bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Control of Uranium Mineralization in Australia
Authors: Rade J. 
Published: May 2009

AbstractA deep seated flow of geoplasma (bathyrheal underflow) subjected crustal blocks to recurring horizontal movements causing north-east trending faults, shearing along anticlines and rotation of the separate crustal blocks. These movements produced extensive faulting and shattering in the South Alligator River area and north of Katherine, providing suitable loci for uranium mineralization. The mineralization occurs as a late phase open fissure filling and two types occur, (i) the nickel–cobalt–native silver type, and (ii) the quartz–pyrite–galena type. These characteristics provide a guide for future prospecting for uranium in Australia.
Boudinage Structure in West Cork, Ireland
Authors: Coe Kenneth 
Published: May 2009

AbstractBoudinage occurs with great regularity in parts of West Cork. The principle break-up of competent beds is into boudins with the separation parallel to the dip of the bedding, but where the exposure permits examination in three dimensions it can be seen that incipient boudinage is developed with separation parallel to the strike of the bedding. The structure is shown to have originated after the main phase of folding by horizontal forces acting on steeply inclined beds. Some unusual features are described.
Fold Structures in the Dalradian Rocks of Knapdale, Argyllshire
Authors: Roberts John L. 
Published: May 2009

AbstractIn the Dalradian rocks of Knapdale in south-west Argyll two groups of minor folds have been developed which share the same axial plane; their fold axes lie at right angles to each other within the common axial plane. Field evidence indicates that the two fold groups are strictly contemporaneous. One group of minor folds plunges at 40° to 020° N., and the other group plunges at 45° to 235° N., the common axial plane dipping at 70° to 305° N. Major structures parallel to both sets of minor folds are developed in the area. The fabric diagram of the fold groups shows tetragonal symmetry and this is taken to indicate that the stress field responsible for the deformation had itself tetragonal symmetry. The maximum compressive stress acted almost horizontally in a N.W.–S.E. direction while extension took place equally in all directions in a plane normal to the axis of maximum compression. The relations of contemporaneous fold structures to three basic strain patterns are briefly discussed.
On Convolute Bedding in the Lower Ludlovian Rocks of North-East Radnorshire
Authors: Holland C. H. 
Published: May 2009

AbstractConvolute bedding is described from the Lower Ludlovian in north-eastern Radnorshire in calcareous siltstones probably of the Monograptus tumescenszone. Examples of true slump-structures from the same area are given for comparison. The mode of formation of the convolute bedding is discussed and reference made to such directional information as is available from a study of the sediments.
Foraminiferal Faunas from the Lapithos Group of Cyprus
Authors: Cockbain A. E. 
Published: May 2009

AbstractThis paper reviews the stratigraphic micropalaeontology of the Lapithos Group of Cyprus, which is now known to be Upper Cretaceous to Lower Miocene in age. A three-fold subdivision, on the basis of planktonic foraminifera, into Lower (Upper Cretaceous) Middle (Danian to Eocene) and Upper (Oligocene to Lower Miocene) Lapithos Formations is suggested and a summary of the outcrops of each formation is given. The foraminiferal faunas of the Lapithos Group are discussed and it can be shown that a planktonic and a neritic faunal assemblage is present in each formation. The Terra Limestone, hitherto considered as part of the Dhali Group, shows faunal affinities with the Upper Lapithos neritic facies and is therefore placed in the Lapithos Group.
Pre-Cambrian Perthosites in Nyasaland
Authors: Morel S. W. 
Published: May 2009

AbstractAttention is drawn to the widespread occurrence of perthosite bodies in the Basement Complex of southern Nyasaland, and a description of these rocks is given.It is suggested that these rocks represent a late stage in the differentiation of basaltic or andesitic magma which produced basic intrusives and volcanics and ultrabasic complexes in the late Pre-Cambrian. These were subsequently metamorphosed at a high grade. The nepheline-syenite gneisses of Port Herald and Tambani are believed to be related to the same series.The remarkable similarities between the late Pre-Cambrian igneous history and that of the Karroo to Chilwa Series period is commented upon, and the occurrence of similar “ring structuress” in both series is described.
The Relation Between the Quartz Fabric and Fold Movements in a Folded Calc-Silicate Rock from the Moines of Scotland
Authors: Dhonau T. J. 
Published: May 2009

