bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology of Gold Grains in Laterite Profiles of Nilambur, Kerala: Implications for the Genesis of Supergene Gold Deposits
Authors: Omana P. K. , Santosh M. 
Published: November 2024

Abstract
Laterite weathering profiles in the Nilambur gold prospect of northern Kerala contain dust, grains and nuggets of gold in the various zones. A close examination of the morphological parameters of gold particles separated from various horizons reveal that those occurring towards the upper part of the weathering profiles have nearspherical or ovoidal shapes with regular grain contours and dull lustre. A porous network of numerous etched pits characterise the grain surface. Towards the lower horizons, the degree of etching becomes less and the grains are xenomorphic with plane crystal faces and irregular to jagged contours. Grain-size in the laterite gold is almost four times larger than that of primary gold in vein quartz, while in individual weathering profiles grain-size shows a relative iDcrease from top to bottom. suggesting dissolution. Various textural patterns including arborescent dendrites, tufts. filaments and petalites of secondary gold have been identified. Spectacular incipient growth of painted gold with increased fineness and bright lustre characterise many of the grains, typifying low temperature chemical reprecipitation. An evaluation of the mechanisms of supergene gold formation suggests that ferrolysis reaction involving oxidation of pyrite was fundamental in mobilizing gold in the Nilambur weathering profiles, testified to by the intimate association between iron oxides and supergene gold grains. Migration was effected by capillarity and fluctuations in water table level. Precipitation was triggered by the reduction of anionic complexes in acidic profiles. The nature of occurrence, morphology and texture parameters of gold grains in the Nilambur laterites indicate that supergene gold genesis is dictated by distinct chemical reactions related to natural weathering processes.
Heavy Mineral Suite in the Barakar Sandstone of Moher-Subbasin, Singrauli Coalfield, Central India
Authors: Aslam M. , Arora M. , Tewari R. C. 
Published: November 2024

Abstract
Heavy mineral analysis of the Barakar Sandstone from a drill core (117 m) from the Moher-Subbasin of the Singrauli coalfield shows relative abundance of epidote, zircon and rutile in the finer (.088-.074 mm) and garnet, muscovite and staurolite in the coarser (0.177-0.149 mm) fraction. Stratigraphically, the heavy species do not exhibit marked variation in their relative abundance, though garnet forms the bulk of the heavy crop at 94 m depth.
The study indicates that basic and acid igneous rocks, low to medium and high-grade metamorphic rocks, and metasedimentary rocks to the south and southeast of the study area, probably the Manpat ridge, supplied the bulk of the sediment debris during the early Permian Barakar times.
Control of Sulphide Mineralization at Bhotang Sulphide Deposit (Sikkim)
Authors: Singh N. N. 
Published: November 2024

Abstract
The copper-zinc-lead sulphide mineralization of Bhotang is confined to the Dalling Group of eastern Himalaya. Confinement of the sulphide mineralization within a litho-unit, and its strong preference to planar and linear fabrics suggests litho-structural control. The dimensional variability and geometrical shape and size of the ore body is the result of later deformational influences. Pinch and swell structure in the ore lenses is common. The arc body shows pronounced zoning. Localization of sphalerile, galena and chalcopyrite indicates differential mobilization in response to repeated deformation and metamorphism under varying temperature conditions. The mode of occurrence of the polymetallic sulphide bodies, their attitudes, dimensional significance and control are described.
Geological Significance of Magnetic Depth Estimates Over Western Part of Cuddapah Basin, South India
Authors: Babu Rao V. 
Published: November 2024

Abstract
Results of interpretation of magnetic total intensity anomalies, observed over the western part of the Cuddapah Basin, have shown that the magnetic sources are, mainly distributed at two levels and they are widely separated in depth. The shalJow sources ranging in depth from 400 m to 1900 m below ground are inferred to be due to shallow basement or due to basic intrusives within the basin sediments. The deeper sources ranging in depth from 5.0 to 8.0 km below ground are attributed to basic intrusives at or within the underlying bas(ment. The wide range of variation in depth to the magnetic sources point to the presence of basement faults paralleling the western margin, particularly around Yadiki and between Parnapalli and Vempalli in the south western part of the basin.
Magnetic interpretation has brought out positive evidence for post-Tadpatri-pre Gandikota and post-Gandikota-pre-Kurnool igneous episodes in this part of the basin and helped to resolve the large discrepancy in the geological estimate of the thickness of Gandikota quartzites. The maximum thickness of Kurnool sedimems is of the order of 500 m and it is likely that the Kurnools have been deposited on an uneven and eroded top of Cuddapahs allowing for local thickening of Kurnool sediments. The results of magnetic interpretation tend to support the concept of sub-basins and the Bairenkonda quartzites appear to have been deposited directly over the Archaean granites and gneisses without the intervention of Papaghni and Chitravati groups of sediments, at least in the southeastern part of the Cuddapah Basin.
Hydrothermal Epidote - An Indicator of Temperature and Fluid Composition
Authors: Absar Ahsan 
Published: November 2024

