bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palynostratigraphy and Correlation of Permian-Triassic Sediments in Budharam Area, Godavari Graben, India
Authors: Srivastava Suresh C. , Jha Neerja 
Published: November 2024

Abstract
The subsurface sedimentary sequences peqaining to the Gondwanas in Budharam Area of Godavari Graben have yielded nearly a complete palynological sequence from Early Permian to Early Triassic represented by Talchir, Karharbari. Barakar. Barren Measures, Raniganj and Kamthi palynofloras. The presence of Jeiosphaerids and Botryococcus in Talchir palynozone indicates marine influence during the deposition of these sediments. The palynological transition from Late Permian (Raniganj) to Early Triassic (Kamthi Formation) is gradual and corroborates with the lithological succession
Structural Geometry and Strain History of the Early Proterozoic Aravalli Rocks of Gorimari, Udaipur District, Rajasthan
Authors: Chauhan N. K. , Sharma B. L. , Mohemmad Sabah A. 
Published: November 2024

Abstract
Detailed mapping and analyses of the structural elements from Gorimari revealed a complex structural geometry and deformation history of the rocks. Only two prominent planar structural elements have been observed i.e., the bedding schistosity (S0S1) and cleavage (S2). The earliest AF1 and the later AF2 folds on every scale are suggestive of reclined geometry. The strain analyses of AF1 and AF2 folds suggest their initiation by buckling and subsequent flattening resulting into class I C geometry. Some of the folds show a complex geometry which may be due to original layer irregularities or may be due to differential flattening because of the variation in thickness of single layer. The values of compressive apparent strain ratio varies from 0.1 to 1.0. Stratigraphically these rocks are equivalent to the Early Proterozoic rocks of Bagdunda. The grade of metamorphism is oflower amphibolite facies.
Radioelement Distribution and Radioactive Heat Generation in the Central Gneissic Complex, Kameng District, Arunachal Pradesh
Authors: Dikshitulu G. R. , Dhana Raju R. 
Published: November 2024

Abstract
The Central Gneissic Complex (CGC) in the Kameng district, Arunachal Pradesh comprises the oldest Sela Group, followed by the Bomdila Group and the youngest Salari Group. The Sela Group consists of migmatite, hornblende granite gneiss, two-mica granite and profuse intrusions of tounnaline granite (Tertiary ?). Along the Main Central Thrust (MCT), the Sela Group overlies the Bomdila Group consisting of augen gneiss, quartzite. quart-mica schist, marble and basic intrusive rocks. The Bomdila Group, in turn, overlies the Salari Group that comprises black shales and intrusive high-Ca granites. Radioelement (U, Th and K) contents, detennined by gamma-ray spectrometry. of 28 granitic and migmatitic samples of CGC indicate that the tourmaline granite and two-mica granite, augen gneiss have the highest U values as compared to that of others. Th content is more in the augen gneiss and hornblende gneiss than in other rock types. In case of K, two-mica granite and tourmaline granite have higher contents than the rest. Radioactive heat, computed from each ofthese radioelements, is highest in the tourmaline granite and two-mica granite, with the other rock types having low to intermediate values. The average total heat generation of CGC is of the order of 9.3 Heat Generation Units (HGU). A value of about 7 HGU is generally taken as the separating value between hot and cold crust and, hence, the higher value of 9.3 HGU for CGC points to the presence of hot crust in the Arunachal Himalaya. The radioactive heat generation and the published high heat flow values in the CGC indicate steep geothermal gradients in the area, which may help in remobilisation and subsequent precipitation/concentration of U in favourable locales.
Search for Placer Gold in Leastern India - A Geomorphological Approach
Authors: Chakrabarti Parthasarathi 
Published: November 2024

Abstract
In eastern India, presence of gold is common both in alluvial and colluvial zones in a sporadic fashion over wide stretches of Purulia district, West Bengal and adjacent Singhbhum and Ranchi districts, Bihar. Regionally, the area is in between the Tamar - Porapahar shear zone in the north and the Dalma range in the south.
Applied geomorphological studies, using remote sensing data products, with morphogenetic approach based on terrain analysis and classification help to outline such zones as manifestations of form - process - material interactions. With this perspective, interpretation of satellite imagery (B & W, TMFCC - LANDSAT) and aerial photographs has led to identification of relics of an 'Older planation surface' of Quaternary age in the Banduan area, Purulia district. West Bengal and Tamar - Ichagarh area, Ranchi and Singhbhum districts, Bihar.
The different terrain units/sub-units, with placer gold concentration, associated with this 'Ranchi - Purulia Older planation surface' are degraded glacis, very degraded glacis. cone glacis. The 'degraded glacis' with latosol/laterite crust (nodular ferricrete only) could be used as a guide horizon for preliminary search of placer 'gold in laterite' or 'lateritic gold' as has been reported from Brazil, Australia, West Africa and some Gulf countries in a similar set up.
SHRIMP U/Pb Zircon Ages of Acid Volcanic Rocks in the Chitradurga and Sandur Groups, and Granites Adjacent to the Sandur Schist Belt, Karnataka
Authors: Nutman A. P. , Chadwick Brian , Krishna Rao B. , Vasudev V. N. 
Published: November 2024