AbstractPetrofabric analyses of quartz c-axes have been made at four locations round a fold in a calc-silicate rock. The movement direction during the folding is deduced from the deformation of an older lineation. Two fabrics are present: the earlier, associated with the deformed lineation, is being replaced by a fabric associated with the formation of the fold. It is shown how the symmetry of the later fabric is related not to the axis of the fold but to the direction of the movement that produced the fold; and how the quartz c-axes lie on a conical surface, giving a small circle on a stereogram plot.
A Note on Cleavages in Crenulated Rocks
Authors: Rickard M. J. 
Published: May 2009

AbstractPublished descriptions and new field observations in Ireland and Canada confirm that strain-slip cleavage should not be classified with fracture cleavage. The termcrenulation cleavageis proposed to replace the generic one of strain-slip cleavage. Crenulation cleavage differs essentially from slaty and fracture cleavage in that it only develops in laminated rocks and is consequently nearly always a secondary structure. Intense metamorphism converts crenulation cleavage into a new schistosity or cleavage with characteristics similar to slaty cleavage. Two fundamentally different types are recognized and it is suggested that crenulation cleavage is a valuable indicator of metamorphic conditions during the various phases of deformation.
Co-existing Pyroxenes in Igneous Assemblages: a Re-evaluation of the Existing Data on Tie-line Orientations
Authors: Brown G. M. 
Published: May 2009

AbstractTie-line data are presented for twelve analysed igneous pyroxene pairs, from which it is demonstrated that a precise point of intersection, at or close to Wo75 En25 in the ternary diagram, does not exist. Eight tie-lines for pyroxene pairs from ultrabasic nodules in basalts are also considered. The tie-lines for metamorphic pyroxenes are compared with the igneous, and are shown to intersect over a similarly wide range, the average (Ca82 Mg18) being the same for both assemblages. It is shown that no conclusions can be drawn as to the genesis of the pyroxene assemblage, from the assumption of a characteristic tie-line intersection point. Optical determinations are considered, and shown to be of little practical value in this particular problem.
The stromatoporoid genus Milleporella Deninger
Authors: Hudson R. G. S. 
Published: May 2009

AbstractThe holotype of the stromatoporoid Milleporella sardoa Deninger, 1906, from the Senonian of Sardinia is redescribed and the genus Milleporella Deninger, 1906, and the family Milleporel-lidae Yabe and Sugiyama, 1935, are redefined. A new superfamily the MILLEPORELLICAE, is founded.
Co-existing Pyroxenes: Some Causes of Variation and Anomalies in the optically Derived Compositional Tie-Lines, with Particular Reference to Charnockitic Rocks
Authors: Wilson Allan F. 
Published: May 2009

AbstractAvailable data from charnockitic rocks (including twenty-eight new pyroxene pairs fromAustralia) suggest that a major cause of variation in optically derived compositional tie-line trends of co-existing pyroxenes is related to the geothermal history of the rocks concerned. It may yet be possible to subdivide the granulite facies, and also to detect mineral instability by critical study of tie-line trends. Recommendations are made whereby mineralogic and structural studies of charnockitic rocks can be integrated to yield more reliable chemical and optical data.
The Old Red Sandstone of Eastern Ekmanfjorden, Vestspitsbergen
Authors: Dineley D. L. 
Published: May 2009

AbstractThe Lower Old Red Sandstone deposits of Ekmanfjorden belong mainly to the Lykta Division, but pale sandstones with Giganthaspis representingthe Kapp Kjeldsen Division also occur in the core of what is probably a N.-S. striking anticline. The lower beds of the Lykta Division are soft, dull and silty and not very fossiliferous; above them are some 1,100 feet of sandstones and conglomeratic beds alternatingwith shales or marls. Locally abundant vertebrate remains include the guide fossil Doryaspis. Various sedimentary structures suggest rapid deposition on a broad shallow delta front.
Sedimentary Structures in the Epidotic Grits of Skye
Authors: Sutton John , Watson Janet 
Published: May 2009

AbstractSedimentary structures in the lowest sub-division of the Torridonian of Skye are described and figured. Trough cross-stratification of the type known as festoon bedding is widely developed in the coarser grits. Finer-grained sandstones show curly-bedding structures due to post-depositional disturbances. Siltstones and mudstones are characterized by a fine lamination and by such structures as ripple-marks, minute graded bedding and desiccation cracks. The orientation of cross-laminae in the festoon-bedded grits indicates that the currents depositing these rocks flowed towards the north-east or east.
New Hystrichospheres from the Upper Jurassic of Dorset
Authors: Sarjeant W. A. S. 
Published: May 2009

