated with pre-Himalayan collision during Precambrian times. The melt produced by anatexis has intruded into the Precambrian Bhimtal-Bhowalj Formation.