bluuebunny/crossref_metadata_2025 huggingface dataset:
The beds above the Carboniferous Limestone in North-West County Clare, Eire
Authors: Hodson Frank
Published: October 2009

The lithological and faunal succession in the beds above the Carboniferous Limestone over an area of about 50 square miles in North-West County Clare is described. This area has the town of Lisdoonvarna at about the central point and includes the Cliffs of Moher on the Atlantic coastline. Some 1300 feet of beds are preserved above the limestone and are to be referred to the upper part of the
Homoceras
and Lower
Reticuloceras
stages of the Namurian. Seventy-three fossiliferous bands, belonging to 10 faunal horizons, have been found and vertical sections measured to show their relationships. The succession, in this part of County Clare, is shown to be very condensed in its lower portion. There exists a considerable non-sequence above the Carboniferous Limestone. The Geological Survey map is shown to embody certain errors and a geological sketch-map is given which attempts to rectify these.
The composite granitic gneiss of western Ardgour, Argyll
Authors: Harry William Trevelyan
Published: October 2009

The Moine Upper Psammitic Group of western Adrgour, Argyll, is steeply folded into an anticline running across country for a number of miles. Along the axis of the anticline is exposed a belt of composite gneisses with a foundation of pelitic Moine schist. The gneisses adjacent to the Moine Upper Psammitic Group are usually oligoclase-biotite-quartz-gneiss still presenting many of the features of pelitic schist. At deeper structural levels the composite gneisses are of granitic composition, containing quartz, microcline, oligoclase and biotite. Replacement textures are pronounced. This composite granitic gneiss develops a subordinate amount of augen-gneiss due to the growth of microcline porphyroblasts. Both the granitic and oligoclase-biotite-quartz-gneiss show migmatitic structures. The latter rock includes types megascopically identical with the
lit-par-lit
regional injection gneisses extensively developed in adjacent districts of the West Highlands of Scotland.

The granitic gneiss was formed by syntectonic advance along pelitic schist of a silica-potash “front” of metasomatism preceded by a Na, Ca, Mg “front” of felspathization, forming oligoclase-biotite-quartz-gneiss. “
Lit-par-lit
injection” types of the latter are ascribed to metamorphic segregation of quartz-felspar folia. Both gneisses are replacements essentially in situ. An attempt is made to explain the textural varieties within the granitic gneiss (augen-gneiss, aplite etc.) by the variable interplay of crystallization and earth-movement during granitization, combined in some cases with metamorphic differentiation.
Graptolites from Anticosti Island
Authors: Barrass Robert
Published: October 2009

In graptolite collection sent to Professor Lapworth near the end of the 19th century are some pieces of limestone from Anticosti Island, Canada. These form the basis of the present study, in which the structure and development of two new species of
Amplexograptus
and a species of
Climacograptus
are described from specimens preserved compressed and in relief. Much of the investigation was carried out using serial sections made with the Croft parallel grinder.

The amplexograptids resemble
Amplexograptus
[
Climacograptus
]
inuiti
(Cox) but were not put into the genus
Climacograptus
because they possess characters relating them to
Diplograptus s.l.
, e.g, a high length ratio of the excavation, long interthecal septa sloping to the axis of the rhabdosome, and a sub-rectangular cross-section. The climacograptid features, e.g. a low length ratio of the excavation, interthecal septa parallel to the axis and a circular or nearly circular cross-section, are shown in
Climacograptus
aff.
scalaris
. Compressed specimens of
Amplexograptus elongatus
(which has very small mesial thecal flanges) show both amplexograptid and orthograptid views and an attempt is made to account for this.

I. Introduction

The material investigated consists of a few small pieces of limestone from Anticosti Island, Canada, included in a collection of graptolites sent to Professor Lapworth at Birmingham towards the end of the 19th century (Bulman 1950). The specimens figured here will be deposited, temporarily at least, with the Department of Geology, Birmingham University. The limestone is from the following three main localities (Twenhofel 1928, fig. 1.): Observation Cliff, North Shore; Macdonald's Cove
The Geological History of the English Channel
Authors: King William Bernard Robinson
Published: October 2009

The geology of the English Channel has long been known to be much more complex than might appear from a study of the land areas on either side. The most important work on the subject was that of Dangeard, who examined a number of dredge samples and published his results in 1929. In recent years investigations with a free-drop cover which collected samples of rock in place, and geophysical work, largely that of Dr. M. N. Hill, have added much new information.

The data now available are brought together and analysed. Maps showing the areas where each major rock group occurs at surface or at depth and estimates of thicknesses have been prepared. From these a map of the outcrops under the Channel and a contour map of the sub-New Red Sandstone—Mesozoic surface (the so-called Palaeozoic floor) have been drawn.

