bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of Fayalite (+Quartz) Assemblage in Gokanakonda Syenite, Prakasam District, Andhra Pradesh
Authors: Srinivasan T. P. , Natarajan R. 
Published: November 2024

Abstract
The Fayalite syenites of Gokanakonda in Andhra Pradesh, India, are mineralogically divided into two types: (1) fayalite-clinopyroxene syenites (FC-syenites) and (2) fayalite-quartz syenites (FQ-syenites). The olivine composition ranges from Fa90-95 and the petrochemistry suggests their successive evolution in that order. The assemblage (fayalite+magnetite+quartz) in these syenites suggests a pressure of 11.5 kb and a temperature of 900°C under constant fo2.
A Rapid Method of Ferromanganese Nodule Mounting
Authors: Mukhopadhyay S. , Banerjee R. 
Published: November 2024

Abstract
A rapid method of sample preparation for ferromanganese nodules and crusts mounting is presented here, by using laminated polyester resin, cobalt napthanate and methyl ethyl ketone peroxide. With this technique vacuum impregnation is not required. Any naturally soft and brittle material can be successfully mounted by this procedure.
Lithofacies and Environments of Deposition of a Part of Talchir Group, Talchir Gondwana Basin, Orissa
Authors: Pandya K. L. 
Published: November 2024

Abstract
The Talchir sequence is divisible into three units named informally as 'Unit A', 'Unit B' and 'Unit C' from the base to the top. Eleven lithofacies have been recognised. The lithofacies associations and their inter-relationships suggest deposition of Unit A in a network of alluvial braided stream environment merging into a lake. Unit B represents three phases of delta advance into a lake basin with the development of prodelta, delta slope, subaqueous delta platform and deltaic distributary sediments. The sediments of Unit C were laid down in a quiet lake basin of moderate depth with the sedimentation being from suspension and chemical precipitation followed by intermittent clastic density underflows.
Deformation Microstructures and Geochemistry of the Mylonitic Augen Gneisses in the Chail Thrust Zone in Satluj Valley of Himachal Pradesh
Authors: Gururajan N. S. 
Published: November 2024

Abstract
Microstructural and geochemical analysis have been carried out on the mylonitic augen gneisses of the Chail thrust zone, in the Satluj valley of Himachal Pradesh. The microstructural features of K-feldspar, plagioclase, quartz and mica indicate that these gneisses have undergone an early deep level ductile deformation followed by a high level brittle deformation. The mylonites and blastomylonites represent ductile deformation products and the cataclasite represents brittle deformation product. The mylonitization is related to thrusting events during the Himalayan Orogeny.
Available geochronological data with high initial strontium ratio suggests that the protoliths of the mylonitic augen gneisses (Svtype granitoid) intruded the Chait formation during Precambrian times. The major element chemistry, with the absense of normative corundum values and low Al-index values indicate a mantle origin.
Appraisal of Environmental Impact of the Construction of Jamrani Dam in Nainital District, Kumaun Himalaya, India
Authors: Anbalagan R. 
Published: November 2024

Abstract
Construction of big dams lead to modification of existing fluvial conditions, in addition to affecting the socio-economic conditions of the people of the area. Analysis of the environmental impact on river-bed morphology, hydrogeological regime, stability of hill-slopes around reservoir, seismicity conditions, land-use and socio-economic conditions due to construction of the proposed 130m high dam across the Gaula River at Jamrani (29°16' : 79°36'36") in the Nainital District, Kumaun Himalaya, indicates that there may not be any adverse environmental impact in the area, but on the contrary the project is likely to bring economic benefits to the Bhabar belt of the Nainital District, by enhancing water availability for domestic, industrial and agricultural needs.
Geochemistry of the Alkaline Rocks of Sarnu-Dandali Area, District Barmer, Rajasthan, India
Authors: Chandrasekaran V. , Srivastava R. K. , Chawade M. P. 
Published: November 2024

Abstract
The alkaline suite of Sarnu-Dandali (comprising ultrabasic alkaline rocks, ijolite, foidal syenite, phonolite and carbonatite) is one of the few occurrences of carbonatite-nephelinite association reported in India. The suite is intrusive into the Lower Cretaceous sedimentaries. The rocks show a continuous gradation from alkali pyroxenite to feldspathic ijolite through micro-melteigite and ijolite, Foidal syenite and phonolite mark the end phase of ijolitic series and phonolites are the last to be emplaced. Carbonatites include sovitic alvikite and ferro-carbonatite varieties. The suite shows a progressive increase in Al2O3, Na2O and K2O and decrease in MgO, CaO, total Iron, MnO and TiO2 with increasing SiO2. Fractional crystallisation has played a dominant role in the evolution of the suite, the major fractional phases being pyroxene and iron oxide mineral.
The Albitite Line of Northern Rajasthan-A Fossil Intracontinental Rift Zone
Authors: Ray Sumit Kumar 
Published: November 2024

