bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative model of grain size and sedimentary structures in lateral deposits
Authors: Allen J. R. L. 
Published: July 2010

AbstractThe secondary flow and transverse changes of water depth in curved stream channels are exploited to develop a quantitative, partly empirical model of the way lithology varies vertically in deposits accumulated through processes of lateral deposition. According to the model, grain size decreases upward in a lateral deposit and the sedimentary structures change from those denoting large stream powers upward to kinds indicative of small powers. The model also shows that the proportion of flat‐bedded sand‐grade material in a lateral deposit is essentially independent of stream power but controlled by channel curvature and hence general sinuosity. The predictions of the model compare satisfactorily with the characteristics of selected coarse members in fining‐upwards cycles of fluviatile origin from Devonian strata in Britain and North America. The model is thought to have value as a tool for environmental interpretations.
The structural relationships of the Loch Borrolan Complex, Scotland
Authors: Woolley A. R. 
Published: July 2010

AbstractThe Borrolan Complex comprises earlier and later rock suites which are separated by an intrusive junction. The earlier suite forms a conformable sheeted complex which has been punched through by a later plug‐like body and includes several distinct magma types; while the later suite differentiated gravitationally in place. Field and microscopic evidence suggests that some of the earlier rocks were emplaced prior to the principal movements on the Assynt Thrust Plane, while the later suite post‐dates the development of the Assynt Thrust, although it is affected by a deformation. It is suggested that the emplacement of the greater bulk of the Borrolan rocks after movement on the Assynt Thrust Plane had ceased excludes the possibility of the Borrolan, and nearby Loch Ailsh, intrusions being the trigger mechanism which set off the great duplication of strata in the Assynt Culmination.
Sedimentation of the Triassic (Scythian) Red Pebbly Sandstones in the Cheshire Basin and its margins
Authors: Thompson D. B. 
Published: July 2010

AbstractThis magnalithofacies, which forms the bulk of two formations, the Bunter Pebble Beds and the Lower Keuper Sandstone, is described and interpreted as the deposits of former low‐sinuosity, largely braided, streams which flowed across a regional palaeoslope inclined to the north‐west. Arid blocks of the Welsh and Pennine Massifs lay to the west and east. Lithofacies A, conglomerate breccia and gravel, is interpreted as a deposit of former channel floors and sometimes bars. Lithofacies B crossbedded pebbly coarse sandstone, formed from large‐scale ripples developed on channel (? braid) bars of flood courses, whilst lithofacies C, argillaceous finer sandstone, represents the large‐scale ripples of quieter channels at lower stage and discharge. Lithofacies D, interbedded fine sandstone and shale, formed a riverplain topstratum deposit and, rarely, a levee. Lithofacies E is similar to D except that the sandstone is coarser and injects the mudstones repeatedly. Lithofacies F, red shales and mudstones (largely the ‘marl’ bands of former authors), may be laterally restricted or extensive. The former bands represent deposits of bar swales and abandoned cut‐off channels of varying stage: the latter suggest the development of a riverplain topstratum. Lithofacies X, soft fine sandstone, is aeolian. These lithofacies are arranged in vertical repetitions of varying thicknesses which are often asymmetric. Allocyclic climatic influence, reflected in varying discharge and sediment load under conditions of net accretion and steady subsidence, is regarded as a dominant factor in the origin of miocycles, megacycles and magna‐cycles, though in smaller repetitions the possibility of channel wandering, and in magnacycles the influence of tectonics, is possible.
Succession and sedimentation of glacigenic deposits at Hendre, Anglesey
Authors: Helm D. G. 
Published: July 2010

AbstractThe application of sedimentological and other techniques in a detailed small‐scale study of Quaternary meltwater deposits around Pentraeth in Anglesey, North Wales has shown that interpretations based solely on surficial form are incorrect. Previous views held that the sediments were deposited sub‐glacially as eskers by meltwater flowing south‐west from decaying ice in Red Wharf Bay.The present work shows that in general the deposits form a coarsening upwards sequence with distinctive divisions corresponding to the lacustrine, deltaic and fluviatile phases of basin filling. The glacigenic sediments were transported by rivers flowing predominantly south‐eastward and deposited in a shallow lake or lakes.
Solution subsidence outliers containing probable Tertiary sediment in north‐east Wales
Authors: Walsh P. T. , Brown E. H. 
Published: July 2010