The history of the area is then reviewed and it is concluded that since the Armorican orogeny the Channel has been an area with a tendency to intermittent downwarps while the surrounding land areas cf Devon and Cornwall on the one hand and Brittany on the other have been areas with intermittent uplift. This leads to the conclusion that many of the present uplands of Palaeozoic rock were blocked out in early times and that the present edges of these areas are not far from the positions they have occupied since New Red Sandstone times. It is suggested that palaeogeographical maps of the Mesozoic in this region should show a
The Dalradian Geology of the Creeslough Area, Co. Donegal
Authors: McCall Gerald Joseph Home
Published: October 2009

In the Creeslough area, folded and metamorphosed Dalradian sediments with sills of metadolerites are intruded by a member of the Donegal granite series. The preservation of original sedimentary features makes it possible to establish a succession of about 6000 feet of sedimentary rocks. The lower beds accumulated slowly in a restricted trough; the appearance of thick gritty quartzites marks an increase in the supply of detritus; the overlying sediments show evidence of emergence and the highest beds indicate a return to slow sedimentation. The intrusion of the dolerite sills produced a thermal alteration of the sediments which has resisted the later orogenic metamorphism.

The major folds run NE.-SW., are overturned towards the north-west and are associated with slides. A phase of orogenic metamorphism, of no high grade, was followed by the uprise of the local phase of the Donegal granite and the development of sillimanite, staurolite, kyanite and garnet along the granite margin. The granodiorite and its aureole rocks were then strongly sheared, probably as a result of pressure from the deeper part of the pluton. A suite of lamprophyre dykes was intruded before the end of the shearing.

I. Introduction

A knowledge of the Creeslough area is important for the study of Donegal geology in that there is here provided a lengthy succession of Dalradian rocks which retain unchanged many of their original sedimentary characters. This circumstance enables their tectonics to be interpreted with confidence. Moreover, the sedimentary rocks and the associated metadolerite intrusions present many problems in metamorphism—the
On the Time Relations between Regional Metamorphism and Permeation in Delting, Shetland
Authors: Flinn Derek
Published: October 2009

The metamorphic rocks of Delting are a thinly bedded succession of pelites, semipelites, impure quartzites, and calcareous rocks, about 36,000 feet in thickness, with a strike approximately north-north-eastward and bedding mostly vertical. Scattered throughout the succession are metamorphosed basic igneous rocks. The earliest recognizable episode after the deposition of the sedimentary rocks was the regional metamorphism. A number of zones of regional metamorphism, equivalent to the Barrovian zones of the South-West Highlands, have been delimited. They show that the intensity of regional metamorphism increased towards the south-west. The next episode was the establishment of two belts of permeation, within which the rocks generally were intensely recrystallized, but not in the same manner in the two belts. The permeation was accompanied by thermal metamorphism of the rocks in the immediate neighbourhood of the belts.

The variation in the intensity of this thermal metamorphism, both within and between the two belts, suggests that the permeation took place after the regional metamorphism. From this, and from the absence of any relation between the distribution of the permeation belts and that of the zones of regional metamorphism, the conclusion is reached that in Delting the regional metamorphism was neither the cause nor the result of the permeation, but that both are the consequence of forces acting on a larger scale and at depth.

I. Introduction

(a) Locality

The area of Delting, which is described in this paper, is a part of the Mainland of Shetland. Four long narrow arms of the sea, Olna Firth
A Review of the Jurassic of Western Sicily Based on New Ammonite Faunas
Authors: Warman Harry Robert , Arkell William Joscelyn
Published: October 2009

The first part of the paper gives descriptions and profiles of four key Jurassic sections in western Sicily from which ammonites have been collected at various levels, and discusses the stratigraphy and the relations of the Jurassic to earlier and later systems. It is shown that thick limestones previously classed as Tithonian belong largely to the Cretaceous and in places are even Eocene. The tectonic implications are discussed. The second part of the paper lists 11 assemblages of ammonites collected in the four sections and ranging in age from Lower Bathonian to Tithonian. Notes on their correlation and òn a number of other assemblages collected in Sicily are also given. Lower and Upper Bathonian and Lower and Upper Oxfordian assemblages new to Sicily are recorded. The Jurassic palaeogeography of Sicily and neighbouring regions is inferred from the vertical and horizontal distribution of the ammonite faunas and their affinities with those in other regions.

Part I.
Structure and Stratigraphy [H. R. W.]

I. Introduction

The field work on which this paper is based was carried out in routine geological investigations on behalf of the D'Arcy Exploration Company during exploration for oil. Acknowledgment is made to the Chairman and Directors of the Anglo-Iranian Oil Company Ltd., of which the D'Arcy Exploration Company is a subsidiary, for permission to publish the following results deriving from these investigations.

In an attempt to amplify our knowledge of the regional stratigraphy, certain major exposures of pre-Tertiary rocks in western Sicily have been examined and the thicknesses
Pre-Seminulan Main Limestone of the Avonian Series in Breconshire
Authors: George T. Neville
Published: October 2009

The Avonian Main Limestone underlying the
Seminula
Zone in Breconshire has hitherto been referred to the
Zaphrentis
, Lower
Caninia
, and Upper
Caninia
zones in apparently conformable but attenuated sequence, lithologically not greatly different from that of the South Crop in Glamorgan. A remapping of the eastern outcrops, however, shows that a widespread development of dolomites, supposedly equivalent in part to the “
laminosa
Dolomites”, is misleading as a guide to stratigraphy; and that thick oolites, variously ascribed to the “
Seminula
Oolite” and the “
Caninia
Oolite”, belong to neither of those zonal limestones. The succession consists of two major rock groups : an Oolite Group of Zaphrentidan age below, and a Calcite-Mudstone Group of Upper-Caninian age above. The Lower
Caninia
Zone is not represented.