Abstract
A 170km long NNE-SSW lineament, extending from the Khetri Copper Belt to the Dudu-Kishangarh sector, is characterised by intrusives of albitite, composed predominantly of aventurine albite. Textural evidences suggest that the albitites, magnetite-albitites and pyroxenites, occurring along the Albitite Line, represent different cumulate fractions derived from the same source magma. The fractures, which tapped the magma chamber are related to an intracontinental rift system.
Cyanophyta (Girvanella) as Micrite Contributors to Permo-Triassic Limestones of Pirpanjal Range, Kashmir Himalaya
Authors: Bhat G. M. 
Published: November 2024

Abstract
Two species of Girvanella (G. ducii and G. wetheredii) have been observed during the course of microfacies analysis of limestones of Pirpanjal range. Observations made on three types of Girvanella clasts (tubules, rafts and oncolites) and the associated allochems have revealed calcified algal contribution to the sediments in the form of algal clasts and production of micrite by boring and perforating activities of the Girvanella. The preservation of porous and delicate Girvanella rafts indicates very little reworking prior to transport and deposition.
Paleochannels of the Palar River West of Madras City: Possible Implications for Vertical Movement
Authors: Narasimhan T. N. 
Published: November 2024

Abstract
Hydrogeological field observations indicatc that the river Palar, which now follows a south-easterly course in the vicinty of Kancheepuram, once flowed towards the north-east during quaternary times. The shift appears to have taken place in four stages. The shifts probably, suggest gently vertical movements to the north of the river. If such vertical movements have indeed occurred, It should be of interest to study their relation in regional vertical motions elsewhere along the east coast and their implications to regional hydrogeology of aquifers.
Silver Mineralisation in Ingaldhal Copper Deposit, Chitradurga Greenstone Belt, Karnataka
Authors: Raghu Nandan K. R. , Vidyadharan K. T. , Naik R. H. , Murthy V. S. 
Published: November 2024

Abstract
Native silver alloyed with gold in varying proportions occurs as tiny inclusions mostly in the sulphide ores of Ingaldhal, Chitradurga schist belt. The data presented establishes the copper deposit as a source of silver metal too and the appropriateness of terming the hill 'Belligudda' (Silver Hill) by the ancient miners is affirmed. The volcanic flows having a dominant tholeiitic character are the actual source of basemetals, as well as precious metals, while tectonism and metamorphism aided by the intrusion of Chitradurga granite pluton have probably caused variable amounts of redistribution and remobilisation.
Petrology and Problems of Dating Karal Rocks
Authors: Ghate Savita , Raghavan Hema , Rajagopalan G. 
Published: November 2024

Abstract
14C dates supplemented by micromorphological studies of Karal rocks are presented. 14C dates, micromorphological analysis and sedimentological processes reveal that the calcite cementation of Karal rock, drift-wood and lithounits have taken place in several phases and not in a single stage. This appears to be the main reason for the discrepancy of 14C dates of the Kara1 and wood samples occurring at the same stratigraphic position and depth.
Studies on the Distribution of Organic Matter and Carbonate Content of Sediments in Mahe Estuary, Northern Kerala
Authors: Sebastian Syriac , George Roy , Damodaran K. T. 
Published: November 2024

Abstract
Sediment samples collected from selected stations in the Mahe estuary during the pre- and post-monsoon periods were analysed for their texture, organic matter and carbonate content. It is observed that finer sediments, mainly clayey silt, constitute the major part of the estuarine substratum. Organic matter in the bulk sediments generally follows the distribution pattern of the sediments, i.e., finer the texture greater the organic matter content, whereas the carbonate content shows an inverse relation with the texture. Studies on seasonal variations show that the post-monsoon sediments have higher proportions of organic matter (average: 4.12%) and carbonate (average: 5.23%) content more than those of pre-monsoon periods. No significant relationship between organic matter and carbonate content is observed during pre-monson (r = -0.35) and postmonsoon (r = -0.27) periods.
LANDSAT Image Enhalncement for Mapping Fluvial Palaeofeatures in parts of Middle Ganga Basin, Bihar
Authors: Philip G. , Gupta R. P. , Bhattacharya A. 
Published: November 2024

