bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pellatispira (Foraminiferida) From the Upper Eocene of Surat-Broach, Gujarat
Authors: Samanta Bjmal K. 
Published: November 2024

Abstract
The foraminiferal genus Pellatispira Boussac is represented by P. crassicolumnata Umbgrove in the Upper Eocene succession of Surat-Broach, Gujarat. The morphology of the species is described and illustrated. The specimens from Surat-Broach originally identified by Rao as Pellatispira inflata Umbgrove var. minor var. nov., P. madaraszi (Hantken) var. indica var. nov. and P. orbitoidea (Provale) are considered to fall within the range of variation of P. crassicolumnata Umbgrove. An analysis of the external and internal structures indicates that the genus Pellatispira is distinct from the typical members of the Calcarinidae, Miscellaneidae and Nummulitidae. It is best retained in the family Pellatispiridae Hanzawa.
A New Phanerozoic Basin in Kinnaur, Himachal Himalaya
Authors: Bassi U. K. , Chopra Suresh , Datta B. M. 
Published: November 2024

Abstract
A Phanerozoic sequence except Carboniferous, has been identified in the eastern part of the Kinnaur district. The strata have yielded a rich invertebrate fauna and ichnofossil assemblage besides plant fossils of Lower Permian age. Four sedimentary cycles punctuated by the Cambrian, Caledonian, Hercynian and Upper Callovian disruptions are identifiable, The rocks of this area have suffered from at least two phases of folding, as reflected in both major and minor structures.
Petrochemistry of the Chengannoor Granite, Alleppey District, Kerala
Authors: Santosh M. , Nair N. G. K. 
Published: November 2024

Abstract
The granite of Chengannoor, Alleppey district, Kerala, having an intrusive relationship with Precambrian charnockite-cordierite gneiss sequence is inferred to be a post-kinematic granite of magmatic origin. The major mineral constituents are mesoperthitic K-feldspar with quartz and two generations of plagioclase. A late/post intrusive potash metasomatism caused changes in the mineralogy and chemical composition of the granite.
Recent K-Ar dating of hornblende from the Chengannoor granite assigns an age of 550 m.y. for the granite (Soman, Golubyev and Santosh. Ind. Jour, Earth Science) (in press).
Significance and Genesis of Early Diagenetic Glauconite-Pyrite Assemblage in the Quilon Limestone, Kerala
Authors: Thrivikramji K. P. , Ghosh Swapan K. 
Published: November 2024

Abstract
Pyrite and glauconite are the only lauthigenic iron minerals present in Quilon Limestone. Pyrite occurs as fossil infiIlings and as disseminated grains having shapes like cubes and framboids. Four morphologically distinct types of glauconite have been identified, viz., capsulated pellets, globular pellets, microfossil casts and moulds. Glauconite occurs as fine sand sized aggregate of clay particles. The colour varies between different shades of green to greyish green.
The XRD pattern of glauconite pellets shows the presence of a mixed layer clay mineral assemblage of chlorite and montrnorillonite. The pyrite-, glauconite- and micrite-fabrics of the limestone show evidence of their formation in early diagenetic stages. Pyrite has formed in a neutral to alkaline pH condition in a localised reducing condition; glauconite also formed in a similar environment. However, overall environment was oxidising in a shallow and quiet inner shelf area.
On the Occurrence of Scheelite in Almora and Chamoli Districts, Uttar Pradesh
Authors: Shukla B. D. , Singh A. K. , Swarup Prem 
Published: November 2024

Abstract
Presence of scheelite is reported in the panned concentrates prepared from stream sediments collected from certain tributaries of Pindar river in Chamoli district. Studies carried out so far show that scheelite mineralisation is strata-controlled occurring within a garnetiferous-mica schist member. The host rocks are (i) green coloured epidote-amphibole rich rock (amphibolite?) and (ii) light coloured quartz-epidotecalcite bodies (boudins ?). Associated minerals are calc-silicates namely, actinolite, diopside, garnet and epidote; calcite is also present mainly in boudins, The garnetiferous schist member has been traced in both the limbs of Almora-Dudatoli syncline, along with the mineralised host rocks. The study indicates possibility of tracing extensive scheelite deposits in the crystalline nappe rocks of Himalayas. The deposits are believed to be of volcano-sedimentary origin, where tungsten is derived from submarine volcanic processes that took place during the deposition of limy argillaceous sediments.
Palaeoenvironment and Stratigraphic Position of Green Sandstone (Lameta: Late Cretaceous) Jabalpur Area
Authors: Singh Indra Bir , Shekhar Shashi , Agarwal Shrish Chandra 
Published: November 2024

