bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Aeromagnetic Data and Regional Geological Interpretation for a Part of the Cuddapah Basin
Authors: Ramanamurthy M. V. , Reddy U. S. N. 
Published: November 2024

Abstract
Based on total intensity aeromagnetic profile data across the Cuddapah Basin, it is possible to distinguish the Cumbum and Bairenkonda Formations of Nallamalai Group. Further subdivision within individual intercalated dolomites and quartzites of Cumbum Formation is also found feasible. This discriminatory criterion can be used to guide mineral exploration, especially in the dolomites of Cumbum Formation. The magnetic variations along the strike of the Cumbum Formation is considered to be due to minor undulations in basin geometry, ref1ecting palaeogeography of pre-Cumbum period. The high magnetic response in Tadpatri and Vempalli Formations is mostly due to their association with basic volcanism.
All along the eastern margin of the basin, there is an ascending magnetic trend which coincides with a thrust. The geometry of Iswarakuppam dome is inferred to be asymmetric and with a tilt towards cast and/or controlled by a crustal fracture. The relative high magnetic response and discordant trend over Kurnool Group of rocks in the western part of the Kunderu Basin is attributed to the occurrence of the basement at shallow levels locally. Regional and areal trend surfaces have been estimated and causative magnetic responses due to basement and overlying metasediments are evaluated. For trend surface analysis, window sizes have been determined and computerization is suggested. From the LANDSAT imagery interpretation, a three stage basin evolutionary trend has been inferred.
A northwest-southeast tectonic break near Cumbum town is proposed, along which the basin oscillated, causing shallowing of the basin to the north and deepening to the south. Further, it is postulated that the northern and southern blocks tilted to east and west respectively moving on a northeast-southwest axis, resulting in the basement rise in the northwest and southeastern parts and gentle slope in the northeastern and southwestern parts in the area of study.
Geology and Ore Reserve Estimates of Rampura-Agucha Zinc-Lead Deposit, Bhilwara District, Rajasthan
Authors: Gandhi S. M. , Paliwal H. V. , Bhatnagar S. N. 
Published: November 2024

Abstract
Rampura-Agucha zinc-lead deposit, located 15 km southeast of Gulabpura in Bhilwara District, Rajasthan, forms a part of pre-Aravalli Banded Gneissic Complex (3.2 to 2.5 billion years old) consisting of gneisses. schists and intrusives of acidic and basic igneous rocks, that occupy predominantly the southeastern plain of Ajmer and Bhilwara. The sequence of rocks from hanging wall to footwall in the deposit is (a) garnet-biotite-sillimanite gneiss/schist, intercalated with amphibolite, calc-silicate, pegmatite and aplite, (b) graphite-mica-sillimanite gneiss/schist, (c) footwall garnetbiotite- sillimanite gneiss with interlayering of granite gneiss, amphibolite, calc-silicate and pegmatite, (d) granite gneiss. and (e) mylonite. The rock units show northeast-southwest strike with steep dips in hanging wall (75°-80° ) and moderate dips in footwall (60°-65°) towards southeast and are suspected to have undergone more than two stages of deformation. Structurally, the deposit is interpreted to represent a doubly plunging. isoclinal, synformal fold with steep northeasterly plunge (65°-70°) in the south and shallow southwesterly plunge (20°-22°) in the north.
Graphite-mica-sillimanite gneiss/schist forms the host for economic mineralization and have a strike extent of about 1400 m. The ore zone is massive, wider in the middle section with tapering ends on either side along the strike. The persistence of ore has been established upto a depth of about 350m and is still open in depth. The economic minerals occurring in this deposit, in the order of decreasing abundance are sphalerite, pyrite, pyrrhotite and galena. The dominant gangue minerals occurring within the ore zone are quartz, felspar, micas (sericite, chlorite and biotite), graphite and sillimanite with negligible amounts of garnet and amphibole. The genesis of mineralization remains unclear, but presently it is interpreted as a volcanogenic massive sulohide that has later been subjected to high grade metamorphism and tectonic disturbances. The total ore reserves have been estimated to be 61.10 million tonnes with 1.57 % Pb, 13.48 % Zn and 9.58 % Fe.
Crustal Structure Along Wular Lake-Gulmarg-Naoshera Profile Across Pir Panjal Range of the Himalayas From Deep Seismic Soundings
Authors: Kaila K. L. , Tripathi K. M. , Dixit M. M. 
Published: November 2024