SummaryFrom assemblages of Upper Jurassic organic-shelled microplankton from Dorset are described five new species of hystrichospheres. Of these, two are attributed to a new genus,Polystephanosphaera; one new species of the genusHystrichosphaeridium, and two of the genusBaltisphaeridiumare also described.
The Wenlock Strata of South Mayo
Authors: Anderson J. G. C. 
Published: May 2009

AbstractSouth of Clew Bay, Co. Mayo, Wenlock strata, cut off to the north by a belt of serpentine marking the Highland Boundary, are divisible into three stratigraphical groups. The succession is repeated by a syncline overturned towards the south, which is modified by north-west cross-folds. The Wenlock strata have undergone low-grade “regional” metamorphism, in spite of which fossils have been preserved at a few localities.
The Feeding Mechanisms of Spire-Bearing Fossil Brachiopods
Authors: Rudwick M. J. S. 
Published: May 2009

AbstractThe lophophores of spire-bearing fossil brachiopods (Spiriferoidea and Atrypoidea) arereconstructed by homological comparison with living brachiopods. It is inferred that all spiral brachidia supported simple spiral lophophores. For each type of brachidium, only one arrangement of the spirolophe could have created an efficient filter-feeding system. The water would have entered the mantle cavity laterally and been ejected medially; but would have been filtered between the whorls of the conical spiralia either outwards (e.g. Atrypa) or inwards (e.g. Spirifer). These are the only possible alternatives: it is probable that both systems were evolved more than once.
Microplankton from the Cornbrash of Yorkshire
Authors: Sarjeant W. A. S. 
Published: May 2009

AbstractAn assemblage of microplankton from the Cornbrash of Yorkshire is described. It consists dominantly of dinoflagellates, including three new species of Gonyaulax and one new species of Pareodinia. A relatively small number of hystrichospheres are present, including new species of Baltisphaeridium, Cymatiosphaera, and Pterospermopsis. The character and significance of the assemblage are discussed.
The Southern Upland Fault in Ireland
Authors: McKerrow W. S. 
Published: May 2009

AbstractThe possibility of the Southern Upland Fault of Scotland continuing to the west coast of Ireland is examined critically. No post-Carboniferous faulting has occurred along this line in Ireland. It cannot be connected with any major fault occurring in the Lower Palaeozoic rocks of County Mayo or County Galway; and there is no evidence that it continues as a structural line to the south-west of Carrick on Shannon.
On the Origin and Occurrence of Basic Bodies Associated with Discordant Bathyliths
Authors: Joplin Germaine A. 
Published: May 2009

AbstractIt is suggested that the rock-suite, characteristic of the discordant bathyliths and ranging in composition from ultrabasic to ultra-acid, is formed from two magmas, a basaltic and a granodioritic, that the basic rocks are emplaced among the geosynclinal sediments before the introduction of the acid magma, and that intermediate rocks are hybrids. Further, it is suggested that hybridization takes place in two stages: first, by reaction between basic rocks and water and carbon dioxide, released from sediments as a result of deep-seated metamorphism, and rising in advance of the acid magma; and secondly, by the magma itself. The first intrusions carry shattered country rocks and are stock-like bodies, and these are followed by successive emplacements of granodiorite, the earliest of which envelop most of the stocks and are, thereby hybridized to form tonalites. Only those stocks near the margins of the later intrusions are preserved, and hence occur as satellites about the larger more acid bodies.The order of intrusion, the grainsize of the basic hybrids, and the occurrence of hornblende is discussed and it is concluded that dioritic rocks and dioritic magmas originate at a high level in the geosynclinal pile.
A Note on the Occurrence of Coal Measures in Eastern County Limerick, Ireland
Authors: Nevill W. E. 
Published: May 2009

AbstractThe purpose of this note is to put on record the discovery of Lower Coal Measure strata in the west of Ireland. The succession is approximately 500 feet thick and includes the Gastrioceras subcrenatum and the Gastrioceras listeri marine bands. Of particular interest is the occurrence of a coarse felspathic sandstone in the cycle of sedimentation which includes the G. listeri horizon: the sandstone is very similar in lithology to the distinctive Clay-Gall Sandstone of the Leinster Coalfield.
Devonian Limestone Pebbles in Central Devon
Authors: Hutchins Philip F. 
Published: May 2009

