bluuebunny/crossref_metadata_2025 huggingface dataset:
Petrography and Geochemistry of the Radioactive Albitites and their Genesis: Maonda Area, North Rajasthan
Authors: Jain Rajan B. , Yadav O. P. , Rahman M. , Thippeswamy S. , Fahmi S. , Sharma D. K. , Singh Govind
Published: November 2024

A partly concealed radioactive alibitized pegmatoid/quartz albitite body (1200 m x 0.5 to 20 m) containing 0.010 to 0.190% U3O8 and 0.007 to 0.076% ThO2 and about 20 brick red coloured albitite lenses varying in dimension from 13 m x 7 m to 220 m x 12-30 m and containing 0.022 to 3.50% U3O8 and 2 are described at Banjaron Ki Dhani, new Maonda in north Rajasthan. Davidite, brannerite, rutile, anatase, zircon, monazite and traces of uraninite have been identified in the albitites. A metasomatic origin for the albitites is suggested. The distribution of albitites along NE-SW to NW-SE and E-W trending weak structural planes and the coincidence of 'Albitite Line' with Kaliguman lineament, demonstrates the tectonic control of albitization.
Precise 40Ar/ 39Ar Age Determinations of the Kotakonda Kimberlite and Chelima Lamproite, India: Implication to the Timing of Mafic Dyke Swarm Emplacement in the Eastern Dharwar Craton
Authors: Chalapathi Rao N. V. , Miller J. A. , Gibson S. A. , Pyle D. M. , Madhavan V.
Published: November 2024

40Ar/ 39Ar age spectra of groundmass phlogopite separates from the Kotakonda kimberlite (Eastern Dharwar craton) and the Chelima lamproite (Cuddapah basin) are dominated by major plateaus at 1401.4±4.6Ma and 1417.8±8.2 Ma respectively. These ages are consistent (within their error limits) with the conventional K-Ar dates on phlogopite separates from the same samples earlier reported by us. This study supports our contention that the emplacement of Kotakonda kimberlite and Chelima lamproite was contemporaneous and these pipes are older than the Anantapur kimberlites (-1090 Ma) of the Eastern Dharwar craton. The agreement of ages obtained by employing more than one technique is a testimony of confidence in our results and, therefore, firmly establishes an episode of Proterozoic mafic potassic magmatic activity in the Eastern Dharwar craton and adjacent Cuddapah basin at ca. 1400 Ma. The concordance of plateaus and correlation of isochron plots for both these bodies suggests that at least these parts of the Eastern Dharwar craton and Cuddapah basin have not been subjected to any subsequent tectono-thermal activity. Our results contrast with the recent suggestion that a ~ 1000 Ma thermal event in and around the Cuddapah basin led to argon loss and was responsible for the variable K-Ar ages of dyke swarms in the Eastern Dharwar craton.
Reworking of BIF into GIF in the Sandur Schist Belt, India: Possible Evidence of Sea Level Changes in an Archaean Proto-Ocean
Authors: Manikyamba C.
Published: November 2024

Granular iron formations (GIF) which are abundant in some Proterozoic, BIF bearing sedimentary basins are reported for the first time from the Archaean Sandur schist belt. These beds show lateral and vertical transition and repetition with oxide facies BIFs. Graded bedding and angular fragments are found in them. They consist mainly of iron and silicon oxides. Their trace clement and REE patterns itre similar to the BlFs from which they have been derived as a consequence of submarine erosion on the shelf through transgfession-regression cycles. Changes in sea level indicated by these structures were probably caused by volcanic activity and associated seismic tremors.
Geothermometry and Mineralogy of Two-Pyroxene Granulites: Evaluation from Mossbauer and X-ray Single Crystal Cation Partitioning of Ca-Poor and Ca-Rich Pyroxenes
Authors: Mitra S. , Princivalle F. , Samanta A. K. , Moon Hi-Soo
Published: November 2024

Fe-Mg ordering as well as Fe2+ and Fe3+ distribution at different sites in coexisting orthopyroxene and clinopyroxene determined by, Mossbauer spectrpscopy and X-ray diffraction (sample 6a), have been used in deciphering the thermal history of two-pyroxene granulites of Sittampundi Complex (India). Orthopyroxenes and clinopyroxenes are compositionally in the granulite field of metamorphism. For orthopyroxenes, the Mossbauer spectra show that Fe2+ is present at M1 and two different M2 sites, while Fe3+ is localised at M1 site alone. For the coexisting clinopyroxenes, Fe2+ occurs at both M1 and M2. Fe3+ is present only at M1 site, but in Ca-rich clinopyroxenes, under high fO2, conditions, it is seen to replace silicon in tetrahedral site.

