bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of Small-Scale Structures in the Kolar Schist Belt, South India
Authors: Mukhopadhyay Dilip K. 
Published: November 2024

Abstract
Well-preserved small-scale deformational structures in the banded ferruginous quartzite in the Kolar Schist Belt indicate four phases of folding (F1- F4 ) , and a shearing movement at low angle to the foliation planes. Both the F 1 and F 2 folds are very tight to isoclinal with attenuated limbs and sharp hinges. They are nearly (but not strictly) coaxial, resulting in type-3 interference pattern. The F3 folds are open and recumbent or gently plunging reclined with axial trend towards NNE-SSW. The folds of the fourth generation (F4) are of the nature of warps with vertical axial planes striking NE through E to SE. It is suggested that the F1 folds were originally isoclinal and recumbent/gently plunging reclined with northerly axial trend, coaxially refolded by upright and isoclinal F1 folds. As the F2 folds became isoclines further squeezing in the same direction was accommodated by a subhorizontal shearing movement at low angle to the foliation planes. resulting in wide variation in plunge of F1-F2 fold axes. The F1-F2 folds and mesoscopic shear zones developed due to an E-W subhorizontal compression acting over a protracted period of time. The F3 folds developed due to gravity induced vertical compression on subvertical foliations. whereas the F4 folds indicate a longitudinal shortening during the relaxation period at the waning phase offolding episodes.
Genus Anisomyon (Gastropoda) from the Cretaceous of Southern India
Authors: Ayyasami K. 
Published: November 2024

Abstract
A new species of the patelliform gastropod genus Anisomyon is reported for the first time from the Indian Cretaceous sediments. Its occurrence, palaeoecology and stratigraphic importance are discussed. A stereopair photograph of this important fossil is given for better resolution.
Hot Vents and Massive Sulphide Bodies on the Southern Parts of the East Pacific Rise (EPR) Seafloor Spreading Centres: Geometep-4
Authors: Roonwal G. S. 
Published: November 2024

Abstract
New ore bodies of sulphide on the diverging plate boundaries on the East Pacific Rise were discovered during the German Expedition Geometep-4 in the South Pacific. The marine sulphides occurring along the rift system are attributed to large-scale hydrothermal circulation through the fractured volcanic rocks on the seafloor. Such hydrothermal plumes in contact with basalt, result in leaching of metals and their subsequent reconcentration and deposition. Certain transition metals such as Cu Zn Fe get concentrated in the form of disseminated, stockwork particulate deposits that may hold commercial value. The occurrence of these deposits on the seafloor can be traced by certain geological, geophysical and biological tools.
Morphometric Studies on a part of Central Indian Ocean
Authors: Kodagali V. N. 
Published: November 2024

Abstract
Morphometric and slope angle studies carried out on a part of Indian Ocean Basin have shown that gentle slope angle ranges dominate, 92% of the area represented by 0-3° slopes. Young's hypothesis of log-normal distribution of slope angle frequencies is found to be valid for deep sea topographic data also. Elevation-relief ratios and ruggedness values are relatively high for the southern portion of the study area whereas these values are less in the northern portion. Some of the features like abyssal hills and the seamount recorded in the region might have been formed due to volcanism. Some secondary topographic features could have resulted due to post-depositional processes. Slope angle, elevation-relief and ruggedness can be used in inferring certain features in the oceanic surface.
Undaturbidite in the Talchir Group, Talchir Gondwana Basin, Orissa
Authors: Pandya K.L. 
Published: November 2024

Abstract
A sedimentary sequence constituted of interbedded sheet sandstones and shales and lenticular channel sandstones exhibits a number of sedimentary structures common in turbidites. These are various types of sole marks, graded bedding, ripple-drift cross laminations, parallel laminations and asymmetric current ripples. The sheet sandstones. show characteristic internal vertical arrangement of structures identical to turbidite sequences while the shales are laminated. Besides, a few rolled boulders and cobbles are found within the sequence.
The combination of sedimentary structures suggests origin by a turbidity current mechanism. The association of lenticular channel sandstones, rolled boulders and cobbles and the grain-size characteristics, on the other hand, suggest it to be undaturbidite, having the characteristics intermediate between tractive and turbidity current deposits. The probable depositional environment of the sequence is discussed.
Some New Data on the Genesis of Granitic Pegmatites
Authors: Shmakin B. M. 
Published: November 2024

