bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grain Size and Petrography of Mesozoic Rocks of Saurashtra Basin, Gujarat, Western India
Authors: Aslam M. 
Published: November 2024

Abstract
A provenance study was conducted on the Mesozoic rocks of Saurashtra basin, Gujarat, in which grain size, mineralogy and petrographical features of sandstones were integrated to arrive at an consistent interpretation.
Textural parameters suggest progressive variation in that mean grain size increases from Than (0. t 98 - 0.117 mm), Surajdeval (0.257 -0.213 mm), through Ranipat (0.5 -0.378 mm), to Wadhwan (0.716 - 0.469 mm). The bulk of the sandstones demonstrate positive (+) skewness in Than and Surajdeval implying that sandstones include greater admixture of fine sediments, as aganist those of Rani pat and Wadhwan which show excess of coarse admixture. By and large, the Dhrangadhra sandstone is moderately to well sorted (s I=0.52 - 0.84 f).
Petrographically, three types of sandstones constitute the Dhrangadhra group of formations, namely, quartzarenite, subarkose and sublitharenite, consisting of quartz, feldspar, lithic-fragments, and mica in order of abundance. Groundmass material consists of cementing material and matrix. Heavy minerals show a preponderance of granet, zircon, tourmaline, staurolite, rutile and epidote. The study reveals a mixed provenance, comprising of acid igneous, metasedimentary rocks of the Aravalli highlands outcropping in the northeastern part of the study area.
Subsurface Flow of Water and its Structural Control in the North Ganges Floodplain of Bangladesh
Authors: Khan Aftab Alam , Sattar Golam Shabbir 
Published: November 2024

Abstract
The surface configuration of the north Ganges floodplain, covering the region Godagari. Rajsbahi (Paba-Boalia), Durgapur, Puthia and Charghat has been determined. The central region of the investigated area shows some prominent north-south elongated elevated zones and an east-west elongated depressed zone. The rest of the investigated area is marked almost by the flat and sloping surface. The subsurface structural configuration has been inferred taking into account the prominent basement faults and the regional geologic cross-sections. It is inferred that the investigated area is located on the downthrown segment bounded by faults. However the region located nearCharghat where the river Ganges has taken almost 90° swing, is relatively an uplifted block.
The occurrence and the flow of grownd water in the investigated area have also been determined. The area covering Paba-Boaliaand Godagari is characterized by short distance recharge and infiltration from the near surface sources for the groundwater occurrence and movement, while the occurrence and the movement of groundwater in the region of Charghat, Puthia and Durgapur depend on the long distance recharge and infiltration from a few near surface sources.
The water table coutour maps both for the dry and the rainy seasons show some prominent diverging patterns. The water table fluctuation map shows that the zone of minimum fluctuation coincides with the zone characterized by diverging pattern. This anomalous situation has been interpreted as due to relatively higher hydrostatic pressure and the existence of an effective barrier of clay of about 50 feet thick oriented in the north-south direction across Charghat, between Soalia and Puthia, and between Paba and Durgapur.
Magnetic Profile Across Gulf of Mannar
Authors: Murty G. R. K. , Satyanarayana Y. , Pradeep Kumar T. 
Published: November 2024

Abstract
A study of the spectral analysis and two-dimensional modelling of magnetic data collected along the track of 200 km traversing the southern part of the Gulf of Mannar indicates the presence of an anomalous body within the basement. The total field magnetic anomaly along the track is well explained by variations in the topogrphy of the anomalous body of normal polarity and uniform magnetisation. The model shows a topographic relief of about 6 km. The presence of volcanic vents in this area suggests that the anomalous body could be more basic in nature having high susceptibilty values.
Basemetal Mineralization Along the Gurji Stream near Askote, Kumaun Himalaya
Authors: Farooq S. , Hasan N. 
Published: November 2024

Abstract
Surface indications of basemetal mineralization were detected in the granitic gneisses along the Gurji Stream near Askote in Pithoragarh district of Kumaun Himalaya. The sulfide minerals occur in the form of stringers and disseminations. Investigations reveal that the mineralization is hydrothermal in nature and is controlled by the structural patterns of the host rocks. Mineralogy of the altered zone and textural relationships of the sulfide minerals indicate a high temperature of the hydrothermal fluids. The similarities in the nature of sulfide mineralization, the mineral assemblages, paragenesis and associated wallrock alteration with the mineralized zone in low-grade schists at Brigaon near Askote suggest that the two mineralized zones are cogenetic.
Clay Minerals as Indicators of the Provenance and Palaeoclimatic Record of the Kashmir Loess
Authors: Dilli K . , Pant R. K. 
Published: November 2024