From the distribution of Fe2+ - Mg, using Mossbauer data, the blocking temperature of intracrystalline ordering in orthopyroxene has been calculated to range between 427 and 699°C, in agreement with the estimated temperature obtained by means of X-ray data of about 500°C; in clinopyroxene it was 680°C as obtained from X-ray data. The recorded inter-crystalline ordering temperature was determined as between 661 and 785°C. The lowering of blocking temperature recorded by intracrystalline Fe2+ - Mg exchange suggests that the cation ordering in the M1 and M2 sites continued in the cooling path of the granulites below the temperature indicated by inter-crystalline distribution, and that the cooling (history) suffered by the host rocks was slow.
Fractal Analysis and Seismicity of Bengal Basin and Tripura Fold Belt, Northeast India
Authors: Sunmonu Lukman A. , Dimri V. P.
Published: November 2024

Northeast India experienced compressive forces from the Himalayan Arc in the north and the Burmese Arc in the east, which led to the development of a number of seismogenic faults, fractures and lineaments. It is observed that the characteristics of earthquakes occurring on an active fault are closely related to the irregularity of fault geometry. Because of their rough appearances over many length scales, faults can be conveniently regarded a. fractal sets, and their georretrical irregularity can be quantified using fractal dimension. We have calculated fractal dimension of the distribution of faults in two tectonic blocks, Bengal basin and Tripura fold belt, in the northeast India. We found that in the spatial sense the fractal dimension and the seismicity are positively correlated.
Quaternary Tectonic History and Terrain Evolution of the Area Around Bhuj, Mainland Kachchh, Western India
Authors: Thakkar M. G. , Mauryara D. M. , Raj Rachnar , Chamyal L. S.
Published: November 2024

The Mainland Kachchh has witnessed several phases of tectonic movements since the formation of Kachchh rift. The structural set up of the area is dominated by two fault systems - an E-W fault system which controls the geomorphic configuration and a NNW-SSE to NNE-SSW fault system which displaces the E-W faults. The Quaternary deposits of the area, alluvial and colluvial fans, channel deposits and miliolites help in categorising Quaternary tectonic activity into two phases. Reactivation of E-W trending faults during Early Pleistocene led to the present landscape configuration and formation of extensive alluvial and coIluvial fans along these faults. The post miliolite phase resulted in movements along transverse faults as evidenced by a very youthful fault scarp morphology and faulting in postmiliolite alluvial sediments along this trend. The mountain front sinuosity values also suggest a younger phase of tectonic activity along the transverse faults. The first order topography and the seismic activity suggest continued tectonic instability of the region.
Palynology in Hydrocarbon Exploration - Advancements in Indian Perspective
Authors: Mehrotra N. C. , Kapoor P. N.
Published: November 2024

Palynology plays an important rote in cost effective exploration and exploitation of hydrocarbons. It consists of study of spores, pollen, dinoflagellate cysts, diatoms, nannoplankton, silicoflagellates, radiolaria, chitinozoa, algae and other organic remains.

Study of spore, pollen, dinoflagellate cysts and nannoplankton help in precise dating of sediments, marking of hiatuses and correlating surface and subsurface samples by giving absolute ages in million years. Source rock study helps in visual typing of kerogen, quantitative assessment of organic matter, paleoenvironment and palynofacies interpretation. Spectral analysis gives precise thermal maturation levels. The integration of source rock parameters helps in deciphering source rock potential facies. Correlation of burial history curves with the source rock potential facies helps in the determination of time and duration of hydrocarbon generation. Examples from different sedimentary basins emphasizing the role of palynology in hydrocarbon exploration are cited.

The biozonal comparisons and absolute pollen frequency (APF) values are being used for interpreting transgressive - regressive cycles. Paleogeographic maps can be reconstructed with palynological data. The chronostratigraphical correlation with seismic stratigraphy is being attempted in geologically synchronous stratal surfaces. Palynological studies support basin analysis leading to stratigraphic evolution and hydrocarbon prospect analysis. They aIso help to build sequence biostratigraphy and delineation of reservoir sands for effective reservoir management.
Sulfur Isotope Geothermometry from the High Grade Metamorphosed Sulfide Deposit at Mamandur, Tamil Nadu
Authors: Chattopadhyay P. K. , Sarkar S. C.
Published: November 2024

Sulfur isotope geothermometric data obtained from the limited study of coexisting sphalerite-galena pair in the high grade metamorphosed Zn-Pb(-Cu) deposit at Mamandur, furnish a wide range of values, from 870° C to 255° C. While the Tmax closely matches with that from silicate geothermometry of adjacent rocks, some other data sets suggesting intermediate range of temperature are correlatable with a retrograde phase of regional metamorphism recorded in the silicates. The low temperatures however, are inconsistent with the silicate geothermometric data and may be taken to suggest resetting of equilibrium in the sulfide pair at lower temperatures without affecting the silicate pairs, as these temperatures were lower than the closure temperature of Fe-Mg partitioning in the latter.
Current Seismicity and Tectonics Near the Gulf of Cambay: Evidences for the Khambat Plume Induced Activity
Authors: Mukhopadhyay Manoj , Arora S. K.
Published: November 2024

The Western Indian shield is seismically active as shown by both historical seismicity records and recently acquired instrumental data. Moderate to large earthquakes have occurred in the region but they do not clearly correlate with known tectonic features or faults. Current seismicity for this part of the shield for the period 1977-97. as evidenced from Gauribidanur Seismic Array (GBA) data, is found to be largely restricted to an area of about 80 km radius which accounts for almost 85 percent of the activity. The area is referred to as the Surat-Daman Seismic Zone (SDSZ) which has a general correspondence to the regional pattern of seismicity over the Western Indian shield established from both instrumental and non-instrumental data for a longer time span. The Indian shield crust is known to exhibit a sharp reduction in crustal thickness from 36 km below the Cambay Rift to about 20 km below the SDSZ within a distance of about 70 km. The thin shield crust is dissected into several faulted blocks that arc deformed to various degrees; some of these crustal blocks are seismically active. These features suggest that seismic activity in the region possibly relates to the fossil trace of the Khambat Plume along the Western continental margin near the Gulf of Cambay. The fossil plume appears to be located at least 100 km eastward onland. Bouguer anomalies over the fossil plume are largely positive with amplitudes upto 130 mgal, rendering further support to the presence of anomalous crust in the region. Available stress data from focal mechanism solutions indicate compressive stress in east-west to NNE-WSW direction. This suggests that stresses responsible for rift tectonics are not significant at the present stage; rather, the plume tectonics seems to be regionally predominant.
Gold in Copper-Uranium Ores of Singhbhum Shear Zone, Bihar
Authors: Krishna Rao N. , Sunilkumar T. S. , Narasimhan D.
Published: November 2024