The Oolite Group is in primary lithology a generally uniform series of almost quartz-free, light-grey, massive crinoidal oolites resting directly on the Lower Limestone Shales. At the plane of the sub-Viséan unconformity it thins rapidly westwards through overstep by the Calcite-Mudstone Group.

Most of the beds of the Calcite-Mudstone Group are quartz-rich finely fragmental algal and foraminiferal limestones, pellet-rocks, and calcite-mudstones. Apart from a prominent band of gritty oolite they consist mainly of organic detritus, the finest grades probably being algal muds.

Variations in thickness of the Calcite-Mudstone Group, especially notable in the neighbourhood of the Vale of Neath disturbance, are partly internal, but arise mainly because of Seminulan overstep. The greater part of the Upper
Caninia
Zone is everywhere missing. The Calcite-Mudstone Group is completely transgressed in
The Lower Carboniferous Stratigraphy of the Omagh Syncline, Northern Ireland
Authors: Simpson Ian Morven
Published: October 2009

The Omagh syncline is a large outlier of Lower Carboniferous rocks in Counties Tyrone and Fermanagh, Northern Ireland. The succession, about 8000 feet thick, is divisible into four lithologically distinct groups. At the base, resting unconformably on Dalradian rocks, is the Omagh Sandstone, a group of siliceous sandstones and conglomerates. It is confined to the eastern half of the outlier and its zonal position is indeterminable. The Claragh Sandstone which follows is characterized by abundantly felspathic sandstones. It overlaps the Omagh Sandstone in the west and rests on Dalradian and Moinian rocks. The fauna suggests a C
1
age.

The third group, the Pettigo Limestone, is dominantly calcareous with a rich fauna indicating a C
2
S
1
age. The Clonelly Sandstone Group at the top of the succession, though mainly arenaceous, is more variable in lithology than the preceding groups. It is referred to the S
2
Subzone.

The gentle folding of the Lower Carboniferous along an E.-W. axis is ascribed to Armorican compression, as is the development of four major faults by lateral slipping along NE.-SW. fault-planes.

The source rocks of the Lower Carboniferous clastic sediments were the Moine and Dalradian rocks of the west and north. Virtually all the sediments were deposited in a marine environment.

I. Introduction

In North-West Ireland several extensive outliers of Lower Carboniferous rocks rest unconformably on an irregularly eroded surface of Dalradian and Moinian metamorphic rocks (Fig. 1). The outliers are the remnants of a once widespread covering of sedimentary rocks. One of the largest of the
The transformation of tillite by migmatization at Mount Fitton, South Australia
Authors: Bowes D. R.
Published: October 2009

From
Dr. Dennis M. Shaw, Department of Geology, Hamilton College, McMaster University, Hamilton, Ontario, Canada.

Dr. Bowes's contention that the tillites have been migmatized at Mount Fitton seems incontrovertible, but I do not believe that all his conclusions on chemical changes are valid. The analyses in Table I and III will be discussed.

First, in Table III, analysis 9310 is rejected from the author's discussion on the grounds that “it does not appear to be part of the usual sequence” (p. 468) although on p. 467 he states that “sericitization ... altered some of the tillite in the early stages”. This analysis will therefore be included in the following. The ranges of variation of some oxides in the three unaltered tillites (Table I) and the five altered rocks (Table III) follow, unaltered rocks first: SiO
2
, 59·51–79·31, 70·99–79·05 : Al
2
O
3
, 8·23–12·43, 10·50–14·39 : Fe
2
O
3
, 0·81–1·78, 0·34–2·07 : FeO, 2·27–4·42, 0·22–2·08 : MgO, 2·32–6·02, 0·17–0·86 : CaO, 1·80–5·79, 0·35–1·72 : Na
2
O, 0·95–1·32, 0·13–2·73 : K
2
O, 2·00–3·72, 5·29–7·54 : TiO
2
, 0·51–0·75, 0·15–0·36 : MnO, 0·03–0·10, tr.-0·04 : P
2
O
5
, 0·09–0·17, 0·04–0·17.

Two facts must be borne in mind. Firstly, no analysis is accurate and therefore small differences between a few analyses are unlikely to be significant. Secondly, every rock type shows a range in composition. This is particularly true of sediments in general, and more so for tillites, even if the matrix alone is considered. The full range in composition cannot be shown by the three analyses of unaltered tillites, so the ranges quoted
Pre-Seminulan Main Limestone of the Avonian Series in Breconshire
Authors: George T. Neville
Published: October 2009

Note by
the Author :—

Professor Alan Wood has kindly drawn my attention to the
Koninckopora
-like appearance of the multicellular specimens illustrated in pl. xii, fig. 5, of my paper. Their detailed structure leaves no doubt that the specimens belong to a species very near, or identical with,
Koninckopora inflata
(de Koninck) as described by Wood (1943,
Q.J.G.S.
98
, 212)—a species of common occurrence in the Calcite-Mudstone Group. The known stratigraphical distribution of
inflata
(Wood, idem., 217) is added confirmation of the Lower Viséan age of the group.

