bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biometric Study of Lepidocyclina (Nephrolepidina) from Kutch, Saurashtra and Quilon (India)
Authors: Saraswati Pratul Kumar 
Published: November 2024

Abstract
The biometric parameters of Lepidocyclina (Nephrolepidina) from the Oligocene - Early Miocene sections of Kutch, Saurashtra and Quilon are studied to evaluate their biostratigraphic importance. Following the biometric concept L. (N.) isolepidinoides is identified in the Early Oligocene sequence of Kutch and L. (N.) sumatrensis from the Early Miocene sections of Kutch, Saurashtra and Quilon. The nephrolepidines of Kutch appear to show agradual sustained change withintelVal of arrested evolution. The average value of parameter - A stagnated at about 42% during Oligocene and increased to nearly 46% in Early Miocene times. The value of C increased from 1.7 in Early Oligocene to 2.6 in Late Oligocene and 3.9 in Early Miocene. During this interval F increased from 1.2 to 2.7. The parameters A, C and F are found to be most dependable in inferring the relative age of the nephrolepidine assemblages from the studied localities. The staggering values of E and dc prevent them from a reliable use in biostratigraphy.
Surface Microtextures of Heavy Minerals from the Bay of Bengal off Gopalpur, Orissa
Authors: Bhatiacharyya Samit , Sengupta Ranadhir 
Published: November 2024

Abstract
Microtextures of heavy minerals separated from the seabed samples collected from the inner shelf off Gopalpur, Orissa are identified under SEM and interpreted to prepare a process-response environment model. Dominance of features induced by mechanical process is noted though textures born of chemical processes depending on residence time are also common over the heavy grains. While microtextures of aeolian and glacial origin are absent in the minerals, recycling of heavies like ilmenite, rutile, garnet and spinel is evident from presence of features induced by both mechanical and chemical processes. Zircon and monazite are the only minerals in the studied suite that bear textures almost exclusively of mechanical origin. Derivation from a single provenance is suggested for these two minerals.
Geochemistry of Amphibolites from the Nellore Schist Belt, Andhra Pradesh, India: An Example of Back-Arc Basin Low-K Tholeiitic Magmatism
Authors: Satyanarayan K. , Dhana Raju R. , Kanungo D. N. 
Published: November 2024

Abstract
Geochemistry of ortho-amphibolites from the Degapudi-Kalichedu area of the Nellore Schist Belt (NSB), an Archaean greenstone belt in southeastern India, has indicated their affinity to a low-K tholeiitic magma derived from an LIL-enriched, apatite-bearing mantle by about 5-20% partial melting, followed by fractional crystallization. Amphibolites range from high-Mg-type early differentiates (massive amphibolite and actinolite schist) to low-Mg-type middle-stage differentiates (schistose amphibolite, hornblende schist and related gametiferous hornblende schist). During and subsequent to the generation of their parental magma, the early crystallizing mineral phases are oli vine-clinopyroxene-plagioclase-magnetite-apatite. A back-arc or marginal basin palaeotectonic setting is indicated for NSB by geochemistry of these amphibolites, with precursors of high-Mg-type emplaced in a narrow basin associated with mature subduction zone system and of low-Mg-type in a wider basin associated with youthful subduction zone system.
Groundwater Management in Parts of Saltora Block, Bankura District, West Bengal
Authors: Sikdari P. K. , Dasgupta N. , Sarkar S. S. 
Published: November 2024

Abstract
Hydrogelogical investigation of the area around Saltora reveals the presence of groundwater under shallow water table condition within the Precambrain anorthositic country rock. VES study indicates that the water is stored within the weathered residuum and the underlying fractured rocks within a depth of 69 m. The groundwater flow is guided by the topography and the fracture system. Chemically the groundwater is suitable for drinking and irrigation purposes. The cardinal aquifer parameters such as permeability, transmissivity and specific yield are oflow order and hence water harvesting structures should be supplemented with groundwater abstraction structures to increase agricultural production and thus the economy of the area. Since the area is drought prone traditional methods of irrigation such as flooding must be ruled out and water should be transported from the source to the field by lined channels or pipes to minimise conveyance and evaporationallosses. Drip irrigation may also be adopted.
Temporal Distribution of Benthic Foraminifera Across KTB in Krishna-Godavari Basin, India
Authors: Jaiprakash B. C. , Soodan K. S. 
Published: November 2024