Abstract
An area in the Middle Ganga Basin, lying around Monghyr, Bihar, has been selected for delineation of fluvial palaeofeatures. The investigation is based on aerial photographs LANDSAT MSS and TM data products and ground data. Digital enhancement of LANDSAT MSS and TM data by linear contrast stretching and ratioing has been found to be highly powerful in identification and mapping of subtle fluvial palaeofeatures. Based on the above interpretation, a summary of the fluvial palaeo-history is presented.
An Unusual Evaporite Association from the Papaghni Group, Cuddapah Basin
Authors: Phansalkar V. G. , Kale Anand S. , Karmalkar Nitin R. , Kale Vivek S. 
Published: November 2024

Abstract
The hitherto unreported occurrence of halite and gypsum casts from the Vempalle Formation is reported. Implications in terms of the early depositional history of the Cuddapah Basin is discussed.
Silver-Bearing Sulphosalts from Rampura-Agucha Massive Sulphide Deposit of Rajasthan
Authors: Mukherjee A. D. , Glahiri Samhita , Bhattacharya H. N. 
Published: November 2024

Abstract
Occurrence of freibergite, argentian pearcitc and miargyrite, from the Rampura-Agucha sulphide deposit is reported.
A Textural and Mineralogical Study of the Beach Sands Between Talapady and Surathkal, Karnataka
Authors: Jayappa K. S. , Subramanya K. R. 
Published: November 2024

Abstract
The beach sediments are medium-sized sand, unimodal, well-sorted to mode-rately sorted, nearly symmetrical and mesokurtic to leptokurtic in terms of their grain size distribution. The sand-silt ratios are very high. The content of heavy minerals is very less compared to the content of light minerals and there is an appreciable percentage of shell fragments. The heavy minerals commonly found in these sediments in the decreasing order of abundance are opaques, garnet, zircon, hornblende, actinolitetremolite, sillimanite, enstatite, rutile, pyroxene, spinel, epidote and kyanite. The percentage of quartz in the light mineral fraction varies from 68 to 99. The provenance of these beach sands is the Netravati river basin of Western Ghats largely consisting of Precambrian granitic gneisses.
Occurrence of Ijolite with Veinlets of Carbonatite in the Deccan Trap at Murud-Janjira, Maharasbtra, India
Authors: Sethna S. F. , D'sa Christopher P. R. 
Published: November 2024

Abstract
Petrographic and petrochemical studies indicate the Ijolite to be somewhat magnesium-rich. The agpaitic index is very close to one and the magma is considered to be of an intermediate type (between miaskitic and agpaitic). The structural setting of the area is of the rift type, as the Panvel flexure occurs just a little to the west of the pluton.
Geochronology and Geochemistry of Granite Plutons from East Khasi Hills, Meghalaya
Authors: Ghosh Subhasish , Chakraborty S. , Bhalla J. K. , Paul D. K. , Sarkari Amitabha , Bishui P.K. , Gupta S. N. 
Published: November 2024

Abstract
Discordant granite plutons at Kyrdem, Nongpoh and South Khasi intrude the basement gneisses and the overlying Shillong Group of metasediments in the Meghalaya Plateau. Porphyritic granitoids ranging in composition from quartz monzonite to granite represent the dominant component in all the three plutons. Common characteristics of these granitoids arc spatial association with hornblende dioritic rocks, dominantly potassic and metaluminous nature. A positive correlation of SiO2, Na2O + K2O, Rb, Rb/Sr and negative correlation of CaO, MgO, FcO(T), Sr, TiO2 with Differentiation Index in the Kyrdcm pluton point to fractional crystallisation processes. Rb-Sr whole rock isochron data of the plutons yield ages in the range 480-690 Ma wiLh initia1 87Sr/86Sr ratios ranging from 0.70948 -0.71482. Absence of post emplacement tcctonolhennal event is suggested by near concordant K-Ar biotite ages.
A protracted thennal event during late Proterozoic-early Palaeozoic (500-700 Ma), possibly related to mantle upwelling, possibly triggered the generation of these granitoids.
Primary Silicate-Melt Inclusions in Olivine Phenocrysts from the Pavagad Igneous Suite, Gujarat
Authors: Hari K. R. , Santosh M. , Chatterjee A. C. 
Published: November 2024