Nature of occurrence of native gold in the uranium ore from Jaduguda and copper ore from Mosabani in the Singhbhum Shear Zone, Bihar, is described. Preliminary data on the gold contents of different ore deposits along the shear zone, and their beneficiation products, are also reported. The native gold particles appear to be of detrital origin.
A Note on the Ostracode Fauna from the Jurassic Beds of Jumara Dome, Kachchh
Authors: Khosla S. C. , Jakhar S. R.
Published: November 2024

The paper records the occurrence of 28 species of ostracodes from the Jurassic beds of Jumara dome, Kachchh. Twenty-three species are assigned to previously established species, while 5 species are left under open nomenc1ature. All the species are illustrated.
Significance of Panned Heavy Concentrate Sampling in Geochemical Prospecting for Gold: A Study from Atkur Area, Gadwal Schist Belt, Andhra Pradesh
Authors: Ananda Murthy S. , Aneel Kumar V. , Krishna Rao P. V. , Mallick Sekhar
Published: November 2024

Heavy-concentrate has been found to be the most suitable sampling medium in geochemical exploration for gold in Atkur area of Gadwal schist belt, Mahabubnagar district, Andhra Pradesh. Au-contents in panned heavy concentrates of soil samples from B-horizon and termite mounds helped in improving gold anomaly contrast. SEM and heavy-concentrate analyses of termite samples reaffirm their utility in exploration for gold. Hence, the study of heavy fraction of soil and termite mound can be used as an important tool to reveal the subtle anomaly present in the conventional samples.
Geochemistry of Groundwater Over Sukinda Ultrabasic - Basic Rocks, Jajpur District, Orissa
Authors: Som S. K. , Joshi R. , Neogi G. , Mukherjee M. M.
Published: November 2024

The geochemistry of groundwater over Sukinda ultrabasic - basic rocks, Orissa, covering an areat extent of about 50 km2, has been investigated to understand the hydrogeology of the area. The dominant geochemical processes were interpreted from geochemical data and mass balance calculations. The entire study area contains two broad lithounits comprising ultrabasic rock at the centre and metabasics at eastern and western flanks, with a general groundwater flow pattern from east to west. The groundwater in the area is fresh, meteoric in origin with high Na, Kover metabasics as well as the northern part of the ultrabasic rock, and high Mg, HCO3- and TDS over the remaining ultrabasic rock. Mineral solubility study of Mg- phases present in the system shows that the present day geochemical conditions are not suitable for Mg2+ precipitation and most likely, serpentine is the dominant Mg2+ contributer in the system. Mass balance calculations based on mixing ratio along the E-W flow path show that K and to some extent Na behave conservatively in the evolution of groundwater. The conservative mixing model presented here evaluates the formation of secondary mineral phases along the flow path.
Geochemistry of Sphene from Granodiorites Surrounding the Hutti-Maski Schist Belt: Significance to Rare Earth Element (REE) Modeling
Authors: Basir S. R. , Balakrishnan S.
Published: November 2024

A study of the distribution of REE in sphene from three granodiorite samples around NNW-SSE trending Hutti-Maski schist belt has been described here. Two distinct sets of sphene-melt Kd, values for REE have been observed among the three sphene-whole rock pairs studied. The chondrite normalized REE pattern of sphene from east (Gajalagatta) and northeast (Uti) granodiorites show LREE enriched and HREE depleted patterns with slight or no negative Eu anomaly. These REE patterns are parallel to the respective whole rock samples. But the chondrite normalized REE pattern of sphene from the sample to west of the schist belt (Ankasdoddi) has markedly depleted Ce and Nd with slight or no negative Eu anomaly and steeply fractionated HREE, resulting in a convex-up pattern. The variation of REE Kd, values of sphenes is not due to differences in the composition of host magmas (because they are all granodiorites with identical major element abundances), but could be a function of temperature of crystallization. Small degrees of fractional crystallization of sphene from granodiorite magmas would result in residual magmas having lower REE abundances either with parallel REE patterns or HREE depleted fan shaped REE patterns, depending on the Kdvalues.