Abstract
The abundance, survivorship and extinctions of smaller benthic foraminifera across Cretaceous/ Tertiary Boundary in a well section GS-II-A in Krishna-Godavari basin appears to be a reflection of tolerance and responses to major geological events such as basinal rise, sea level drop, hiatus and widespread Deccan volcanism. During the terminal Cretaceous the marine environment possibly suffered declining CaCO3 level and anoxic conditions.
Towards the top of Cretaceous (Zones M -16/17), smaller calcareous benthic foraminifera show a decline in relative abundance of the order of 35 %. The relative abundance oflow O2 tolerant arenaceous foraminifera shows a gain of 20% to 25%. A hiatus of the order of less than 8.5Ma encompasses KTB. A major transgressive phase after an anoxic stage above KTB hiatus reestablishes equable conditions for the proliferation of smaller calcareous benthic foraminifera. This relative decline of calcareous benthic foraminifera and survival abilities of arenaceous benthic foramini fera is suggestive of gradual and possibly stepwise elimination process under ecological stress over a prolonged period caused by a chain of KTB events.
Grain Size Distribution and Mineralogy of the Suspended Sediments of Mahanadi River
Authors: Chakrapani G. J. , Subramanian V. S. 
Published: November 2024

Abstract
Considering the enormity of sediment load transported by the Mahadnadi river (approximately 15.74*106 tonnes/year), a,study has been conducted to uncover the groinsize distribution mid clay minerals present in the suspended load which is found to be poorly sorted, mostly fine skewed and very leptokurtic. Increasing water discharge not only increases mean size but improves the sorting of sediments. Sediment size ranges from 1-25 μm and are mostly derived from the sedimentary formations in the basin. Thc Hirakud dam constructed in the Mnhanadi river basin traps coarser scdirnents. Illite is the dotninant clay mineral followed by knolinite, chlorite and montniorillonite. Futher, clays do show preferences to specific size ranges.
The Jurassic Foraminifera from the Patcham-Chari Formations of Jhurio Hill (Jhura Dome), Kachchh, Western India
Authors: Mandwal Niti , Singh S. K. 
Published: November 2024

Abstract
The Patcham-Chari Formations of Jhurio Hill, Kachchh, have yielded a rich and diverse microfossil assemblage dominated by foraminifers. 95 foraminiferal species are being reported from this section assignable to 47 genera belonging to eighteen super families. The present foraminiferal assemblage suggests a Bathonian-Oxfordian age for the Palcham-Chari Formations of Jhurio Hill and also helps to demarcate the Bathonian/Callovian as well as Callovian/Oxfordian boundaries in this area.
Majhgawan Diamondiferous Pipe, Madhya Pradesh, India - A Review
Authors: Chatterjee A. K. , Rao K. S. 
Published: November 2024

Abstract
The alkaline ultrabasic diatreme at Majhgawan has an idealised geological setting being intruded into the platformal Kaimur sandstones of the Lower Vindhyan Supergroup (1400-1100 Ma) overlying cratonic Bundelkhand granite basement (2550 Ma) which is a typical archon as per Janse (1992). Recent Rb/Sr age data indicate 1042 Ma (Smith 1992) and 1067 Ma (Anil Kurnar and Gopalan 1992) for the Majhgawan pipe. The pipe with surface dimension of 500 × 320 m is a carrot shaped body reminiscent of a typical kimberlite with minimal erosion. The pipe rock has been classified as lamproite by Scott Smith (1989, 1992a) who has termed it as olivine lamproitic lapilli tuff of crater facies. High TiO2(4-6%), less abundance of typical heavy indicator minerals (HIM) like group-10 pyrope garnet and ilmenite and overall petrological characters of the pipe strongly reflect lamproite nature. High amounts of certain minor elements such as Ba (3000 ppm), Sr (1000 ppm) and REE (high La, U/Th ratio) also indicate its lamproitic character.
On the other hand the typical carrot shape of the plug, almost concentric distribution of diamonds, mode of presence of mantle-derived xenocrysts, overall chemistry with high MgO(25%) low K2O(1%) and fair amounts of Cr and Ni are highly characteristic of kimberlitic nature. Broad petrographic characters coupled with abundance of xenocrysts and occurrence of country rock xenoliths and geochemical charecteristics suggest it is in several aspects typical kirmberlite rather than lamproite. The garnet population with fair amount of harzburgitic pyrope and larger share of lherzolitic variety indicate characteristics almost intermediate between kimberlite and lamproite.
Irrespective of the nature of the diatreme in any exploration model for search of new primary sources in the area, the spesific nature of HIM of the Majhgawan rock has to be kept in view (i.e.rather less abundance of garnet that too more of group-9 type, predominance of high magnesia spinellchromite, absence of ilmenite etc). The Majhgawan diamonds (42% gem) are predominantly curve faced modified forms indicating signs of resorption.
Geochemistry, Age and Origin of Alkaline and Ultramafic Rocks of Salem, Tamil Nadu, South India
Authors: Reddy B. M. , Janardhanan A. S. , Peucat J. J. 
Published: November 2024