Abstract
Fluid inclusion studies in olivine phenocrysts from alkali olivine basalt, iddingsite basalt and three-phenocryst basalt of the Pavagad igneous suite, an outlier of the Deccan Trap, indicate the presence of highly evolved primary silicate-melt inclusions with various daughter crystals of olivine, pyroxene, plagioclase and opaques. High temperature experiments using a heating stage indicate homogenization in the range of 1040 to 1240 °C. The gas bubble within these inclusions show melting close to the triple point forpure carbon dioxide and homogenize into liquid phase between 25 and 31 °C, denoting densities of 0,70-0.50 g/cm3. Trapping pressure estimated from CO2 equation of state barometry is about 3.8 kbar, which translates to a depth of formation of ca. 10 km. This correlates well with an independent depth estimate of 10-14 km derived from combined melt and fluid homogenization data. The melt inclusion chardcteristics in the Pavagad suite suggesllhatlhe olivines equilibrated from a slow cooling system at high pressure conditions, the parental melt having a probable alkali olivine basalt composition.
Ostracoda in the Estuarine Sediments, Pulicat Lake Estuary, East Coast, India
Authors: Sreenivas K. , Raju B. N. , Honnappa  , Reddi K. R. 
Published: November 2024

Abstract
Thirteen Recent ostracode taxa belonging to 11 genera, 4 families and 1 suborder were identified and illustrated following the classification suggested by Morkhoven (1962-1963) with slight modifications. The species were studied for their distribution. percentage of total shells of species with reference to number of larva, juvenile, adult specimens, male, female ratios, colour pattern and to assess the nature of the estuary and its environs. An attempt has been made to calculate the percentage of biological factor, i.e., predation.
The Birth History of Two Granitic Plutons of the Bhilangna Valley of Garhwal Himalaya: A Geochemical Approach
Authors: Islam R. , Purohit K. K. , Thakur V. C. 
Published: November 2024

Abstract
On the basis of geochemical study, two granitic plutons are identified in the Bhilangna valley of the Garhwal Himalaya, viz. the Chaili porphyritic granite gneiss (CPGG) and the Ingedinala granite gneiss (IGG). Both, CPGG and IGG rocks fall in the quartz rich zone (QRZ) of chemical-mineralogical typology of Dcbon and Le Fort, 1982. CPGG and IGG are strongly peraluminous, S-type granites and enriched in Si and K and depleted in Ca and Sr. The unusually high K2O suggests introduction of LILE during metasomatic processes. Both, CPGG and IGG are crustally derived and produced due to the partial melting of psammo-pelitic sediments. Probably the source materials for CPGG and IGG are same, attested by the geochemical similarities. The Q-Ab-Or plots of CPGG and IGG revealed that the temperature higher than that of the 'minimum' melt was attained during anatexis. During the Himalayan orogeny, intracontinental subduction took place along MCT and provided channels for the metasomatic fluids which induced K and Rb metasomatism and subsequently modified the nature of CPGG and IGG.
Pellatispira-Bearing Upper Eocene Subcrops in Tanot-I Well, Northwest of Jaisalmer, Rajasthan and their Significance
Authors: Kalia Prabha , Banerjee Amit 
Published: November 2024

Abstract
Late Eocene strata bearing Pellatispira crassicolumnata, Silvestriella tetrahedra, Nummulites fabianii, Nummulites striatus and Asterocyclina stellata have been identified in the subsurface samples from Tanot-I well 145 km northwest of Jaisalmer Earlier in the Rajasthan region, the sea was considered to have finally withdrawn by the Late-Middle Eocene. The present record of strata of Late Eocene age supports the hypothesis of oceanic subduction followed by obduction of the Indus Basin. The presence of Late Eocene in Kirthar and Sulaiman Ranges, Pakistan, and Jaisalmer, India and their absence in Kutch can thus be explained.
Lithofacies Analysis, Benthic Foraminifera and Depositional Environments of the Chhasra Member: A Transgressive Tide and Storm Affected Early Miocene Sequence in Kachchh, India
Authors: Wahi Sanjay , Tandon S. K. , Sharma V. 
Published: November 2024