Partial melting of granitoid rocks, leaving minor amounts of sphene in the residue gives rise to melts with lower REE abundances than the source. The REE patterns of the melts are parallel to the source if one set of REE Kd sphene-melt values are considered. If the other set of Kd, values are used, the partial melts have (fan shaped) REE patterns with more depletion for heavy REEs.
Evidence of Epithermal Activity and Gold Mineralization in Newania Carbonatite, Udaipur District, Rajasthan
Authors: Golani P. R. , Pandit M. K.
Published: November 2024

The geological, geochemical and C- and Pb-isotopic evidence available on the Newania Carbonatitic Body (NCB) in southern Rajasthan are not entirely incontrovertible from the point of view of carbonatite magmatism. Based on recognition of calcite-lined vugs, 'dog-tooth spar' and 'jig-saw puzzle' structure, the hematite bearing ankeritic carbonates (the ankeritic 'carbonatite') are considered as epithermal emplacements into dolomitic (magnesio-) carbonatite. Seven samples collected from hematite bearing ankeritic (±sideritic) carbonates, which constitute an important component of the NCB, have given gold values ranging between 0.93 to 1.36 ppm. The significance of this find lies in the association of gold with oxides and carbonates of hydrothermal affinity.
Petrology of Basic Granulites from Maruturu Near Anakapalle in the Eastern Ghats Granulite Belt
Authors: Rao A. T. , Srinivasa Rao K. , Srinivas S.
Published: November 2024

Basic granulites frequently occur in garnetiferous quartzo-feldspathic gneisses and rarely in garnetiferous sillimanite gneisses, calc-silicate rocks and quartzites in the entire Eastern Ghats Granulite Belt (EGGB). Commonly these basic layers are parallel to the foliation and are occasionally boudinaged. These share a common tectonic and metamorphic history with those of the associated litho-units. There are also unusual basic granulite dykes which crosscut the foliation in quartzo-feldspathic gneisses, folded calc-silicate rocks and basic granulites at Maruturu near Anakapalle in the EGGB. The two generations of basic granulites are even grained with a polygonal annealed mosaic and characterised by the mineral assemblage: coexisting pyroxenes and plagioclase. The mineral composition data of coexisting pyroxenes indicate large scale equilibrium at granulite facies conditions. Both types of basic granulites have almost similar bulk composition and have tholeiitic affinity. The basic granulite dykes have low contents of REE with a smooth distribution pattern and a general decrease from LREE to HREE. The revival of basic magmatism during post D1 and D2 at Maruturu reveals that extensional set-up recurs in the EGGB. The basic granulites of Maruturu are correlated with Proterozoic metabasic dykes in East Antarctica and Western Australia. The 1300 Ma basic granulites reported in Maruturu and Rayagada in the vicinity of Maruturu indicate that these intrusive basic bodies are coeval with the dyking events in Eastern Albany Mobile Belt in Western Australia and Vestfold Hill Block in Prydz Bay region in East Anatarctica.
A Note on Glandulina spinata Cushman - A Rare Foraminiferal Species from Inner Shelf Sediments of Bay of Bengal, off Karikkattukuppam, Near Chennai, Southeast Coast of India
Authors: Rajeshwara Rao N. , Khare Neloy , Periakali P.
Published: November 2024

Studies on Recent foraminifera from inner shelf sediments of the Bay of Bengal, off Karikkattukuppam, near Chennai (latitude 13°04'N; longitude 80°17'E), revealed the presence of a rare foraminiferal species. Taxonomic observations reveal this spinose taxon to be Glandulina spinata Cushman and is reported herein for the first time from Indian waters. Available data suggest it to be a tropical, inner shelf dwelling taxon, with a preference for muddy substrate.
Geochemical Discrimination Diagrams: A Simple Way of Replacing Eye-Fitted Field Boundaries With, Probability Based Classifier Surfaces
Authors: Agrawal Salil
Published: November 2024

The subjective, eye-fitted, field boundaries in geochemical discrimination diagrams constitute one of the possible reasons for their often-noted inability to determine the source regime/tectonic environments of igneous rocks. A simple method is described here to replace the eye-fitted field boundaries between the groups with the probability based classifier surfaces. It involves projection of the assignment rules obtained from linear discriminant analysis onto the binary or ternary discrimination diagram of raw variables. The method is illustrated by obtaining classifier surface between I- and S-type granites in Na2O-K2O space and between Anorthosite/Rapakivi (AR) and Ring Complex (RC) granites in Na2O-MgO space. The need for explicitly ensuring adequacy of samples, selection of suitable variables, evaluation of rate of misclassification and a better understanding of the unique influence of tectonic environments on magmatic process is emphasized for optimizing the performance of the classifier surface.
Late Archaean-Early Proterozoic Rb-Sr Isochron Age of Granite from Kawadgaon, Bastar District, Madhya Pradesh
Authors: Singh Yamuna , Chabria T.
Published: November 2024

Whole-rock Rb-Sr analysis of ten granite samples from Kawadgaon, Bastar craton, yield an isochron corresponding to an age of 2497±152 Ma (2s) and initial 87Sr/86Sr ratio of 0.7142±0100(2s). The data suggest emplacement of Kawadgaon granite during the ca. 2500 Ma Archaean-Proterozoic transitional event in the craton.
Late Archaean Granitoid With a Ring Structure Around Chandra, Mandya District, Karnataka
Authors: Krishnamurthy P. , Sarbajna Chanchal
Published: November 2024

A ring-like structure is defined by a late Archaean granite around Chandra. It is a fertile granite with a parental status akin to the rare metal pegmatite-hosted deposits of Li-Be-Nb and Ta around Allapatna-Marlagalla. This observation has important implications for new exploration targets for rare metal pegmatites in southern Karnataka and also geological evolution of the terrain as a whole.
Interpretation of Gravity Field Over the Perinthatta Anorthosite, Northern Kerala
Authors: John Kurian P. , Radha Krishna M. , Nambiar C. G. , Murthy B. V. S.
Published: November 2024

