bluuebunny/crossref_metadata_2025_split huggingface dataset:
The alleged subaqueous sliding of large sheets of sediment in the silurian rocks of north wales
Authors: Boswell P. G. H. 
Published: February 2007

AbstractSince reference is made from time to time to examples of supposed subaqueous sliding on a large scale in the Silurian rocks (Salopian Series) of Denbighshire, North Wales, for the purpose of supporting inferences about the mode of origin of certain intraformational disturbances, the stratigraphical evidence in Denbighshire is reviewed. On the basis of zoning by means of graptolites (or shelly faunas where available), the boundaries of the alleged sheets of slipped material prove to be transgressive. In particular, the largest ‘contemporaneously‐disturbed’ sheet includes parts of the undisturbed succession ranging in age from the nilssoni zone to the tumescens zone. Its supposed base would have to cross its supposed surface, so that it would appear to have a negative thickness—of minus 1,000 feet or more. Acceptance of the hypothesis of large‐scale sliding on the sea‐floor in this area is thus incompatible with a belief in the value of graptolites as zonal indices in the Salopian rocks.
Some unrecorded overflow channels in North‐East Lancashire
Authors: Dean Vernon 
Published: February 2007

AbstractFollowing a brief review of the previous work in the area, the existence of a small lake in the Sabden Valley, the gradual development of Lake Accrington and its subsequent division into Lakes Altham and Blackburn, are discussed in detail. Evidence is also given for the formation of a large lake (Lake Ribchester) in Ribblesdale. The paper also describes the later history of the Altham‐Ribchester‐Blackburn drainage, the origin of the Feniscowles and Hoghton Gorges, the final unsealing of the Ribble Basin, and the formation and history of Lake Hacking in Ribblesdale.
Corrie‐glaciation in the upper eden valley, westmorland
Authors: Rowell A. J. , Turner J. Selwyn 
Published: February 2007

AbstractA series of morainic deposits, regarded as due to corrie‐glaciation, is described from the Upper Eden Valley on Mallerstang and Ravenstonedale Commons. They lie between 1,250 and 2,000 O.D., chiefly around 1,500‐1,750 O.D. Well‐marked moraines, both lateral and transverse, are present, as well as typical hummocky morainic topography. Some of the glaciers issued from typical corries, and there are transitions from these to long, slightly recessed scars, likewise developed in the basal Millstone Grits. The corrieglaciation is regarded as later than the main Dales and Edenside glaciation' and may be contemporaneous with a recently‐discovered solifluction deposit on the Lunds to the south, in the Upper Ure Valley, and with outwash fans in Ravenstonedale at the foot of the Howgill Fells.
The silurian succession at cwm graig DDU (breconshire)
Authors: Straw S. H. 
Published: February 2007

AbstractThe Silurian rocks of Cwm Graig Ddu consist mostly of blue and grey shales and mudstones, all of Ludlow age, the succession extending from the nilssoni Zone of the Lower Ludlow to the Holopella Grits and Shales at the top of the Upper Ludlow. They are overlain by the Tilestones of the Lower Downtonian. The rocks are exposed along the side of the Brecon road on the western side of the valley, in the cliffs at its head, and in the roadside quarries beyond its head. The succession, generally, closely resembles that of the Builth district, but differs in detail. The Lower Ludlow rocks contain many slumped bands which vary in thickness from several inches to many feet.
On the carboniferous nautiloids: Some middle Viséan species from the isle of man
Authors: Turner J. Selwyn 
Published: February 2007

AbstractA collection of Middle Viséan nantiloids from the Isle of Man is described, together with two specimens from beds probably of the same age in Derbyshire. The genera Vestinautilus de Ryckholt, Stroboceras Hyatt, and Domatoceras Hyatt are more closely defined on the basis of their type‐species, and the opportunity is taken to refigure the types of Stroboceras hartti (Dawson) and Domatoceras umbilicatum Hyatt. The types of Orthoceras gesneri Phillips (non Fleming) and Nautil is bistrialis Phillips are also refigured and described. With the stricter definition of genera adopted in this paper several new genera and species are necessary to receive the specimens described, and the family Temnocheilidae Mojsisovics is revived for, inter alia. Temnocheilus McCoy and Knightoceras Miller and Owen.
Breccias in the manx slates: Their origin and stratigraphic relations
Authors: Gillott J. E. 
Published: February 2007