Abstract
The provenance of Kashmir loess and its palaeoclimatic significance has been probed using minerological techniques. As many as ten palaeosols (buried soils) have been recognised within the loess profiles. Their mineralogical composition is almost uniform throughout the profilcs. Qu'artz is the dominamt mineral (&gt;60% of the total) and is followed by feldspar and pyroxene suggesting that the loess is derived primalily from a region where both acid and basic rocks and their equivalent metamorphic derivatives predominate. The clay mineral suite consists principally of illite and stnectite, which are negatively correlated. Kaolinite and chlorite are also present (&lt;10% each of total). elemental composition of the different lithounits generally correlate well with the mineralogical data. These studies suggest that the loess was derived from the rocks within the valley itself. Crystallinity parameters of illite are found to be very sensitive to Quaternary climate change and are correlated with deep sea palaeoclimatic record.
Middle Archaean Age of Sargur Group by Single Grain Zircon Dating and Geochemical Evidence for the Clastic Origin of Metaquartzite from J. C. Pura Greenstone Belt, Karnataka
Authors: Ramakrishnan M. , Venkata Dasu S. P. , Kroener A. 
Published: November 2024

Abstract
The middle Archaean J. C. Pura greenstone belt of Sargur Group underlies the Dharwar angular unconformity along the Kibbanahalli arm of Chitradurga schist belt. It consists essentially of periodotitic komatiite (serpentinite), basaltic komatiite (dark amphibolite), rare BIF and minor metaquartzite. In view of the ongoing debate on the origin of Sargur quartzite as to whether it is a chemogenic, biogenic or detrital-rich chert or quartz arenite, the study of J. C. Pura metaquartzite is important as it will have a direct bearing on the depositional setting of the metaquartzite in particular, and the Sargur association in general. In the absence of primary sedimentary structures, accessory zircons in the metaquartzite provide the main clue to its origin. Euhedral zircons with minor rounding of pyramidal terminations in the metaquartzite suggest little mechanical corrosion and negligible sedimentary transport. These zircons are interpreted as detrital grains and the host rock as siliciclastic in origin. Geochemical parameters like Al2O3 vs TiO2, SiO2 and K2O, trace element spider plots, REE patterns and La/Sc ratio indicate a significant continental contribution, low Fe and Mn content, low TiO2-normalised values and variable Co/Zn and Ni/Zn ratios preclude major sea water hydrothermal activity. The proximal provenance indicated by euhedral zircons did not apparently have a significant felsic volcanic component since such rocks are neither present witnin the schist belt nor found as enclaves in the surrounding gneisses. Furthermore, the Sr, Zn, Y, Yb values of the metaquartzite are lower than that of felsic volcanics and pyroclastics, thereby ruling out their prevalence in the source area. The most likely source would therefore be the widespread early Archaean continental crust of southern India made up of granitoids. The metaquartzite was probably deposited as quartz arenite in shallow marine enviroment close to the continent. The associated pillowed komatiite also lends support to this environmental interpretation.
Euhedral zircons from J. C. Pura metaquartzite were dated by single grain evaporation technique which yielded a Pb-Pb age of 3230 ± 5 Ma. This date representing the maximum age of the Sargur metaquartzite is fully in accord with previous Sm-Nd model ages and SHRIMP U-Pb zircon ages (ca 3200 Ma) of Sargur rocks from nearby areas. The Sargur Group is pervasively intruded by gneisses and granites around 3000 Ma. Still older gneisses seen in the neighbourhood such as the Gorur gneiss of 3300 Ma age may constitute a possible basement to the Sargur supracrustals and represent widespread early Archaean granitic crust of the Dharwar craton.
A Study on the Plant Communities in Relation to Copper Mineralisation around Rakha Mines, Singhbhum Copper Belt, Bihar
Authors: Chand Gyan , Venu P. 
Published: November 2024