AbstractThe pale‐coloured clays and lignites of presumed Tertiary age from the upper parts of the Mochras borehole (Wood and Woodland 1968) are not the first such materials to be recovered from the existing Welsh landscape. Similar clays and sands, and, occasionally, pebble beds and lignites have been recorded from over twenty localities, preserved beneath Glacial deposits in solution subsidence cavities in the Carboniferous Limestone. The best known such occurrence is the isolated mass at Flimston, Pembrokeshire, which has long been thought to be of Tertiary age (Dixon 1921).The others are scattered along the Carboniferous Limestone outcrop of north Wales between Llandudno in the north‐west and Mold in the south‐east. Their proximity to each other, and records of fossil remains in some of them suggested that it might be possible to effect a regional stratigraphical correlation. Certainly, whatever their age, they form a critical stratigraphical reference in hypotheses concerning the geomorphological evolution of the Welsh landscape.The Flintshire and Denbighshire occurrences are reviewed in the light of information recorded by Maw (1865 and 1867), Strahan (1890) and others, and information forthcoming from recent excavations and augering is presented.It is concluded that, like the pocket deposits of Derbyshire (with which there are numerous analogous relationships) the north Wales pockets are probably solution subsidence outliers of a sheet of fluvio‐lacustrine Tertiary sediments, in part at least 70 m thick, the product of Palaeogene deep weathering, that formerly spread over much of the area of north Wales now occupied by the Alun, Clwyd and Conway catchments.
The Ballybofey Anticline: A solution of the general structure of parts of Donegal and Tyrone
Authors: Pitcher W. S. , Shackleto R. M. , Wood R. S. R. 
Published: July 2010

AbstractA tight early fold, the Ballybofey anticline, trends south‐eastwards across central Donegal. South‐west of its axial trace the Dalradian strata are inverted so that the rocks high in the Series occur at the lowest structural level, next to, and facing downwards, the supposedly Moinian psammites in the core of the Lough Derg antiform. Rapid facies changes occur in the Dalradian rocks across the Caledonian strike.
A continuous seismic profile survey of Windermere
Authors: Howell Frank T. 
Published: July 2010

AbstractContinuous seismic profile devices, modified for use in freshwater have been used on Windermere to determine the total thickness of lakebed sediments and the morphology of the underlying bedrock. The survey detected two overdeepened irregularly shaped rock basins. The northerly one approaches 110 feet (34 m) below sea level and contains 70 feet (21 m) of sediment. The corresponding dimensions of the Southern basin are 120 feet (37 m) and 130 feet (40 m) respectively. Glacial scouring is postulated as the origin of the rock basins. Some profiles show two types of sediment; the higher parts of which are known to be Post Glacial.
The origin of banding in the Main Donegal Granite, N.W. Ireland
Authors: Berger A. R. 
Published: July 2010

AbstractThis Caledonian pluton exhibits a regular, sub‐vertical banding in which layers of dark, relatively fine grained trondhjemite alternate with layers of light, coarse grained granite. The textures and the presence of cross‐cutting bands of granite indicate that the light bands were derived by potash feldspathization of the trondhjemite. The geometry of the banding indicates that it formed during the “synplutonic” deformation of the pluton, largely in situ. The bands formed by segregation of alkalies into dilatant zones of movement produced during the deformation of partly consolidated magma.
The faunal stratigraphy of the Kirkby Moor Flags of the type area near Kendal, Westmorland
Authors: Shaw R. W. L. 
Published: July 2010

AbstractThe rocks generally referred to the Kirkby Moor Flags have been mapped in the Kendal area, roughly bounded by Underbarrow, Sedbergh and Kirkby Lonsdale. The succession is divided into four units: the Lower Underbarrow Flags, the Upper Underbarrow Flags, the Kirkby Moor Flags and the Scout Hill Flags. These represent a redefined succession derived from what had been lumped together as ‘Kirkby Moor Flags’. These units correlate with the Upper Leintwardinian, the Whitcliffian and the Downtonian of the Welsh Borderland. Proof that rocks of Downtonian age occur is demonstrated in an unbroken succession of uniform lithology. Ostracodes form an invaluable part of the fauna in both subdivision and correlation of the succession.The fauna of the Kirkby Moor Flags and the Scout Hill Flags can be classified into assemblage groups which possibly represent communities of species.
A geoelectrical investigation of the drift deposits in Northwest Lancashire
Authors: Worthington P. F. 
Published: July 2010