AbstractThe Manx breccias, previously described as crush‐conglomerates of tectonic origin, are ascribed to sub‐aqueous sliding. The stratigraphical succession in the Manx Slates of the northern part of the Isle of Man is deduced, with the aid of the way‐up evidence provided by graded bedding and current bedding. The significance and position of fossils which Bolton claimed he found in the Manx Slates are reviewed and it is concluded that the specimens of Dictyonema probably came from the Isle of Man. The way‐up evidence indicates that the slate at the alleged fossil locality (Cronk Sumark) belongs to the youngest exposed division of the Manx Slates, so that other divisions are probably older then Tremadoc.
The ordovician succession near llanystwmdwy caernarvonshire
Authors: Harper J. C. 
Published: February 2007

AbstractA section in the River Dwyfach shows the main Snowdon Lavas and Tuffs to be overlain by a series of sediments and tuffs with a Longvillian fauna near the base. These sediments are followed by black graptolitic shales belonging to the Dicranograptus clingani and Pleurograptus linearis zones overlain by Ashgill mudstones with Phillipsinella parabola.
Notes on the structure and relations of the pre‐cambrian and ordovician rocks of southwestern lleyn (Caernarvonshire)
Authors: Shackleton R. M. 
Published: February 2007

AbstractThe oldest visible Pre‐Cambrian rocks in Lleyn are pillow lavas and sediments of the Gwna Group. They are succeeded by rhyolitic tuffs (Gwyddel Beds). Schists and gneisses have been formed from these rocks. The Sarn adamellite intrusion is related to the gneisses. The Pre‐Cambrian rocks are unconformably overlain by Ordovician.
The borrowdale volcanic series of the dunnerdale fells, lancashire
Authors: Mitchell G. H. 
Published: February 2007

AbstractIn the Dunnerdale Fells, south‐west of Coniston, Lancashire, a succession of tuffs, andesites and rhyolites, over 8,000 ft. thick, forming the lower part of the Borrowdale Volcanic Series, has been mapped. These rocks are overlain with marked unconformity by the Coniston Limestone Series, which dips steeply south‐eastwards and oversteps most of the Borrowdale succession in a south‐westerly direction. The Borrowdale Series is affected by two major periods of earth‐movements, the earlier of pre‐Caradoc and the later of Devonian age. The general dip of the Borrowdale Series is eastwards. It shows little folding but is traversed by large tear‐faults with northerly trend. An important belt of faulting closely follows the outcrop of the Coniston Limestone and includes reversed faults. Both sets of faults appear to be of Devonian age.
A deep borehole for oil at croxteth park, near liverpool
Authors: Magraw D. , Ramsbottom W. H. C. 
Published: February 2007

AbstractA deep borehole has recently been drilled in search of oil and natural gas near Croxteth Park, Liverpool. The borehole penetrated Recent and Glacial deposits and a minimum of 1,306 ft. of Permo‐Triassic sandstones before crossing the large Croxteth Fault and entering rocks of the Millstone Grit Series. Thereafter, a sequence of strata extending from almost the top of the Millstone Grit down to beds in the upper part of the Carboniferous Limestone Series has been proved for the first time in the area. The limestones have yielded a large fauna.
Goniatites from the upper viséan shales of county Leitrim, Eire
Authors: Moore E. W. J. , Hodson F. 
Published: February 2007

AbstractViséan goniatites from the top of the P1 Zone are described. Eight new species and one variety are erected. A new genus Hibernicoceras is proposed for the reception of some of these. Observations are made on the genus Prædaraelites of Schindewolf.
The stratigraphy of the moel Hebog district between Snowdon and Tremadoc
Authors: Shackleton Robert Millner 
Published: February 2007

AbstractThe succession of Cambrian and Ordovician rocks in the area between Snowdon and Tremadoc is described. The Upper Cambrian includes Ffestiniog Beds with the Lingulella Band, and part of the Dolgelly Beds. The unfossiliferous Pennant Slates and Quartzites may be Upper Cambrian or Lower Ordovician. Many localities for Llanvirn graptolites are recorded. The Caradoc includes graptolitic slates below, and sediments and volcanic rocks with several shelly faunas above. The Snowdon Volcanic Series includes basalts and basaltic agglomerates. Some intrusions are related to the Snowdonian vulcanicity, others to the Caledonian deformation.
The progress of geology in the U.S.S.R.
Authors: Tomkeieff S. I. 
Published: February 2007