Gravity surveys have been carried out over the Perinthatta anorthosite and the adjoining areas and the results are discussed. The Bouguer anomaly map reveals the absence of any conspicuous gravity anomaly corresponding to the pluton and thus precludes the existence of larger mafic portions of the pluton in the immediate subsurface region. The residual gravity map obtained by regional-residual separation method shows a minor positive gravity field of irregular shape with localised highs of 6 - 12 mgal within and around the anorthosite body. TWo-dimensional gravity interpretation of profiles across the pluton suggests subjacent nature and lensoid shape for the anorthosite which is underlain by small isolated cylindrical bodies (? 2.5 km diameter) of higher density (2.9 gm/cc) extending 3 - 7 km downwards. These cylindrical bodies are inferred as either the mafic/oxide rich portions of the pluton sagged down during crystallization or the individual feeders of the plagioclase-rich mushes, which coalesced in the upper crust to give rise to the massif.
Fossil Polyplacophora (Mollusca) from Upper Talchir Sediments of Dudhi Nala, Hazaribagh, Bihar
Authors: Sengupta Siddhartha , Chakraborty Abhijit , Bhattacharya H. N.
Published: November 2024

External casts comparable with Polyplacophora (Mollusca), collected from the sand/silt-mud alternation facies (turbidite) of upper Talchir sediments of Dudhi Nala, West Bokaro basin, Hazaribagh district, Bihar are described and illustrated here for the first time. These sediments were reported to be unfossiliferous. Polyplacophoran morphology of the fossils indicate a marine link of the West Bokaro basin during the upper Talchir times. Dudhi Nala area is presently considered to be yet another locality proximal to the eastern limit of the Lower Permian marine incursion in the Indian peninsula along the Raniganj-Daltonganj-Manendragarh-Umaria belt.
Significance of the Archaean Bimodal Volcanics from the Ramagiri-Schist Belt in the Formation of Eastern Dharwar Craton
Authors: Mishra Meenal , Rajamani V.
Published: November 2024

The central arm of the trident shaped Ramagiri schist belt includes a central block which consists predominantly of bimodal (mafic-felsic) volcanics, apart from minor metasedimentary units. The geological set up of the various rock types suggests that the central block could be a tectonic melange. The metatholeiites and the felsic volcanics of the central block show similar LREE - enriched and fractionated REE patterns; the metatholeiites however. show a much larger variation in abundances. It has been suggested that the protoliths to the Ramagiri central mafic suite of bimodal volcanics were formed by different extents of melting of the metasomatically enriched mantle sources and were emplaced in an island arc setting. We suggest here that partial melting of similar metatholeiites, constituting an arc crust, at - 8 kbar pressures and at -1000 °C temperatures, produced magmas to the associated felsic volcanics. The geochemical characteristics of the mafic and felsic volcanic rocks in the Ramagiri belt, as well as the adjoining Sandur belt, have many similarities to those of the modern day island arc volcanic suites. The idea that the Phanerozoic style magmatic and accretionary tectonic processes operated during the Late Archaean suggested from the studies of granitic rocks in the Eastern Dharwar craton is corroborated by the metavolcanics of the Ramagiri schist belt.
Geoenvironmental Appraisal of Haryana
Authors: Thussu J. L.
Published: November 2024

Haryana primarily an agricultural State is rapidly transforming into an industrial State. Most part of the area in the State is occupied by vast stretches of Quaternary Alluvial plains separating the rocks of Delhi Supergroup in the south and west and Siwalik in the northeast. Various geomorphic landforms have been identified. Central Alluvial Plains occupy about ninety five percent of the total area of the State while the hard rocks are exposed only in five percent of the total area. Based on geological, geomorphological set up and geochemical studies, it has been possible to conclude that the potential environmental hazards distinctly differ in each land form. Two types of environmental hazards, viz., natural hazards and biotic or anthropogenic hazards have been recognised. The natural hazards, viz., salinity, salt efflorescence, sand remobilisation, bad land and water logging mainly affect the Central Alluvial Plains, while biotic or anthropogenic hazards, viz., mining, quarrying, wastage disposal, leakage from canals and excess drawal of water affect all the geomorphic landforms. Effective management controls have been suggested to mitigate the natural hazards and proper planning measures to control biotic hazards.
Microtextures on Quartz Grains of Campanian-Maastrichtian Sediments of Ariyalur Group of Tiruchirapalli Cretaceous, Tamil Nadu - Implication on Depositional Environments
Authors: Madhavaraju J. , Ramasamy S.
Published: November 2024

Studies on the quartz grains of the Campanian-Maastrichtian sediments of the Ariyalur Group of Tiruchirapalli Cretaceous, Tamil Nadu, using Scanning Electron Microscope (SEM) have brought out nineteen distinct microtextures. They have been grouped into features based on their mode of origin. Of these, thirteen are of mechanical and five mechanical and/or chemical origin while one distinctly chemical. The quartz grains of the Ariyalur Group sediments show a wide range of conchoidal fractures, straight steps and arcuate steps formed during the liberation from the metamorphic and igneous source rocks. The microtextures - v's, pits, straight and curved scratches are characteristic of the marine environment. The frequency of these features is higher in the grains from the Sillakkudi, Kallankurichchi and Ottakkovil Formations. Rarity of these features on quartz grains from the Kallamedu Formation is suggestive of variation in transport and depositional conditions. It has been inferred from the microtextures that the source for the quartz grains in the Ariyalur Group sediments has been the nearby Precambrian crystalline basement.
Estratificación del riesgo de transmisión de malaria en la región del Caribe Colombiano, 2008-2020
Authors:   Instituto Nacional de Salud de Colombia, Acuña-Cantillo Luis , Olivera Mario J. ,   Instituto Nacional de Salud de Colombia, Cortés-Alemán Luis ,   Secretaría de Salud de Bolívar, Chaparro-Narvaez Pablo ,   Instituto Nacional de Salud de Colombia, Padilla-Rodriguez Julio C. ,   Red de Gestión de Conocimiento, Investigación e Innovación en Malaria
Published: November 2024

