bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Rhyolitic Injection-Breccia in Tuff near Allt Slapin, Strath, Skye, Scotland
Authors: Ray P. S. 
Published: May 2009

SummaryA rhyolitic breccia-body is emplaced within an indurated mafic tuff which outcrops along the south-western margin of the Beinn na Caillich granophyre mass in the Isle of Skye. The breccia provides evidence of two distinct processes in operation during and prior to emplacement. The tuff which includes felsic rock debris has an intrusive near-vertical junction with the Liassic sediments. It is believed that the tuff was emplaced within a pre-existing volcanic channel. The sequence of post-Liassic eruptive activity in this area ended with the emplacement of the granophyre.
Petrography and Geochemistry of Some Basic Sills and Dykes from Southern Rhenish Schiefergebirge
Authors: Schulze E. G. , El-Hinnawi Essam E. 
Published: May 2009

AbstractThe petrographical and geochemical characteristics of some basic sills and dykes from Southern Rhenish Schiefergebirge are described. The dykes are generally more altered than the sills and are classified into two types according to their relation to the lead-zinc veins found in the area. The distribution of some trace elements in the sills and dykes is given and the nature and mechanism of alteration are discussed.
Plateau lavas and diabase dikes of northwestern Newfoundland
Authors: Strong D. F. 
Published: May 2009

SummaryThin undeformed tholeiitic plateau lavas and associated diabase dikes occur intermittently along the western margin of the Appalachian mountain system, and are clearly exposed at its northern extremity in northwestern Newfoundland. In Newfoundland there are consistent chemical differences between the diabase dikes and the plateau lavas which indicate that they were derived from different primary magmas. These differences, along with apparent age discrepancies, could be taken as supporting suggestions of several periods of continental rifting, but such an interpretation is not favoured by the present author.
Ipswichian mammalian fauna from the Beeston Terrace at Boulton Moor, near Derby
Authors: Jones P. F. , Stanley M. F. 
Published: May 2009

SummaryMammalian remains are reported from a Pleistocene terrace deposit in the lower Derwent Valley near Derby, which is a correlative of the Beeston Terrace of the nearby River Trent. The faunal assemblage is characteristic of the Ipswichian interglacial and compares favourably with previous finds at other Ipswichian sites in southern Britain. The discovery is significant as it provides the strongest evidence so far for a dating of the Beeston Terrace which is critical to the Pleistocene chronology of the region.
The Late Quaternary history of east-central Ireland
Authors: McCabe A. M. , Hoare P. G. 
Published: May 2009

SummaryThe drift succession in east-central Ireland is the result of a series of ice movements spreading from major centres of dispersion within theIrish Sea Basin and over the north-central Irish plain, and from local mountain sources. These glaciations have produced laterally and vertically complex sequences of deposits. The large-scale events influenced almost the entire area; problems of correlation emerge when considering episodes of relatively restricted extent such as those associated with upland ice-caps in the S and the hitherto unreported readvances which interrupted the withdrawalof ice-sheets across the northern part of the region under examination. Thetask of assigning the older units to particular Quaternary cold stages is frustrated by the absence of interstratified organic horizons. Two possible models of glaciation are considered: one may be regarded as ‘traditional’; the other requires a much shorter period of time by assuming that the stratigraphy records differences in the relative strengths of essentially contemporaneous ice-masses.
High-potassium granites in the Masirah ophiolite of Oman
Authors: Abbotts I. L. 
Published: May 2009

SummaryMasirah Island lies off the SE coast of Oman and comprises a fully developed, though tectonically disturbed ophiolite, unconformably overlain by early Tertiary limestone. The ophiolite consists of harzburgites, cumulate gabbros, a sheeted dyke complex, and pillow lavas with sediment intercalations. Within the ophiolite occur granites the geochemistry of which, particularly their high K2O and Rb, and low Zr and Zr/Nb, ismore typical of a continental crust environment and suggests that at the time of their formation continental crust existed beneath or immediately W ofthe Masirah Ophiolite.
The zonal pattern of metamorphism in the Scottish Highlands and the displacement along the Great Glen Fault: discussion of paper by G. A. Chinner
Authors: Winchester J. A. 
Published: May 2009