AbstractThis brief survey of the development of geology and of the teaching of geology in the Soviet Union is the first of its kind in English and is intended merely to introduce the subject and to induce English geologists to learn Russian and so make available for themselves the immensely rich scientific resources of the U.S.S.R., or failing that, to make themselves acquainted through the medium of abstracts and translations with the geological work being done in the U.S.S.R.The article is intended as a guide and it comprises sections dealing with the history and multifarious branches of geology as it exists in the 1950's. There is space only for major developments in the organisation of teaching and research, and for outstanding contributions to the science of geology, associated generally with the names of the principal geologists of the U.S.S.R. The article also includes very brief bibliographical references.
Mid‐ordovician structures in South‐Western Snowdonia
Authors: Rast N. 
Published: February 2007

AbstractTectonic and stratigraphical relationships of the Snowdon Volcanic Series are described from a critical locality near Beddgelert. Here a Caradocian pre‐cleavage fault of Caledonoid trend is identified and it is suggested that this structure was important in determining the disposition of the largely subaerial Caradocian volcanic rocks. Regional considerations suggest that while basic Ordovician volcanic rocks of Wales are largely pillow lavas and therefore submarine, the acid volcanic rocks are mainly ignimbrites and therefore subaerial. It is suggested that such subaerial vulcanicity owes its origin to the build up of magma blisters.
Ordovician ignimbrites in the Berwyn Hills, north Wales
Authors: Brenchley P. J. 
Published: February 2007

AbstractTwo ignimbrite horizons are recognised in a Caradoc marine sequence. The uppermost, the Pandy Ash forms a single mappable unit, but is shown to consist of at least three separate flows, including both welded and non‐welded tuffs. Locally lahars occur.
Potassium‐argon measurements on the granites and some associated Rocks from Southwest England
Authors: Miller J. A. , Mohr P. A. 
Published: February 2007

AbstractNew isotopic age determinations on all the granites of southwest England are presented and discussed in relation to the data of previous workers on the Dartmoor and Land's End granites, and with particular reference to the dating of the Hercynian orogeny in that region and to the more precise fixing of the Carboniferous‐Permian boundary. The possibility of a measurable non‐contemporaneity of the individual granites is shown, and their ages compared with those of Armorica and central Europe.The different granite phases within the composite plutons and the various associated late magmatic processes of pegmatitic injection, pegmatoid metasomatism, greisenisation, tourmalinisation and hydro‐thermal mineralisation, are shown to be pene‐contemporaneous.Some data on basic igneous rocks relative to the history of the Variscan fold‐belt in southwest England, and particularly to the Hercynian orogeny, are discussed.Age data on the Wolf Rock and Epsom Shoal phonolites are presented; their Mesozoic extrusion raises problems not yet resolvable.
The Nod Glas sediments of Caradoc age in north Wales
Authors: Cave R. 
Published: February 2007

AbstractTwenty feet to thirty feet of black shale, phosphorite and limestone exposed near Welshpool, Montgomeryshire, exhibit a facies which enables a correlation to be made between the Welsh graptolitic Nod Glas shales of Caradoc age and the shelly Onnia Beds of south Shropshire.Graptolitic evidence suggests that the visible thickness of the Nod Glas near Welshpool belongs to the top of the Dicranograptus clingani zone, and the shelly fauna indicates the zone of Onnia gracilis.At the base of the Nod Glas throughout Montgomeryshire is a phosphatic horizon of variable development.
A shelly fauna from the Snowdon volcanic series at Twll Ddu, Caernarvonshire
Authors: Dean W. T. 
Published: February 2007

AbstractTrilobites and brachiopods are described and figured from the Caradoc Series of the Twll Ddu district, northeast of Snowdon. They indicate a Longvillian age for the Banded Pumice Tuffs of the Bedded Pyroclastic Series, and exhibit affinities with corresponding faunas in South Shropshire as well as other parts of North Wales and Northern England.
The syntectonic foxdale‐archallagan granite and its metamorphic aureole, isle of man
Authors: Simpson Alexander 
Published: February 2007