Abstract
The correlation between the type of mineralization in granitic pegmatites and the depth of their formation is supported with new data. The fluid pressure in pegmatites is 2-3 times greater than that of the calculated lithostatic pressure due to the over-pressure of volatiles in the closed pegmatite system. Experimental work shows that during cooling the pegmatite melt saturated with volatile components divides into two or three fluids. Such a 'liquation' provides an explanation for many of the complex structures and peculiarities of the mineral composition obsei ved in pegmatites.
In many regions heterogeneous pegmatites (primarily magmatic or metamorphic) may converge through the processes of albitization and muscovitization. A specific group of post-magmatic pegmatite-like bodies can be formed as well.
The Prakasam Alkaline Province in Andbra Pradesh, India
Authors: Leelanandam C. 
Published: November 2024

Abstract
The Prakasam alkaline province is essentially composed of three major nepheline syenite plutons at Elchuru, Purimetla and Uppalapadu, and one silica-oversaturated (syenite and quartz syenite) pluton at Settupalle. These four post-orogenic plutons, all occurring in the Prakasam District of Andhra Pradesh, display dissimilar internal structures and variable rock associations; they are almost exclusively salic and generally show evidence of passive emplacement.
The gross petrographic characteristics of the individual plutons are presented, and a generalised discussion on the petrogenetic aspects is included. The undersaturated and oversaturated syenites of the province are supposed to have formed from a critically undersaturated hornblende syenite magma by branching differentiation mechanism. The gabbros represent tholeiitic magmatism preceding the emplacement of alkaline rocks, and the ferrosyenites represent the final product of a closed system fractionation (with Jow fO2) of magma that gave rise to gabbro-anorthosite complexes.
The geological setting of the plutons is portrayed and the tectonic significance of the province, especially in its regional context, is highlighted. The feldspathoidal plutons of the province are conspicuously confined to an extremely narrow linear belt which is close to the known basement fracture zone, with which the major Bouguer gravity axis runs in close paralJelism ; this belt lies at the junction between two (granitegreenstone and gneiss-granulite) terrains.
The localisation of feldspathoidaI plutons at the western margin of the middle Proterozoic mobile belt and their absence in the cratonic region is significant. The over-all development of the mobile belt is speculated in the light of currently fashionable tectonic models. Crustal shortening and thickening of the mobile belt due to collision tectonics, predate the emplacement of the alkaline plutons; the lithosphere controls the character of the magmatism, and pre-existing abyssal faults determine the location of alkaline magmatism.
Angular Unconformity Between Manikaran Quartzite and Chlorite Phyllite, Rampur Window, Kulu District, Himachal Pradesh
Authors: Sen D. B. 
Published: November 2024

Abstract
An angular unconformity between Manikaran quartzite and overlying chlorite phyllite is observed near Dharmoar, Parvati valley section of the Rampur window. The chlorite phyllites were deposited over the deformed and eroded surface of the quartzites. It is suggested that this unconformity has influenced the control of uranium mineralisation in the rocks of Rampur Group of the area.
Least Squares Modelling of Crystal Fractionation in Pavagarh Lava Flows of Gujarat
Authors: Mukherjee Pulok Kr. , Gupta Praveen Kumar 
Published: November 2024

Abstract
The Pavagarh Hill is made up of a lava suite comprising seventeen horizontal flows. Its geochemical variation provides compelling evidence that there exists genetic relationship among the various flows and hence it offers an interesting case study for crystal fractionation process. In this paper, least squares modelling, using the massbalance relation has been carried out, to determine the most probable phases and their amounts that must be extracted from or added to a flow to obtain the composition of the next younger flow. The stability of the model was tested by performing singular value analysis. The outcome of this modelling supports the hypothesis that the whole series is a result of crystal fractionation in two episodes with first and eleventh flow serving as the parent magma for the two sub-series. However, minor amount of magma mixing was needed to explain the evolution of lower series. Further, on the basis of the estimated phase proportions, that need be subtracted or added, the trace element abundances in derivative magma are computed, using Rayleigh fractionation law, and are found to be comparable with the observed values.
Stratigraphy of the Penganga Group Around Adilabad, Andhra Pradesh
Authors: Chaudhuri Asru K. , Dasgupta Somnath , Bandyopadhyay Goutam , Sarkar Subir , Bandyopadhyay P. C. , Gopalan K. 
Published: November 2024