Referring to Viséan overstep in Pembrokeshire, Professor O. T. Jones has reminded me that in present outcrops the oldest rocks upon which the
Seminula
Zone rests are of Silurian age. The words “and Pre-Cambrian” should therefore be deleted from the last sentence of section x on p. 310.
Analysis of Minor Structures Near Ardmore, County Waterford, Eire
Authors: Dawson-Grove Glascott Eyre
Published: October 2009

Geologically, the Ardmore area consists of Upper Devonian and Lower Carboniferous rocks lying in E.—W. folds which are transected by N.—S. faults.

The orientations of all planar features were measured in localities chosen for detailed examination. The joints, veins and shear-planes were plotted stereo-graphically, and, from the resulting contour diagrams, structural maps were prepared.

It has been established that the area has suffered three main phases of deformation—N.—S. compression, E.—W. tension, and clockwise shear, probably in that order. Deductions are drawn on the interrelation of the fracture-planes exemplified by the cleavage, joints, faults and other manifestations of crustal deformation.
The Lithology and Structure of a Boulder-Bed in the Dalradian of Mayo, Ireland
Authors: Elwell Royston William Dunlop
Published: October 2009

Exposures of a boulder-bed resembling those of Donegal have been found in North-West Mayo. The boulders are granitic in aspect, though severely affected by cataclasis, and the matrix is foliated and generally semi-pelitic. The probable succession in North-West Mayo and the position of the boulder-bed in it have been determined, but no correlation with other areas has yet been established.

For the most part the boulders are about equidimensional, but locally they are intensely deformed. Many of the deformed boulders are markedly elongated and flattened. The elongation is parallel to the regional lineation, which generally plunges to the south-east.

Although several analyses of pebble deformation in other areas are interpreted as indicating a main movement parallel to the elongation, it is considered that the Mayo boulders have been rolled and thus extended in
b
. This conclusion is strongly suggested by more than one line of evidence. Firstly, certain mullion structures (with a south-easterly plunge corresponding to the direction of boulder elongation) were found to have their peripheries determined by complex folds that have required considerable movement at right angles to the mullion trend. Secondly, mapping in North-West Mayo has revealed large-scale folding that plunges to the south-east. Thirdly, the shapes of many of the deformed boulders are not such as would be expected if they had been extended in
a
, though they might well have been produced by rolling and flattening.

Petrofabric investigations have been carried out on some of the boulders, and the relationship between fabric orientation and deformation is briefly discussed in the paper.
The Conodont Fauna of the Keisley Limestone
Authors: Rhodes Frank Harold Trevor
Published: October 2009

Conodonts are comparatively rare in the Keisley Limestone, but the fauna includes a variety of forms, comprising 17 genera. Three of these genera,
Keislognathus
,
Rosagnathus
and
Strachanognathus
are new, and five new species are also described. The fauna is compared with others of a similar age, and the ranges and stratigraphical value of the conodont genera are considered.
An Appinitic Facies Associated with Certain Granites in Jersey, Channel Islands
Authors: Wells Alfred Kingsley , Bishop Arthur Clive
Published: October 2009

The rocks here referred to as appinites form part of the essentially dioritic facies marginal to both the north-western and south-eastern complexes in Jersey. Mineralogically they are characterized by abundant long prismatic amphiboles, rich in titanium. Many of these contain cores of mica or felsic material, the nature and origin of which are discussed.

The country rock commonly occurring in association with the appinitic rocks is dioritic in both complexes; and at Ronez in the north of the island it contains relicts which prove it to be, at least in part, metasomatized gabbro. The diorites and appinites both consist of essentially the same mineral assemblage and, whilst the latter are not metasomatic in the generally accepted sense of the word, there is no doubt that a large proportion of their substance has been derived from gabbro by way of a series of changes initiated by the nearby granites. The changes by which gabbroic material was converted into dioritic have been continued and accentuated, presumably by emanations from the granite, with the local building up of strong flux concentrations, which led to the formation of " pockets " consisting of crystal mush with interstitial liquid. It was from this " magma " that the appinitic rocks crystallized, under essentially pegmatitic conditions. It was demonstrably mobile, and a turbulent fluxional structure is highly characteristic.

Textural interpretation receives critical attention in the paper, particularly in so far as it concerns replacement phenomena. The observed changes in mineral contents are consistent with crystallization from a magma, and follow the lines of Bowen's discontinuous reaction series, which must be extended at the low temperature end to include phases usually regarded as secondary, but here unquestionably primary.

An unusual feature, occasioned by the special environmental conditions, has been the growth of amphibole and apatite crystals of a hollow-shell type, in which crystallization starts on the outside and progresses towards the centre.