Abstract
SHRIMP U/Pb dating of zircon grains from a schistose acid volcanic rock from the Daginkatte Formation in the Chitradurga Group of the Late Archaean Dhwar Supergroup in western Karnataka has yielded a precise concordant age of 2614 ± 8 Ma which indicates the time of melt crystallisation. In contrast, zircons from similar schistose acid volcanic rocks in the Vibhuti Gudda Formation of the Sandur Group in the Sandur schist belt of eastern Karnataka yielded less precise concordia intercept ages of 2658±14 and 2691±18 Ma.
Zircons from high-strain grey gneisses which appear to be the oldest recognisable component of the Late Archaean granite complex adjacent to the Sandur schist belt have an imprecise age of 2719 ± 40 Ma. Zircons from the youngest recognisable granite adjacent to the belt have also yielded an imprecise, but younger, age of 2570 ± 62 Ma. The ages show that granite emplacement and deformation adjacent to the Sandur schist belt took pIace in a period of c.150 Ma.
The imprecise ages of zircon in the acid volcanic rocks in the Sandur Group and the adjacent granites are related to Neoproterozoic loss of lead which may have been an effect of either weathering or a regional thermal event. We favour the latter in the light of the record of Pan-African thermal effects in the east and south of southern Peninsular India.
Geochemistry, Petrogenesis and Tectonic Setting of Proterozoic Mafic Dyke Swarms, Eastern Dharwar Craton, India
Authors: Pamganamamula Rao V. , Puffer John H. 
Published: November 2024

Abstract
Extensive swam of thick (10 to 80 m) en echelon Proterozoic dolerite dykes have intruded the Archaean gneissic/granitic rocks of the Eastern Dharwar Craton of Peninsular India. Dykes in the southern half of the craton, including a cluster of 12, strike mostly E-W, whereas those exposed in the northern half including two clusters of 25 and 6 dykes, strike NW and ENE, as well as E-W and N-S. All the dykes sampled from the southern group plot along a continuous tholeiitic fractionation trend and are characterised by low concentrations of FeO(T), TiO2, and P2O5 (an LFTP group) averaging 11.5,0.85, and 0.15 wt% respectively. About two-thirds of the 25 dykes sampled from the northern group are also LFTP dykes, but the remaining third (a HFTP group) contain much higher FeO(T), TiO2, and P2O5 (averaging 152.2, and 0.45 wt/%). The HFTP is clearly enriched in high field strength and heavy rare earth elements compared to the LFTP group, suggesting independent magma sources.
The LFTP dyke population is chemically rlnlike any plume or island are related magmatism and differs from most continental-rift related, within-plate tholeiites. It is, however, similar to the Mesozoic rift related olivine normative dolerite dyke population of Eastern North American province and its low- Ti (LTQ) counterpart. The chemical composition of the LlTP population is consistent with a MORBlike source that has experienced considerable crustal contamination.
The HFTP dyke population is chemically typical of continental flood basalt (CFB) magmatism, such as the Deccan basalt, and is interpreted as magma derived from a plume source that has assimilated some lithospheric rock.
Major Ion Chemistry of Groundwater in Delhi Area: Chemical Weathering Processes and Groundwater Flow Regime
Authors: Datta P. S. , Tyagi S. K. 
Published: November 2024