Abstract
Green Sandstone (Green Sand) of Lameta sediments, in Jabalpur area, makes a conspicuous basal lithounit of the succession. It is made up of clean sand without any shale intercalations, and ranges in grain size from medium to fine sand. Largescale cross-bedding in the form of large festoons is the most dominant structure, showing mostly a bipolar current pattern, where one direction is more prominent. The sandstone also exhibits branched Thalassinoides-type burrows. The Green Sandstone represents deposit of an estuarine channel with tidal influences exclusively by marine processes. The prominent southerly palaeocurrent direction at Chui Hill is interpreted as local ebb-current direction.
Nannoplankton from Rc9-156 in the Southeastern Arabian Sea
Authors: Shankaranarayana Guptha M. V. 
Published: November 2024

Abstract
A deep sea core RC9-156 collected in the Arabian Sea at a water depth of 4583m was analysed for calcareous nannoplankton and dissolution studies. Twelve species of nannoplankton were identified and based on the assemblage, it is suggested that the age of the sediment is late Quaternary. The alternate fossiliferous and un-fossiliferous bands encountered in the core is attributed to the fluctuations in the rate of sedimentation by the river Indus during glacial and interglacial periods.
Clay Mineral Distribution on the Kerala Continental Shelf and Slope
Authors: Purnachandra Rao V. , Nair R. R. , Hashimi N. H. 
Published: November 2024

Abstract
Seventy-five sediment samples collected from the Kerala continental shelf and slope during the 17th and 71st Cruises of RV Gaveshani were analysed by X-ray diffraction for clay mineral content. The distribution of total clay &lt; 4μ fraction) indicates low percentages &lt; 10%) on the outer shelf and high percentages on the inner shelf (20 to 50%) and upper continental slope (11 to 47%). The clay minerals are composed of montmorillonite (smectite), kaolinite, illite and gibbsite and the nonclay minerals are quartz and feldspar. Kaolinite and gibbsite have low values on the outer shelf and high values on the inner shelf and slope, while illite increases in the offshore direction. However, montmorillonite behaves differently from others in having high values on the outer shelf and low values on the inner shelf and slope. These variations in the clay mineral distribution have been attributed to differences in the energy of the various environments and due to size segregation of the minerals.
Petrology of Quartzo-Feldspathic Schists/Phyllites Associated With Manganese Formations of North Kanara and Kumsi, Karnataka
Authors: Sivaprakash C. 
Published: November 2024

Abstract
Rocks associated with manganese formations in Supa, Dandeli and Bisgod (North Kanara district), and Kumsi (Shimoga district) areas consist of quartz ± muscovite± biotite ± plagioclase ± chlorite ± calcite ± ankerite ± ilmenite ± pyrite ± pyrrhotite ± K feldspars ± epidote ± rutile ± apatite. Whole-rock compositions correspond to greywacke, clay/shale and suggest deposition in reducing environments. Muscovite is phengitic, Chlorite is mainly ripidolite variety. Plagioclase is dominantly albite. Ilmenite in some rocks is manganoan. Phase relations between coexisting minerals suggest that they have formed with a close aporoach to equilibrium. Compositions of coexisting pyrite and pyrrhotite, and of phengite suggest temperatures of formation of 300-400°C and pressures 2-4 kb corresponding to greenschist facies conditions.
Diversity and Dominance of Living and Total Foraminiferal Assemblages, Pennar Estuary, Andhra Pradesh
Authors: Reddy K. R. , Jagadiswara Rao R. 
Published: November 2024

Abstract
A quantitative study has been made of the distribution of recent foraminifera in 180 samples of bottom sediments collected from 15 stations in the Pennar estuary. The diversiiy and dominance of the living and total foraminiferal assemblages have been studied by calculating diversity indices and by relating the number of species with the per cent dominance and the average number of species with the average cumulative percentage of genera.
On the Interrelationship Between Two Granitic Units of the Singhbhum Granite Near Karanjia, Mayurbhanj District, Orissa
Authors: Chattopadhyay Basab K. 
Published: November 2024