In the sequence of paramorphic changes, the inheritance by a later phase of the internal structure of the earlier one which it is replacing, in accordance with the principle of least disturbance of the original Si-0 lattice, is strikingly displayed in these rocks.

Problems of classification and nomenclature are involved and receive due attention in the paper.
The Silurian Rocks of the Talerddig District, Montgomeryshire
Authors: Bassett Douglas Anthony
Published: October 2009

The paper deals with the ground between Dinas Mawddwy (Pugh 1928) and Tarannon (Wood 1906). The rocks of the area are grits, siltstones, shales and mudstones forming part of a greywacke suite. They are subdivided into the Gelli, Talerddig and Dolgau groups (Upper Valentian) and the Denbighshire Group (Lower Wenlockian).

Some of the beds, for example the blue shales in the Dolgau sequence, are remarkably constant throughout the area, but in general, beds, members and groups exhibit pronounced variation in thickness and, to a lesser extent, in lithology. There is a general thinning eastward and southward, the latter being contrary to the regional attenuation towards the geosynclinal axis.

The rocks are folded into a series of major and minor folds associated with which there is well-developed cleavage and jointing but little faulting. Three fold-sets are distinguished : a predominant NNE.-SSW. set, a less-pronounced E.-W. and an insignificant NW.-SE. set. The area is, therefore, dominated by the NNE.-SSW. structures prevalent in the Harlech, Plynlimon and Van domes to the west and south, but also contains some E.-W. structures related to the Berwyn dome to the north-east.
The Geological Evolution of Wales and the Adjacent Regions
Authors: Jones Owen Thomas
Published: October 2009

The thicknesses of the Lower Palaeozoic rocks in the region are represented by isopachytes, and by summation isopachytes are constructed for the Cambrian, Ordovician and Silurian systems, as well as for the Lower Palaeozoic. In the centre of the geosyncline the rocks may have reached a thickness of nearly 40,000 feet and the slope at the base of the Palaeozoic on its eastern flank was about 16°. The average rate of accumulation of the sediments is estimated for each system.

Earth-movements which preceded the deposition of the Old Red Sandstone affected an area extending for some miles on each side of the Irish Sea. Within this area the Old Red Sandstone rests unconformably on all earlier formations, but to the eastward it follows conformably on Silurian rocks.

Evidence is adduced that the so-called Caledonian movements which folded the Lower Palaeozoic rocks of Wales occurred after the deposition of the Lower Old Red Sandstone, and, further, that the formation probably attained a thickness of many thousands of feet over large areas in Wales and in England where it no longer occurs.

It is inferred that the sediments were derived largely from the products of tropical or sub-tropical weathering and that they were mainly products of river action. The Upper Palaeozoic is estimated to have attained a thickness in South Wales of 20,000 to 24,000 feet.

The effects of post-Carboniferous movements and the subsequent history of the area are briefly reviewed.
Pediplanation and Isostasy: An Example from South Africa
Authors: King Lester C.
Published: October 2009

An outline is given of late Mesozoic and Tertiary erosional and depositional cycles in South Africa. The elevations of these surfaces are compared with elevations calculated, allowing for isostatic recovery between successive cycles of erosion. Concurrence between the two sets of elevations is noteworthy. Isostatic recovery thus seems to occur as a simple function of erosion and deposition under the pediplanation principle.
A geophysical study of the granite problem
Authors: Bott Martin Harold Phillips
Published: October 2009

Following an introductory account of granite petrography, hypotheses for source and emplacement of granite are classified in a form suitable for geophysical assessment. The evidence of the negative gravity anomalies associated with post-tectonic granites is summarized and considered in its various aspects of space, mass and density. For comparison with observations, gravity fields are calculated for the types of mass distribution expected for the various hypotheses. The seismological evidence of Gutenberg's low-velocity lithosphere channel is also considered.

The gravity results indicate that batholiths have considerable extent in depth and hence forcible intrusion is unlikely to be the main mechanism in post-tectonic granite emplacement. The negative anomalies demonstrate that the emplacement involves a considerable over-all removal of mass from the regions now occupied by the granite, but there is no support from the gravity anomalies for the hypothesis that the bulk of this now resides in the country rocks as a basic front. The evidence suggests that both downward diffusion of surplus mass and stoping are possible primary mechanisms. Geophysical, geochemical and geological observations conspire to support the idea that a true granitic layer, underlying the metasedimentary rocks, provides the source material for granite.