Abstract
Groundwater is moderately to highly saline in all parts of Delhi area. No definite explanation has emerged so far about the source of salinity. Study of major ion chemistry of groundwater has been conducted to identify the source of major ions in terms of chemical weathering processes. The chemistry of groundwater is dominated by carbonate weathering. The excess of sodium ion over chloride ion can be attributed to silicate weathering to a certain extent. The groundwater in northern and western parts of the area is primarily alkaline and secondarily saline and in the southern and southwestern parts it is primarily saline and secondarily alkaline. Highly correlated positive linear trend between sodium and chloride indicates mixing of two groundwater bodies with different end member composition (i.e. fresh and saline). Multicomponent mixing may also be taking place within the local flow regimes. The large lateral variation of chloride concentration indicate recharge and discharge zones of local flow regime. Local recharge to the unconfined aquifer is more dominant than recharge from lateral flow. The very high Cl and SO4 contents in some groundwaters seem to be related to long evaporative and to sulphur oxidising conditions in topographically low area.
Scanning Electron Microscopy of Quartz Grain Surface Textures of the Gondwana Sediments, Barapukuria, Dinajpur, Bangladesh
Authors: Rahman M. H. , Ahmed F. 
Published: November 2024

Abstract
Surface textural analysis of 43 Gondwana quartz grains of Barapukuria area, northern Bangladesh was performed by Scanning electron Microscope (SEM) to identify different types of textures and to draw their implications regarding transportational and/or depositional environments. Eighteen (18) individual types of surface textures, namely the pitted surface, conchoidal fractures, straight and arcuate steps, fracture planes/plates, adhering particles, angular and rounded outlines, relief, concavities, irregular solution features, gullying, silica globules, silica pellicle and crystalline overgrowths were identified.
A detailed investigation of the above mentioned surface textures of quartz grains suggest that the Gondwana sediments of Barapukuria area were transported a moderately long distance through a high energy aqueous medium and finally came to rest in a silica saturated depositional environment. Diagenetic activities at the post depositional period were distinctly prominent.
Paleogene Sequence Analysis and Seismic Evaluation of Wedge Out Prospect in Northwestern Part of Surat Depression, Bombay Offshore Basin
Authors: Dwivedi A. K. , Bajpai A. K. , Srivastava H. C. , Thakur R. K. , Lal N. K. 
Published: November 2024

Abstract
The use of seismics to recognise and map stratigraphic traps is becoming an important phase of exploration activity in mature hydrocarbon provinces, world over. The stratigraphic wedge-outs have provided excellent trapping mechanism in some of the giant fields of the world. Surat depression is known to be the main kitchen for the hydrocarbon occurrences in Bombay High and around. Commercial accumulations have been encountered in Mid-Tapti and South Tapti fields of Surat depression. These accumulations are in structural traps. However, further updip, over Saurashtra shelf, the exploratory efforts have remained limited due to the absence of any structural prospects, The present paper deals with the interpretation of close grid seismic data with an objective to: i) identify seismic sequences and the depositional environments and ii) to map stratigraphic trap at levels equivalent to Eocene sands with oil indications encountered in the earlier drilled exploratory wells.
Geochemistry of Polyphase Gneisses from Schirmacher Oasis, East Antarctica
Authors: Hussain S. M. , Divakara Rao V. 
Published: November 2024

Abstract
Gamet-biotite gneisses (GBG), augen gneisses (AG) and quartzo-feldspathic gneisses (QFG) constitute the main litho-units in the granulite terrain of Schirmacher Oasis, East Antarctica. The GBG and AG show chemical and mineralogical similarities. The QFG differs from GBG and AG both in major and trace elements. Overall composition of these different polyphase gneisses indicate increase in silica and alkalies from GBG to QFG and decrease in CaO, FeO and MgO. In trace elements Rb increases from GBG to QFG, while Sr and Ba increase in AG and decrease in QFG. The REE distribution patterns in GBG. AG and QFG differ in that, the total REE in GBG is 160.70, in AG 148.32 and the QFG 119.30. The LREE/HREE and Cen/Tbn ratios of GBG and QFG are similar while in AG these differ slightly (GBG = 5.16 and 3.18; AG = 6.93 and 5.10; QFG = 5.62 and 3.90 respectively). Majority of the gneisses exhibit negative Eu anomaly (GBG = 0.55; AG = 0.35; QFG = 0.43) except two from AG having no anomaly. Overall major, trace and REE abundances in the garnet-biotite and augen gneisses suggest their origin by progressive metamorphism of a pelitic source. Partial melting of GBG locally appears to have formed quartzo-feldspathic gneisses. These gneisses resemble the metapelites of the Eastern Ghat granulite terrain and Kerala khondalite belt of India in their overall compositions.
Quantitative Radiolarian Assemblages in Surface Sediments from the Central Indian Basin and their Paleomonsoonal Significance
Authors: Gupta Shyam M. 
Published: November 2024