Abstract
Epidote tends to form under a rather restricted temperature range, generally above 250° C. The thermal regime inferred by contouring the depths of the first occurrence of epidote in an area may be compared with fluid inclusion temperatures measured in associated quartz and calcite veins to work out temperature fluctuations during a mineral-depositing event. In geothermal areas, however, thermal regime depicted by the epidote-temperature map may also be compared with the present-day temperature distribution. A case-study is presented here from the Ohaaki-Broadlands geothermal field, New Zealand.
As epidote is deposited by high pH, CO2-deficient fluids, its association with minerals forming under relatively Low pH and high CO2 partial pressure conditions, i.e., clay minerals and calcite (only when there is a large scale precipitation) suggests disequilibrium and a possibility of more than one hydrothermal events.
Quaternary Deposits of Narmada with Special Reference to the Hominid Fossils
Authors: Khan A. A. , Sonakia A. 
Published: November 2024

Abstract
The upper 70 m to 90 m of the Narmada alluvium was deposited in a single aggradational episode with minor pauses when dissection of the alluvium produced two terraces (NT3-NT2). The sediments of this aggradation episode constitute three lithostratigraphic units viz., Boulder conglomerate, Sohagpur and Shahganj Fomations. The sediments of the alluvial phase are underlain by a boulder bed of glacio-fluvial origin. Thus, the fossiliferous boulder conglomerate, the basal unit of the alluvium marks a disconformity between the lower glacio-fluvial boulder layer and the upper fluvial sediments. The fossiliferous basal boulder conglomerate is considered to be of middle Pleistocene age.
Felsic Volcanics in South Khetri Copper Belt, Rajasthan and their Metallogenic Significance
Authors: Golani P. R. , Gathania R. C. , Grover A. K. , Bhattacharjee J. 
Published: November 2024

Abstract
Felsic volcanics in the south Khetri Copper Belt (KCB) occur interlayered with fine grey banded phyllitic quartzite which often contains fine carbonaceous matter. The volcanics include crystal tuff, ultrafinely laminated grey tuff and pumice. They have been recognised in field on the basis of vesicles and rare amygdules; and under microscope by embayed and resorbed quartz phenocrysts. Glass is altered and incipiently recrystallised. Devitrification textures like spherulites are intact in rare cases. The relatively unaltered tuffs fall in dacitic field of Total Alkali-Silica (TAS) diagram. The tuffs are intimately associated with baryte and ironstone layers at places. Recent work in the south KCB indicates that sulfide mineralisation is polymetaHic. It is stratabound hosted by felsic volcanics and fine carbonaceous phyllite and quartzite. The mineralised zones show wall-rock alteration in the form of profuse silicification and sericitisation. These features when seen in conjunction with the occurrence of concordant baryte and ironstone layers, indicate that the sulfide mineralisation is volcanic-exhalative type.
Active Himalayan Frontal Fault, Main Boundary Thrust and Ramgarh Thrust in Southern Kumaun
Authors: Valdiya K. S. , Rana R. S. , Sharma P. K. , Dey P. 
Published: November 2024