Syn- and post-emplacement uplift of granite batholiths and the origin of mantled gneiss domes are attributed to isostatic-type phenomena depending on the granite mass deficiency.
The glaciations of East Anglia and the East Midlands: a differentiation based on stone-orientation measurements of the tills
Authors: West Richard Gilbert , Donner Joakim Jalmar
Published: October 2009

Measurements of the long-axis orientation of stones in Older Drift tills of East Anglia and the East Midlands have been made to determine the direction of ice movement. The directions of preferred orientation of the long axes of the stones, together with the stratigraphical evidence of certain of the tills measured, give a pattern of direction and stratigraphy in which three successive episodes of ice advance may be distinguished. These are named the Cromer, Lowestoft and Gipping advances. The Cromer Advance deposited the North Sea Drift, the Lowestoft Advance Pennine Drift in the East Midlands and chalky boulder-clay (including Baden-Powell's Lowestoft Boulder-clay) in East Anglia, and the Gipping Advance chalky boulder-clay (including Baden-Powell's Gipping Boulder-clay) both in the East Midlands and East Anglia. Measurements of the long-axis orientation of stones in Older Drift tills of East Anglia and the East Midlands have been made to determine the direction of ice movement. The directions of preferred orientation of the long axes of the stones, together with the stratigraphical evidence of certain of the tills measured, give a pattern of direction and stratigraphy in which three successive episodes of ice advance may be distinguished. These are named the Cromer, Lowestoft and Gipping advances. The Cromer Advance deposited the North Sea Drift, the Lowestoft Advance Pennine Drift in the East Midlands and chalky boulder-clay (including Baden-Powell's Lowestoft Boulder-clay) in East Anglia, and the Gipping Advance chalky boulder-clay (including Baden-Powell's Gipping Boulder-clay) both in the East Midlands and East Anglia.

The presence of interglacial deposits below the till of the Cromer Advance (Cromer Forest Bed Series), and between the tills of the Lowestoft and Gipping advances (Hoxne Interglacial) makes it possible (a) to recognize two glaciations, the first including the Cromer and Lowestoft advances, the second the Gipping Advance, and (b) to correlate the two glaciations respectively with the Elster and Saale glaciations of North-West Europe. The Lowestoft and Gipping glaciations as now defined correspond with those so-named by Baden-Powell except that the Lowestoft Glaciation is taken to include the Cromer Advance.
A Late-glacial deposit at St. Bees, Cumberland
Authors: Walker Donald , Godwin Harry
Published: October 2009

Peat and mud beds lying in the Middle Sands at St. Bees have been reinvestigated. The peat which was described underlying the Scottish Readvance boulder-clay has been eroded away. None of the three remaining organic layers within the Middle Sands is of interglacial age. Pollen analysis has shown two of them to be Post-glacial and one Late-glacial. The latter covers a complete interstadial period, probably, but not certainly, the Allerød.
The Buchan anticline of the Banff nappe of Dalradian rocks in North-East Scotland
Authors: Read Herbert Harold , Farquhar Oswald Cornell
Published: October 2009

The Dalradian rocks involved in the Buchan anticline in Aberdeenshire belong to four groups: (1) the Ellon Gneisses, in part migmatitic, equated with the Ben Lui-Ben Lawers groups of the standard Lower Dalradian of Perthshire, (2) the Mormond Hill Quartzite, placed in the Upper Dalradian, and conformably followed eastwards by (3) the Collieston Beds of greywacke facies, and lastly, (4) the Fraserburgh Beds of similar facies occurring west of the Mormond Hill Quartzite, from which they are separated by a dislocation.

The Buchan anticline is a structure imposed on the great recumbent fold of the Banff nappe, this being made of a migmatitic core of the Lower Dalradian Ellon Gneisses, separated from the Upper Dalradian by a dislocation, the Boyne lag. The anticline is considered to result from the eastward and upward movement of the migmatized core of the great fold. As a consequence, the Collieston Beds are piled up to the east in front of the brow in a gigantic stack of small recumbent folds. West of the tectonic aggregation of Mormond Hill Quartzite which caps the Ellon Gneiss anticline, the Fraseburgh Beds have slid down a gentler tectonic slope into the Turriff syncline—they are characterized by broad, gentle, synclinal portions and narrow, steeply overtuned, anticlinal portions. These cover movements are considered to be activated by a bulging upwards deep down in the migmatitic core of the Banff nappe; the Collieston and Fraserburgh Beds are shed off on the two sides of the maximum rise.

As the movements ended, an essentially thermal metamorphism, effected by heat-conduction from the migmatite core and characterized by regional andalusite and cordierite, was overprinted on the folded cover. The metamorphic zones form a metamorphic "anticline" two miles west of the tectonic anticline. In the centre of this metamorphic "anticline", the migmatite front has risen highest into the cover folds.
The geographical distribution of brachiopods in the British Middle Lias
Authors: Ager Derek Victor
Published: October 2009

A study of the rhynchonelloid and terebratuloid faunas of the zone of
Pleuroceras spinaturn
in the Lower Jurassic of the British Isles has revealed a pronounced lateral variation in the distribution of genera and species. Four distinct faunal provinces are distinguished within the British area, and two of these are subdivided into two and three subprovinces respectively. The palaeo-ecological and palaeogeographical implications of the distribution are discussed.

The Mendip, Moreton in Marsh and Market Weighton axes are shown to have acted as faunal barriers in
spinatum
Zone times. The ironstone facies of the Midlands provided a strongly selective environment. There are marked affinities between the brachiopod fauna of South-West England and that of Normandy, and also between those of Yorkshire and western Germany. The Hebridean region is believed to have been populated by migratory streams from both the above faunas, together with a third stream coming presumably from the north. A strong and ,effective faunal barrier existed along the line of the Pennines, possibly connecting with the Moreton in Marsh axis.