AbstractThe presence of locally abundant pebbles of Middle Devonian Limestone in the New Red Sandstone near North Tawton, Devonshire, is recorded. It is suggested that these were derived in Permian times from a nearby outcrop of Devonian limestones which projected through the Culm Measures of the mid-Devon syncline.
Age of Zircon from the Kunait Syenite Complex, South-West Greenland
Authors: Moorbath S. , Taylor S. R. , Upton B. G. J. 
Published: May 2009

AbstractThe age of zircon from the Kunait pluton in south-west Greenland has been measured by the lead-alpha method. The experimental data indicate a Cambrian age and the bearing of this result on the general geology of the area is briefly discussed.
On Post-Glacial Pelicans in Britain
Authors: Forbes C. L. , Joysey K. A. , West R. G. 
Published: May 2009

AbstractA bone found in the peat near King's Lynn, Norfolk, has been identified as belonging to a pelican. This is the fifth fossil record from East Anglia but it is the first to be accurately dated, and it can be correlated with Godwin's pollen zone VII–VIII (Iron Age). Other fossil pelican bones from East Anglia and Somerset are identified as those of the Dalmatian Pelican rather than the White Pelican which now visits parts of north-west Europe.
Composite and Multiple Intrusions of Lamlash-Whiting Bay Region, Arran
Authors: Srirama Rao M. 
Published: May 2009

AbstractIn South-East Arran there are many Kainozoic composite and multiple intrusions, mostly in the form of sills, composed of basic, intermediate, and acid rocks, xenolithic enclosure of, basic members by less basic ones being common. The pyroxene of all the rock types is a normal augite and not a pigeonite. Contact hybridization has played an important role in the partial or complete digestion of xenoliths. The genesis of the different members of the intrusions is attributed to the complex process of deep-seated hybridization of two types of magmatic material of contrasting basic and acid composition. The order of injection of magma is, invariably, from basic to acid, though in the intrusions, the spatial sequence of the rock types varies much; their complicated structures are ascribed to a series of pulsations of contaminated magma with its composition tending progressively in the acid direction.
Granite: Some Tectonic, Petrological, and Physico-Chemical Aspects
Authors: Reynolds Doris L. 
Published: May 2009

AbstractGranites of the main movement-phase of an orogenic zone form an integral part of the tectonic pattern being characteristically located at the intersection of cross- and main-folds. Here, an older granitic core pierces upwards through the anticlinal vault to form a diapir-fold in which migmatization, synchronous with movement, leads to the evolution of granodiorite. At higher structural levels where pressure is lower K-granites occur. Only at sub-volcanic levels has evidence of melting been found.Recent hydrothermal investigations, by Bowen and Tuttle, show that synthetic haplo-pitchstones whichbeginto crystallize at minimum temperatures become richer in K as pressure decreases. These results are closely comparable with evidence provided by the sub-volcanic K-microgranites (migmatized Caledonian granodiorite) of Slieve Gullion, but have no application to the granodiorites.
Note on the Structure and Microstructure of Thecia swinderniana (Goldf.)
Authors: Lafuste Jean G. 
Published: May 2009

AbstractA study of thin sections of Thecia swinderniana (Goldfuss) shows the trabecular nature of the skeleton. It also appears that there are neither horizontal pores not vertical tubules in the walls, which are compact. A review of genera regarded by various authors as allied to Thecia leads the writer to retain in the family Theciidae only Thecia Edwards and Haime and Angopora Jones, the genus Romingerella Amsden being considered a synonym of the latter.
The Metasomatic Rocks Associated with the Criffell-Dalbeattie Granodiorite
Authors: Phillips W. J. 
Published: May 2009