Abstract
The Siwalik front has been lifted up 60-90 m against the Holocene IndoGangetic plains. The movements on the Himalayan Frontal Fault are evident from 6-15° northward tilting of Late Pleistocene Dun Gravel, and spectacular incised meanders in streams breaking through the hill barrier, and uplift in three episodic phases of the fluvial terraces resting on the tilted Dun Gravel.
In southeastern Kumaun, dextral strike-slip movement on an active fault has caused 6 km westward deflection of the Kali (Sharada) River from its consistently southerly course. Movements of fault blocks in the Siwalik domain have given rise to minor horsts and grabens, and caused blocking of streams and rivers, leading to fonnation of lakes now represented by intramontane fluviolacustrine terraces.
The Main Boundary Thrust registers variable neotectonic movements. While the Lesser Himalaya rides over the Lower Siwalik, lifting (by 70 m) the recent fluvial deposits of the Ladhiya River in the east. it is the Siwalik that has risen up relative to the Lesser Himalaya in the central and western sectors. The amount of displacement of the fluvial terraces and colluvial cones is of the order of 40 to 30 m in the Nainital area and 30 to 10 m in the Mandal valley.
Quaternary episodic movements have rejuvenated the old mature topography of the Lesser Himalaya. Movements on faults and thrusts in the southern belt are evident from abrupt narrowing in the fault zones into deep gorges of wide meandering streams, development of cascades and knickpoints and triggering of huge debris avalanches on steepened slopes. Damming of streams by colluvial cones and fans have resulted in the formation of lakes in the Bhawali-Shyamkhet area, east of Nainital.
Are the Vinjamur Rocks Carbonatites or Meta-Limestones?
Authors: SubbaRao K. V. , Le Bas M. J. , Bhaskar Rao B. 
Published: November 2024

Abstract
New whole-rock rare earth element (REE) data for the metacarbonate rocks interbedded with schists at Vinjamur in the Nellore Schist Belt of Andhra Pradesh, show low total REE contents (S9-128 ppm) that are inconsistent with an igneous carbonatitic origin but which correspond more closely with a sedimentary limestone origin. The REE data of these rocks however, do not give absolute discrimination between marbles of meta-limestone and metacarbonatite origin. Micro-probe analytical data give better discrimination, and the chemical compositions of the calcite, micas, amphibole, plagioclase, apatite, monazite and staurolite in the Vinjamur marbles give strong and consistent evidence of a metamorphosed sedimentary rather than an igneous origin.
Field Relations and Petrology of Khandek Alkali Olivine Basalt Plug, Eastern Kachchh, Gujarat
Authors: Bandyopadhyay Amitava 
Published: November 2024

Abstract
A plug-like body of alkali olivine basalt occurs within the lower member of Wagad Formation near Khandek emplaced along a regional fault. Field relations indicate that the plug is post-Mesozoic, and late-to-post-tectonic in relation to the Late Mesozoic tectonic acitvity in the area. Plagioclase, clinopyroxene (titanaugite with 2Vz = 51°-55°) and olivine occur as major phenocrysts and augite, plagioclase, interstitial nepheline and palagonite are present in the groundmass. The rock contains nepheline both in the mode and in the norm. Lower Zr/Nb ratio is indicati ve of a mantle plume type origin for the alkalic magma. The fault apparently served as a conduit for the magma. AhotspotormantIe plume type origin for this alkali basalt has been suggested.
Palaeomagnetic and Geochemical Study of Precambrian Kawar Volcanic Formation (Bijawar Traps), Central India
Authors: Poornachandra Rao G. V. S. , Mallikharjuna Rao J. 
Published: November 2024

Abstract
The Bijawar Group of rocks unconformably overlie the 2555 Ma Bundelkhand Granite massif and contain in its lower sub-group the Kawar Volcanic Formation exposed near the Bhusor village (24° 39'N; 79° 51' 3O"E) SW of Panna.
The Kawar volcanics are fine grained, magnesium rich tholeiites, basalt to basaltic andesite in composition, with spinifex texture. The immobile trace elements suggest that these volcanics were emplaced in a continental environmental setting in rapid succesion with a low residence time. The REE pattern reveals that these rocks were derived from a depleted mantle source. A comparison of average chemical compositions of Mahakoshal and Gwalior basalts with a Kawar volcanics suggest that these were originated in different environmental conditions although they had previously believed to be the same.
Detailed AF and thermal demagnetization of 20 oriented block samples from 4 sites revealed a characteristic stable remanence in the Kawar volcanics with a declination of 254.9 and inclination of -64.0 (K = 70.75, a95, = 8.32, N = 4). The corresponding VGP, located at p = 27.6° N, Lp = 129.3° E (dp = 6.29, dm = 13-26), appears to be approximately 2000 Ma when compared with other Indian Precambrian data. This age is in agreement with the stratigraphic position above the Bundelkhand granite massif.
Organic Maturation Study of Permian Coal Seams, Rajmahal Basin, Bihar
Authors: Singh Mahendra P. , Singh Prakash K. 
Published: November 2024