Abstract
Deep Seismic Soundings along Wular lake-Gulmarg-Naoshera profile across Pir Panjal range of the Himalaya have delineated the Srinagar and Jammu synclines, each having a maximum sedimentary thickness of about 18 km. In the Srinagar syncline, the thickness of Karewas (velocity 2.8 km/sec) varies bctween 0.5 km to 1.1 km near Babarishi. Karewas are underlain by Triassic limestones (velocity 4.55 km/sec) having a thickness of 2.0km near Muquam, increasing to 3.6 km south of Sopur. Its thickness decreases to 1.2 km near Babarishi. The third layer with velocity 5.8 km/sec is inferred as Panjal Traps having a thickness of 2.5 to 3.0km. A system of 3 high angle faults is also indicated in the Srinagar valley. In the Jammu syncline, the exposed Murrees and Middle and Lower Siwaliks (velocity 3.8 to 4.6 km/sec) indicate a total thickness of about 3 km near Naoshera overlying the Waishnodevi limestones (velocity 5.8 km/sec). A number of low angle faults have been delineated in the Jammu syncline.
The deeper crustal section is divided into three major blocks bounded by deep faults, the northern block being downfaulted with respect to the southern block. In the southern block, Moho is at a depth of 44km near, Main Boundary Fault, 57km under Pir Panjal range, 51 km under Babarishi. Moho is at a depth of 63 to 69km north of Muquam. Under the Great Himalaya, Moho starts rising from 78 km depth in the deepest part to 67 km under the Nangaparbat shot point.
Orthophosphates in the Shallow Groundwaters of South India
Authors: Sahgal R. K. , Ramesan V. 
Published: November 2024

Abstract
Detectable amounts of phosphates occur in the groundwaters of many parts of South India. Excessive concentrations occur in isolated parts either due to pollution of village wells or other cultural practices. The results of analyses carried out in 1982 and 1983 show significant differences indicating a general variability in the source. The excessive phosphate content in Chirala (10mg/l) and Bapatla (7mg/l) need further investigation. In most of the other areas, local geology and prevalence of phosphate bearing minerals play an important role in giving the observed phosphate content. Developing towns with no proper sewerage also show higher phosphate content in groundwater (e.g.; Karimnagar in Andhra Pradesh gives phosphate up to 1.5 mg/l).
Origin of the Palghat Gap in South India -A Synthesis
Authors: Subramanian K. S. , Muraleedharan M. P. 
Published: November 2024

Abstract
The east-west trending Palghat Gap across the Western Ghat hill ranges is a part of a well-defined low level landform along 10°45'N latitude in south India. The Nilgiri hills to the north and the Anai Malai-Palni hills to the south of the gap are marked by remnant plateau landforms representing a planation surface of Jurassic age. Field evidences are against block faulting and uplift of the hills to the north and south in post-Jurassic times to account for the elevation of the Jurassic surface and the evolution of a low level landform in between the hills. Results of recent studies do not support marine incursion in the gap area to carve out a low level landform.
It is put forward that crustal upwarp along an east-west axis coinciding with the Palghat Gap elevated the Jurassic surface; the brittle crustal rocks along the axis got ruptured by tensional stresses resulting from upwarping; and the ruptured rocks were eroded with comparative ease by fluviatile action. LANDSAT imagery (MSS Band 5 and 7) bears out the signature of an easterly flowing palaeo stream (Proto-Amaravati), which apparently dried up in post Mio-Pliocene times because of a change in the climatic pattern.
The upwarp of the continental crust is considered to be a natural response to correct the imbalance in equilibrium resulting from the erosion of crustal rocks and deposition of stupendous amounts of sediments in taphrogenic basins on the east coast. From the Plate tectonics angle, the elevation of the continental crust may be attributed to tremendous pressure exerted on the crust by vertical thermal plume activity related to Deccan trap volcanism.
X-Ray Fluorescence Analysis of Major, Minor and Selected Trace Elements in New IWG Reference Rock Samples
Authors: Govil P. K. 
Published: November 2024