Abstract
Alkaline rocks spatially associated with magnesite bearing dunites occur in the vicinity of Salem, Tamil Nadu. This association occurs with in the gneiss-charnockite terrain and is confined to the intersection of two deep seated lineaments. Based on mineralogy the alkaline rocks are recognised as missourite, shonkinite and syenite.
The alkaline rocks have high Mg numbers and are enriched both in compatible and incompatible trace elements. Majority of the samples show ultrapotassic character and are enriched in REE (30-200 ppm) with LREE enrichment and no Euanarnoly. The Rb-Sr isochron gives an age of 808 ± 18 Ma and shows fairly high Sr initial ratio of 0.7051 ± 1. The unusual chemistry of these rocks suggests that they are derived, from an enriched mantle source, with the dunite representing the mantle residua.
S-Isotopic Study On Baryte From the Andiyappanur Area, North Arcot District, Tamil Nadu
Authors: Kumar Mary K. , Veera Baskar D. , Sharma Mithilesh , Chabria T. , Dhanar Raju R. 
Published: November 2024

Abstract
Sulphur-isotopic dataon fifteen samples of baryte from the quartz-baryte rock occurring along a shear zone east of the Elagiri Syenite pluton at Andiyappanur, Tamil Nadu have shown a narrow range of +5.1‰ to +9.5‰, with an average of +6.70‰, for d34SCDT. The data, in conjunction with the field and petromineralogical characteristics, indicate hydrothermal-type mineralisation of baryte. Association of relatively earlier formed sulphides like pyrite, molybdenite and galena, and later formed sulphates like baryte and jarosite in this quartz-baryte rock is attributed to dual behaviour of sulphur in the magmatichydrothermal system, with formation of sulphides at depth under reducing conditions and of sulphates in the shallower oxidised zones.
Recent Ostracoda of the Goguleru Creek, East Coast of India
Authors: Shyam Sunderk V. V. , Varma K. U. , Naidu T. Y. 
Published: November 2024

Abstract
Thirty-three species of Ostracoda have been identified from the Goguleru creek and the adjacent open beach, east coast of India. Of these, the following five species are described as new: Copytus coromandalensis, Loxoconcha guhai, Neocytheromorpha goguleruensis, Paijenborchellu keiji and Paradonostoma bhatiai. Keijia dernissa(Brady), 1868 is recorded for the first time from Indian waters.
Mineralogy and Geochemistry of the Carbonatites of the Sevathur and Samalpatti Complexes, Tamil Nadu
Authors: Viladkar S. G. , Subramanian V. 
Published: November 2024

Abstract
The Proterozoic carbonatites and associated pyroxenites and syenites of Tamil Nadu are emplaced in the Precambrian gneissic rocks. The carbonatite complexes are located along a major NE trending lineament. In Sevathur, dolomitic carbonatite is predominant over sovite and ankeritic carbonatite whereas in Samalpatti, sovite and silico-sovite form the major bulk of carbonatite mass with small dykes of dolomitic and ankeritic carbonatites. In different types of carbonatites, in addition to calcite, dolomite and ankerite, phlogopite, amphibole, magnetite, and apatite are found in varying amounts between 2% and 10% with accessory amounts of pyrochlore, perovskite, monazite, NbiImenorutile, zircon, baddeIeyite, pyrite, ilmenite, galena and thorite. Both mica and amphibole show change in composition from Fe-rich in syenite and sovite to Mg-rich in the dolomitic carbonatite. The carbonatites are enriched in Ba, Sr, Nb, REE's, Th and U in comparison to the primitive mantle values. Pyroxenites are characterized by high abundances of Mg, Cr and Ni and, low abundances of Nb and Zr. The petrographic evidence, with globules silicate rocks surrounded by carbonatitic matrix is sufficiently clear to suggest a genetic link between syenite and carbonatite by liquid immiscibility.
Evidence of Bioturbations in the Delhi Supergroup of Haryana
Authors: Dasgupta G. , Prasad Sheo 
Published: November 2024

Abstract
Bioturbation signatures in the form of trails and traces have been recorded from the Proterozoic Delhi Supergroup of rocks exposed in Southern Haryana. These structures bear strong resemblance to the similar traces and trails reported from correlatable Alwar and Ajabgarh Group of rocks of Rajasthan. In this note the authors report and discuss the possibilities of such structures being biogeneic or abiogenic.
Geochemistry and Tectonic Significance of Ongarbira Volcanics, Singhbhum Craton, Eastern India
Authors: Raza M. , Alvi S. H. , Abu-Hamatteh Z. S. H. 
Published: November 2024