Certain forms are thought to have been restricted to particular areas throughout considerable spans of Jurassic time.
The Criffell-Dalbeattie granodiorite complex
Authors: Phillips William John
Published: October 2009

The Criffell-Dalbeattie granodiorite complex is composed of three granodiorie' and associated quartz-dioritic rocks. Four-fifths of the area of exposed “ granitic ” rocks is occupied by the main Criffell-Dalbeattie granodiorite and the greater part of the paper is devoted to a study of the petrology, structure and emplacement of this granodiorite pluton. It is concluded that the main granodiorite was emplaced as a magma by the forceful displacement and some assimilation of the country rooks.

The western end of the complex is considered in relation to the main pluton. The her-grained intermediate granodiorite was emplaced before the main pluton and itself intrudes the Bengairn quartz-diorite which flanks its north and west' margins. The Bengairn quartz-dioritic rocks are considered to have developed by the metasomatic transformation and mobilization of permeated hornfelsic material. It is suggested that the intermediate granodiorite magma may represent the h a 1 result of the metasomatic transformation of the country rooks, and it is postulated that a relatively small movement and internal circulation of the mobilized permeated material would be sufficient to give the essentially magmatic features exhibited by the intermediate granodiorite. The close association of the intermediate granodiorite with the Bengairn quartz-dioritio rocks may well be an indication of the possible origin of the granodioritic magmaa by the “ magmatization ” of permeated hornfelees in regions not much lower than the one now exposed in this area.

The more basic composition of the later main granodiorite is attributed to the effect of the assimilation it accomplished during its longer and more active life as a magma. The porphyrite-porphyry minor intrusions and the fine-grained granodiorite may be related to various stages in the crystallization of the granodiorite magma which finally consolidated as the central porphyritic granodiorite.
The Ardara granitic diapir of County Donegal, Ireland
Authors: Akaad M. Kamal
Published: October 2009

The composite diapir of Ardara, County Donegal, foreibly displaced contact-altered Dalradian rocks of its envelope by folding, thrusting and shearing. The intrusion consists of a granodiorite core surrounded by a mantle of course tonalite. The outer part of the core is made up, in the north, of contaminated quartz-diorite and, in the south, of less contaminated granodiorite. These rocks, and the tonalite, are well foliated. The central part of the core is composed of uncontaminated and unfoliated biotite-granodiorite

The emplacement of the body is believed to have begun with the movement of granodiorite magma along a pre-existing thrust-plane. The magma came in contact with basic rocks of an older complex and mobilized part of this complex, sweeping it upwards as a plastic skin which consolidated to form the tonalite mantle. Magma contaminated with basic material accumulated within this mantle to form the quartz-diorite and the slightly contaminated southern granodiorite. The outer part of the body cooled and developed radial fractures.

A new upwelling of essentially uncontaminated granodioritic magma pierced the still molten core of the pluton, causing remobilization and further distortion of the envelope. Radial fractures, later followed by tangential fractures, were again formed. At a late stage, the solidifying pluton rose vertically, with resultant shearing of its envelope.
The volcanic rocks of the area between Fishquard and Strumble Head, Pembrokeshire
Authors: Thomas Godfrey E. , Thomas Trevor M.
Published: October 2009

Volcanic rocks of Ordovician age, of widespread occurrence within North Pembrokeshire, attain their maximum development in the Pen Caer peninsula, embracing the area immediately north-west of Fishguard and culminating seawards in Strumble 1 Head.

Referred to as the Fishguard Volcanic Series, these rocks are assignable to the Lower Llanvirnian. They reach a maximum thickness of some 3600 feet near Strumble Head itself, but attenuate rapidly towards the south and east so that at Lower Fishguard Harbour they are reduced to some 850 feet.

A well-defined tripartite subdivision is evident over the greater part of this area ; these components in upward succession are the Lower Rhyolite Division, the Pillowlava (Spilite) Division and the Upper Rhyolite Division.

Although pillow-lavas predominate within the Pillow-lava Division, this is made up of a diverse group of rocks, the detailed petrography of which reveals many unusual features. Its thickness of approximately 3000 feet in the extreme north of the Pen Caer peninsula contains the greatest local development of pillow-lavas in Wales. A discovery of particular interest is the presence of an intra-formational series intercalated within the dominant pillow-lavas.