SummaryThe zonal pattern of metamorphism in the Scottish Highlandsis more complex than that suggested by Chinner. It has been disrupted by major tectonic dislocations and cannot be interpreted as a simple thermal anticline. Retrogression and inversion of zones seen in NW Scotland may resulteither from structural perturbation or the interference effects of superimposed metamorphism. A sinistral displacement of the Great Glen Fault still seems to match the metamorphic patterns in the opposing blocks, even if allowance is made for a major downthrow to the SE.
A new Lampadosocrinus from the Upper Carboniferous of Oklahoma, U.S.A.
Authors: Strimple H. L. 
Published: May 2009

SummaryThe rare cladid inadunate crinoid genus Lampadosocrinus is presently known from 2 species, L. minutus (Peck) and L. obtusus Strimple and Koenig, of lower and middle Mississippian age (Tournaisian, Lower Carboniferous). Lampadosocrinus frustulum sp.nov. is described from the Lower Pennsylvanian (Namurian B or C. Upper Carboniferous) of Oklahoma, U.S.A. Some difficulties encountered in orientation of the theca of microcrinoids presently classified as cladid inadunates are discussed.
Theoretical considerations on mechanical parameters of joint surfaces based on studies on ceramics
Authors: Bahat Dov 
Published: May 2009

SummaryMorphological features of brittle fracture in glass, ceramics and rocks include fracture origin, mirror plane, mist, hackle, radial striations and concentric undulations. The plume structure which characterizes many joint surfaces is analogous to striations or ‘grainy steps’ developed on fracture surfaces of ceramics. Joint surfaces with plumose structures result essentially from tensile failure, but may also be affected by shear stresses. The ellipticity of the plumose structure commonly observed reflects a region of secondary tensional strain parallel to bedding developed due to anisotropic elastic properties of the rock as a result of formational loading. Striations and hackles may have similar orientations. A distinction between them is important since hackles on a joint surface indicate a rapid fracture whereas striations can result from a slow fracture. Intense undulations without hackling may indicate a slow fracture. A smooth mirror plane on a joint surface indicates that while the fracture had been formed, stresses had reached a certain maximum and then subsided. On the other hand, a joint surface that shows a mirror plane with hackle around its boundaries indicates that no decrease of stresses occurred during fracture, and fracture was possibly produced under a constant stress. Since AH is a material property, the fracture stress σfresponsible for a rapid fracture may be calculated following a determination of the mirror constant AH of the rock by σfrH½=AH
The geology of Kong Karls Land, Svalbard
Authors: Smith D. G. , Harland W. B. , Hughes N. F. , Pickton C. A. G. 
Published: May 2009

SummaryThe only substantial descriptions of the small, generally ice-bound archipelago in eastern Svalbard were from an expedition led by Nathorst in 1898 which landed in Kong Karls Land for fourteen days. Our paper amplifies those findings, from work with a helicopter-borne expedition in 1969. The easternmost of the three main islands, and all the small islands, are formed of basic igneous rocks of Cretaceous age. Two of the main islands, Svenskøya and Kongsøya, are formed of latest Triassic to early Cretaceous strata, protected by caps of Cretaceous lava that determine their shape and the general topography. The third, Abeløya, is basaltic throughout.
Amplification of the Wolstonian Stage of the British Pleistocene
Authors: Shotton F. W. 
Published: May 2009

SummaryThe lithostratigraphical division of the Wolstonian Stage of the British Pleistocene is reviewed in the light of borehole records along the line of the M 69 motorway. The Wolston Clay is divided into 5 members. The evidence from the M 69 shows that 2 periods of glacier advance were separated by a major period of recession of the order of 104 years, in which most of the sediments of Glacial Lake Harrison were deposited. It is argued that this recession was interstadial rather than interglacial.
Radioelement concentrations in British Tertiary Granites
Authors: Tammemagi H. Y. 
Published: May 2009

SummaryThe radioelement concentrations of K, U, and Th have been determined for 9 samples of granite from the Western Red Hills, Isle of Skye, Scotland, and for 10 granite specimens from the Mourne Mountains, Ireland, and are compared to 2 published results for Lundy Island granite. The concentrations are distinctly different for each of the 3 centres, and although the data do not provide conclusive proof, they favour generation of the granites by fractional crystallization of basic magmas.
Retiolitids from the Llanvirn and Darriwillian
Authors: Crowther P. R. , Jenkins C. J. 
Published: May 2009