Introducción: la transmisión de la malaria en Colombia es heterogénea y de intensidad variable a escala regional. En la región del Caribe se registra transmisión de baja intensidad y alta receptividad. Objetivos: estratificar el riesgo de transmisión de malaria en la región del Caribe colombiano 2008-2020. Materiales y métodos: estudio descriptivo retrospectivo en 167 municipios, a partir de fuentes secundarias. Se adaptó la metodología de estratificación de Organización Panamericana de la Salud. Se utilizaron medidas de frecuencia absoluta y frecuencia relativa como porcentajes, proporción de especies parasitarias y la mediana del índice parasitario anual. Resultados: el 77% de los municipios (128) se clasificaron en estrato de riesgo 2, el 19% en estrato de riesgo 3 (31) y el 5% en estrato de riesgo 4 (8), estos últimos situados en los departamentos de Bolívar y La Guajira. En la región se notificaron 31.198 casos de malaria, el 84,1% por P. vivax. El 75% fueron aportados por los departamentos de Bolívar (Siete municipios) y La Guajira (un municipio). Conclusiones: la distribución del riesgo de transmisión de malaria en esta región es heterogénea y focalizada. El territorio presenta condiciones favorables para la transmisión de la enfermedad. Estos hallazgos son insumos para la toma de decisiones.
POCUS en paciente con falla cardiaca aguda, diagnóstico de una etiología inusual: reporte de caso
Authors:   Universidad de Antioquia, Narvaez-Orozco Alejandro , Agudelo-Quintero Cristian Camilo ,   Universidad de Antioquia, Arcila-Cano Nicolás ,   Universidad de Antioquia, Atencia-Flórez Carlos José ,   Hospital Universitario San Vicente Fundación
Published: November 2024

Introducción: la falla cardíaca es un problema de salud pública globalmente. La mayoría de los pacientes que consultan a urgencias con diagnóstico conocido, se presentan como falla cardíaca crónica agudamente descompensada y en menor proporción los que debutan de novo. Además de identificar las manifestaciones clínicas, el proceso diagnóstico debe estar dirigido a la búsqueda de una posible etiología, la cual podría sospecharse inicialmente mediante el interrogatorio y examen físico. Objetivos: describir, explorar y evaluar la utilidad de la ultrasonografía a la cabecera del paciente (POCUS, point of care ultrasound) en el abordaje inicial del síndrome de falla cardíaca en el servicio de urgencias. Métodos: presentamos un caso de una paciente de 60 años sin antecedentes, que consulta al servicio de urgencias con síndrome clínico de falla cardíaca, en la cual los hallazgos a la auscultación y la ultrasonografía realizada con un dispositivo de bolsillo, facilitó la toma de decisiones y el tratamiento final de una etiología poco usual. Conclusiones: la ultrasonografía a la cabecera aplicada a la estructura y función cardíaca (FOCUS, focused cardiac ultrasound) podría dar un valor agregado en el enfoque inicial del síndrome de falla cardíaca.
‘AWAKENING’ FOSSILS IN CHINA: INTERNATIONAL EFFORTS IN PUBLISHING PALAEONTOLOGIA SINICA
Authors: SUN CHENGSHENG
Published: November 2024

The Palaeontologia Sinica founded in China in 1922, was one of the most important Chinese academic journals with international influence in the first half of the 20th century. It originated from Ding Wenjiang’s (V. K. Ting, 1887–1936) emphasis on paleontological research in China. The success of its publication was also due to the strong support of Swedish geologist Johan G. Andersson (1874–1960) and the academic guidance of American paleontologist Amadeus W. Grabau (1870–1946). Mainly based on fossil collections in most parts of China at the time, 126 monographs of the journal were contributed by 50 authors from different countries, and various fossils lying dormant in the land of China were brought to light.
A HISTORY OF 20TH CENTURY GRAPTOLITE STUDIES IN MALAYSIA: THE ROLE OF CLIVE RODERICK JONES
Authors: SAPARIN MUHAMMAD AQQID , ISMAIL MOHD SUHAILI
Published: November 2024

The stratigraphy of Peninsular Malaysia (formerly Malaya) was first described by Scrivenor (1931) in ‘Geology of Malaya’, which at that time recognized no strata older than Carboniferous age. In 1955, Clive Roderick Jones (1933–2022) discovered the first Malaysian graptolites on the small island of Pulau Tanjung Dendang, Langkawi, consequently demonstrating the presence of much older strata. The Early Paleozoic marine stratigraphy first discovered by C. R. Jones in the NW Malay Peninsula was subsequently recognized in other parts of SE Asia and became a characteristic element of the Gondwana-derived ‘Sibumasu’ terrane. This paper provides an account of the hidden history of the early discovery of graptolite fossils in Peninsular Malaysia after the re-examination of Jones’ graptolite fossils collection. The background to the events that led to this important finding, as well as its consequences for later stratigraphical research in Malaysia, were documented by Jones himself, complemented with the collection of field records, archives of papers and photographs. A biographical outline is presented of Jones and his career as a geologist in the Geological Survey Department of Malaya and his role in the development of geological research in Southeast Asia during the second half of the twentieth century.
PREHNITE – THE FIRST MINERAL DISCOVERED IN SOUTH AFRICA AND THE FIRST NAMED AFTER A PERSON
Authors: CAIRNCROSS BRUCE , MASTER SHARAD
Published: November 2024