Abstract
The Proterozoic sequence around Adilabad, Andhra Pradesh comprises a distinct lithostratigraphic unit of 'Group' status and has been given the name Penganga Group. The Penganga Group has been classified into three Formations which are, in order of younging, Pranhita Sandstone, Chanda Limestone and Sat Nala Shale. The sequence is dominated by limestones and shales which were deposited in relatively deep water environment and, thus, contrast sharply with the conglomerate, sandstone and shallow water limestones of the Pakhal Group. Radiometric dating of fresh glauconites from middle part of the Penganga Group gives an age of 770 ± 30 Ma. Thus, the Penganga Group is the youngest of all other Proterozoic sequences in Pranhita-Godavari Valley.
Basalt Microlapilli in Deep Sea Sediments of Indian Ocean in the Vicinity of Vityaz Fracture Zone
Authors: Nagender Nath B. , Iyer S. D. 
Published: November 2024

Abstract
Two cores recovered from the flanks of Mid-India oceanic ridge in the vicinity of Vityaz fracture zone consist of discrete pyroclastic layers at various depths. These layers are composed of coarse-grained, angular basaltic microlapilli in which labradorite is the major mineral set in a glassy mesostasis. Chemically the microlapilli are similar to Mid-Indian oceanic ridge basalts. The microlapilli are suggested to have been formed by the process of granulation, transportation and deposition, during Late Quaternary when lava of low viscosity erupted from small vents on a segment of Vityaz fracture zone.
On the Validity of the foraminiferal Species Globotruncana Renzi Gandolfi
Authors: El-Nakhal Hamed A. , El-Naggar Zaghloul R. 
Published: November 2024

Abstract
The validity of the Late Cretaceous planktonic foraminiferal species Globotruncana renzi Gandolfi, and the relationship between this species and Globotruncana angusti-carinata Gandolfi, are discussed. It is suggested that G. renzi be dropped since it is a junior synonym of G. angusticarinata.
Malanjkhand: Proterozoic Porphyry Copper Deposit, M.P. India
Authors: Sikka Deshbandhu 
Published: November 2024

Abstract
The Malanjkhand porphyry copper deposit is estimated to contain 789 million tonnes averaging 0.83% Cu @ cut-off-grade of 0.20% Cu, 0.004wt% Mo, 0.2 gm/T Au, 6 gm/T Ag. 448 million tonnes 0.84% Cu (millhead grade) are available for open pit mining to a depth of 100 MRL. The deposit can support a mine, mill, smelter and refinery complex to produce 100,000 TPY of cathode copper at an installed cost of US$557.126 millions.
The deposit is arcuate in shape, 2,600 meter long, 142 meter wide, 900 meter deep and open for exploration at depth across and along strike. The deposit consists of a large body of primary copper ore in granitic rocks and is overlain by a cap of oxidized ore (7.532 million tonnes 0.8 wt % Cu). The granitic rocks are biotite granite, quartz diorite, granodiorite and adamellite (quartz monzonite). The granitic rocks are 1684±67m.y. and 1816±73m.y., (Middle Proterozoic age). Hypogene alteration includes sericitization, saussuritization, chloritization, propylitization, silicification, potassic and sodic alterations. The main primary copper mineral is chalcopyrite. The secondary copper minerals are a number of copper sulfides, sulfates, carbonates, oxides, native copper and chlorides.
Probable Causes of the Failure of Kantalai Dam- Sri Lanka
Authors: de S. Jayawardena U 
Published: November 2024

Abstract
The Kantalai reservoir dam collapsed in April, 1986. National and international investigators have observed that the failure could have occurred mainly due to three reasons.
Firstly, failure of mortar joints in the sluice barrel, secondly, vibration effect that may have affected while installing a pump house by driving piles. Finally, dewatering of seepage water from the intake well during the stage of excavation for the same construction.
A brief geological investigation in the area around the dam-site of the oldest reservoir in Sri Lanka was carried out within the first 48 hours of the disaster. Geological structure, rock types and weathering conditions of the foundation rocks were visually observed with special attention to the locations where the failure occurred.
The block material, charnockite. is an excellent rock but showed signs of extensive spheroidal weathering. The author wishes to point cut that the failure to remove these weak residual materials prior to construction of the dam could have been a major contributing factor that led to reservoir leakage through these materials. Continuation of further weathering and erosion of finer particles due to leakage could have been another factor to accelerate the process of collapse of the dam. Observations evidenced that the joint orientation, rock foliation and its structure do not comply with the ideal geological requirements for a dam-site.
A Study of the Rare Illite Deposits Around Mujjur, Near Gadag, Karnataka State
Authors: Khoshroo Ali , Devaraju T. C. 
Published: November 2024