Abstract
Results of the plant distribution pattern with reference to copper mineralisation in Singhbhum copper belt, Bihar are presented. In the heart of mineralised zone, Hyptis suaveolens or Croton roxburghii dominates. In areas under moderately high level of copper, the dominant species is not uniform and some of these stretches are dominated by Hyptis suaveolens or Croton roxburghii while other have shown Cymbopogon martini or Anogeissus latifolia or Shorea robusta or Diospyros melanoxylon. In contrast, sampling zone containing low levels of copper (around 200 ppm and less) is dominated by either Evolvulus aislnoides or Lantana camara or Woodfordia fruticosa. Areas that contain low copper values are also demarcated by Blumea oxyodonta and Polygonum plebejum. Overall analysis indicates that species varied in the copper tolerance and plants like Hyptis suaveolens and Croton roxburghii dominate when log copper values reach around 4.0. Species like Acacia torta, Diospyros melanoxylon and Holarrhena antidysenterica showed their maximum numbers when log copper values are between 2 and 3. It is suggested that the species combination and community structure are dependent on substrate copper levels.
Distribution of Calcium Carbonate in the Sediments of the Visakhapatnam Shelf, Central East Coast of India
Authors: Murty P. S. N. 
Published: November 2024

Abstract
The distribution of calcium carbonate in Visakhapatnam shelf sediments is controlled by the mollusca shells and shell fragments and foraminifera. The high concentrations near the river mouths are indicative of the detrital contribution also. The concentrations decrease from top to sub-bottom levels due to more dilution by the detritus from the adjoining area and less deposition of non-detrital calcium carbonate in the geological past.
Holocene Sea Levels of Visakhapatnam Shelf, East Coast of India
Authors: Mohana Rao K. , Rao T. C. S. 
Published: November 2024

Abstract
The Holocene sea level changes in the shelf areas off Visakhapatnam was studied from sediment distribution pattern and shallow seismic profiling. Morphological features on the shelf indicate a Late Pleistocene regression down to about -130 m below the present sea level. A major stillstand of the transgressive sea was recorded at about -80 m where coarse carbonates and shallow water fauna predominate. During this period algal barrier reefs with reliefs varying from 2 to 8 m were developed between -85 m (10790 ± 170 years B.P.) and -100 m (12530 ± 170 years B.P.). Buried reefs observed at about -60 m give a clue for a possible strandline at this depth. Coarse clastic sand patch having mean size of around 1.0 Phi between -20 to -30 m suggests another strand line. The sea level rise during Holocene transgression seems to be discontinuous with temporary pauses.
The Origin of the Iron Ore deposits of Donimalai area of Sandur Schist Belt, Karnataka State, India
Authors: Murthy P. S. N. , Chattterjee A. K. 
Published: November 2024

Abstract
Donimalai area is located in the SE portion of the Sandur Schist belt of Precambrian age. There are 6 ore deposits comprising 9 ore bodies having more than 150 million tonnes of high grade hematite ore in Donimalai area.
Banded Iron Formation (BIF) is the host rock for the iron ore deposits. Basaltic rocks, shales with tuff, dolerite and quartz veins are other important litho-units in this area. Principaly the BIF consists of alternative bands of iron oxides and chert belonging to oxide facies.
Hard laminated ore, medium hard laminated ore, soft laminated ore, friable powdery ore and blue dust are the major ore types with minor occurences of lateritic/limonitic ore and shally ore.
Leaching of silica has resulted in the origin of friable ore and blue dust. Leaching of silica followed by enrichment of iron oxide by the circulating solutions has given rise to hard laminated ore, medium hard laminated ore and soft laminated ore depending upon the degree of enrichment. Shaly ore occurs at the contact of deposit 1 with shale. It is formed due to the enrichment of shale by iron-rich solutions, Original material of shale has been replaced followed by enrichment of iron oxide giving rise to shaly ore.
Laterite ore/laterite occurs parallel to the surface of the ground with a thickness varying between 2-10 meters. They also occur along steeply dipping fault planes upto depths of 100-150 meters. parallel to the bedding. Geomorphic evolution of planation surface around 1000 mt. R.L. was responsible for the formation of flat surfaced laterites/lateritic ores. Activity of solutions along fault planes parallel to bedding has caused lateritisation/limonitisation at deeper lavels also.
Rb-Sr Systematics of Granitoids of the Central Gneissic Complex, Arunachal Himalaya: Implications on Tectonism, Stratigraphy and Source
Authors: Dikshitulu G. R. , Pandey B. K. , Krishna Veena , Dhana Raju R. 
Published: November 2024