Abstract
Major and minor oxides: SiO2, Al2O3, TiO2, CaO, MgO, Na2O, K2O, MnO, P2O5. Fe2O3(T) and a few selected trace elements Zr, Y, Sr, Rb, V, Ba, Cr. Ni, Co, Cu, Zn in the IWG standards AN-G. BE-N and MA-N have been determined relative to USGS geochemical reference samples and synthetic standards by using a PW1400 XRF analyser with P851 computer system in an attempt to get usable values for the standards.
Samples prepared in duplicate were repeatedly (ten times) analysed to check the reproducibility of the data which is within the range of ± 1.0 % of reported values for all the major and minor elements, ± 5% for trace elements and ± 10% for the trace elements at concentrations below 10 ppm. The average values are found to be in good agreement with the proposed values. The results on MA-N granite were found to be very reproducible and MA-N may be used as a replacement of USGS-Gl or G2 which are no longer available.
Algal Structures from the Upper Krol-Lower Tal Formations of Garhwal and Mussoorie Synclines and their Palaeo-Environmental Significance
Authors: Tewari Vinod C. , Fasiullah Qureshy M. 
Published: November 2024

Abstract
Algal pisolites, oncoids, columnar stromatolites and columnar layered stromatolites have been recorded from cherty dolomitic limestones from Upper Krol and Lower Tal formations. The algal mat facies show bird's eye structures and irregular fenestral fabric suggesting an intertidal supratidal environment of deposition for Upper Krol (D and E) Formation of Garhwal syncline. The basal Lower Tal Formation of Mussoorie syncline also represents a complex algal oncoidal-stromatolitic (protected tidal flat/lagoonal) facies with restricted circulation. The association of phosphorite with stromatolites and oncoids proves the phosphorite to be deposited in a shallow water environment. The presence of pyrite and associated black shales indicate an erobic condition.
Fluoride Ingestion into the Natural Waters of Hard-Rock Areas, Peninsular India
Authors: Ramesam V. , Rajagopalan K. 
Published: November 2024

Abstract
The Vedavati River Basin falling in the central part of Peninsular India is a typical drought prone hard-rock terrain. Many places in it show high fluoride content (maximum 11 ppm) in the ground waters. Detailed studies on the distribution and geochemistry of fluoride were conducted in the basin between 1974 and 1979. User oriented map showing fluoride distribution giving mean and standard deviation is compiled. The leachable fluoride in the soils is more significant in contributing the fluoride-rich water rather than the mere presence of fluoride-bearing minerals in the rock.
Occurrence of a Podocopan Ostracod Palmenella Mckenzii Sp. Nov. in the Marginal Water Bodies, East Coast of India
Authors: Annapurna C. , Rama Sarma D. V. 
Published: November 2024

Abstract
Distinguishing characters relating to carapace and soft parts of a new podocopan ostracod, P. mckenzii inhabiting the shallow backwaters of Bimili and lower reaches of the Vasishta Godavari estuarine system on the east coast of India, are described.
Cachar Earthquake of December 31, 1984 is it a Signal for the Beginning of Seismic Activity?
Authors: Gupta Harsh K. 
Published: November 2024

Abstract
The Cachar earthquake of December 31, 1984 is significant on two counts: i) It occurred in a region identified to be experiencing dilatancy stage precursory to a large earthquake by Gupta and Singh (1980), ii) An earthquake of magnitude exceeding 6 has occurred in the vicinity of the Shillong Plateau after a lapse of four decades. This may be signal of beginning of a seismically active period in the vicinity of Shillong Plateau similar to the one between 1869 and 1943 when six large earthquakes occurred in this region.
Pellatispira (Foraminiferida) from the Upper Eocene Kopili Formation of Garo Hills, Meghalaya
Authors: Samanta Bimal K. 
Published: November 2024

Abstract
The foraminiferal genus Pellatispira Boussac is represented by P. crassicolumnata Umbgrove, P. inflata Umbgrove, P. irregularis Umbgrove, P. madraszi (Hantken) and P. orbitoidea (Provale) in the Upper Eocene Kopili Formation of Garo Hills, Meghalaya. This is the first record of such an assemblage from the Indian region. Vacuolispira Tan is treated as a synonym of Pellatispira Boussac, while Biplanispira Umbgrove is considered as generically distinct from Pellatispira. The larger foraminiferal fauna of the Kopili Formation exhibits a close affinity with that of Upper Eocene succession of Indonesia.
The Deformation and Strain Analysis of the Gandemara Conglomerate from the Archaean Iron-Ore Group Rocks, District Singhbhum, Bihar
Authors: Srivastava Deepak C. 
Published: November 2024