Abstract
Two magmatic units of the Singhbhum Granite complex intersect near Karanjia (85°88'E, 21°45'N), Mayurbhanj district, Orissa; these are (i) Bhaunra porphyritic biotite granite and (ii) Karanjia leucocratic fine to medium-grained granodiorite. Presence of xenoliths of porphyritic granite within the leucocratic granodiorite as well as dykes of leucocratic granodiorite cutting across the porphyritic granite indicate the distinctly younger age of the granodiorite.
Statistical studies indicate that significant compositional difference exists between the two granitic bodies in respect of important mineralogical variables. Field evidences along with structural analysis and statistical analysis of the compositional data suggest a magmatic origin for both the units of granitic rocks with a large proportion of liquid at the time of emplacement.
Study of the areal variations of several modal attributes of the two granites using moving average isopleth maps indicates systematic areal variation in composition. The compositional isopleths in the porphyritic granite body are clearly truncated by contact with the younger granodiorite.
Clay Mineral Diagenesis in Parts of the Western Indian Ocean
Authors: Dilli Kailas , Rao C. N. 
Published: November 2024

Abstract
Drill core samples of DSDP sites 241 and 250 in the Somali and Mozambique Basins respectively have been examined to understand the nature and extent of burial diagenesis in the deep-sea pelitic sediments of the western Indian Ocean based on X-ray diffractometry and partial chemical analysis. The clay mineral suite is almost identical in both the basins with montmorillonite being the dominant mineral. Illite and kaolinite are present in minor amounts white chlorite is present only in traces. The sediments are in early diagenetic stage. The apparent breakdown of kaolinite and illite and the adsorption of K by the clay minerals has resulted in montmorilloniteillite mixed layers being the only phase present at depth. The mineral trends observed suggest that diagenesis is indeed initiated at much shallower depths as proposed by Matter.
The Jutogh Klippe of the Simla Area of the Himachal Himalaya: Its Geology and Structural Evolution
Authors: Srikantia S. V. , Bhargava O. N. 
Published: November 2024

Abstract
The Jutogh klippe near simla is the highest allochthon in the Himachal Himalaya. Its base is defined by the Jutogh Thrust. Five mappable lithostratigraphic formations are recognised. These are variously represented, in the ascending order, by carbonaceous phyllite and schist of Panjerli Formation; quartzite unit of Manal Formation; phyllite, schist and quartzite of Bhotli Formation; quartzite unit of Khirki Formation and carbonaceous schist, crystalline limestone of Taradevi Formation.
S0 and S1 are the prominent planar surfaces with local development of S2 and S3. F1, F2 and F3 are the three generations of folds. F1 is in minor scale as appressed and reclined folds related to tectonic transport and F2 and F3 having formed after the emplacement of the thrust sheet. F2 is the most pervasive structure along NW-SE, folding the klippe into an open synform. F3 is a larger cross-fold along WSW-ENE and is responsible for culminations and depressions of F2 folds.
The direction of tectonic transport is from ENE to WSW and F2 folds indicate a compression along the same direction.
Nature of the Narmada-Son Lineament
Authors: Das Bhagwan , Patel N. P. 
Published: November 2024

Abstract
Critical examination of the several sections along the lineament from Handia to Barwaha have led to the identification of ten major and several minor faults in the area. They constitute a wrench system. The largest Badel-Dhasar-Ajnaskhurd fault is a primary first order right lateral wrench fault typically associated with the second order right-handed and the third order right lateral wrench faults. The Barjar-Bhadlipura fault is interpreted as a complementary first order left lateral wrench fault. The Badel-Dhasar-Ajnaskhurd and Barjar-Bhadlipura faults represent a first order set of conjugate shears. This would mean that the first order regional stress direction had WNW-ESE orientation. Folds related to the wrench faults have developed in the Precambrian rocks of the area. The most important Badel-Dhasar-Ajnaskhurd fault of the area around Chandgarh forms part of the Narmada-Son lineament. The Narmada-Son normal wrench fault steeply dipping towards south and Pachmarhi-JabaJpur normal fault dipping towards north constitute a graben structure.
The Narmada-Son lineament has existed since late Archaean and has got rejuvenated from time to time.
A New Classification of Bauxite-Bearing Lateritic Plateaux
Authors: Szabo E. 
Published: November 2024

