bluuebunny/crossref_metadata_2025 huggingface dataset:
Tear Faults in the Barnesmore area, Donegal
Authors: Leedal G. P. , Walker G. P. L.
Published: May 2009

Tear faults cutting the Barnesmore Granite in County Donegal are described. The Lough Belshade fault trends N.E.–S.W., and there has been a lateral movement along it in a left-handed or sinistral sense of 2·2 miles; it is believed to be of the same age as the Great Glen Fault. The Barnes Lough Fault crosses and displaces the Lough Belshade fracture, and may be, in part at least, Tertiary. Although the movement along it is much smaller, it has taken place in the opposite sense.
A Study of Calcite Twinning in the Strathavon Marble, Banffshire
Authors: Clark R. H.
Published: May 2009

It is possible, from study of twinned calcite grains in a thin section of marble, to locate the most probable positions of the applied stresses likely to have caused the twinning. By this means inferences may be drawn as to the stress system operative during the late stage deformation of the marble.

Marble outcrops over an area of about 5 square miles, in the Tomintoul region of the Scottish Highlands, have been investigated. It has been found that a consistent stress pattern exists for the area as a whole. The calcite twinning can best be explained by a N.E.–S.W. compression applied normal to the trend of the regional fold axis, followed by a mild N.–S. squeeze.
On the Occurrence of Anthraconauta tenuis (Davies and Trueman) in North Staffordshire
Authors: Myers J.
Published: May 2009

The finding of Anthraconauta tenuis (Davies and Trueman) at Etruria, North Staffordshire, just above the basal limestone of the Newcastle-under-Lyme Beds suggests that the base of the Tenuis Zone, hitherto placed at the base of the Keele Beds, should be brought down to the base of the Newcastle-under-Lyme Beds.
The Petrography of Dickitic Sandstones in North Wales and Northern England
Authors: Smithson Frank , Brown George
Published: May 2009

The clay mineral, dickite, is a common rock-forming mineral of many Carboniferous sandstones in North Wales and Northern England and of Middle Jurassic sandstones over much of North-East Yorkshire. It occurs as well-shaped authigenic crystals associated with highly altered mineral assemblages, including partly dissolved feldspar which is one of the probable sources of the alumina and silica.
Thrusting and other movements in the Durham Permian
Authors: Trechmann C. T.
Published: May 2009

The Permian in Durham is the most internally disturbed of the newer or covering beds of England. In deep borings it is a dark dolomitic rock full of sulphates and chlorides; at the surface it has quite a different appearance. The Permian and overlying Secondary beds seem to have been lowered by downwarping. During the subsequent differential uplift and denudation the area remained a land surface and the sulphates were removed by penetrating water, not by subaerial weathering. Horizontal and low angle thrusts occur in the Sunderland area above about the middle of the underlying Coal Measure basin. The movements may have been induced by diminution in rock volume following solution and segregation accompanied by attraction or packing together of the mass of the formation.
Solution Subsidence Outliers of Millstone Grit on the Carboniferous Limestone of the North Crop of the South Wales Coalfield
Authors: Thomas Trevor M.
Published: May 2009

A record has been made of the outliers of Basal Grit occurring on the Limestone of the North Crop of the South Wales Coalfield, some of which have not previously been located. The solution subsidence theory to account for their present anomalous levels when compared with the parent Grit outcrop to the south has been enlarged upon, and an attempt has been made to determine the mechanism of this subsidence which ranges in vertical extent up to a maximum of approximately 600 feet. The outliers are of economic importance since their predominant crumbly quartzose sandstones are a source of almost pure silica sand.
Negative Gravity Anomalies over Acid “Intrusions” and their Relation to the Structure of the Earth's Crust
Authors: Bott M. H. P.
Published: May 2009

The results of gravity surveys over various exposed and buried acid intrusions are summarized. Some sample density determinations are discussed. It is found that the acid intrusions considered are almost invariably associated with negative Bouguer anomalies, which are certainly often caused by direct density contrast between the less dense acid intrusive, and the denser country rock. This has two immediate implications. (1) Large negative Bouguer anomalies over “granites” may suggest magmatic origin. (2) These gravity anomalies, supported by seismological and seismic evidence, and the petrological distribution of igneous rocks, lead to the postulation of a denser “metasedimentary” layer overlying the “granitic” layer. The bearing of this on the mechanism of intrusion is briefly discussed.
Bajocian Ammonites Collected by Sir Henry Hayden near Kampadzong, Tibet
Authors: Arkell W. J.
Published: May 2009