Abstract
The coals are sub-bituminous to high volatile bituminous in rank and show evidences of "bituminization" stage of maturation. They have distinctive petrographic characteristics being rich in secondary liptinites such as exsudatinite (nil to 7.66%), bituminite (0.94 to 28.88%) and fluorinite (nil to 0.99%). The rock-eval data suggest that they are hydrogen-rich and have immature organic matter-kerogen type 1II. The study corroborates the earlier contention regarding the onset of 'oil window' at Rom of 0.5% and suggests that the paleodepth of burial of the coal bearing horizon in the Rajmahal basin was from 1890 to 2970m. The loss of cover has been estimated to range from 1440 to 1720m
Geochemistry and Petrogenesis of a Supracrustal Granite from Dalhousie, Himachal Himlaya
Authors: Mukherjee P. K. , Purohit K. K. , Rathi M. S. , Khanna P. P. 
Published: November 2024

Abstract
A two mica granite body occurs in and around Dalhousie (Himachal Himalaya) as an intrusion into the core of an antiform at the southern flank of the Dhauladhar range. The rocks near the contact are enriched in biotite (bio&gt;mus), whereas those of the core are more enriched in muscovite (mus&gt;bio). Otherwise the major mineralogical make-up and their whole rock chemistry are monotonous. The rocks are weakly to moderately peraluminous in nature. The trace elemental characteristics are very similar to the average upper crust and follow more closely with the mean felsic S-type trend.
The low normative as well as calculated modal quartz and high NazO content suggest their origin from a less mature sedimentary source. The ubiquitous Eu anomaly, depleted Sr with enriched Rb and non-involvement of plagioclase or alkali feldspar in the fractionation model further implies that there was abundant feldspar in the source and more calcic plagioclase were left out in the residue that selectively retained Eu and SI- and released Rb in its early fraction of melts. It was noted that only -10% fractionation of solids mainly consisting of biotite and muscovite with minor amounts of feldspar are required to account for the major elemental mass balance requirement between the compositional differences. Whereas the depletion of REEs as well as other trace element abundances in the more . fractionated samples from the central part of the intrusion were modeled and attributed due to fractionation of minor quantity of REE enriched phases (~1.5%) like monazite, apatite and zircon. However, the Zr requirement in this model is insufficient. Nevertheless, the observed nearly three times depletion in REEs, Zr, Th and P may be required to be explained in a similar way involving such REE sink accessory phases. The haplogranitic phase relations suggest that the emplacement of the granitic magma took place under water-sufficient condition at a shallower depth (-2-3kb.) whereas magma generated at relatively deeper level but restricted to a depth where plagioclase is stable rather than garnet. The water requirement was homogeneously made available internally by the breakdown of hydrous minerals like micas and aH2O was sufficiently high. This also led to high oxidizing condition of the magma causing higher population of Eu3+ as compared to Eu2+ that might have behaved much similar to other adjacent MREEs (Sm and Gd) which occurs in 3+ state.
PGE-Ag-Au Mineralization in a Cu-Fe-Ni Sulphide-Rich Breccia Zone of the Precambrian Nuasahi Ultramafic-Mafic Complex, Orissa, India
Authors: Baidya Tapan K. , Mondal S. K. , Balaram V. , Parthasarathy R. , Verma R. , Mathur P. K. 
Published: November 2024

Abstract
The Precambrian ultramafic-mafic plutonic complex of Nuasahi, Orissa in the Eastern Indian Shield represents at least three suites of magmatic intrusion: (i) an interlayered sequence of enstatitite, websterite (± olivine), dunite, chromitite, harzburgite and orthopyroxenite; (ii) massive gabbroic suite with minor bodies of norite, anorthosite and bands of titaniferous magnetite and (iii) dykes and sills of dolerite and clinopyroxenite. A prominent breccia zone is developed near the interface of the first and second magmatic suites in the eastern part of the complex including the Shankar chromite lode and the ultramafic host of the first suite, and the gabbro-noritic rocks of the second suite. This breccia zone is enriched in Cu-Fe-Ni sulphides and has become the principal site for concentration of PGE, gold and silver. On a whole, Pd dominates over Pt in the sulphide-bearing Shankar chromite lode and the adjacent orthopyroxenite as well as gabbro in this breccia zone. The chromite-sulphide association is the most enriched part for PGE, gold and silver. Ag is positively correlated with Pd. The breccia zone which was developed prior to the gabbroic emplacement into the chromiferous ultramafics. represents a sulphide-rich metasomatic zone leading to maximum concentrations of PGE, Au, Ag in this zone alongwith formation of various sulphides, oxides and silicates. Both Pt and Pd are considerably higher and Ir is lower in the present area than in chromite-sulphide associations from ophiolitic complexes and Alpine-type massifs. Rather, Pt, Pd and Ir values compare better with the chromite-sulphide associations from layered intrusions.
BORROWED ILLUSTRATIONS OF GLOSSOPETRAE WITH SHARK’S HEAD: STENO AND THE VATICAN COLLECTION OF MERCATI
Authors: YAMADA TOSHIHIRO 
Published: November 2024