AbstractThe small exposed granite at Foxdale is merely part of a much larger intrusion, the Foxdale‐Archallagan granite, which underlies the country‐rock of Manx Slate Series at shallow depth. The granite is post‐F1 in age. It is a syn‐tectonic intrusion and was emplaced during the second (F2) movementphase in the Caledonian tectonic chronology of the Isle of Man. Its final consolidation was achieved during the following F2‐F3 static interval.The aureole metasediments consist of porphyroblastic contact phyllites and schists similar to those produced by regional metamorphism. A textural study has demonstrated that the para‐crystalline movement responsible for the directional fabric in these rocks is of tectonic origin and F2 in age.Despite the penetrative, syn‐crystallization F2 deformation of its envelope, the granite itself is little affected though a mild F2 shearing is visible on its southern fringe. Post‐crystalline deformation of the cooled aureole by S3 and F3 crumples took place during the third movement‐phase. Suggestions are made concerning the form of the Foxdale‐Archallagan intrusion in depth. The temporal relationship of the pluton to other syn‐tectonic F2 acid intrusions in the Isle of Man is considered.
Influence of tectonics and palaeoenvironment on late cretaceous clay sedimentation in the upper benue trough, Nigeria
Authors: Enu E. I. 
Published: February 2007

AbstractThe Late Cretaceous sedimentary sequence in the Upper Benue Trough consists of seven formations. Outcrop samples from the type localities of these units were analysed by X‐ray diffraction for their day mineral content. The composition and distribution of the clay minerals are influenced by tectonics, relief and water depth. Three main depositional phases are recognizable on the basis of clay mineral assemblages, two of which are associated with tectonic movements. The first phase, characterized by the presence of chlorite, illite, kaolinite and mixed‐layer clays is common to Albian‐Cenomanian sediments. This phase is succeeded by mixed‐layer clays and smectite‐rich, Turonian‐Early Santonian sediments.The re‐occurrence of chlorite and illite in association with kaolinite and mixed‐layer clays in the Post‐Santonian sediments constitutes the third depositional phase.These clay mineral assemblages are indicative of two periods of tectonism (Albian and Late Santonian) and an intervening Turonian‐Early Santonian period of quiescence in the Upper Benue Trough.
New evidence for the relative age of the Ercall Granophyre and its bearing on the Precambrian‐Cambrian boundary in southern Britain
Authors: Cope John C. W. , Gibbons Wes 
Published: February 2007

AbstractRecent extension of the Ercall Quarry, Shropshire, has revealed an unconformable contact between the Ercall Granophyre and overlying Lower Cambrian sediments. Five metres of basal conglomerate with rare granophyre clasts overlie a weathered granophyre surface and precludes the possibility that the granophyre is intrusive into the quartzite. The age of the Cambrian quartzite is reviewed and is considered to be most probably late Tommotian. The granophyre is therefore pre‐late Tommotian, but has been radiometrically dated as 533 ± 13 Ma (Rb‐Sr WR, Patchett et al. 1980) and 531 ± 5 Ma (U‐Pb zircon, Compston et al. in Cowie and Johnson 1985). If these independent dating methods are recording the age of granophyre intrusion, then the absolute ages of both the Comley Series Lower Cambrian faunas, and therefore the Precambrian‐Cambrian boundary, are younger than is generally recognized.
The stratigraphy, structure and regional significance of the Moine Rocks of Mull, Argyllshire, W. Scotland
Authors: Holdsworth R. E. , Harris A. L. , Roberts A. M. 
Published: February 2007

AbstractTwo right‐way‐up Moine lithostratigraphic units—the Shiaba (older) and Assapol (younger) Groups—are distinguished in the Ross of Mull. These were intruded in the west by the post‐tectonic, Ross‐of‐Mull granite complex at 414 ± 3 Ma. Apparently undisturbed inclusions of Moine metasediments within the granite permit the boundary between the lithostratigraphic units to be followed westward almost to the supposed trace of the Moine thrust in the Sound of Iona. The Shiaba and Assapol Groups which have a transitional, albeit attenuated, stratigraphic contact are correlated with the Morar and Glenfinnan Divisions of Inverness‐shire, the Sgurr Beag ductile thrust (slide) normally found at the Morar/Glenfinnan Division boundary being absent. This implies that the stratigraphic relationship between these two divisions, which is elsewhere obscured by the thrust, is uniquely preserved on Mull.Within a local, D1‐D4 sequence, D2 and D3 structures are dominant. Originally subhorizontal D2 folds are intensely curvilinear on all scales about an originally flat‐lying, NNW‐SSE trending stretching lineation (L2). In sections parallel to L2, D2 minor folds display a constant sense of vergence throughout the Ross‐of‐Mull Moine Rocks, overturning generally NW‐NNW. The present day structure is dominated by the almost upright, SSW‐plunging D3 Assapol synform which overprints all earlier structures. Tentative correlation of the deformation sequence with that of Inverness‐shire, suggests that the D1‐D2 structures of Mull, with accompanying moderate‐to‐high‐grade metamorphism, may be Precambrian, while the D3 Assapol synform may be Caledonian.The presence of migmatites of kyanite grade means that metamorphic grade, established during MS1‐MP2, is anomalously high for Moine rocks lying close to the supposed Caldonian front. This suggests that they may lie within one of the higher Caledonian thrust nappes of the North Highland Moine—possibly the Knoydart nappe, where metamorphic grade is comparable. The greenschist facies metamorphism and single phase of deformation affecting the ‘Torridonian’ rocks of Iona presents a significant contrast to the Moine rocks of the Ross of Mull. A major fault in the Sound of Iona is implied, but the Moine thrust itself probably does not outcrop.
A Fissure‐Controlled Acidic Volcanic Centre (Ordovician) at Yr Arddu, North Wales
Authors: Howells M. F. , Campbell S. D. G. , Reedman A. J. , Tunnicliff S. P. 
Published: February 2007