Seven species of ammonites from the Lungma Limestone of Tibet are described and figured. The assemblage is Middle Bajocian, of the Sowerbyi and Sauzei Zones, and possible also Humphriesianum Zone, and indicates that the formation is condensed. Its affinities are chiefly with European faunas, but it has one species in common with the Pamirs and another with Western Australia.
Current-Bedding in the Moine Series of North-Western Scotland
Authors: Wilson Gilbert , Watson Janet , Sutton John
Published: May 2009

This note records a number of observations of orientation of current-bedding in the Moine Series of Inverness-shire, Wester Ross and Sutherland, in the North-Western Highlands of Scotland. The foreset beds have been found to have a dominant dip towards the north, thus suggesting that the Currents responsible for the transport of the material forming these beds flowed from the south.
A Metamorphic Boundary in the Moine Schists of the Morar and Knoydart Districts of Inverness-shire
Authors: Lambert R. St. J.
Published: May 2009

A re-examination of the Moine—Sub-Moine boundary of the Morar dome shows it to be a zone of transition between two metamorphic states. Some notes on the structure accompany a mineralogical description of the changes across the boundary; discussion is made of evidence that the metamorphic boundary transgresses the geological boundaries. The schists of the core are thought to be in a lower metamorphic state than those of the envelope.
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

In 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

The 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

The 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

Well-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

A 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

Study 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

General 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.
Preliminary Notes on the Geology of Kilimanjaro
Authors: Wilcockson W. H.
Published: May 2009

A preliminary account of the geological results of an expedition to the volcanic massif of Kilimanjaro is given. The structure and succession at each of the main eruptive centres is described. The probable ages of volcanicity are discussed.
The Hecla Hoek Succession in Ny Friesland, Spitsbergen
Authors: Harland W. B. , Wilson C. B.
Published: May 2009

A 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

Structures 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

The 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.
An Old Red Sandstone-Carboniferous Limestone Series Junction at Tongwynlais, North of Cardiff
Authors: Evans W. D. , Cox A. H.
Published: May 2009

This paper records details of measured sections across the Old Red Sandstone-Carboniferous junction in the neighbourhood of Cardiff.
Monelasmina besti, a new Schizophoriid Brachiopod from the Upper Devonian of Western Canada
Authors: Pedder A. E. H.
Published: May 2009

Monelasmina, 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

Minor 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

New 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

The 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

An 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

The 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

The 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

Valley 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.
On some Spore Specimens from British Upper Carboniferous Coals
Authors: Balme B. E.
Published: May 2009

Eight spore types from Upper Carboniferous coals of Britain are described and figured, and their stratigraphical distribution and possible relationships are discussed. One new genus and five new species are instituted.
Carbonatite Structure: Tororo Hills, Eastern Uganda
Authors: Williams C. E.
Published: May 2009

The 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

This 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

The 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

Many 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

The 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

A 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

The 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

Material 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

The 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

Re-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

In 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

The 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

Diopside-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

The 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

A 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

Orbicules 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

A 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

The 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

The 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

Menevia 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.
A Redescription of some Type Specimens of British Ordovician Bryozoa
Authors: Spjeldnæs Nils
Published: May 2009

Five species of Ordovician Bryozoa are redescribed, based on the type specimens of Lonsdale (in Murchison, 1839: “Favosites fibrosa” (1843: “Ptilodichtya” dichotoma), Phillips (1848: “Favosites” favulosa), and McCoy (1850: “Nebulipora lens” and “Ptilodichtya explanata”). Six other species are discussed and some of them figured, but the preservation of the material does not allow a complete redescription of them.
The Lower Hecla Hoek Rocks of Ny Friesland, Spitsbergen
Authors: Bayly M. B.
Published: May 2009

The Lower Hecla Hpek rocks of Ny Friesland are described petrographically, and evidence is presented relating to some granitic rocks in this group whose mode of origin is uncertain.
Apparent Coincidences in the Life-history of the Moine Schists
Authors: Phillips F. C.
Published: May 2009

A review of the progress of knowledge concerning the Moine Schists shows that, whereas about twenty years ago many geologists supported Horne's contention that the Moine sediments were pre-Torridonian, there has been recently a marked swing towards Peach's view that they are the equivalents of the Torridonian. The interpretation of the structural petrology of these schists in the light of this change of opinion is then discussed.
Sedimentary Differentiation as a Factor in the Moine-Torridonian Correlation
Authors: Kennedy W. Q.
Published: May 2009