Abstract
Clays are localized in their occurrence to the sheared and deeply weathered rhyolite-rhyodacite). These contain illite in association with minor proportion of neoforrned chlorite and a large proportion of relic quartz. XRD, IR and thermal properties of Mujjur illite correspond to pure illite. The clays are characterized by higher alkalies (K20 4.7%), with correspondingly low PCE value of 1420°C, absence of swelling minerals and very low CEC and dye adsorption.
Archaean Shelf-Facies and Stromatolite Proliferation in Dharwar Supergroup, North Kanara District, Karnataka
Authors: Srinivasan R. , NAQVI S. M. , Vasantha Kumar B. 
Published: November 2024

Abstract
The stromatolitic cherty dolomite of KaIche is a lithostratigraphic equivalent of the carbonate rocks of the Joldhal Formation of Archaean age. Morphotypes suggest development in subtidal to lower intertidal zone of the Dharwar seas. Some of the forms observed near Kalche are comparable to the domical forms observed near Kumsi in the Shimoga schist belt and Vanivilaspura in the Chitradurga schist belt. The morphotypes observed in these regions contrast with the actively and passively branched columnar stromatolites observed near Dodguni and Bhimasamudra in the Chitradurga schist belt where the stromatolites evolved in an intertidal environment. Diversity of morphotypes of stromatolites appears to have occurred in the Archaean itself, although such diversity appears to have attained stratigraphic significance by the middle Proterozoic.
Terrace Evolution in the Jakh-Bargal Area, District Nainital, Kumaun Lesser Himalaya, Uttar Pradesh
Authors: Kumar Anjani 
Published: November 2024

Abstract
Three levels of depositional terraces are well developed along the Ghat Gad and Khairna valley suggesting three phases of uplift. The rate of deposition in the Ghat Gad valley might have been greater than the rate of uplift, while in the Khairna valley the rate of deposition perhaps lagged behind the rate of uplift. Waterfalls, debris. Fans and triangular fault facets also suggest uplift. Landslide debris have contributed towards the formation of terraces ( = T2 terrace) in Garjauli and Barga) areas. Drop IQ the river profiles of Khairna and Ghat Gad being of the order of 40 m/km and 100 m/km respectively, indicating that the Ghat Gad has a very high down-cutting capacity. The formation of new terraces in the area can thus be attributed to the continuing slow rise of the terrain and high down-cutting capacity of the rivers, west of Garampani fault.
Geomorphotectonics of the Basement in a Part of Upper Son Valley of the Vindhyan Basin
Authors: Das L. K. , Mishra D. C. , Ghosh D. , Banerjee B. 
Published: November 2024

Abstract
Ground magnetic survey of part of central India covering the Vindhyan Basin of the upper Son valley region has delineated some subsurface vsolcanogenic Proterozoic rifts below the Vindhyan cover and several faults which have controlled the tectonics of the region. The magnetic map in general shows four distinctly different domains with magnetic anomalies differing both in amplitude and their nature. In general, the Vindhyan basin is characterized by low amplitude broad anomalies while the Mahakoshal (lower Proterozoic) Group depicts large amplitude sharp anomalies due to the presence of high susceptibility (2-19 × 10-3 CGS units) ferruginous rocks in them. The domain boundaries are either faults or indicate formational contacts between the different types of rocks with contrasting susceptibility values.
The subsurface basement relief map of the Pre-Vindhyan topography determined by 2-dimensional Harmonic Inversion of the magnetic data reveals an asymmetric graben structure with the southern boundary fault between the Vindhyans and the Mahakoshals as the most prominent linear structure.
Correlation of Deep Shock Earthquakes With the Dynamic Centre of the Solar System
Authors: Murthy S. R. N. 
Published: November 2024

Abstract
Dispositional patterns of outer planets and the resultant angular momenta have been exammed for the deep shock earthquakes which occurred during the first half of this century. It is observed that there exists a correlation between the disposition of resultant angular momenta (the dynamic centre) of the outer planets and the terrestrial longitude of the place of deep earthquakes.
Geochemistry and Genesis of the Abar River Granite, Northwest of Udaipur City, Rajasthan
Authors: Rahman Abdul , Zainuddin Syed M. 
Published: November 2024