SummaryA new record of an early retiolitid,Reteograptussp., from the topmost Llanvirn strata of Abereiddi Bay, South Wales, is described and figured. An approximately contemporaneous upper Darriwillian form from Gisborne, Victoria,Orthoretiolites? speciosus(Harris) is redescribed and shown to differ radically from bothReteograptussp. andR. geinitzianusHall, the type species of the genus.
NW-SE trending monoclines in the Dalradian of Banffshire, Scotland
Authors: Hewitt R. A. 
Published: May 2009

SummaryThe Durn Hill Quartzite of Redhythe Point, near Portsoy, can be divided into an eastern shear zone and a western foliated zone. The latter region is typical of most quartzites between the coast and Keith. NW-SE trending flexures, pure shear folding and wrench faults, interfere with the dominantly NE-SW trending folds of the steep limb of the Boyndie Syncline. Possible large scale NW-SE trending monoclines were identified at Redhaven, Aberchirder and Rothes. Such structures bring down the older fold axial traces and isograds towards the NE.
Evaluation of a New Zealand Tremadocian trilobite
Authors: Wright A. J. 
Published: May 2009

SummaryDionide hectoriReed, 1926, is shown on the basis of new collections from the type area in New Zealand to be a Tremadocian ceratopygide close toHysterolenus. The species was placed inTaihungshaniaby Kobayashi (1941). It was provisionally retained in the Taihungshaniidae by Lu (1975) who madehectoritype species of a new genusHectoria(nonHectoriaTrechmann, 1918). Ruapyge nom.nov. is proposed here for the reception ofhectori. The original length/width ratio is determined by Wellman's method, with little consistency in results. Data from the strain ellipses constructed by Wellman's method are then used to calculate values for the attitude of the line of no finite longitudinal strain. The values obtained graphically do not agree with those derived from a formula given by Ramsay (1967); this contradictory situation is in need of explanation.
Danubian deviations and mantle diapirism: a possible origin of the Carpathian Arc
Authors: Crawford A. R. 
Published: May 2009

SummaryMantle diapirism centred in Transylvania is suggested as the explanation of the Carpathian Arc and the Pannonian Depression, deviation of the Danube from a formerly straight course, and the trends of the Eastern Alps and horsts and troughs in the Bohemian Massif and Poland. Central location in Transylvania is at the crossing-point of deep fractures, parts of great circles, most conspicuously displayed in Transcaucasia and along the Zagros Main Thrust line. Mantle diapirism extended westward from Transylvania along each lineament in Hungary. Pannonian deep lithosphere may be a subcrustally thinned extension of the Bohemian Massif, with a relict unthinned fragment appearing as the Dobrogean Massif. This extended massif would originally have lain almost parallel to the western boundary of the Russian Platform and to the present Dinaride belt.
Volcanic pebbles from Pleistocene gravels in Norfolk and Essex
Authors: Hey R. W. , Brenchley P. J. 
Published: May 2009

SummaryIn the pre-Anglian Pleistocene of East Anglia and Essex are unfossiliferous gravels with pebbles of flint, quartz, quartzite, chert and volcanic rocks. All appear to belong to the Kesgrave Sands and Gravels of Rose & Allen (1976), which are largely or wholly fluviatile and probably of Beestonian age. Forty-six of the volcanic pebbles, from three different localities, have been examined microscopically. Almost all are fine-grained acid igneous rocks or vitric tuffs, evidently derived from a single suite. Various possible source-areas are considered, of which North Wales, with its Ordovician volcanics, is thought to be the most likely.
Differentiated dyke rocks of Mer Mundwara, Rajasthan and their metallogenic significance
Authors: Viswanathan Sivaramasubramania 
Published: May 2009

SummaryThe differentiated dyke rocks of Mer Mundwara comprise a subalkaline series which includes basalts and dolerites, and an alkaline series which includes theralites, porphyritic alkali syenites and nepheline syenites. These intrude into the coarse grained Precambrian granites which, in their turn, are subjacent bodies in the Aravalli system of metamorphic complex of archaean age. Absolute age of basic volcanics is 56±8 Ma, thus relating their emplacement to Deccan Trap volcanism in the Cretaceo-Eocene times in Central and Western India. Petrochemical characteristics of the basic rocks exemplify an alkaline character and so indicate that the basaltic magma of Mer Mundwara is tectonically and genetically different from the Deccan basalts which are in the main tholeiitic. The geological setting, petrography and major and minor element chemistry (Na > K and abundance of Nb, Co, Sn and V) relegate the dyke rock suite to the alkaligabbroic formations of Borodin (1974) with their parent magmatic source in the upper mantle. The alkaline igneous rocks of Mer Mundwara strongly suggest a possible occurrence of rare earths, niobium, zirconium and fluorine in industrial concentrations and also thorium and phosphorus.
Middle Ordovician facies and trilobite faunas in N America
Authors: Shaw F. C. , Fortey R. A. 
Published: May 2009