Abstract
The Archaean I.O.G. metasediments exposed near Gandemara have undergone three successive deformational phases, D1, D2 and D3 of varying intensities. The quartzite pebbles from oligomictic conglomerate arc considered as the markers for finite strain analysis. Strong correlation between major and minor axes of the ellipses (sections of the pebbles along XY, YZ and XZ planes) and good linear fitting to the axial-ratio plots imply that these markers came from the same population. High values of fluctuation 'f' and nearly symmetric Rf/f patterns (IYSM values) indicate large initial axial-ratios (Ri &gt;Rs) and random predeformational fabric respectively. The axial-ratios of strain ellipses (Rs) in XY, YZ and XZ sections are 1.5, 1.83 and 2.5 respectively and these correspond closely with the ß values. The three dimensional strain analysis reveals that most of the pebbles have undergone flattening (?=0.2 to 0.4) corresponding to the low amounts of strain (es =0.6 to 1.0). Available structural relations and evidences from strain analysis strongly suggest that the conglomerate has been dominantly deformed during D1 phase and subsequently modified during D2 phase.
Distribution of Calcareous Nannoplankton from the Sedilnents of the Northwestern Continental Shelf of India
Authors: Shankaranarayana Guptha M. V. 
Published: November 2024

Abstract
Fifty-four snapper samples from the northwestern continental shelf of India have yielded fifteen species of calcareous nannoplankton along with a few reworked ones. Among the species encountered, Gephyrocapsa oceanica was most predominant, being distributed in all the stations. The patchy and sparse distribution of nannoplankton suggests that the flora has undergone intense grazing. Low diversity of nannoplankton indicates a marginal environment.
Stratigraphy of the Purana Supergroup Around Ramgundam, Andhra Pradesh
Authors: Chaudhuri A. 
Published: November 2024

Abstract
Middle and Late Proterozoic Purana Supergroup at Ramgundam in the Pranhita Godavari valley is separated from the underlying granites and gneisses of the Basement Complex and the overlying Gondwana Supergroup by two major unconformities. Evidence is adduced to show that two other major unconformities divide the Purana sequence into three chronologically independent units correlatable with the Mallampalli Subgroup and the Mulug Subgroup, two major divisions of the Pakhal Group, and the Sullavai Group in adjacent areas, viz., Mancherial and Mulug.
Both the Subgroups of the Pakhal Group comprise of silici-clastics at the base and are followed by carbonates while the Sullavai Group is constituted entirely of siliciclastics. Detailed section measurements show rapid facies variation, both lateral and vertical, to be a characteristic feature of the Pakhal formations. Formations in the Sullavai Group are regionally more uniform in character.
Lonar Crater, India: A Crypto-Volcanic Origin
Authors: Subrahmanyam Burra 
Published: November 2024

Abstract
One of the largest natural crater in the world is situated at Lonar (J9°59'N : 76°31'E) in the Buldhana district, Maharashtra. The crater is located in Deccan basalts and controversy exists about its origin. The earlier theories suggested a volcanic eruption. Morphological resemblance with other terrestrial craters, physical evidences like the identification of very high pressure shock deformation features and shatter cones have favoured an impact origin. Bore holes drilled could not establish a sufficient thickness of brecciated zone which is a prerequisite for an impact crater. Gravity and magnetic (Vertical Force) measurements favour a crypto-volcanic origin for the crater associated with a volcanic pipe or a carbonatite plug.
Petrology of the Carbonatites and Associated Rocks of Sung Valley, Jaintia Hills District, Meghalaya, India
Authors: Krishnamurthy P. 
Published: November 2024

Abstract
In Sung Valley, (Lat : 25°31' -25°36'N : Long; 92°05' -92°10'E) the Shillong Series rocks comprising mainly quartzites and phyllites are intruded by a N-S trending, roughly oval shaped body of pyroxenite covering an area of about 35 km2 and into which the following genetically related rock types have been emplaced in order of decreasing age and abundance. Peridotites (stock-like bodies), ijolites (ring dyke and plug like), carbonatites (incomplete cone sheets) and syenites (sheets, dykes and veins). Minor dykes and veins of magnetite-serpentine rock, ijolite and melilite-bearing types with a rough radial disposition are also present. Fenitization, due to both ijolites and carbonatites, has affected older rocks resulting in wollastonite-rich aegirine-augite bearing rocks, K-feldspar-aegirine-augite veins and oversaturated potassic syenites.
Carbonatites are mainly sovites with minor beforsite and types rich in magnetite and apatite are present. Average abundances of trace elements (values in ppm) characterizing carbonatites such as Bu (549), Sr (3134), La (50-100), Ce (489), Y (50), Nb (372), Zr (179) and P2O5 (5.7) wt% are comparable to those found in reported intrusive carbonatites. The weathered mantle of the carbonatites and the contact zones between carbonatites and pyroxenites have resulted in soils rich in pyrochlore, apatite and magnetite. It is postulated that the carbonatites may be differentiates of an ijolitic magma, in turn derived (liquid immiscibility?) from a parental mela-nephelinite or alkali picritic magma. The ultramafic suite could represent the cumulates from such a picritic source.
Deformational and Crystallization History of the Delhi Group Rocks, Around Narnaul, Haryana, India
Authors: Bhola A. M. , Varadarajan S. 
Published: November 2024