The chemical differences which exist between the Moine and Torridonian rocks of the Scottish Highlands are of the same nature and order of magnitude as those between extreme end members of the Norwegian Sparagmite Formation. It is concluded that in Scotland, as in Norway, a unilateral trend of sedimentary differentiation operated from north-west to south-east across the direction of the Caledonian geosyncline and led to chemical grading of the arenaceous sediments transverse to the trend of the late Pre-Cambrian depositional basin.
An Unusual Pyroxene-rich Xenolith in the Diorite of the Glenelg-Ratagain Igneous Complex
Authors: Nicholls G. D.
Published: May 2009

A xenolith composed essentially of green pyroxene, microperthitic potash felspar, sphene, apatite, and iron ore, has been discovered in the diorite of the Glenelg-Ratagain igneous complex. it is believed to be an impregnated skarn rock associated with igneous activity earlier than the intrusion of the diorite. Introduction of P, Ti, and Na is considered to be important in the formation of the skarn.
Notes on Thecal Variation in Monograptus
Authors: Bulman O. M. B.
Published: May 2009

Thecal modifications in certain Monograptids are discussed on a basis of restorations which distinguish the theca from the remainder of the “thecal segment” of Törnquist. There seems little support in those bi-form Monograptids examined for the view that the less modified thecae reflect an incomplete development, and in general the new thecal types appear to represent transformations which commonly originate proximally or at least are more highly developed proximally. A possible analogy between this colonial development and metamerism is suggested.
The Age of the Malvern Folding
Authors: Mykura W.
Published: May 2009

New floral and lithological evidence from the tongue of Coal Measures extending from the Wyre Forest Coalfield into the northern part of the Abberley Chain establishes that the eastward overturning along the Malvern axis is of late- or post-Morganian age. Minor folding along this axis may have taken place prior to the deposition of the Upper Coal Measures. This, however, had little topographic effect as during the deposition of the Upper Coal Measures the northern end of the Malvern axis remained an area of relatively rapid subsidence.
A Note on the Occurrence of Intergrowth between Diopsidic Augite and Albite and of Hydrogrossular from King Island, Tasmania
Authors: Scott Beryl
Published: May 2009

A description is given of an intergrowth between augite and albite found in Spilitic lavas from King Island, Tasmania. Hydrogrossular is found pseudomorphing olivine and also in veins and vesicles in certain rocks of the same volcanic suite.
On the Direction of Certain Valleys
Authors: Harrison K. , Thackeray A. D.
Published: May 2009

In 1907 there appeared a memoir by F. W. Harmer, in which he suggested that a number of gorges—those at Malton and Ironbridge among them—might have originated as spillways consequent upon the blocking of the natural line of drainage by glaciers. A few years previously, Professor Kendall (1902) had interpreted some abandoned valleys in Yorkshire on the same hypothesis; a further exposition was given by Kendall and Wroot in 1924. In the present paper we propose a more fundamental origin for these channels.
Some Aspects of the Distribution and Migration of Trilobites in the British Lower Palaeozoic Faunas
Authors: Stubblefield C. J.
Published: May 2009

Certain conclusions on distribution and migration have been reached by Dr. W. K. Spencer2 from his detailed studies of Palaeozoic Asterozoa and in conversation he has frequently expressed the wish that he might be able to compare these with data derived from similarly focused studies of other animal groups. It is reasonable to assume that the final story of migration of faunas in the Lower Palaeozoic British area cannot be told until the inequalities of fossil-collecting and naming have been overcome and until more is known of the stratigraphical position of certain faunas; any conclusions made at the present stage are tentative and are offered as an incentive to research.
Upper Gault near Aylesbury, Bucks
Authors: C. W.  , Wright E. V.
Published: May 2009

During the summer we paid two visits to the site of a sewer trench that was being dug from Aylesbury along the London Road towards Tring. At the time of our visits excavation was being carried on in the village of Aston Clinton.
The Mica-Pegmatites of Kodarma, India
Authors: Roy S. K. , Sharma N. L. , Chattopadhyay G. C.
Published: May 2009

The mica mines of the Kodarma area in the Hazaribagh district of Bihar contribute as a single unit the largest quantity of muscovite (locally known as “Ruby mica”) to the world. The mica-pegmatites of this area have attracted the attention of geologists and mining engineers since the beginning of the last century, but still many petrological problems connected with them have not been satisfactorily solved. During recent years the present authors have studied the geology of the Government Reserve Forest of Kodarma; and they intend to discuss in this paper the origin and the characteristic features of the Kodarma pegmatites and to review the literature already existing on this subject.
On a Collection of Reptilian Bones from the Oolite of Stow-on-the-Wold, Gloucestershire
Authors: Reynolds S. H.
Published: May 2009