AbstractThe Yr Arddu Tuffs (Ordovician) are a sequence of predominantly welded acid ash‐flow tuffs in the outlier centred on Yr Arddu (North Wales). The tuffs accumulated above a NNE‐trending fracture, the Yr Arddu Fracture, which had previously influenced sedimentation. The heterogeneity of the tuffs and their restricted development suggest that they represent proximal accumulations from small or suppressed (boiling‐over) eruption columns. The eruptions and emplacement developed, at least in the initial stages, in a submarine environment. Lithological, geochemical and palaeontological evidence indicates that the tuffs represent the earliest eruptive phase of the Lower Rhyolitic Tuff Formation. They were later intruded by comagmatic rhyolite domes, whose alignment reflects the continued influence of the early fracture.
The pre‐Caledonian Inishkea Division of northwest Co. Mayo, Ireland: Its geochemistry and probable stratigraphic position
Authors: Winchester J. A. , Max M. D. 
Published: February 2007

AbstractThe dominantly metasedimentary schists and gneisses of the Inishkea Division of the Erris Complex form a distinct rock group, structurally overlying the Grenvillian Annagh Division orthogneisses and underlying Dalradian metasediments, in the northwest County Mayo metamorphic inlier. A regression line for the Inishkea Division schists, defined by Rb–Sr whole rock analysis, suggests a metamorphic age of about 800 Ma, with a provenance age of about 1000–1300 Ma. The major and trace element chemistry is distinct from both the Annagh Division and Dalradian rocks, although sometimes similar to that of the Erris Group, and it suggests that the Inishkea Division originated as greywackes with associated intrusives. Local variations of the chemistry exist, but no systematic subdivision of the Division has been made. Amphibolite pods within the schists are metamorphosed and deformed tholeiite dykes, which are similar in chemistry to the younger metadolerites seen in the Annagh Division. While the geochemistry suggests that the Inishkea Division rocks are similar to both the Moine Assemblage and Grampian Group rocks of Scotland, the isotopic data suggest that they may have been deposited and then initially metamorphosed during the interval between the Grenville metamorphism of the Moine Assemblage and the onset of Dalradian and Erris Group deposition.
The nature and field relations of the Ordovician Maumtrasna Formation, County Mayo, Ireland
Authors: Graham John R. 
Published: February 2007

AbstractThe nature and field relationships of the Maumtrasna Formation of the Partry Mountains, Co. Mayo, show that the formation underlies the regionally mappable Glenummera Formation, which is of Llanvirn age, and it is laterally equivalent to the Rosroe and Derrylea Formations, also of Llanvirn age. The formation rests unconformably on two different volcanic domains, the basic volcanics of the Bohaun Volcanic Formation to the northwest (of unknown age) and the largely acidic volcanics and sediments of the Tourmakeady Volcanic succession to the southeast (Arenig). It is not the youngest formation in the Ordovician succession of the South Mayo Trough, as was previously thought.This largely conglomeratic unit forms a coarsening upward sequence deposited on alluvial fans which were inundated by a marine transgression at the base of the Glenummera Formation. Clasts in the conglomerates are mainly of granite and porphyry with a minor metamorphic component. The source is interpreted as an arc rooted on a metamorphic basement which lay to the south and east. The suggestion that this area was present day Connemara finds little support. This area may expose some of the ‘hidden’ geology of the Midland Valley of Scotland.