Abstract
The paper presents a classfication of bauxite-bearing lateritic plateaux, on the basis of the author's experiences on laterites and lateritic bauxites in West Africa, Southeast Asia and Central America. The criteria of classification are, surface area of the plateau, shape or the plateau (both vertical and horizontal view), altitude, parent rock(s), index of dissectedness, morphology, and ore tonnage per unit area. The classification is computer-compatible and is recommended for practical investment decisions.
Parallel Scarp Retreat and Drainage Evolution, Pachmarhi Area, Madhya Pradesh, Central India
Authors: Venkatakrishnan Ramesh 
Published: November 2024

Abstract
This study is the outcome of field and topographic map interpretations to evaluate the relationship between scarp retreat and associated drainage pattern evolution. The area under study is composed of gently north-dipping series of Gondwana (Triassic) sediments overlam by Deccan Trap basalts (Cenozoic). These sediments have been exhumed within an elliptical iniler, the Central India Gondwana Basin, due to domal uplift parallel with the Narmada river rift valley which lies to the north of the study area.
The near east-west trending Pachmarhi Scarp developed within the Pachmarhi Sandstones is about 160 kilometers long and as much as 280 meters 10 height along the north-south minor axis of the dome. Outliers of the Pachmarhi Plateau (Upland Landscape) aligned parallel to the present scarp and some distance from it suggests parallel scarp retreat to the north.
Numerous drainage lines on the Lowland Landscape south of the Pachmarhi Plateau are aligned parallel to the Pachmarhi Scarp and are interspaced with sandstone outilers astride the interfluves. The resulting rectangular drainage pattern also suggests former scarp positions. Continuing scarp retreat exhumes the underlying Bijori Shales on which evolves the Lowland Landscape.
Scarp recession is believed to have been initiated by strike-streams developed along the feather edge of the northerly-tilted Pachmarhi Sandstones. Post-Deccan Trap uplift parallel to the Narmada rift valley lead to the entrenchment of major drainage lines that maintained their course across the axis of uplift and are hence considered antecedent. Minor streams that were defeated by the uplift occupied litho-tectonicc 'weak zones' both parallel to the scarp and at large angles with it, creating the rectangular and barbed drainage patterns. The Narmada river rift valley has acted as a recurrently active local base level at least since the post-Deccan Trap uplift and has had a major influence on 'stepped landform' evolution in the study area.
A Modified Sequential Extraction Technique and its Usefulness in Geochemical Exploration
Authors: Purushottam A. , Murty B. V. S. R. , Chandra S. , Subba Rao N. , Syamala Rao A. , Basu P. C. , Sood N. K. 
Published: November 2024

Abstract
Sequential extraction techniques for determination of trace metals associated with different phases in soils/stream sediments are being increasingly used for geochemical exploration in recent years. The existing techniques do not provide for the separate determination of Copper, Lead or Zinc present in the secondary mineral form, although in many soils and stream sediments, these metals exist in such phases. Based on laboratory studies, the sequential extraction technique suggested by Chao and Theobald (Jr) has been modified to include an additional step to provide for determination of Copper, Lead and Zinc present in their commonly occurring secondary mineral forms. Making use of the modified scheme, stream sediment samples from Ahobilam area in Cuddapah Proterozoic basin have been analysed. Metal contents of samples in the primary and secondary mineral phases were found to be good indicators for Pb and Zn mineralization in zones 2 and 3. Subsequent field check revealed Ph-Zn mineralization in t he above two zones.
Provenance Control of Diagenesis in Clayey Sediments in the Northern Part of Western Continental Shelf of India
Authors: Bhattacharya N. 
Published: November 2024

