bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Superposition of Caledonoid Folds on an Older Fold-System in the Dalradians of Malin Head, Co. Donegal
Authors: Reynolds Doris L. , Holmes Arthur 
Published: May 2009

AbstractIn the Malin Head promontory an Older fold-system, with thrusting and folding about N.W.-trending axes, was followed by Caledonoid folding about N.E.-trending axes. The limbs of the Older folds, both major and minor, now lie in the sheet- dip of the Caledonoid folds, the dips of the Caledonoid limbs being equivalent to the plunges of the axes of the Older folds. Most of the S-planes are shared in common by the two fold-systems. The only exceptions are those that outline the closures and rising parts of the Older fold-system, and these form zones in which the S-planes strike at right angles to the Caledonoid trend. By reference to the outcrop-forms in the area described, and with the aid of plasticine models, it is demonstrated that the outcrop-forms of folded folds are readily recognjzable, and that they provide visible evidence of the approximate axial directions and relative ages of the two fold-systems. By comparative study of outcrop-forms on the models and structures seen in sections cut at right angles to each of the fold-axes, it is found that the structures differ radically from those constructed by projecting the outcrop-forms on planes normal to the axes. The “down-the-plunge” method of viewing a geological map thus provides no clue to the actual three-dimensional structure of folded folds.
A Xenolithic Monchiquite Dyke Near Glenfinnan, Inverness-shire
Authors: Walker G. P. L. , Ross J. V. 
Published: May 2009

AbstractThe remarkable xenolithic dyke described in this paper is one of the little-known swarm of camptonite and monchiquite dykes of probable Permian age in the Northern Highlands of Scotland. It is the first intrusion containing xenoliths of ultrabasic rock to be recorded from the Glenfinnan area, although such xenoliths have been described from vents or intrusions of probable or known Permian age in Caithness in the extreme north of Scotland, and in Ayrshire and elsewhere in the south of Scotland.
Geology and Geography of the London–North Sea Uplands in Wealden Times
Authors: Allen P. 
Published: May 2009

AbstractThe uplands seem to have consisted of an interior highland north of the Thames made principally of Upper Palaeozoic rocks, and a marginal vale-and-scarp lowland of Jurassic strata on the south. This lowland bordered the Wealden morass. Much of the highland exceeded 1,000 feet. It was probably a high-level peneplain resurrected by end-Purbeck earth-movements. Two main rivers entered the swamps and account for most of the detritus. Their probable relations recall those of the contemporary rivers in Belgium.
The Petrogenesis of a Spilitic Rock Series from New Zealand
Authors: Battey M. H. 
Published: May 2009

AbstractWell-preserved examples of spilites show marked affinities with certain tholeiites in texture, chemistry, differentiation trend, and in some aspects of their mineralogy. The presence in them of albite and apparently primary chlorite, in association with unaltered augite, is ascribed to the influence of water as a component of the magma, and the high content of alkali in the basic members to retention of volatile oxides present in tholeiitic magma. Evidence is lacking of large-scale metasomatism by external agencies and the postulate of a special primary magma seems unwarranted. A series may be traced, in rocks of different environments, from “dry tholeiite” to “wet tholeiite” to spilite.Four new rock analyses and one of chlorite are given.
The Pen-y-gader Dolerite and its Metasomatic Effects on the Llyn-y-gader Sediments
Authors: Davies R. G. 
Published: May 2009

AbstractA petrochemical study of the Pen-y-Gader dolerite has been made. The intrusion produced a mild thermal metamorphism in the country sediments and then a late-stage metasomatism affecting the dolerite as well as producing spilosites and adinoles in the country rocks. The main metasomatism involved the introduction of sodium with small amounts of boron and fluorine into the sediments. The range of activity beneath the intrusion was governed by the porosity of the sediments affected, coarsegrained bands being followed for greater distances. The chemical and mineralogical variations within the dolerite have also been compared with those observed in certain of its ophitic neighbours.
The Small-scale Structures of South-Eastern Cowal, Argyllshire
Authors: King Basil C. , Rast Nicholas 
Published: May 2009

AbstractStudy of the small-scale structures of South-Eastern Cowal provides information about the movement history in an assemblage of grits and slates wherein the original sedimentary structures and textures are discernible. A sequence of folds of both Caledonoid (NE–SW) and cross-fold (NW–SE) axial directions can be recognized, with corresponding successive cleavages or schistosities. In the rocks of higher metamqrphic grade towards the axial region of the Cowal anticline the earlier structures are largely obscured by recrystallization.
Depth-Volatile Relations in Coalfields
Authors: Suggate R. P. 
Published: May 2009