Abstract
The granite is fine-to coarse-grained and constitutes mainly of quartz; K-feldspar and plagioclase. Among accessories, muscovite, biotite, chlorite, zircon, apatite and sphene are common. K-feldspar is generally microcline with perthitic intergrowth. The albite grains have similar optical orientation as that of the microcline; they are inferred to have formed by the ionic exchange of K by Na. The rock ranges in composition from granodiorite to granite. Variation trends of the plots of major and trace elements on Harker's diagram indicate that the granite is not formed by a simple fractional crystallization or partial melting of common homogeneous source. Plots on Rb, Ba and Sr ternary diagram reveal that it is a least differentiated normal granite type. Molar concentration of Al/(Na+K+Ca) &gt; 1.1 and Rb/Sr ratio of 0.53 indicate a peraluminous source of the granitic magma. High silica content, and the mineral assemblages of the granite correspond to S-type granite.
Distribution and Factor Analysis of Benthic Foraminifera in Nizampatnam Bay, East Coast of India
Authors: Sreenivasa Rao P. , Yeruku Naidu T. , Satyanarayana G. 
Published: November 2024

Abstract
Benthic foraminifera from surface sediments of Nizampatnam Bay were studied to determine modern distribution of important assemblages. Q-mode factor analysis of the data distinguished four significant factor assemblages that account for 91.9% of the information given in original data matrix. These assemblages are: 1. Asterorotalia, 2. Quinqueloculina and Spiroloculina, 3. Ammonia and Ammobaculites, 4. Amphistegina. These assemblages show response to environmental variables such as substrate and organic matter content. Abundance of Asterorotalia and Ammonia assemblages (factors I and III) probably reflects organic enrichment of fine sediments in the bay. Quinqueloculina and Amphistegina assemblages (factors II and IV) are found in the sandy substrate in the form of reworked fauna.
Groundwater in the Peninsular Indian Shield: A Framework for Rational Assessment
Authors: Narasimhan T. N. 
Published: November 2024

Abstract
The population of peninsular India relies heavily on groundwater for drinking purposes, agriculture and industrial needs. Critical to the well-being of this population is the judicious exploitation of this vital resource. India has made significant investments of physical resources and trained man-power over the past four decades towards a systematic exploration and development of groundwater resources. This goal will be greatly facilitated by directing the overall planning of these activities on the basis of a framework that is specific to the physico-chemical process that govern the hydrogeologic conditions of peninsular India. Competing with this need is the equally important need of providing the minimal requirements of clean water in critical regions of deficiency. The challenge is to formulate a plan that balances the two objectives in a complementary, winning manner. From a technical view point, very little attention has so far been devoted in peninsular India to the understanding of the vadose zone that spans the region between the land surface and the flucluating water table. A quantitative knowledge of the dynamics of water storage and release from this zone is of paramount importance to the management of groundwater resources in the peninsular Indian shields. The hydrogeology of peninsular India can offer exciting intellectual challenges to students of natural sciences.
Petrochemistry of Piemontite-Bearing Assemblages in Calc-Silicate Rocks from Sausar Group, India
Authors: Fukuoka Masato , Mondal A. , Guha Dipayan , Chattopadhyay G. 
Published: November 2024

Abstract
Piemontite-garnet bearing assemblages with or without braunite, occur in calc-silicate rocks in Sausar Group, India. The studied assemblages equilibrated under similar physical condition of metamorphism, at a high fO2 regime. Chemically both piernontite and garnet are enriched in Mn in braunite-bearing assemblages, as compared to the braunite-free ones. petrographic features show that garnet+calcite±hematite are the late overprints in these assemblages, derived through a devolatilization reaction involving piemontite+precursor carbonate+quartz±braunite. The study shows that in the braunite-bearing assemblages, the 'maximum' Mn3+ content of the piemontite was not dictated by the mere presence of braunite, but it is rather correlatable with the modal abundance of braunite. Further, the XMn3+ in the piemontite and the modal abundance of braunite have a direct relationship with Al/Mn, Mn/Al+Si and Si/Al) ratios in the bulk composition of the assemblages. In the present situation the Al-Mn3+-Fe3+ distribution coefficients amongst equilibrating piemontite-garnet pairs show strong dependence on the bulk chemical composition.