SummaryThe generic composition of trilobite faunas around the perimeter of North America during the Medial Ordovician is related to the regional palaeogeography deduced from field evidence. Major divisions into shelf, shelf-edge (biohermal mounds) and slope (upper and lower) can be recognized. The Caradoc immersion of the N American plate resulted in landward invasion of pre-adapted slope forms. Some of these genera had European origins and their appearance is due to migration in deeper water facies accompanying closure of the Proto-Atlantic ocean. There is no obvious repeat of Cambrian biomere patterns in the Ordovician although some later Ordovician trilobites, especially shelf inhabitants, had their origins in earlier Ordovician biohermal or slope communities. The origin and composition of the Remopleuridid faunal Province is briefly discussed.
On some quartz-plagioclase veins in the Connemara schists, Ireland
Authors: Yardley B. W. D. 
Published: May 2009

SummaryQuartz-plagioclase veins in staurolite schists often have margins depleted in the vein minerals. In some cases vein formation has simply involved recrystallization of groundmass grains into large vein grains in a closed system. The driving force for this process is reduction of strain energy and surface free energy. It is suggested that the veins initiate when grain boundaries have been opened up by hydraulic fracturing during medium grade metamorphism. The segregation process can be explained by a model of local equilibrium between grains and a continuous pore fluid similar to that commonly applied to metasomatic reactions; however, no phase change occurs.
Wave effect on sea grasses in the West Indies: the formation of the bare sand zone
Authors: Mitchell-Tapping H. J. 
Published: May 2009

SummaryAn examination of narrow zones of bare sand, usually averaging 10 m in width, situated between the patch reef and the sea grass beds (Thalassia and Cymodocea), shows that they appear to be primarily the result of wave action. Experiments were conducted in the U.S. Virgin Islands over a period of 5 years, which show the effect of subsurface interference of wave patterns in the forming of these bare sand zones. It is thought by the present author that these sand zones are a major factor in the equilibrium balance of sand quantity necessary for on and offshore transportation, and also in the balance of sand retained behind the patch reefs of the West Indies.
Dating post-metamorphic hydrothermal mineralization in the Lizard complex, Cornwall
Authors: Seager A. F. , Fitch F. J. , Miller J. A. 
Published: May 2009

SummaryTwo new total degassing argon-40/argon-39 age determinations are quoted for crystals of adularia from hydrothermal veins within gabbro of the Lizard, Cornwall. The apparent ages of 147±3 Ma and 201±4 Ma obtained suggests the presence of at least two phases of hydrothermal mineralization long after the close of metamorphism.
Rumanian graptolites from boreholes on the Moesian Platform
Authors: Rickards R. B. , Iordan M. 
Published: May 2009

SummaryRecent collections of graptolites from the Călărasi, Ianca-Berlescu and Tăndărei boreholes have helped to refine the stratigraphy of Silurian (Wenlock, Ludlow) and Devonian rocks of the Moesian Platform. Fourteen species are recorded for the first time from Rumanian strata, others are left under open nomenclature, whilst well-preserved specimens of the following species provide additional information on their detailed morphology and hence upon their relationships and evolution: Monocliniacis sp., Holoreriolites (Balticograptus) cf. balticus Eisenack, Saetograptus cf. rams (Teller), Monograptus kolihai Bouček, ?Cyrtograptus sp., Barrandeograpus pulchellus (Tullberg), and ?Neodiversograptus ex gr. nilssoni(Barrande).
Trace-element and isotopic data and their bearing on the genesis of Precambrian spilites from the Athapuscow aulacogen, Great Slave Lake, Canada
Authors: Olade M. A. D. 
Published: May 2009