Abstract
The percentage data of 47 radiolarian coarser taxonomic groups in the surface sediments from the central Indian Basin was subjected to cluster and factor analyses. The R-mode cluster analysis resulted in 3 dominant clusters which represent surface, subsurface and deep water dwelling radiolarian groups. The Q-mode factor analysis resulted into three dominant factors. The factor-1 is characterized by Pyloniids group dominating the southwestern part with higher salinity (&gt;34.5/ppt), low sea surface temperature &lt;27°C) and high potential primary productivity (&gt;0.2 mgC/m3/h) during the southwest monsoon. The factor-2 is characterized by Spongodiscids group dominating the northeastern part with lower salinity &lt;34.5/ppt). warmer SST (&gt;28°C), and poor potential primary productivity &lt;0.2 mgC/m3/h) during the southwest monsoon. The factor-3 is characterized by Euchitoniids group dominating a transitional area between the two factors.
Facies Analysis of the Late Proterozoic Nagthat Formation, Nainital Hills, Kumaun Lesser Himalaya
Authors: Shukla U. K. , Pant Charu C. 
Published: November 2024

Abstract
The Proterozoic Nagthat Fonnation of Nainital area is composed mainly of fine- to coarse-grained quartzarenite with subordinate amount of pebbly sandstone, conglomerate, siltstone and silty shales. On the basis of such parameters as grain size, primary structures, palaeocurrent and morphology of lithounits, seven major lithofacies have been distinguished in the Nagthat sequence. These are, medium to coarse-grained gravelly quartzarenite (Lithofacies A), bar cross-bedded medium-grained quartzarentite (Lithofacies B), horizontally laminated fine-grained quartzarenite (Lithofacies C), fine to medium-grained channelised quartzarenite (Lithofacies D), fine-grained quartzitic sandstone (Lithofacies E), silty sandstone-shale (Lithofacies F) and matrix supported conglomerate (Lithofacies G).
Lateral and vertical distribution of constituent lithofacies demonstrate deposition of Nagthat sediments in a progradational (regressive) barrier island system, in subtidal upper shoreface and channels, subtidal longshore bars, foreshore beachface, tidal channels (inlets), intertidal sandflat-channel and mixed flat environments, and occasionally as gravity flows in subtidal gravelly channels.
Age, Ontogeny and Dimorphism of Macrocephalites triangularis Spath - The Oldest Macrocephalitid Ammonite From Kutch, India
Authors: Daitai Kalyanbrata , Bhaumik Debasish , Jana Sudipta K. , Bardhan Subhendu 
Published: November 2024

Abstract
Macrocephalites triangularis Spath is the oldest macrocephalitid species in Kutch. Judging from the associated taxa and comparison of similar macrocephalitids and other forms between Kutch and other parts of the world, a Late Bathonian age for M. triangularis is reaffirmed. Previous systematic description was based on only two specimens. A fair number of well preserved specimens has enabled us to trace the ontogenetic development and decipher sexual dimorphism. The importance of this species in the evolution of later rnacrocephalitids of Kutch is explored.
Terrain Analysis and Spatial Assessment of Landslide Hazards in Parts of Sikkim Himalaya
Authors: Mehrotra G. S. , Sarkar S. , Kanungo D. P. , Mahadevaiah K. 
Published: November 2024

Abstract
Landslides and slope instability problems are quite common in Sikkim Himalaya. Recent developmental activities in this region have aggravated the incidence of landslides to a great extent. The ongoing developmental activities, therefore, call for delineation of safe and unsafe zones.
The present study involves the preparation of landslide hazard zonation map of East Sikkim Himalaya in a semiquantitative way by evaluating various terrain factors like lithology, structure, slope, landuse and drainage in relation to existing landslides. A numerical weightage called Landslide Susceptibility Value (LSV) has been assigned to each factor and Landslide Susceptibility Index (LSI) of each category of factor maps has been catculated. Based on the proposed methodology landslide hazard zonation map of the area is prepared showing five zones of slope instability. This map may serve as a base map for any developmental activities to be planned in the terrain. An attempt has also been made to establish the relationships of various geoenvironmental factors with the landslide activity with an objective to develop an appropriate methodology for landslide hazard zonation.
Neotectonic Control on Drainage System in Gangetic Plain, Uttar Pradesh
Authors: Singh I. B. , Ansari A. A. , Chandel R. S. , Misra A. 
Published: November 2024