Abstract
The Ongarbira volcanics of middle Proterozoic age occur with the Sahedba sedimentaries in the south of Singhbhum shear zone. The volcanics are of tholeiitic composition with high content of MgO (&gt; 8%) and high MgO/Al2O3, ratio (&gt; 0.6). In terms of REE data these rocks show LREE depleted patterns which resemble those of basaltic rocks from Dalma volcanic belt and basaltic komatiite of Kolar schist belt. MORB- normalized incompatible element patterns of these rocks display distinct enrichment of LILE including Th and depletion of HFSE and marked trough at Nb and Ta. These features suggest a subduction zone component in the source of Ongarbira volcanics. Nb-normalized ratio spidergrams and incompatible element ratio plots Ce/Yb- Ta/Yb-, Th/Yb- Ta/Yb and Th- Hf- Ta are consistent with their eruption in a subduction related environment. REE modelling spggests that they were generated through 14 to 18 percent partial melting of a LREE depleted source. The source was probably selectively enriched in LILE by materials derived from the subducting slab.
Geochemical-Geological evidences indicate that Ongarbira volcanics were probably erupted on a thin continental crust or even on oceanic crust as a result of a southward plate convergence below the Singhbhum craton.
The Lower Paleozoic Granitic Magmatism Near Ranikhet, Kumaun Himalaya: Major and Trace-Element Geochemistry and Tectonic Setting
Authors: Rashid S. A. , Zainuddin S. M. 
Published: November 2024

Abstract
The Lower Paleozoic Ranikhet granitic rocks lie in between the tectonically active South and North Almora thrust zones and contain two types of granites: a Gneissose granite (GG) and a younger Porphyritic granite (PG). Both the phases show a good correlation in some of the major elements, whereas a wide scatter is observed in the trace-elemental abundances. These Ranikhet granites are Rb rich and Sr poor, they reveal peraluminous characteristics and correspond to the S-type granites. A syn-collisional tectonic environment for these granites is revealed by their Nb+Y and Rb concentration. Lower Paleozoic granites reported all along the Lesser Himalayan belt extending from Munsehra, NW Himalaya to Palung, Nepal Himalaya represent the widespread magmatic activity around the end of the Cambrian times. These granites support for the exitence of a syn-collisional tectonic environment in the early Paleozoic period.
Effects of Metasomatism on the Country Rocks Around the Carbonatites of Kudangulam Area, Tamil Nadu
Authors: Ramasamy R. 
Published: November 2024

Abstract
Amtdst a chamockitic terrain, a new occurrence of carbonatite-metasomatic complex has been reported from Kudangulam area, near Cape Comorin, Tamil Nadu. Petrography and geochemistry of the metasomatic rocks formed around the carbonatites indicate that the carbonatitic melt associated with fenitizing solution degassed through deep faults present in this area by reactivation of continental rifting during Post-Tertiary Period.
Gravity and Magnetic studies Around Lotapahar, Singhbhum District, Bihar-An Application to Uranium Exploration
Authors: Dash J. K. , Allipeera P. , Markandeyulu A. 
Published: November 2024

Abstract
The potential capabilities of gravity and magnetic methods in the evaluation of geologic structures have been effectively utilised. Using these methods, semi-detailed surveys were conducted around the radioactive occurrences at Lotapahar (22°36'30"N. and 85°35'E.), in the western sector of the Singhbhum shear zone, primarily to decipher structural features, the common host for Uranium mineralisation.
The interpretation of gravity and magnetic data enabled delineation of a ENE-WSW trending fracture zone. Forward modelling of a gravity profile yields the sub-surface disposition of this fracture zone and facilitated planning of boreholes for uranium exploration in the area. The magnetic and the regional gravity maps indicated the contact of Chakradharpur granite and metasediments of the Iron Ore Group which is indistinct on the surface.
Holocene Sea Level Fluctuations On Western Hndian Continental Margin: An Update
Authors: Hashimi N. H. , Nigam R. , Nair R. R. , Rajagopalan G. 
Published: November 2024