AbstractGeneral considerations relating to the use of analyses for determining depth-volatile relations in coalfields are discussed. New evidence from New Zealand is presented and British evidence reviewed. A maximum rate of downward decrease of volatiles is inferred at 23 per cent volatiles, and a depth-volatile band from 42 to 5 per cent volatiles is presented. British coalfield sequences fit the band, rendering unnecessary the complex geological explanations for differing rates of downward decrease of volatiles given by previous authors. Tectonic pressure is rejected in favour of depth of burial as a cause of rank differences.
The Hecla Hoek Succession in Ny Friesland, Spitsbergen
Authors: Harland W. B. , Wilson C. B. 
Published: May 2009

AbstractA stratigraphical outline of the Hecla Hoek succession summarizing post-war work in Ny Friesland is presented for the first time. This shows a geosynclinal series of sediments reaching down at least 15,000 m. below Cambrian in a more or less continuous succession. It is compared with other Hecla Hoek successions in Svalbard.
Structural Geology of the Manx Slates
Authors: Gillott J. E. 
Published: May 2009

AbstractStructures including folds, cleavages, faults, joints, and lineations are described. Three periods of folding are distinguished to which three cleavages are related. In order of decreasing age the cleavages are flow-cleavage, fracture cleavage, latest fracture cleavage. The main fault systems trend north-north—east, approximately east—west, and north-west. Joints follow two principal directions. These are north-west—south-east, and north-east—south-west. The dominant lineation is north-east—south-west. At right angles to this is a north-west—south-east lineation which affects all visible foliation. It is confined to a faint crinkling.
Notes on the Cheiruracea and Phacopacea
Authors: Temple J. T. 
Published: May 2009

AbstractThe cephalic characters which the post-Cambrian trilobite families Encrinuridae, Pliomeridae, Cheiruridae, and Phacopidae have in common are discussed, together with others which illustrate the distinctness of the Phacopidae. The importance of growth-rate studies is emphasized, particularly with reference to the frontal lobe of the glabella. The Calymenidae share most of the features common to the Cheiruracea and Phacopacea, and are considered to be closely related to them, and the Odontppleuridae also share certain features. The possibly neotenous origin of the Cheiruracea and Phacopacea is discussed.
Monelasmina besti, a new Schizophoriid Brachiopod from the Upper Devonian of Western Canada
Authors: Pedder A. E. H. 
Published: May 2009

AbstractMonelasmina, previously known only from the Frasnian of Europe, is described and figured from the Hay River formation (Frasnian) of the Northwest Territories, Canada. The specimens are referred to a new species, M. besti.
Cross-Folding in the Gramscatho Beds at Helford River, Cornwall
Authors: Lambert J. L. M. 
Published: May 2009

AbstractMinor folds in the Gramscatho Beds at the mouth of the Helford River have two predominant trends: W.S.W.-E.N.E., and N.W.-S.E. Main folds on W.S.W.-E.N.E. axes and cross folds on N.W.-S.E. axes have sub-parallel apical planes and occur in alternate zones which trend N.E.-S.W., parallel to the strike of the cleavage. The relations between the two systems of folding suggest that they are virtually synchronous.It is concluded that the style of folding can be explained by a unidirectional regional stress acting normal to the apical planes of the folds.
The Ammonite Zones of the Middle Jurassic Beds of East Greenland
Authors: Callomon J. H. 
Published: May 2009

AbstractNew discoveries have established the presence of nine ammonite zones in the Middle Jurassic beds of East Greenland. The top two are Lower Callovian; the remaining seven yield ammonites unknown from extra-Boreal provinces and are presumed to range down through the Bathonian, possibly into the Bajocian.
Ptygmatic Structures and their Formation
Authors: Wilson Gilbert 
Published: May 2009

AbstractThe conditions under which ptygmatic veins develop occur when the country-rock—as in a granitized area—is locally less competent or more yielding than quartzo-felspathic magma which may intrude it. Veins therefore which are being driven forward by pressure from behind, will buckle plastically if they encounter a resistance during injection, and a succession of such buckles will produce a typical ptygmatic vein. The amplitudes of the flexures so formed depend on the relative physical states of the vein and host-rock; so for any particular vein there is usually a more or less constant size for the tortuosities developed. The mechanism explains several features observed in examples of ptygmatic veins, and has been reproduced experimentally in the laboratory. The contortions are therefore not necessarily due to the deformation of the veins by post-injection flowage or tectonic movements of the country-rock.
An Unusual Appinitic Sill Near Killin, Perthshire
Authors: Harry W. T. 
Published: May 2009