AbstractThe field relations and petrography of a number of small rock bodies occurring near Rockcliffe at the southern margin of the Criffell-Dalbeattie granodiorite are described. The evidence suggests that they were formed by the metasomatic replacement of greywacke and shale hornfelses by Na-bearing and later K-bearing solutions which preceded the ascending granodiorite magma. This metasomatic transformation brought about the development of two distinctive rock types. Equigranular quartz-dioritic rocks which generally grade into the hornfelses are regarded as the result of static metasomatic replacement of the hornfelses with no appreciable movement of the permeated rock. In contrast, rocks of similar mineralogy but occurring as sharply bounded bodies with a conspicuous porphyroblastic texture, are thought to have attained their characteristic features by a certain amount of metasomatic mobilization of the permeated material. Because of the intrusive appearance of these porphyroblastic rocks and their occurrence near the margin of the granodiorite pluton they are here referred to as “marginal porphyrites”.
The Mode of Cladial Generation in Cyrtograptus
Authors: Thorsteinsson R. 
Published: May 2009

AbstractThe morphology of Cyrtograptus rigidus Tullberg n. subsp. A is described from uncompressed material. Particular attention is directed to the sequence of development of the connecting structure of cladium and main branch, which is demonstrated with the aid of figured growth stages of cleared and uncleared specimens. Also discussed is the intimate relationship of relative rate of growth of characters of cladium to those on the main branch. Cursory study of numerous other uncompressed species of Cyrtograptus in the author's collection reveals that the principles of cladial development outlined here are of general application.
Structural Observations on the South-East Lizard
Authors: Sanders L. D. 
Published: May 2009

AbstractGeometry of the boundary of the serpentine in the south-east Lizard indicates that it is a sheet. The serpentine sheet rests on hornblendic gneisses and their migmatized equivalents; the upper part of this basement represents a thrust-sole in which bodies torn from the base of the serpentine are enclosed. Coastal erosion of rocks beneath the serpentine tends to marginal collapse of the unsupported sheet, so that slipped masses may conceal its base.
Carboniferous Goniatites from Blacklion, Co. Leitrim, Ireland
Authors: Hodson Frank 
Published: May 2009

AbstractThe holotype of Brancoceras enniskillense Foord, 1903, is shown to be a specimen of Beyrichoceras excavatum (Phillips), 1836, the suture line of which has been misinterpreted. It is associated with Beyrichoceras castletonense (Bisat), indicating the presence of the Upper B2 subzone in the Carboniferous Limestone, of Blacklion.
The Mourne Mountains Granites—A Further Study
Authors: Brown P. E. 
Published: May 2009

AbstractChemical analyses and petrographic data are given of the eastern granites of the Mourne Mountains. It is shown that the main bulk of the granite is a uniform highly siliceous biotite-bearing type and that the intrusion of this was preceded by a smaller amount of less siliceous and more variable hornblende-bearing granite. The ferromagnesian minerals have a high iron to magnesium ratio.
Note on Factors Governing the Porosity of Wind Deposited Sands
Authors: Kolbuszewski J. 
Published: May 2009

AbstractAfter establishing average velocity of wind/average porosity curve for wind deposited sands, where it was shown that low wind velocity produces higher porosity than high wind velocity, further investigation was made and sands of various characteristics were used. It was established that the velocity of wind/porosity of deposit relationship is a more complicated function than was previously expected and some of the reasons are explained. The first indication of the influence of shape of the grain and the specific gravity of grains on the obtained results is registered. Further steps in the research are indicated.
A New Species of Lepidostrobus containing unusual Spores
Authors: Chaloner W. G. 
Published: May 2009

AbstractA new species of Lepidostrobus, L. zea, is described. Two cones, from Yorkshire and from Ayrshire, and some isolated megasporangia are known. The megaspores have long been known, occurring isolated in coal, and have been described as Triletes auritus Zerndt. The microspores, also known previously from coal macerations, are of the type described as Endosporites globiformis (Ibrahim) (E. zonalis (Loose) and the C1 type of Raistrick). Endosporites has hitherto been regarded as cordaitalean (gymnosperm) pollen, and this is the first record of Endosporites from a lycopod.
Gravity Measurements in Durham and Northumberland
Authors: Hospers J. , Willmore P. L. 
Published: May 2009

AbstractGravity measurements in Durham and Northumberland in the region of the Alston Block are described, and their reduction as well as the accuracy of the results discussed. It is shown that the results between and near Newcastle and Durham are fully consistent with the conception of a horst, uplifted between the Ninety Fathom Dyke and the Butterknowle Fault. The observations along the valley of the East Allen, however, require an entirely different explanation. It is concluded that a closed area of negative anomalies occurs, centred near Wear Head. This is interpreted as due to a granite intrusion not yet exposed by denudation. The mineralization of the area is discussed and it is shown that it supports the foregoing interpretation.