Prehnite is the first mineral discovered by Europeans in South Africa during the late 18th century, and the first mineral named after a person, Hendrik von Prehn, who allegedly discovered the mineral specimens. The acquisition of these specimens, their type-locality, and the processes in naming prehnite involved some of the leading scientists at that time. Various names had been proposed for prehnite including rochonite, emeraud du Cap, chrysolite, oisanite, prase, chrysoprase, shorle vert du Cap, until final acceptance in 1793 as prehnite. The district of Cradock in the Eastern Cape Province, South Africa is entrenched in the literature as the location of von Prehn’s specimens, yet no documentary evidence exists to support this claim. In contrast, several other prehnite occurrences are known from further inland, hosted in similar geological environments to those in the Cradock district, and it is concluded that the type-specimens came from one of these hinterland locations, within the Karoo Basin of South Africa.
Exploring Alzheimer's Disease Subtype Replicability
Authors:   , Taylor Alexei , Zhang Fengqing
Published: November 2024

Alzheimer's disease (AD)-related tau pathology, which is highly correlated with AD-specific cognitive decline, has been suggested to follow a typical pattern initiating from the medial temporal lobe and spreading into the lateral temporal, parietal, and frontal and occipital lobes, at varying levels of severity. However, atypical patterns which disproportionately affect medial temporal regions relative to cortical regions, or vice versa, have previously been identified through neuropathologically confirmed postmortem studies. These typical and atypical AD subtypes have distinct demographic and clinical characteristics, broadly replicated using hypothesis-driven methods and data-driven clustering of in-vivo imaging data. However, the consistency of individual-level subtype assignment is poor. Further, how tau-defined versus atrophy-defined subtypes differ is unclear given their complex spatiotemporal relationship. While many AD subtyping studies focus on novel subtype discovery, the current study proposed a method to evaluate individual-level subtype assignment replicability, by defining individual-level subtype assignment consistency as being assigned the same subtype by a majority of hypothesis-driven methods. Assignment consistency and stability were examined using a nested cross-validation procedure to compare reference data-driven clustering methods to the proposed semi-supervised clustering informed by hypothesis-driven findings. These comparisons were explored under 3 different aims: (i) Examine constraint vs non-constraint clustering methods using single-modal atrophy or tau imaging features, (ii) Assess the benefit of unsupervised feature selection on these clusterings, and (iii) Assess the benefit of multimodal clustering with constraints from either modality. In reference to this project's definition of an AD subtype, it was determined that (i) constraint methods had higher performance and stability than non-constraint methods, (ii) unsupervised feature selection offered slight improvements in performance and stability, and (iii) multimodal clustering offered greater gains in interpretability based on subtype features and clinical characteristics. Overall, findings from this dissertation project contribute to the literature on AD subtypes by recommending an objective framework for validating subtype replicability.
Pengaruh Homophily Based Collaborative Learning dan Academic Engagement terhadap Writing Skill
Authors: Utomo Prasetio , Degeng Made Duanda Kartika , Soepriyanto Yerry
Published: November 2024

Writing skill is often regarded as a complex ability in English language learning, requiring more precision in grammar and vocabulary than listening, speaking, and reading. Teaching writing skills effectively requires special attention, such as implementing homophily-based collaborative learning, which groups students based on shared interests. This study also investigates the impact of academic engagement on writing skills. This quasi-experimental research employed a posttest-only control group design. The experimental class utilized homophily-based collaborative learning, while the control class used standard collaborative learning. Data were collected through questionnaires and posttests. The results indicated that the homophily-based collaborative learning class achieved higher writing skill scores compared to the standard collaborative learning class. Additionally, students with high academic engagement scored higher in writing skills than those with low academic engagement. No interaction was found between the learning model and academic engagement on writing skills. Therefore, teachers are encouraged to form learning groups based on homophily principles to achieve better outcomes and to provide additional support to learners with low academic engagement to optimize their results.

Abstrak
Writing skill seringkali dianggap sebagai keterampilan yang kompleks dalam pembelajaran Bahasa Inggris. Writing skill membutuhkan ketelitian dan kehati-hatian dalam grammar dan vocabulary yang lebih besar daripada listening, speaking, dan reading. Sebagai keterampilan yang kompleks, pembelajaran writing skill membutuhkan perhatian khusus agar pembelajaran dapat berjalan dengan optimal. Sebagai contoh dengan menerapkan collaborative learning dengan pembentukan kelompok berdasarkan prinsip homophily. Model ini menekankan mekanisme belajar secara kolaboratif berdasarkan peminatan topik belajar. Selain itu, penelitian terkait academic engagement juga perlu dilakukan untuk mengetahui pengaruhnya terhadap writing skill. Penelitian ini berjenis quasi experiment dengan posttest only control group design. Kelas eksperimen menggunakan homophily based collaborative learning sedangkan kelas kontrol dengan collaborative learning. Pengambilan data dilakukan dengan angket dan posttest. Penelitian ini menemukan kelas dengan homophily based collaborative learning memperoleh nilai writing skill yang lebih tinggi dibadingkan collaborative learning. Pebelajar dengan tingkat academic engagement yang tinggi juga menghasilkan nilai writing skill yang lebih tinggi dibandingkan academic engagement rendah. Tidak ditemukan adanya interaksi antara model pembelajaran, academic engagement, dan writing skill. Selanjutnya, guru dapat menyusun kelompok belajar berdasarkan prinsip homophily untuk mendapatkan hasil belajar yang lebih baik. Guru juga perlu memberikan perlakuan khusus kepada pebelajar dengan academic engagement rendah agar dapat mencapai hasil belajar yang optimal.
Implementation Project-Based Learning Model On Electrical Motor Installation
Authors: Mustaqim Bima , Sibuea Abdul Muin , Siagian Sahat , Junaidi Agus , Amin Muhammad , Baharuddin Baharuddin , Ampera Dina
Published: November 2024