AbstractA surface resistivity survey around and to the south of Garstang has indicated a predominance of boulder clay, with some sands and gravels, in an overburden of markedly variable thickness and lithology. The survey techniques, data processing and interpretation are discussed. The data suggest that the Lower Boulder Clay may be represented northeast of Garstang, with the Middle Sands present over a much wider area. The major subdivision, the Upper Boulder Clay, seems to be overlain by patches of presumed Upper Sands. Possible isopachytes of these four suggested subdivisions are presented, and certain hydrogeological implications briefly mentioned.
Minor thrust faults in the Avonian of the North Crop of the South Wales Coalfield
Authors: Roberts J. C. 
Published: July 2010

AbstractSmall‐scale thrust faults are described from the North Crop of the South Wales Coalfield in strata of Avonian age. Two main sets occur which strike at east‐west and north‐south respectively, and show apparent stratigraphic zonation. It is suggested that the sets were initiated during the early stage of deformation of the area in response to primary and secondary resolved compressional forces.
The Stratigraphy of the Ordovician rocks of Anglesey
Authors: Bates D. E. B. 
Published: July 2010

AbstractArenig sandstones, grits and conglomerates rest unconformably on pre‐Cambrian rocks (the Mona Complex) and are of variable thickness and facies. Higher Arenig and Llanvirn shales, grits, conglomerates, shaly breccias and ironstones are related to contemporaneous fault movements, with abundant slump structures and rare turbidites. A pre‐Caradoc break in sedimentation was followed by deposition of shales, cherty shales, sandstones, breccias and conglomerates on Llanvirn, Arenig and pre‐Cambrian rocks. The Carmel Head Thrust acted as a major line controlling sedimentation, with upthrow to the north. Lower Silurian graptolitic shales at Parys Mountain rest on an acid volcanic group of Caradoc (?) age.
Melting relations of some oceanic basalts
Authors: Tilley C. E. , Thompson R. N. , Lovenbury P. A. 
Published: July 2010

AbstractThe melting relations of a group of oceanic basalts—olivine basalts, tholeiitic to midly alkaline, and high‐alumina tholeiites are determined. The liquidi of these rocks follow closely the course of the temperature—iron enrichment relationship of Kilauean thoeliitic basalts, ranging from 1430°C for an olivine enriched tholeiite, to a tholeiite of liquidus temperature of 1190°C, the liquidus phase of the assemblages being either olivine or plagioclase.
Comparative petrology of the leucocratic syenites of the Northwest Highlands of Scotland
Authors: Parsons I. 
Published: July 2010

AbstractThe normative mineralogy of the Loch Borralan, Loch Ailsh and Loch Loyal leucosyenites is compared to the System Ab – Or – An ‐ Qz. At Borralan, the upper quartz‐syenites of Cnoc‐na‐Sroine plot within the plagioclase volume, the lower perthosites within the alkali feldspar volume. This mineralogy cannot have been attained by in situ crystal fractionation. The Ailsh rocks plot within the plagioclase volume, the Loyal syenites within the alkali feldspar volume. The three complexes cannot have been derived from a single magma body at depth, and are not precisely coeval.
Pre‐Cambrian landscapes in Northwest Scotland
Authors: Stewart A. D. 
Published: July 2010

AbstractAn old land surface carved out of basement gneisses is extensively preserved beneath Torridon Group sandstones (deposited ca. 750 m.y. B.P.). Contoured reconstructions show that relief declines westward from 2000 ft (600 m) to almost nothing over a distance of 25 km. North‐northeast trending zones of similar dissection can be traced for 160 km. Weathering up to 2 m deep is locally present in the flat zone. The essentially unweathered land surface forming the mountains probably originated by dissection of a palaeoplain. The flat zone is probably, but not certainly, a relatively young pediplain. All land forms are thought to have developed before, not during, deposition of the overlying sediments.
The mineralogy and origin of interbedded clay wayboards in the Lower Carboniferous of the Derbyshire Dome
Authors: Walkden G. M. 
Published: July 2010