Abstract
Precambrian Central Gneissic Complex (CGC) in the Kameng district of Arunachal Pradesh comprises the oldest Sela Group thrusting over the Bomdila Group, with the Salari Group being the youngest. Augen gneiss of the Bomdila Group, granite of the Salari Group and hornblende granite gneiss of the Sela Group define Rb-Sr isochron ages of 1914 ± 23, 1536 ± 60 and 481 ± 23 Ma, respectively. The 481 Ma age on the hornblende gneiss from the oldest Sela Group is attributed to the resetting of Rb-Sr clock due to tectonic imprint of the Main Central Thrust (MCT). The 1914 Ma age of the augen gneiss, the oldest reported so far from the Arunachal Himalaya, is either the emplacement age or latest metamorphic event. The 1536 Ma old emplacement age of the granite intruding the black shale of the Salari Group disproves the hitherto considered Gondwana age for the black shale, and, thus, necessitates revision in its chronostratigraphy. (87Sr/86Sr)i of the hornblende granite gneiss and Salari granite is high (0.719 and 0.709) indicating a crustal source for these, whereas it is low for the augen gneiss (0.703) suggesting an inherited signature of the upper mantle source together with some crustal contamination. Rb-Sr whole-rock isochron ages from the Arunachal Himalaya are correlatable with those reported from other parts of the Indian Himalaya. These cumulatively point to at least three major periods of activity in the Himalaya at ca. 2060 ± 250, 1530 ± 90 and 530 ± 75 Ma.
Hydrogeology of Madras City Aquifers
Authors: Ballukraya P. N. , Ravi R. 
Published: November 2024

Abstract
Subsurface lithological mapping has shown the presence of a crystalline rock ridge along the east coast of Madras City, and the aquifer above this ridge shows some characteristic features distinct from those on the western side. The presence of a fresh water ridge along the coast has checked the intrusion of sea water even though water levels are as low as 3m below mean sea level at certian places. Several pockets of brackish ground water have been identified which have been established as due to the presence of tanks and depressions therein. Identification of marine sands below the alluvium in some places gives an idea of the marine transgression that had occurred during Tertiary periods. Studies indicate that most of the alluvium is of estuarine origin, and that the crystalline ridge along with part of the east coast may be updergoing slow uplift.
Orbicular Structures from a Diorite body within the Granitoid Complex of Nellore Schist Belt
Authors: Srinivasan K. N. , Roop Kumar D. 
Published: November 2024

Abstract
A diorite body spread over an areaof 10 sq km, with proto-orbicular and orbicular structures is recorded for the first time near Rapur, Nellore district, Andhra Pradesh. It occurs within the post-tectonic granitoids emplaced along the thrust zone between Nellore Schist Belt and the Proterozoic Cuddapah Basin. It is 'proto-orbicular' in nature with concentric rims of felsics and mafics, having radial and tangential arrangement of plagioclase and biotite respectively. Orbicules are of both crystallothrausmatic and esboitic. The core and matrix are by and Iarge similar in composition. Graphic sand granophyric textures point to igneous origin of the orbicular diorite and the associated granitoids.
Xenotime Placers in Parts of Mahan River Basin, Surguja District, Madhya Pradesh
Authors: Rai S. D. , Banerjee D. C. 
Published: November 2024

Abstract
Several inland placers containing commercially viable resources of xenotime have been described from the Chhotanagpur granite gneiss terrain of Gumla district, Bihar and Raigarh district, M.P. Recent surveys in the adjoining western sector of Surguja district, have confirmed xenotime as a significant minor constituent (3-5 %) in the heavy mineral assemblages (1-4 %) of the various tributaries , of Mahan river.
The assemblage is typical characteristic of a granite migmatitic provenance. Geomorphologically, few of these occurrences are developed over limited extents as poorly sorted sediments in low order, less mature streams having steeper slope and smaller depth with an insignificant flood plain development. Mineralogically, the heavy mineral assemblages consist of ilmenite ± garnet (10-40 Wt%) with monazite (40-70 Wt%), zircon (10-20 Wt%) and magnetite (traces to 5 Wt%). A few of these placers are being investigated as potential sources for Yttrium as their heavy mineral suites, quantitatively, have a higher total content of xenotime and nronazite for upgradation to a marketable product acceptable to the chemical industry.
Fluidized Sediment Movements and Deposition - A case study from Bisrampur, Singhbhum Dt., Eastern India
Authors: Das Subhasish , Manta Santansua 
Published: November 2024