Abstract
Recent marine sediments coupled with sea-bottom cores, parting shales and insoluble clay residues of carbonate reservoirs in northeastern continental shelf of the Arabian Sea were investigated for studies of clay mineral diagenesis to evaluate respective roles of source conditions and environment of deposition. The material was also compared with those from selected weathering profiles on basalts and/or diabases. The data indicate an uniform distribution of montmorillonite and expandable mixed-layers with little kaolinite over the continental shelf diluted by sporadic occurrences of degraded illite and chlorite off the Saurashtra coast and beyond in the north and northwest upto the international boundary. These clays were derived by weathering from basalts/diabases and so have not responded to diagenetic changes even at depth. Occurrence of illite and chlorite mixed with montmorillonite and expandable mixed-layers could have resulted from material brought in by the Indus river. The factors of source and inheritance seem to have been the governing criteria for structural failure of these clays against diagenetic processes. However, clay mineral diagenesis indicates that hydrocarbons discovered in this area are independent of the associated clay mineral characters with regard to their genesis and entrapment.
A Proterozoic Intracratonic Basin, Dyke Swarms and Thermal Evolution in South India
Authors: Drury S. A. 
Published: November 2024

Abstract
The spatial and temporal relationships between mid-Proterozoic, intracratonic sedimentation in the Cuddapah Basin and earlier Proterozoic basic dyke swarms are analyzed in the context of thermal and mechanical models for crustal doming, erosion and subsidence. The dyke orientations imply that the Archaean crust of South India was thermally warped into an elliptical dome with a roughly E-W axis, under varying regional tectonic conditions. Thermal relaxation of this dome, after erosion and crustal thinning, laid the basis for sedimentation in the Cuddapah Basin, whose deepest part lay to the SW of its present outcrop. Late-Proterozoic sedimentation of the Kurnool rocks must have been initiated by a later, separate thermal event.
Ion Exchange Properties of Lateritic Soil from Calicut Kerala
Authors: Raymahashay B. C. , Bhavana P. R. , Rao K. S. , Mehta V. K. 
Published: November 2024

Abstract
The lateritic soils developed over Precambrian crystalline rocks near Calicut have relatively high Cation Exchange Capacity. At the same time, the soils are highly efficient for phosphate uptake. Both of these properties are traced to the presence of halloysite of intermediate hydration in the soils. Experimental results have been interpreted in terms of the structure of soil minerals.
Pressure - Temperature Estimates of the Iron Formations of Sivasamudram Area, Karnataka
Authors: Mahabaleswar B. , Anantha Murthy K. S. , Basavanna M. 
Published: November 2024

Abstract
Through a consideration of major element chemistry it is inferred that the orthopyroxenes and clinopyroxenes of the iron formations are ferrohypersthene and ferroaugite respectively, whereas the garnets belong to pyralspite series. The opx and garnets are rich in Mn content, which may be due to bulk composition of the host rock and oxygen fugacity. The P-T estimates give values of 7.5 to 8 Kbars and 607°C to 657°C.
Palaeocurrent and Clastic Dispersal Pattern of the Proterozoic Alwar Group around Jaipur, Northeastern Rajasthan
Authors: Singh S. P. 
Published: November 2024

Abstract
The Proterozoic Alwar Group of tje Jaipur area, northeastern Rajasthan, includes two formations: the Rajgarh Formation, predominantly comprising conglomerate-feldspathic quartzite-arkosic grit association with subordinate phyllite and schist; and Kankwarhi Formation, representing an interbedded sequence of thinly bedded quartzite, phyllite and schist. These sediments were accumulated in tidal flat and fluvial environments in a fault-controlled basin.
Palaeocurrent study reveals that sediments were transported by external agency (river) from southeast, south, and southwest, and were dispersed within the depository by offshore and onshore currents and also by across-slope currents. The dispersal pattern so obtained is in close agreement with a coastal environment and hence it is suggested that cross-stratification can be utilized for palaeocurrent studies and palaeogeographie reconstruction even in a tectonically deformed terrain.
A New Triassic Fish (Actinopterygii; Saurichthiformes) from the Yerrapalli Formation, Pranhita-Godavari Valley, India
Authors: Jain Sohan L. 
Published: November 2024

Abstract
Yerrapalli Formation (late Lower Triassic or early Middle Triassic) in the Pranhita-Godavari Valley is characterized by a fauna consisting of a capitosaur amphibian, dicynodonts and an erythrosuchid. The first piscine member, Saurichthys, is recorded from this formation.