Abstract
The regional metamorphic rocks of Precambrian age belonging to the Delhi Group, around Narnaul, show complex deformational-crystallization history. The first deformation phase, F1 of Delhi orogeny produced isoclinal folds overturned towards southeast plunging in NNE-SSW directions associated with most pervasive foliation S1. The later deformation phases, F2, tight to open folds, and F3, open folds produced crenulation cleavages S2 and S3 (rare). These three deformational events have been correlated with the crystallization periods of the more important minerals in pelitic schists and amphibolites.
The study reveals that mineral assemblages were identical during the first and second deformation phases. The index minerals garnet, staurolite, kyanite, hornblende started forming either during F1 folding or immediately after F1 and continued till the close of F2 folding with incipient crystallization of micas during F3 phase. Mineral assemblages in the pelitic schists display a single staurolite-kyanite zone. Mineralogical reactions ,indicate metamorphism under amphibolite condition below 650°C with minimum temperature 540°C and pressure 5.5 kb (PL =Ptotal) in this part of the Aravalli belt.
Mineralogy and Chemistry of Manganese Nodules from the Southern Part of Carlsberg Ridge
Authors: Karisiddaiah S. M. 
Published: November 2024

Abstract
Petrographic study indicates that the nucleus of nodules is generally composed of clay, volcanic glass, basalt fragments, and earlier nodules. Polished sections indicate typical collomorphic globular segregations and partly crystalline oxides of todorokite. Scanning electron micrographs indicate that they are made up of small and large botryoids; and occasional platelets of todorokite, within cavities formed due to post depositional recrystallization. X-ray diffraction patterns do not show any peaks of todorokite due to poor crystallinity, while d-MnO2 is seen in all the nodules studied. The nodules analysed show: Mn 15.01-21.40%, Fe 10.07-20.10%, Cu 0.07-0.32%, Ni 0.32-0.57%, Co 0.07-0-21%, and also have a Mn/Fe ratio less than 2. The nodules are of hydrogenetic, secondary origin, source being volcanogenic.
Chitradurga Schist Belt - An Archaean Suture (?)
Authors: Naqvi S. M. 
Published: November 2024

Abstract
Chitradurga schist belt is a 450 km long linear feature of Archaean age and composed of several types of volcanic and sedimentary rocks. It has been deformed by 3-phases of folding rendering elucidation of stratigraphic sequence complicated. The volcanic rocks range in composition from Spinifix Textured Peridotitic Komatiite (STPK) to rhyolite. Volcanism appears to have occurred, at least at two diflerent stratigraphic levels in the belt. The STPK, basalt and rhyolite suites are not genetically related with each other, except in Gadag, where basalt-rhyolite may be cogenetic phases of the same suite. Chemogenic sediments have a higher order contribution and enrichment from volcanogenic exhalative component. Graywacke sedimentation is recognized at two stratigraphic levels. The graywackes of the central part of the belt and those from the Gadag part of the belt differ very much from each other in their abundance of rock fragments, plagioclase/K-feldspar and Na2O/K2O ratios, Fe2O3, MgO, Cr, Ni, Zr, Rb and Sr abundances. Detrital mineral content and REE pattern of the graywackes of the central part are similar to those from other areas of the world of the same period and appear to have been derived from mixed, but predominantly tonalitic source. Gadag graywackes, on the other hand, appear to have had a predominantly volcanic source. Folded BIF horizons too are inferred to form a significant part of the source areas. Gadag part of the belt is the youngest as the Bagewadi-Kodkal conglomerate contains porphyritic granite pebbles along with rhyolites. This progressive younging and widening of the belt to the north is governed by the attitude of the axial plane foliation and plunge of the fold axes. It also probably reflects the style of the opening of a rift in the Archaean continental crust. Gravity data support such a rift origin. Horizontal EW compression is an essential feature of the Chitradurga schist pointing to its being a probable late Archaean suture.