Abstract
Critical studies of a part of Singhbhum basin around Bisrampur, Singhbhurn district, Bihar, show that the metasediments (considered to belong to the Dhanjori Group) lie unconformably above the Singhbhurn Granite. However a few tongues of the granite that occur within the metasediments have been explained as thrust slices of the basement within the cover rocks. Though three phases of deformation have been recorded here, and the general outcropgattern has been largely controlled by the second phase of deformation, there has not been any marked change in the spatial disposition of the coarser clastics. The shape of pebbles within the conglomerate, though often triaxial, cannot be correlated with the deformational history. This calts for original triaxiality of the pebbles. The high proportion of clastmatrix indicates that they were deposited under a two phase flow mechanism: a gravity mass flow aided by a high turbulent flow. Relatively high amounts of solid material in the fluid with variable particle size can create such a turbulent motion and the resultant scattered dispersion possibty accounts for the randomness in pebbleorientation. Accumulation of huge coarse clastics is, however, attributed to gravity mass flow. The general lack of turbidite structures in these litho-units can be attributed to flow inhomogeneity, flow velocity, nature of depositional substrate, relative significance of head-versus-body spilling from turbidity current. Presence of primary structures in arenaceous rocks and occurrence of these rocks as isolated bodies point to vigorous reworking and redeposition of the bottom sediments after cessation of the main flow. The huge pile of the rnicaceous phyllites probably represents relatively rapid deposition of silt grains from a highly concentrated mud-dominated turbidity current or very fluid silty debris flow deposited during the waning phase of turbidity flow. The entire load was deposited possibly over a shallow shelf edge. Retention of the original grain fabrics and the sedimentary structures in these metasediments, even though they are very close to a regionally developed shear zone, points to the existence of focally developed, sheltered low stress regimes provided by the Granite basement.
Establishment of Gravity Stations and Inference of Crustal Thickness around Mormugao Harbour and NIO
Authors: Subba Raju L. V. , Krishna K. S. 
Published: November 2024

Abstract
Complete descriptions and basic facts of nine gravity stations of Marmugao harbour are presented. They exhibit a maximum Bouguer difference of 2.12 mGal in an overall distance of about 2 km. Keeping in view the limited amount of data, certain broad and tentative conclusions regarding crustal structure are drawn.
Campanian - Maastrichtian Nannoplankton biostratigraphy of the Narsapur claystone Formation, Krishna-Godavari Basin, India
Authors: Saxena R. K. , Misra C. M. 
Published: November 2024

Abstract
Nannoplankton biostratigraphy of the Campanian - Maastrichtian 870 metre thick argillaceous subsurface sediments below the Lowest trap of Narsapur area, Krishna-Godavari Basin has been presented in the paper. These infratrappean sediments are assigned to Micula nurus and Arkhangelskiella cymbifomis zones of Late Maasbichtian age and undifferentiated CC 19-CC 23 nannoplankton zones of the Campanian age. Occurrence of global Late Maastrichtian marker Micula murus just below the lowest trap is significant and considered to be important short lived nanno-event in Late Maastrichtian times. The initiation of oldest volcanic eruption in the Narsapur area is around 67.0 Ma. (middle of Micula mums zone) and it is correlated with the lowest limit of the Deccan volcanism in Razole area.
The Role of Telluric (TE) and Magnetotelluric (MT) Methods in the Exploration of deep Sedimentary Basins
Authors: Adam A. , Nemesi L. , Arora B. R. 
Published: November 2024

Abstract
After, a methodical overview of the magnetotelluric and telluric methods, the paper with the help of test example from the Pannonian basin (Hungary) illustrates the effectiveness of a combined telluric and magnetotelluric methods in the study of basement structures of deep basins. It is strongly emphasized that in the case of such adeep basin me relation between the gravity map and basin structure may be totally distorted by the crustal-mantle anomalies, first of all by the intrusion of mantle material of high density. Recognising the merits of combined telluric-magnetotelluric method in the exploration of sedimentary basins for hydrocarbon traps, the significance of the application of these methods to Indian sedimentary basins is highlighted. Usefulness of electrical conductance map, derived from these investigations, in demarcating thermally favourable zones of hydrocarbon maturation is envisaged.