AbstractInterbedded clays, or clay wayboards, from the Lower Carboniferous Limestones of Derbyshire and Staffordshire, are discussed in terms of their geological relationships, textural features and mineralogy, and comparison is made between these clays and other interbedded argillaceous materials from the area. It is concluded that the clay wayboards are the argillation products of contemporaneous volcanic ashfalls, and lie within the definition of K‐bentonites.Stratigraphical and palaeogeographical aspects of clay wayboard distribution are briefly discussed, and it is shown that despite the probable widespread extent of individual clay horizons they are only of limited value for the purposes of correlation.
The geological significance of a negative gravity anomaly in the South Wales Coalfield
Authors: Thomas M. D. , Brooks M. 
Published: July 2010

AbstractThree gravity traverses across the eastern half of the South Wales Coalfield indicate a local, elongate, negative Bouguer anomaly of a few milligals amplitude bordering the southern rim. The anomaly has a maximum amplitude of 4 mgal near Maesteg and attenuates eastward, dying out in the vicinity of the East Crop. Two possible geological causes of the anomaly are examined, namely a local thick sequence of normal Upper Carboniferous strata and a discrete, low‐density body of Carboniferous age with no apparent surface expression. The former, uncontroversial explanation requires rock densities at variance with measured values. In the case of the hypothetical low density body which can explain the anomaly, a variety of possible ages and configurations are discussed.
The Pleistocene history of Wales and the borderland
Authors: Bowen D. Q. 
Published: July 2010

AbstractThe Pleistocene rock‐stratigraphic record is accorded more or less traditional time‐stratigraphic interpretation which was held widely before application of an Irish developmental model in 1960. The following sequence of events are recognised: (1) Complete glaciation, of indeterminate age, which antedated the raised beach interglacial. (2) The raised beach episode which is shown to be the last (Ipswichian) interglacial. (3) The last (Devensian/Weichselian) glaciation, followed by possible readvance in northwest and northeast Wales; prior and subsequent to glaciation periglacial conditions obtained. It is shown that the Irish model, relying heavily as it does on the equation of rock and time stratigraphy, is inapplicable in Wales.
The age and stratigraphy of the Sholeshook Limestone of Southwest Wales
Authors: Price D. 
Published: July 2010

AbstractLocal developments of the Upper Ordovician Sholeshook Limestone are briefly described and inter‐correlated on the basis of their trilobite faunas. The base of the formation is diachronous and overlies the Mydrim Shales unconformably. The base of the normally succeeding Slade and Redhill Mudstones is also diachronous and to the north and west of Haverfordwest this formation contains strata laterally equivalent to the main part of the Sholeshook Limestone.It is suggested that the Sholeshook Limestone falls within the Cautleyan Stage of the Ashgill Series. This extends the range of several trilobite species normally regarded as Middle Ashgill (Rawtheyan) indices.
The sub‐drift surface of the Mersey and Weaver catchment and adjacent areas
Authors: Howell F. T. 
Published: July 2010

AbstractEvidence from 1,450 boreholes and coastal seismic profiles adds further precision to the form of the sub‐drift channels of South Lancashire and North Cheshire. These channels resemble sub‐aerial valleys, but commonly have ungraded profiles locally reaching at least 289 ft (87 m) below O.D. In some places they are still below present sea level, 40 miles (64 km) inland. It is suggested that previous views of origin can be reconciled by considering them to be river valley Systems, partly rejuvenated by low Pleistocene sea levels, and locally modified by sub‐glacial meltwater.
Vesicles and related structures in lavas
Authors: Whitford‐Stark J. L. 
Published: July 2010

AbstractA review of certain late‐stage textures in subaerial, submarine and lunar extrusive rocks is presented, together with a genetic classification of vesicles. The term paravesicle is introduced for hollows in lavas caused by the introduction of a gaseous phase into the lava after extrusion. Examples taken from the andesitic lavas of the Borrowdale Volcanic Series are used to illustrate the usefulness of studying such features.
The structure of the Taff Gorge area, Glamorgan, and the stratigraphy of the Old Red Sandstone—Carboniferous Limestone transition
Authors: Gayer R. A. , Allen K. C. , Bassett M. G. , Edwards D. 
Published: July 2010