Abstract
A 40m thick Early Miocene sequence occurring near Naliya has been investigated for its sedimentary facies and benthic foraminiferal biofacies. The changing depositional environments of the sequence have been interpreted to represent (a) supratidal to (b) supratidal-intertidal and (c) subtidal (limited clastic influx) to ultimately subtidal (increased clastic influx) palaeoenvironments. The lowest part of the section shows evidence of emergence which together with benthic foraminiferal population dominated by Pararotalia nipponica - Loxostomwn lobatwn (water depths of 05-10m) suggests a supratidal environment.
The middle part of the stratigraphic interval has been subdivided into a lower and upper part on the basis of an intervening calcrete (calcretised shell limestone) horizon. The lower part of this interval represents lagoonal and high intertidal environments.
The upper part of this interval shows development of cross bedded and wave-rippled sandstones representing beach ridge-tidal inlet sequence. Other lithofacies include shell layers having predominance of one kind of organism. Some of these shell banks are wave sorted. Biofacies II -Hanzawaia nipponica - Cibicides lobatulus characterises this part of the section and indicates water depths of - 5Om.
The upper part of the sequence is composed of silt which contains Ammonia beccarii -Pseudorotalia gaimardi in abundance. This interval is frequently interspersed by oyster-Pecten beds and indicates subtidal environment with increased influx of siliciclastics.
The changing depositional environments show that these Early Miocene rocks represent a transgressive, tide-dominated, storm affected sequence.
Pliocene Soricidae (Insectivora, Mammalia) from Kashmir Intermontane Basin, Northwestern Himalaya
Authors: Kotlia B. S. 
Published: November 2024

Abstract
The earliest as well as the first Episoriculus (Tribe Soriculini; Subfamily, Soricinae) in Asia is described from the Pliocene sediments of the Karewas of Kashmir, India. Based on the examination of nearly all lower and upper dental elements, a new species, Episoriculusrepenningi sp. nov. is proposed. In addition; the only record of tribe Beremendiini in Southern Asia is discussed based on limited material. The presence ofhoih tribes in India offers evidence of faunal similarity between Europe and Southern Asia during Late Cenozoic. The age of the sediments yielding fossil shrews is about 2.4 Ma.
Sediment Transport Direction Derived from Grain-Size Statistics on the Continental Shelf Off Mangalore, West Coast of India
Authors: Narayana A. C. , Pandarinath K. 
Published: November 2024

Abstract
Grain-size statistics are employed in sediment transport studies. The alongshore transport of sediment in shallow regions (30-50m depth) and deeper regions (&gt;l50m depth) is in north and south directions, whereas in the depth range of 50-75m, the sediment transport direction is towards the south. The onshore-offshore sediment transport study reveals that the sediment transport direction is towards onshore where fluvial influence is absent and the direction is towards both onshore and offshore where the fluvial influence is prevalent. The studies further reveal the different energy regimes of transportation.
The Origin of Myrmekites in the Granitic Rocks of Ambagaspitiya, Sri Lanka
Authors: Mathavan V. 
Published: November 2024

Abstract
Myrmekite occurs in four distinct modes in the granitic rocks of Ambagaspitiya. Intragranular myrmekite (1) occurs completely within microcline grains, while marginal myrmekite (2) is confined to the rims of microcline grains and these two types of myrmekites are abundantly developed in the studied rocks. They invariably show corrosion features and the myrmekitic quartz may either protrude into or lie entirely in the adjacent microcline grain. Rim myrmekite (3) and intergranular myrmekite (4) occupy pJagioclase-microcline, and microcline-rnicrocline interfaces respectively. The four modes of occurrence of myrmekites described here are interpreted on the basis of exsolution and Becke's metasomatic exchange models in the light of the inferred geological history of the granitic rocks of Ambagaspitiya.
The study supports the view that myrmekite is polygenetic and different types of myrmekites in a suite of rocks may be formed by more than one unrelated process.
Tectonic Slices of High-Grade Rocks in the Delhi Fold Belt of North-Central Rajasthan
Authors: Fareedduddin  , Sharma A. K. , Bose U. 
Published: November 2024

Abstract
The occurrence of tectonic slices of high-grade rocks in Pilwa-Chinwali-Arath area, about 25 km NNW of Ajmer is described. They occur in discontinuous strips Over a distance of 25 km within the Alwar metasediments of middle amphibolite facies. The high-grade sequence comprises charnockite-enderbite, two pyroxene granulite, pelitic granulite, leptynite, garnetiferous augen gneiss and garnetiferous amphibolite. Their tectonically-controlled occurrence and comparable mineral parageneses, the highgrade granulite facies rocks of the study area show striking similarity to those of Sandmata metamorphites emplaced in the Archaean Banded Gneissic Complex.