Reptilian bones, first observed by Mr. C. I. Gardiner in 1935, are found in two quarries in the Chipping Norton Limestone (top of Inferior Oolite,fuscaandzigzaghemerae). These two quarries are the New Park Quarry, about 2½ miles N.W. of Stow-on-the-Wold, and the Oakham Quarry which lies about a mile W.N.W. of Little Compton. The bones occur in a hard cream-coloured limestone which is worked for road-metal. Fossils other than reptilian remains are not common, but among those found in the New Park Quarry is an ammonite determined by Mr. J. W. Tutcher asParkinsonia neuffensisOppel. The great majority of the bones come from the New Park Quarry, but the Oakham Quarry yielded certain of the crocodilian, theropod, and sauropod bones.
On Certain Aspects of the Physiography of the Coast Ranges of Kenya Colony, near Mombasa
Authors: Busk H. G.
Published: May 2009

It will have been observed in our consideration of the physiography of the north-eastern corner of the Northern Frontier Province of Kenya Colony that there is strong evidence in support of the existence of fault scarps, which date their first uprising from the Jurassic age. The evidence in the Coast Province in the neighbourhood of Mombasa is not so clear, but if we examine this in the light of that from the northern frontier, it will be seen that there is a strong suspicion that the coast ranges, too, are horsts, dating their first rise from the Jurassic.
A Miocene Limestone from Cyprus
Authors: Reed F. R. C.
Published: May 2009

The western peninsula of Cyprus, which is known as Akama or Akamas, is somewhat inaccessible and its geological features little known. It was not visited by the present writer in 1929, but Mr. C. P. Manglis, mining engineer of Nicosia, has recently traversed it and collected specimens of a fossiliferous Miocene limestone with interesting characters in places where no fossils had previously been found, and he informs me that a ridge of the Trypanian Series outcrops along the central part of the peninsula (though this is not indicated on Bellamy's map), and that there is also an abundant effusion of andesitic lavas. The limestones are white in colour and mostly hard, compact, or semicrystalline; they contain massive compound corals, generally in a poor state of preservation, their internal structure being often largely obliterated. Apart from corals, the rocks have only yielded a few large boring Lithodomi and some indeterminable small fragmentary impressions or casts of small gasteropods and lamellibranchs. It is to be remarked that Gaudry recorded' from the Miocene of Cyprus only one species of coral, Astraea [Orbicella] guettardi Defr., and that was from another part of the island. But limestones containing corals similar to those collected by Mr. Manglis occur in various parts of the Mediterranean basin, and we may especially compare those species described by Felix, Daus, Schaffer, Oppenheim, Blanckenhorn, Gregory, and Kühn from the Miocene of Asia Minor, Syria, Persia, Egypt, and Cyrenaica. The Miocene corals of Cilicia appear to be in, many cases identical with those in this collection, and bearing in mind the proved tectonic relations of Cyprus with the mainland, this is what we should expect. The literature on these Miocene corals is very extensive, and Kiihn has recently (Palaeontographica, lxxix, Abt. A, 1933) given a useful list of references which have been consulted in identifying the specimens in this collection.
The Yorkshire Dogger
Authors: Rastall R. H. , Hemingway J. E.
Published: May 2009

In an earlier paper in this magazine it was stated that we were then engaged on a general study of the Yorkshire Dogger. This subject has proved to be so complicated and far-reaching that it is not possible to present all the results in a single paper of any reasonable length. Moreover, as will be seen later, owing to noteworthy local changes in lithology of the Dogger and to its stratigraphical relations certain very definite types can be recognized, characteristic of large and well-marked areas. This feature lends itself readily to serial publication and the present paper deals with the most accessible, if not perhaps the most interesting area, namely the coast from Peak (Ravenscar) to Saltburn. This part of the outcrop is referred to for convenience as the coastal Dogger.
The Yorkshire Dogger
Authors: Rastall R. H. , Hemingway J. E.
Published: May 2009