AbstractAn unusual appinitic sill intrudes and thermally alters regionally metamorphosed Dalradian sediments near Killin, Perthshire. The sill is composed of ultrabasic, basic, dioritic, and acid varieties, the last two being present only in minor quantity. The dioritic intrudes, and is chilled against the ultrabasic type. The appinitic varieties and contact Dalradian rocks are described together with their field relationships.
A Study of Granite Relief from South-West Africa
Authors: Mabbutt J. A. 
Published: May 2009

AbstractThe writer describes the relief forms and destructional processes occurring in a group of granite hills in Damaraland, South-West Africa. The hills are attributed to the dissection of a former erosion surface by rejuvenated streams. Drainage incision has followed longitudinal and diagonal joint lines, which control the orientation and sub-division of individual groups of granite domes. The destruction of granite masses by plating, or the unloading of Unweathered shells, produces the dome outline, whereas the development of vertical jointing leads to granite tors. Domes may be cleaved along transverse joints to form secondary domelets, or split longitudinally to form narrow whalebacks. The former are lowered by plating to flat dome forms the latter are reduced by marginal fracturing, here termed mural weathering. Further wastage is by slow granular disintegration on low granite outcrops.
The Moinian Inlier of Rosses Point, near Sligo, Eire
Authors: Lemon G. G. 
Published: May 2009

AbstractThe following note provides the first detailed description of an inlier of metamorphic rocks occurring in the core of an anticline of Carboniferous Limestone at Rosses Point, three miles north-west of Sligo.The metamorphic rocks are shown to belong to the kyanite zone; comparison with the Lough Derg area suggests a Moinian Age.
Notes on some Pleistocene Sections at Barrington, Cambridgeshire
Authors: Sparks B. W. 
Published: May 2009

ABSTRACTValley fill exposed in chalk pits at Barrington consists of two beds, which differ markedly in lithology and in the nature of the molluscan fauna contained in them. The lower bed is thought to predate the Boulder Clay, which caps the high ground, and the upper bed is considered to have been derived from the Boulder Clay. The lower bed, a chalk solifluxion, apparently spread into the Cam valley and covered the famous Hippopotamus bed. Both the Hippopotamus bed and the present depth of the Cam valley, therefore, probably predate the Boulder Clay.
Carbonatite Structure: Tororo Hills, Eastern Uganda
Authors: Williams C. E. 
Published: May 2009

AbstractThe carbonatite plugs of Eastern Uganda represent the final phase of Elgon type volcanoes. The types of structure observed in the carbonatites are discussed and a general description of the structural components of the Tororo Hills is given. It is suggested that the ring features originated through the congealing in the conduit of the central portion of the carbonate mass.
The Great Glen Crush-Belt
Authors: Eyles V. A. , MacGregor A. G. 
Published: May 2009

AbstractThis paper provides field and petrographic evidence believed by the authors to indicate that the Great Glen, over a lateral distance of some 40 miles between Fort William and Foyers, is flanked on the south-east by a broad crush-belt characterized by intense cataclasis and localized mylonitization. Most of the detailed evidence has not previously been published.
On the Early Pebble Gravels of the Thames Basin from the Hertfordshire-Essex Border to Clacton-on-Sea
Authors: Warren S. Hazzledine 
Published: May 2009

AbstractThe erratic rocks of the early pebble gravels are similar to those of the Oxford plateau drift, and reasons are given for concluding that they belong to the drifts of the proto-Thames, and are earlier than the southward diversion of that river by an advancing ice-sheet. Comparisons with the constituents of the later deposits of the Clacton channel are also discussed.
Cross-folds
Authors: Rast N. , Platt J. I. 
Published: May 2009

AbstractMany recent investigators report the presence of “ cross-folds ” in mountain chains. The common right angle relations between such folds and the main trends suggest that they are genetically allied. Following the original suggestion of Argand, it is proposed that the superficial cross-folds are due to basement control (passive segmentation), whereas those in the deeper parts of geosynclines have been brought into being by the limitations of space (active segmentation).
On the Relationship between Migmatization and Structure in Mid-Strathspey
Authors: Mackenzie David H. 
Published: May 2009