The learning process in vocational high schools is a determining factor in producing graduates of vocational high schools who are in accordance with their competencies. The learning process will determine whether the learning objectives will be achieved. This study aims to develop a project-based learning device on the installation of electric motors. The method used is User Centered Design with data processed from teachers and students. The results of the implementation of project-based teaching materials for teachers are Good and students are Fairly Good. The project-based learning device is practical enough to make it easier for students to understand the learning of installing electric motors with guidance from teachers. These findings confirm the great usefulness of this model in facilitating a comprehensive understanding of the Installation of Electric Motors. Through its significant role in this subject, this model has developed into a versatile reference model. This model is not only easy to apply in various academic domains, but also effectively enriches students' learning experiences in various subjects. As a result, this model becomes a very valuable tool in supporting a deeper and more holistic learning and teaching process.

Abstrak
Proses pembelajaran di sekolah menengah kejuruan merupakan faktor penentu untuk dapat melahirkan lulusan pendidikan menengah kejuruan yang sesuai dengan kompetensinya. Proses pembelajaran akan menentukan apakah tujuan pembelajaran akan tercapai. Penelitian ini bertujuan untuk mengembangkan perangkat pembelajaran berbasis proyek tentang pemasangan motor listrik. Metode yang digunakan adalah User Centered Design dengan data yang diolah bersumber dari guru dan siswa. Hasil implementasi bahan ajar berbasis proyek untuk guru adalah Baik dan siswa adalah Cukup Baik. Perangkat pembelajaran berbasis proyek cukup praktis untuk memudahkan siswa memahami pembelajaran pemasangan motor listrik dengan bimbingan dari guru. Temuan ini menegaskan kegunaan besar model ini dalam memfasilitasi pemahaman yang komprehensif tentang Pemasangan Motor Listrik. Melalui perannya yang signifikan dalam subjek ini, model ini telah berkembang menjadi model referensi yang serba guna. Model ini tidak hanya mudah diterapkan di berbagai domain akademik, tetapi juga secara efektif memperkaya pengalaman belajar siswa di berbagai mata pelajaran. Sebagai hasilnya, model ini menjadi alat yang sangat berharga dalam mendukung proses pembelajaran dan pengajaran yang lebih mendalam dan holistik.
Peranan Tingkat Penerimaan Learning Management System Terhadap Kemampuan Self Regulated Learning
Authors: Halimah Nur , Degeng Made Duananda Kartika , Soepriyanto Yerry
Published: November 2024

Technology acceptance can be a key factor influencing Self Regulated Learning capabilities. Learning Management System is present as a technological innovation that has been widely adopted in the world of education and training as an online learning medium. LMS implementation is expected to be able to improve users' SRL capabilities. However, the success of LMS implementation is very dependent on the level of acceptance of the LMS itself. This research aims to determine whether there are differences in the level of Self-Regulated Learning ability between groups of learners who have high and low levels of acceptance of the LMS. This research design uses quantitative methods with one way anova data analysis techniques. The research results found that there were differences in SRL abilities between groups of learners who had high and low levels of LMS acceptance.

Abstrak
Mengajarkan senyawa kimia secara menarik itu cukup menantang karena kompleksitas materi dan sulitnya mengkontekstualisasi berbagai unsur kimia dalam kehidupan sehari-hari. Penelitian ini mengeksplorasi penggunaan alat AI dan metode bercerita untuk merancang pembelajaran kimia yang menarik bagi siswa kelas sepuluh. Penelitian ini dilakukan di Bandung Alliance Intercultural School, melibatkan lima belas siswa yang membuat ebook untuk mengajarkan senyawa kimia kepada siswa kelas dua. Data dikumpulkan melalui observasi dan penilaian rubrik. Alat AI seperti ChatGPT, Gemini, dan CanvaAI digunakan untuk mencari ide cerita, mengembangkan alur cerita, dan membuat gambar. Intervensi dari siswa diperlukan untuk memastikan kontennya sesuai usia dan menarik. Sifat kolaboratif proyek ini mendorong kepemilikan dan keterlibatan siswa. Temuan menunjukkan bahwa metode bercerita yang diperkaya dengan AI dapat membuat pelajaran kimia lebih interaktif dan relevan. Sayangnya, generalisasi hasil penelitian ini terbatas karena dilakukan di satu sekolah saja. Penelitian selanjutnya harus mereplikasi metode ini di lingkungan pendidikan yang beragam dan menggunakan desain eksperimental untuk mengukur efektivitas AI dan metode bercerita dalam pendidikan kimia.