SummaryThe nature and timing of ‘spilitization’, and the original composition of ‘spilitized’ Precambrian lavas fron the Athapuscow aulacogen, Great Slave Lake (Canada) are investigated, using geochemical and Rb/Sr isotopic methods. Relationships and abundances of trace elements of petrogenetic significance suggest that the spilites were not derived from alkaline basaltic magmas, but show petrogenetic affinity with tholeiitic basalts from continental or volcanic island environments. This new interpretation conforms well with the supposed tectonic and geologic environment in which the lavas and pyroclastics were erupted. Assuming an ‘open system’ behaviour for Rb and Sr during intense metasomatism, the isochron age of 1872 Ma obtained for the lavas is considered as the time of ‘spilitization’. This age, when compared with geochrono metric data obtained by other techniques, suggests that the time interval between initial volcanism and subsequent ‘spilitization’ event was brief, and probably related to diagenesis or burial metamorphism during rapid subsidence and sedimentation commonly associated with rifting within aulocogens. A relatively low initial 87Sr/86Sr ratio of 0.7018±0.0005 obtained for the lavas either reflects the low Sr isotope values characteristic of diagenetic pore fluid in Precambrian seas, or suggests that the original ‘primitive’ initial ratio was not adversely affected by the ‘spilitization’ process.
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Observations on the Kaiserstuhl loess
Authors: Smalley I. J. , Krinsley D. H. , Vita-Finzi C. 
Published: May 2009

SummaryExamination of Kaiserstuhl loess material by scanning electron microscopy reveals fine material adhering to the major particles, fracture features, carbonate overgrowths and signs of particle weathering; all of which appear typical of loess material. The carbonate overgrowths included discrete rhombic crystals, which are possibly dolomite. Alpine and Northern glaciers could have provided fine quartz material for the Kaiserstuhl loess; an Alpine source seems more likely, with perhaps some fluvial transportation involved.
Conodonts from horizons with Goniatites crenistria Phillips in North Wales and the Isle of Man
Authors: Austin R. L. , Aldridge R. J. 
Published: May 2009

SummaryCarboniferous conodonts are reported from knoll limestones of B2 age in North Wales and of P1a age in the Isle of Man. The faunas from both localities are associated with Goniatites crenistria Phillips and other diagnostic goniatites. The faunas are closely similar and indicate a correlation with the Avonian conodont zone of Mestognathus beckmanni–Gnathodus bilineatus.
The early Tertiary deep-water sandstones near San Sebastian, Spain; some aspects of diagenesis
Authors: Knox G. J. 
Published: May 2009

SummaryNear San Sebastian, northern Spain, are outcrops of a system of deep-water fans deposited beyond the mouth of a submarine canyon from southward flowing currents. The sandstones consist of mixed siliciclastic detritals and carbonate fragments. The latter includes a derived heterogeneous marine fauna. Carbonate content varies and has played a major part in diagenesis. Early cementation by limited quartz and to a greater extent calcite involved local expansion. Later compaction has led to prominent pressure-solution phenomena of calcite and quartz with formation of microstylolites. Leaching owing to weathering has led to removal of some carbonate and formation of kaolinite from micas.
Pyroclastic flow deposits in the Adrano area of Mount Etna, Sicily
Authors: Duncan A. M. 
Published: May 2009

SummaryActivity on Etna is predominantly effusive with eruption of lavas of Hawaiitic composition. However, near Adrano some pyroclastic flow deposits outcrop among prehistoric lavas. The chemistry of the pumiceous fragments in these pyroclastic flows suggests they were erupted from magma of benmoreitic composition. This represents some of the most evolved and differentiated magma that has been produced by Etna. The presence of these deposits indicates that in the past Etna has displayed much more explosive activity than has been observed in historic times.
Brecciated lavas from County Limerick, Ireland, and their significance
Authors: Strogen P. 
Published: May 2009

SummaryField relations of Carboniferous lavas in Limerick indicate that flow took place in shallow water in many cases. A possible flow mechanism is proposed for these lavas. Brecciation of the flows took place after emplacement due to steam release from underlying limestones, which frequently became thixotropic and injected upwards into the denser lava.
A Possible Extension of the Ratagan Igneous Complex, Wester Ross and Inverness-shire
Authors: Dhonau T. J. 
Published: May 2009

AbstractAn intrusion associated with the Ratagan Complex (Nicholls, 1950) outcrops in Glen Lichd, east of the main omplex. It is separated from the main complex by the Strathconon fault. The intrusion consists of red medium-grained leucocratic granodiorite and adamellite.