ABSTRACT
It is well known that fossils of shark’s teeth were named as ‘tongue stones’ (glossopetrae in Latin) because of their similarity in shape to the tongues of animals. However, Nicolaus Steno (1638–1686) decidedly revised this kind of explanation in the latter half of the seventeenth century. He recognized them as shark’s teeth in his treatise of 1667, adopting the figures of a shark head with teeth in its mouth and fossil ‘tongue stones’ borrowed from the then unpublished manuscript on the Vatican mineral collection by Michele Mercati of San Miniato (1541–1593). This article reconsiders the role of the palaeontological illustrations in this process because Mercati himself had recognized the similarity of the shapes of the shark teeth and glossopetrae but he could not neglect the difference of material between them. Although Steno’s skill as a comparative anatomist convinced him of the organic origin of the fossils, there were still problems of sedimentation to solve. We will first review the opinions of early modern naturalists concerning fossil objects and then focus on how Steno solved the problem to pave the way for his epoch-making dissertation Prodromus (1669). At the same time, we will pay attention to how the set of figures would continue to be borrowed by such authors as Paolo Silvio Boccone (1674), Michael Bernhard Valentini (1704), and Gottfried Wilhelm Leibniz (1749, originally circa 1691). In the meantime, the original manuscript with figures was published in 1717 as Metallotheca Vaticana by Giovanni Maria Lancisi, the Italian anatomist and one of Steno’s acquaintances. Lancisi made annotations to this text that suggested the fossil controversy was evolving, citing the names of Cesalpino, Steno, Boccone, and Vallisneri. Thus, we can understand how the illustrations with its hidden text functioned well in the fossil controversy by the strategic usage by Steno of the Vatican collection, a sort of ‘museum on paper’.
THE DINOTHERIUM AND THE ACROPOLIS: ALBERT GAUDRY’S RECONSTRUCTION OF THE EXTINCT FAUNA OF ATTICA AND THE MAKING OF GREECE INTO A EUROPEAN STATE (1850s–1860s)
Authors: MONNIN VICTOR 
Published: November 2024

ABSTRACT
Between 1862 and 1867, Albert Gaudry (1824–1908) published Animaux fossiles et géologie de l’Attique, a seminal work describing and depicting the rich collection of mammalian fossils that he assembled during his scientific expeditions in Attica, Greece. This paper will focus on how Gaudry’s collection and reconstruction of the extinct fauna of Attica articulated itself with geopolitical, cultural, and economic concerns regarding the newly independent Greek state and its place within Europe. Since the Greek War of independence against the Ottomans between the 1820s and 1830s, European nations sought to secure a series of strategic advantages in the region. France for example invested a lot of capital, military, and cultural resources in the newly independent Greek state in hope of cementing France’s influence in the Mediterranean. Between 1853 and 1854, Gaudry was sent on a mission by the French government to evaluate the agricultural production of countries of the ‘Orient’, including Greece. Gaudry was tasked with gathering information intended to facilitate the advancement of agriculture in France’s colonies as well as the planning of future investments in the Eastern Mediterranean. In his report published in 1855, Gaudry explicitly defined the restoration of Greece’s agricultural industry as a sine qua non condition for Greece’s establishment as a European state. It was during this official mission that Gaudry learned about the existence of exceptionally rich fossil sites in Attica. He returned on multiple occasions to collect thousands of fossil specimens from these sites. In Animaux fossiles et géologie de l’Attique and in his subsequent publications on the same fossils, Gaudry regularly articulated the reconstruction of extinct mammals and their environment with inspired descriptions of the ruins of Athens. In his writings, the reconstruction of a Greek geological past inhabited by a grandiose and harmonious megafauna echoed the celebration of Ancient Greece as the cradle of Western civilization. This paper will comment on the complex interplay between three temporalities which informed Gaudry’s work on the mammalian fossils of Attica: (1) the reconstructed paleontological past, (2) the idealized Ancient Greece, and (3) the present geopolitical context.