The Dogger of the coast from Peak to Kettleness is essentially a sideritic sandstone, and except in the Sandsend-Mulgrave district, is entirely unfossiliferous. This type of coast Dogger is well exposed at Hawsker Bottoms. To the naked eye it is a brownish sandstone of fine grain with very abundant white specks, a few small lenses of pale grey mudstone, and a very small number of bright green grains. Under the microscope it is seen to be a fairly well-graded sandstone with a few larger clastic elements, including both quartz and felspar as well as those mentioned above. The quartz grains are extraordinarily angular, doubtless due to corrosion by the matrix, and many of them are compound, i.e. microquartzites of various kinds. Felspar, mainly orthoclase and perthite, is abundant. A few flakes of chloritic chamosite and still more rare grains of typical speckled glauconite represent the green grains mentioned above. The matrix is somewhat oxidized, but still shows the usual well-formed rhombohedra of siderite, most of them with darker cores. The most notable point is that the sand grains rarely touch and are often widely spaced in the matrix, indicating simultaneous deposition of clastic elements and matrix, which is not a cement in the usual sense (Text-fig. 5). In this and in subsequent papers the term “ cement ” is used to connote that interstitial bonding material subsequently added to a bed of incoherent detrital grains which were lying in contact with each other before its infiltration : “ matrix ” is used for that interstitial material between detrital grains which are not in contact and which was therefore deposited contemporaneously with them, forming a part of the original sea floor deposit.
Foraminifera in Boulder Clays from the Wexford Coast of Ireland (With a note on the generic name Streblus Fischer)
Authors: Macfadyen W. A.
Published: May 2009

Four samples were sent to me by Mr. A. Farrington, two pairs collected from separate boulder clays, in each of two localities. The purpose was to investigate whether it would be possible to differentiate the two clays by their respective content of microfossils.
A Note on the Genera Staurocephalus and Sphaerocoryphe, with the Description of a New Species of Sphaerocoryphe
Authors: Begg J. L.
Published: May 2009

There has been some confusion between the trilobite genera Staurocephalus and Sphaerocoryphe. This is probably due to a similarity in the bulbous character of the anterior glabellar lobe common to both genera as well as to the genus Deiphon and the Australian form Onycopyge. King (1920, pp. 532–4), in view of the character of a hypostome of Staurocephalus preserved in the British Museum and figured by Salter, was of opinion that this genus should be removed from the Cheiruridae, but hesitated to place it in the Encrinuridae. Raymond, in Eastman's Zittel (1913, p. 725), includes Staurocephalus and Sphaerocoryphe in his subfamily Deiphoninae, which he defines as Cheiruridae with a bulbous anterior lobe. His diagnosis of Staurocephalus is “Glabella with two pairs of lobes behind the bulbous portion. Cephalon with a denticulate border, and pygidium similar to that of Pliomera”. Sphaerocoryphe has only one pair of lobes behind the bulbous anterior lobe. It is necessary to consider the characteristic features of the genotypes of the two genera.
The Composition and Properties of Shore and Dune Sands
Authors: Barrett W. H.
Published: May 2009

This work was undertaken in an attempt to assess the significance of minor variations in composition and properties of sand samples collected from the same locality and derived from a common source.
Some Lower Palaeozoic Contacts in Pembrokeshire
Authors: Jones O. T.
Published: May 2009

During the excursion of the Sedgwick Club to Pembrokeshire at Easter this year the junctions between certain of the rock groups were examined under unusually favourable conditions with interesting results.
The Geology of British Oilfields 2. The Geology of the Oilfields and some Prospective Oil Areas in Canada
Authors: Hume G. S.
Published: May 2009

Petroleum is produced in Canada in New Brunswick, Ontario, North-West Territories, and in Alberta. Recently a new oilfield has been opened up on the Alberta-Saskatchewan boundary at Lloydminster. Prospecting at the present time is also being undertaken in Gaspe Peninsula of Quebec and in the Peace River Block of British Columbia.
Age Determination of Carboniferous Basic Rocks of Shropshire and Colonsay
Authors: Urry W. D. , Holmes Arthur
Published: May 2009

The helium method of determining the ages of fine-grained basic igneous rocks has now been so far developed as to be applicable to various geological and petrological problems, particularly where geological periods are involved, as in the problem here discussed. For details of the history of this development up to the beginning of 1937 reference may be made to Holmes, 1931; Urry, 1933; Lane and Urry, 1935; Urry, 1936 (b); Holmes and Paneth, 1936; and Holmes, 1937. During 1937 it was found that many of the helium-ratios on which the ‘helium’ time-scale had been based were too high, because of a previously unsuspected error in radium determination due to reliance having being placed on a radium standard which was seriously at fault. To clear up this embarrassing situation an immediate effort was made by several investigators in collaboration, and the first fruits of their work have recently become available (Evans, Goodman, Keevil, Lane, and Urry, 1939).