AbstractThe distribution and form of the products of migmatization in the area are described and the close relationship between migmatization and folding in time and space is demonstrated. Synoptic diagrams of the linear structural elements for various parts of the area are given. The sheaves of β-axes, small folds and lineations widen with increase in migmatization, presumably due to increasing mobility of the rocks during the migmatization process.
The Goniatite Girtyoceras cf. weetsense Moore from the shales above the Jew Limestone, Northumberland
Authors: Johnson G. A. L. 
Published: May 2009

AbstractA new Yoredale goniatite locality in the shales above the Jew Limestone (Lower Carboniferous) at Temon, near Greenhead, Northumberland, has yielded a fauna including Girtyoceras cf. weetsense Moore; a lower P2 age (Bollandian) is indicated. The fauna and lithology of the goniatite-bearing shale is described and the lateral correlation of the Jew Limestone discussed. It is suggested that the base of the Jew (= Hardraw = Oxford) Limestone is the most satisfactory horizon for the P1–P2 boundary in the northern Pennines.
The Aberfoyle Anticline, Callander, Perthshire
Authors: Stone M. 
Published: May 2009

AbstractThe succession in the Upper Dalradian is described. The author follows Anderson in correlating the Leny and Ben Ledi Grits. Way-up evidence indicates that the Leny Limestone does not occupy a syncline as previously supposed, but is a stratigraphical intercalation in the Leny Grits. It is shown from way-up evidence and structural analysis that the Aberfoyle Anticline closes downwards and is a synform.
Salterolithus caractaci (Murchison) from Caradoc Strata near Welshpool, Montgomeryshire
Authors: Cave R. 
Published: May 2009

AbstractMaterial belonging to the genus Salterolithus has been examined from Trilobite Dingle, Welshpool, and it is found that S. caractaci and S. intermedius (Wade 1911) are conspecific, the older name taking priority. Trilobite Dingle is the type locality for S. intermedius and also for the restricted species caractaci. A new variety is established for the forms occurring slightly higher in the sequence than S. caractaci.
The Lustleigh Fault in North-East Dartmoor
Authors: Blyth F. G. H. 
Published: May 2009

AbstractThe north-eastern area of Dartmoor is traversed by a series of straight valleys which follow fault lines. One fault-system, which crosses the granite from near Lustleigh north-westwards to Stickle-path, is described in detail, and its relationships to structures in a wider area are briefly discussed.
The contact between Tertiary Granophyre and Torridonian Arkose on Minishal, Isle of Rhum
Authors: Hughes C. J. , Wadsworth W. J. , Emeleus C. H. 
Published: May 2009

AbstractRe-examination of the contact between granophyre and arkose on Minishal, Isle of Rhum, shows it to be a tectonic junction in which the effects of crushing and shearing have been largely obscured by contact alteration.
Downtonian (Silurian) Eurypterida from Perton, near Stoke Edith, Herefordshire
Authors: Kjellesvig-Waering Erik N. 
Published: May 2009

AbstractIn this review of the Downtonian Eurypterida of Perton, Here-fordshire, a new genus Salteropterus and a new family Hugh-milleriidae are proposed, and the family Pterygotidae accordingly emended. Hitherto unknown morphological details of the Perton Eurypterida are described and discussed.
Varying Trends in the Metamorphism of Dolerites
Authors: Sutton John , Watson Janet 
Published: May 2009

AbstractThe metamorphism of Pre-Cambrian dolerites in the Northwest Highlands is described and compared with that of basic rocks in the Southwest Highlands, Banffshire and other regions. The first products of metamorphism are not the same in every area. It is suggested that the trend of regional metamorphism differs according to the environment in which it took place, and that a sequence of changes established in one area cannot be used as a standard by which to judge the changes in other areas. In particular, rocks of high metamorphic grade have not invariably passed through stages characterized by low-grade minerals.
The Production of Amphibolic and other Skarn Rocks from Limestone at Cor, Co. Donegal
Authors: Gindy Amin 
Published: May 2009

AbstractDiopside-skarns, epidote-skarns, and garnet-skarns together with very coarse amphibole-rocks are produced at the contact of limestone and epidiorite by diffusion of trondhjemitic material along the contact. The amphibole-rocks are unusual types, for the formation which material may have been drawn from the epidiorite side the contact.
Evidence Bearing on the Age of the Saline Series in the Salt Range of the Punjab
Authors: Ghosh A. K. , Sen J. , Bose A. 
Published: May 2009