AbstractLithostratigraphical and structural mapping of the Taff Gorge area, Glamorgan, has revealed a number of E‐W trending folds and thrusts. These were developed during the early stages of the Hercynian deformation as a result of an approximately N‐S principal compressive strain. Coeval with the folding, a conjugate set of sub‐vertical wrench faults, symmetrical about the principal compressive strain, divided the area into tectonic blocks and to some extent controlled the progressive development of folds and thrusts within the individual blocks. Later Hercynian deformation gave rise firstly to oblique‐slip and finally to dip‐slip movement on the faults.The lithological transition between the Old Red Sandstone and Carboniferous Limestone is described in detail, including the diagenetic history of the limestones. Marine horizons are shown to be present within the dominantly fluviatile Old Red Sandstone, and the base of the Carboniferous Limestone is defined at the base of the lowest limestone of the continuous marine sequence. Studies of spores, macroplants, conodonts and brachiopods indicate that the whole of the Upper Old Red Sandstone and Lower Limestone Shale in the Taff Gorge are of Tournaisian age.
The structure of the Lower Palaeozoic rocks of Anglesey, with special reference to faulting
Authors: Bates D. E. B. 
Published: July 2010

AbstractThe principal structures of the Lower Palaeozoic rocks of Angelsey are described. Tight folding, with variably developed slaty cleavage and a first phase of reverse faulting, took place probably in late Silurian times, along axes which are parallel to pre‐Cambrian foliation trends. A second phase of reverse faulting followed basic dyke intrusion and was succeeded by normal faulting and mineralization. Joint production was a comparatively late feature. A technique for analysing fault data, in terms of stress axes, is outlined and applied to faulting within the Lower Palaeozoic rocks.
The structure of the Moine‐like rocks near Lough Derg, County Donegal, Eire
Authors: Borradaile G. J. 
Published: July 2010

AbstractThe Moine‐like rocks are shown to have major, southward‐leaning, isoclinal F2 folds which may be synchronous with the nappe‐like Ballybofey Antiform of the overlying Dalradian rocks. The deformation of the immediately adjacent Dalradian rocks is consistent with a previous suggestion that they are in contact with the Moine‐like rocks along a major tectonic slide.
A geophysical interpretation of the structure of the Vale of Clwyd, North Wales
Authors: Collar F. A. 
Published: July 2010

AbstractDetailed gravity and resistivity surveys have been made in the Vale south of Denbigh, and from the combined interpretations a Trias isopachyte map has been produced. The gravity interpretation indicates that the en echelon faults of the western side extend across to the Vale of Clwyd fault, and separate a complementary set of en echelon synclines. These structures are systematically arranged in a pattern that may be attributed to dextral wrenching, and are discussed against a range of literature on that subject. The wrenching may have been a prolonged activity that commenced during Carboniferous times.
Structure and stratigraphy of the Borrowdale Volcanic rocks of the Kentmere area, English Lake District
Authors: Soper N. J. , Numan N. M. S. 
Published: July 2010

AbstractThe Borrowdale Volcanic rocks of Kentmere have been reinvestigated. A previous structural interpretation (Mitchell 1929) involving Caledonian isoclines superimposed upon pre‐Caradocian NNE trending folds is shown to be incorrect; neither set of structures exist. The geometry of the major structural elements in the area, the Nan Bield Anticline and the Caledonoid cleavage, is described. Evidence is adduced which suggests that the anticline was formed in pre‐Caradocian time as a large open fold trending approximately E‐W. Its present geometry and that of the Wren Gill Monocline result from the superimposition of the regional end‐Silurian cleavage obliquely and inhomogeneously across this pre‐existing fold.The volcanic succession is divided into four compositionally and petrographically defined formations. In upward sequence these are the Nan Bield and Wren Gill formations (andesitic lavas and tuffs), Kentmere Formation (mainly dacitic pryoclastic rocks) and the Garbourn Formation (andesites and dacites), totalling over 2800 m. It is thought that much of this succession was deposited subaqueously.
A resistivity section of Holy Island (Anglesey)
Authors: Habberjam G. M. , Jackson A. A. 
Published: July 2010

AbstractAn account is given of the use of square array resistivity techniques to derive an apparent resistivity section down the length of Holy Island (Anglesey). Possible interpretations of this section in terms of the distribution of true resistivity with depth are given and discussed briefly in relation to proposed geological structure.
On the thermodynamics of open systems in geology
Authors: Ostrovsky I. A. 
Published: July 2010

AbstractSemipermeable membranes are necessary conditions for the realisation of equilibrium open systems in the Earth's crust. Membraneless cases, as at the boundary Earth‐Atmosphere, are rather exceptional. The application of the D. S. Korzhinskii's thermodynamics of open systems to mineral equilibria in rocks may be justified only if the perfect mobility of components is proved independently viz: by means other than the analysis of mineral paragenesis alone.