Abstract
A new Holocene curve is generated for the western Indian continental margin. While constructing this curve careful selection of the dates were made by giving due considerations to the genetic characteristics of the dated material. This new curve shows a low at 100 m depth around 14,500 years BP and a rise to 80.m depth around 12,000 years BP showing a rate of 10m/1000 years which was followed by astillstand for about 2,000 years. From 10,000 to 7,000 years it rose at a very high rate (20 m/1000 years). Beyond 7,000 years BP it showed minor fluctuations.
The Gabbros of Prakasam Alkaline Province, Andhra Pradesh, India
Authors: Vijaya Kumar K. , Ratnakar J. 
Published: November 2024

Abstract
The gabbro plutons of Boggulakonda, Settupalle, Purimetia, Pasupugallu and Chimakurti in the Prakasam alkaline province (PAP) in Andhra Pradesh occur in a narrow zone (east of the Cuddapah basin) within the Precambrian amphibolites and granitic gneisses. The plutons are emplaced into preheated country rocks as either crystal mushes and multiple intrusive pulses or convective stirring. The chief rock types of the plutons are gabbro, norite, anorthosite, troctolite and rare pyroxenite.
The gabbros are of high-alumina olivine tholeiitic type, excepting those in Pasupugallu pIuton which are of alkali olivine basaltic type. In general, all the gabbros are derived by shallow melting within the mantle. The liquidus olivine temperatures (T° Iiq) of gabbros (excepting a few cumulate rocks) range from 1102° to 1412° C. The Boggulakonda, Purimetla and Pasupugallu gabbros are formed by fractionation of olivine and plagioclase. The Settupalle gabbros represent melts which are derived by a process of "continuous me1ting"(?). The Chimakurti gabbros are derived by "adiabatic melting" in a rising diapir. All the plutons have experienced olivine fractionation prior to their emplacement and differentiated under PCO2/PH2O conditions.
Trace Metal Contents of Iron Sulfide Minerals From the Tertiary Carbonaceous Clays of Kerala
Authors: Padmalali D. , Santhosh S. , Suresh Babu D. S. 
Published: November 2024

Abstract
The Tertiary carbonaceous clay deposits of Kerala abound in iron sulfide minerals such as pyrite and marcasite. Pyrite is confined mainly to the Quilon beds and marcasite to the Warkalli beds. Manganese, Zn, Pb, Ni, Co, Cd and Cu are substantially high in marcasite than in pyrite. Trace metals (except Zn) are markedly high in the carbonaceous clays of the Warkalli section than in those of the Pozhikkara section. The observed variation in the trace metal contents of sulfide minerals as well as carbonaceous clays of the two sections might have resulted from differences in depositional environments.
Hydrogeological Mapping in the Deccan Basalts - An Appraisal
Authors: Kulkarni Himanshu , Deolankar S. B. 
Published: November 2024

Abstract
A great deal of diversity exists in the approaches to hydrogeological mapping of the Deccan basalts. For any hydrogeological siudy in the Deccan basalts to be fruitfully applicable, there is an ardent need to standardise the procedure towards hydrogeological mapping. To overcome practical difficulties iil the hydrogeological mapping of the Deccan basalts, a systematic approach which is based onoa lithological model observed widely over the Deccan basaltic province is proposed here. The approach incorporates mapping on a suitable scale that defines the inhomogeneities in the hydrogeological character of the basalts. Detailed acquisition and systematic representation of data (such as recording the configuration ofinflow zones in wells) and the capacity of extrapolation over the Deccan basaltic terrain render this approach more user-friendly.
Foraminiferal Ecosystem in Relation to Coastal and Estuarine Sediments of Kovalam - Tuticorin, South India
Authors: Jayaraju N , Reddi K. R. 
Published: November 2024

Abstract
A total of 180 bottom water and sediment samples each were collected both in monsoon (1990) and premonsoon (1991) periods from coastal and estuarine environments of Kovalam-Kanyakumari Tuticorin, South India. Fifty four benthic foraminiferal taxa were reported belonging to three suborders - Rotalina, Miliolina and Textularina. The fauna was thus related to ecological ingredients viz., salinity, organic matter, calcium and phosphate. Salinity showed an erratic relation whereas other parameters exhibited slight positive bearing with living crop in both the seasons. The living fauna have limited number of taxa with Ammonia beccarii and Asterorotalia dentata being dominant in both the seasons. Faunal density, diversity and distribution increases gradually towards Tuticorin. Inter play of ecological parameters coupled with substrate character could be the reason in faunal abundance and diversity along the east coast. The results lead to the conclusion that the type and size of the substrate is more important in regulating the foraminiferal density and diversity in the study area than mineralogy of the sediment. Investigations reveal that the monsoonal season is more congenial than premonsoonal season to the foraminifera. The provenance of the sediment is a metamorphic terrain dominated by Precambrian gneisses, schists and ferruginous quartzites belonging to Peninsular shield.