AbstractThe Punjab Saline Series has been assigned to the Cambrian and also to the Eocene. Gee has described field evidence which points to a Cambrian age, but Sahni has found microscopic plant and insect remains which have been interpreted as demonstrating an Eocene age. The application of Schultze's technique (also adopted by Sahni) to samples from the undoubted Cambrian rocks of the Salt Range has shown that these too occasionally contain a microflora which includes elements that are not so far known to be indigenous to Cambrian rocks. Its occurrence awaits explanation.
A Monchiquite Vent, Stob a' Ghrianain, Inverness-shire
Authors: Hartley J. , Leedal G. P. 
Published: May 2009

AbstractA description is given of a monchiquite vent which cuts Moine rocks in Inverness-shire. Similar vents considered to be of Permian age are common in the Midland Valley of Scotland and the Orkney Islands but no example has yet been described in detail from the Highlands.
An Occurrence of Orbicular Structure, of Metasomatic Origin, in the Gold Coast.
Authors: Conybeare C. E. B. 
Published: May 2009

AbstractOrbicules consisting of cores of pargasite and epidote with rims of plagioclase, in a matrix composed mainly of pargasite, plagioclase, and epidote, are described and attributed to the metasomatic action of alkaline fluids permeating crushed amphibolite.
Scourie Dykes and Laxfordian Metamorphism
Authors: Bailey E. B. 
Published: May 2009

AbstractA review is offered of some of the conclusions reached by Teall and his Survey colleagues on the Lewisian Complex of the North-West Highlands, especially such as have been strengthened by recent work by Sutton and Watson. In other directions support is given to Peach and Gunn's view that the Loch Maree sediments are later than the Scourie Dykes and not, as dough tentatively suggested, intruded by sills fed from these dykes; also new hypotheses are advanced concerning Laxfordian folding of the Scourie Dykes at Loch Maree, and Caledonian thrusting of Assynt type of Lewisian over Laxford type at Durness.
Chalcedony and Flint
Authors: Midgley H. G. 
Published: May 2009

AbstractThe possibility of interaction between the alkalies in cement and flint and chalcedony has made it necessary to investigate the constitution of these minerals. It had always been thought that these minerals were a mixture of quartz and opal, but experiments have led to the belief that this is not true and that the minerals are composed of a quartz network with a large number of micropores.
The Place of the Trimingham and Norwich Chalk in the Campanian-Maestrichtian Succession
Authors: Jeletzky J. A. 
Published: May 2009

AbstractThe Maestrichtian is considered an independent stage younger than and equal in rank to the Senonian stage; in its type-area it includes, besides the Maestricht Tuff, such older formations as the Chalk of Ciply and of Spiennes, the Kunrade Limestone, upper beds of the Gulpen Chalk, and even some part of the Hervian Greensands. The zone of Pachydiscus egertoni forms the base of the Maestrichtian stage.In its type locality the Campanian stage includes the zone of Bostrychoceras polyplocum; at the same time its uppermost beds are at any rate not older than the uppermost beds of the Senonian stage in its type area. The zone of B. polyplocum thus forms a part of the Senonian stage.The true Belemnella lanceolata (Schloth.) is restricted to the Trimingham Chalk. Belemnitella ex. gr. mucronata (including “Belemnites lanceolatus” von Sharpe and Blackmore non Schloth.) are, on the contrary, all but confined to the Norwich Chalk and older beds of the English Upper Chalk. Accordingly, a new zonal name “Zone of Belemnella lanceolata” is recommended for the Trimingham Chalk, and the zone of Belemnitella mucronata should, in the opinion of the writer, be restricted to beds older than the Trimingham Chalk.The Trimingham Chalk is assigned to the Lower Maestrichtian, while the Norwich Chalk represents the Upper Campanian (including the B. polyplocum zone).
New names for the Trilobite Genera Menevia Lake and Psilocephalus Salter
Authors: Stubblefield C. J. 
Published: May 2009

AbstractMenevia and Psilocephalus are names in current use for two genera of Trilobites respectively occurring in the Middle Cambrian and Tremadoc rocks of Wales; both are now known to be invalid, having previously been used for other animals, and the new names Meneviella and Psilocephalina are proposed to replace them.