Abstract
Study of remotely sensed data and SOl topographical maps with some field observations has helped in the identification of lineaments controlling the drainages, using various indications like displacement of Siwalik hills, skewness of fan surfaces, preferential alignment of river channel, knick points, distorted meanders, abrupt change in river courses, escarpments and asymmetrical terraces. The northern part of the Gangetic plain, the Piedmont zone shows two major lineaments, i.e. NNE-SSW and NW-SE, developed as conjugate strike slip features, with some evidences of gravity component. The NW-SE direction of the conjugate system is very prominent in Central Alluvial Plain and has controlled the major drainages. These lineaments have caused abrupt change in flow directions of many streams; and in parts, have behaved as gravity fault with NE blocks as downthrown side. The drainage in the Marginal Alluvial Plain (southern part) is essentially controlled by the reactivated basement lineaments of predominantly SW-NE direction. The drainage of northern and central part of Gangetic plain is controlled by newly developed lineaments formed due to compressional stresses of the Himalaya while drainage in southern part is controlled by reactivated basement lineaments.
Crustal Influences in the Petrogenesis of the Malani Rhyolites, SouthWestern Rajasthan: Combined Trace Element and Oxygen Isotope Constraints
Authors: Maheshwari A. , Coltorti M. , Sial A. N. , Mariano G. 
Published: November 2024

Abstract
The Malani volcanics of Gurapratap Singh and Din belong to a basalt-andesite -dacite-rhyolite association of Precambrian age. The preponderance of rhyolites over basic and intermediate rocks is a significant feature of the area. The rhyolities are characterised by chemical features, which indicate their A-type affinity. The study rules out their cogeneticity and suggests the crustal involvement in the genesis of Malani rhyolites.
A New Look at the Olivine-Lamproitic Rocks of the Maddur-Narayanpet Area, Mahbubnagar District Andhra Pradesh, India
Authors: Chalapathi Rao N. V. , Madhavan V. 
Published: November 2024

Abstract
The olivine- lamproitic/kimberlitic rocks occuring in parts of the Mahbubnagar district of Andhra Pradesh are re-examined in the light of new petrological and geochemical data. The titanium poor &lt;3 TiO2, wt%) phlogopites, presence of primary calcite and composition of perovskites in these rocks are akin to those found in kimberlites. Calcium-rich iron silicate - kirschsteinite is being reported for the first time from Indian kimberlites in this work. The geochemical signatures of these rocks like potassic (K2O &lt;3 wt%) character, magnesian rich nature (&gt;30 wt% MgO), high Mg numbers (73-82) and incompatible element enrichment levels further characterise them to be kimberlites. The abundances and the chondrite normalized distribution patterns of their REE are remarkably different from the olivine lamproites of Western Australia. It is put forward here that all these occurrences are true kimberlites and not olivine-lamproites resembling those of Western Australia, as suggested by some workers elsewhere. It is further argued that all the kimberlites of Mahbubnagar district are genetically related and are different in this aspect from atIeast one kimberlite from the Anantapur district - Chigicherla pipe-2, the latest pipe find in the Anantapur district, suggesting that the Mahbubnagar kimberlitic activity could be unrelated to the southern Anantapur.
Electrical Resistivity Surveys for Groundwater in the Upper Gunjanaeru Catchment, Cuddapah District, Andhra Pradesh
Authors: Janardhana Raju N. , Reddy T. V. K. , Nayudu P. T. 
Published: November 2024

Abstract
Integrated geological, hydrological and geophysical (electrical resistivity) surveys have been used to delineate groundwater potential zones in Upper Gunjanaeru catchment (latitudes 13°43'45" and 14°1'44" N. and longitudes 79°15'16" and 79°27'38" E.) in Cuddapah district, Andhra Pradesh. The main lithological units in the catchment are alluvium, shales and quartzites. Preliminary pump tests in selected borewells indicate discharge variations from 6,600 lph to 48,000 lph and the respective transmissivities (T) range from 11.5 x 104 lpd/m to 36 x 104 lpd/m.
Forty five vertical electrical soundings were carried out using Schlumberger configuration. The data was interpreted with the help of three layer master curves and auxiliary point charts. Sounding curves suggest a few three layer geoelectrical sections H, A, K & Q type and a number of four layer sections of HK, KH, HA and AK types. Horizontal geoelectrical cross sections for selected depth levels are presented and discussed. The study indicates that the groundwater resources are mainly confined to the boulder, weathered and fractured zones in the study area except in southern parts where the groundwater is confined to the weathered and fractured zones.