Near Goodwick the two rhyolite divisions reach a combined vertical thickness of some 2500 feet, easily the greatest thickness of Ordovician rhyolitic rocks recorded in Pembrokeshire. Breccias, agglomerates, intercalated ashes or tuffs and perlitic or nodular varieties are of common occurrence, but flinty flour-banded types predominate.
The structure and stratigraphy of part of the Pre-Cambrian outcrop between Church Stretton and Linley, Shropshire
Authors: James John H.
Published: October 2009

The use of top and bottom criteria combined with cleavage has shown that the succession is normal for the lower groups of the Longmyndian. The presence of a major overstep of the Mintonian (Portway Group) on to the Synalds Group in Deadmans Batch, with the complete elimination ofthe intervening Lightspout Group, suggests an unconformity at the base of the Mintonian. The eastward creep of the Bayston Group at the expense of the Mintonian when traced from north to south of the area, together with a variation in the dip and strike between these subdivisions, points to another, and possible greater, unconformity above the Mintonian. Although dipping to the west, top and bottom structures show the western half of the Bridges Group and the Oakswood Group to be inverted. This implies a major synclinal structure in the Wentnorian, as the eastern half of the Bridges Group and the Bayston Group have a normal succession. The Uriconian to the west has an inverted and unconformable relationship with the Wentnorian, the unconformities having combined to eliminate the Strettonian and Mintonian.
Interglacial plant remains from the Wolvercote Channel, Oxford
Authors: Duigan Suzanne L. , Sandford K.S.
Published: October 2009

The Wolvercote Channel contains deposits with a fauna indicative, first, of warm and then of temperate conditions. These are overlaid by a peaty layer containing plant remains, itself succeeded by deposits indicative of cold conditions. Clement Reid and Bell recorded 23 different flowering plants from the peaty layer. From material in the Oxford University Museum some of Raid's labelled specimens have been re-examined, and further material not labelled by him has now been identified. The newly identified plants include
Atriplex
cf.
hastata
Linnaeus, cf.
Cardarmine pratensis
Linnaeus,
Draba
cf.
incana
Linnaeus,
Pastinaca sativa
Linnaeus,
Potamogeton
cf.
filiformis
Persoon or
pectinatus
Linnaeus, P. cf.
perfoliatus
Linnaeus,
Potentilla
sp.,
Rumex
cf.
acetosa
Linnaeus, cf.
Saxifraga
sp., and
Festuca
sp. The ranges and habitat preferences of these plants, together with the plants identified earlier by Reid and by Bell, support a tentative conclusion that the climate was cool temperate. What is more certain is that the landscape was, at least locally, incompletely covered with vegetation.
Pollen analysis of the Nechells interglacial deposits, Birmingham
Authors: Duigan Suzanne L. , Godwin H.
Published: October 2009

Pollen diagrams from a deposit of silts and clays at Nechells, Birmingham, are presented. The vegetational history of the deposit and the extent to which the pollen analytical results can be used to determine the age of the deposit and the climatic conditions under which it was laid down are discussed.
Microplankton from the Kimeridge Clay
Authors: Downie Charles
Published: October 2009

Planktonic organisms found in the Upper Kimeridge Clay of England are described. This plankton comprises dinoflagellates, hystrichospheres, coccolithophores and bodies of uncertain affinity. Coccolithophores and dinoflagellates alternate as the dominest members ; the abundance of the former varies considerably. The mode of occurrence is described and the stratigraphic value discussed.
A geomorphological comparison between Eastern Brazil and Africa (Central and Southern)
Authors: King Lester C.
Published: October 2009

Large parts of central and southern Africa and of eastern Brazil form “stable shield regions” that have escaped orogenic deformation since the late Palaeozoic.

Similar erosional processes operating upon similar terrain in both regions have produced series of denudational and depositional land-forms that are closely comparable upon both the continental and local scales.

Both sub-continents have been subjected to periodic uplift, and in each the uplifts have conformed to a differential pattern that was repeated for the region at each epeirogenic episode ; in the two sub-continents the general pattern of repeated deformation is similar both in space and time.

In both regions, from the Carboniferous until approximately the Jurassic, sedimentation prevailed over denudation, but from the Jurassic onwards denudation exercised the dominant role and the principal features resulting are suites of cyclic land-forms. In each subcontinent the accumulative desert phase of the Triassic was concluded by the outpouring of floods of plateau basalt. The Jurassic denudation produced everywhere a landscape, termed “Gondwana”, of extraordinarily smooth planation, from which all subsequent scenery has been carved.

The following denudational cycles and the related deformations and sedimantary phases are common to both regions:—

1. The Gondwana denudational cycle, followed by the late Jurassic deformations and the early and mid-Cretaceous sediments.

2. The post-Gondwana denudational cycle, followed by the mid-Cretaceous disturbances and the late Cretaceous and early Cainozoic sedimentary series.

3. The “African” and “Sul-Americana” denudational cycles, followed by mid-Cainozoic epeirogenesis and late Tertiary marine and continental deposition.

4. The late Cainozoic denudational cycle, followed by epeirogenesis at the close of the Cainozoic and Quaternary sedimentation.

5. Quaternary valley incision and sedimentation.

The episodes of uplift and warping synchronized with well-established episodes of orogeny in other parts of the world.
The stratigraphy and structure of the Cotherstone Syncline
Authors: Reading Harold Garnar
Published: October 2009

The Cotherstone area is a physical and geological depression lying between the two upstanding block areas of the northern Pennines. Structurally it is an asymmetrical syncline pitching gently to the east.

The succession of Carboniferous rocks displayed ranges from late P
2
to late E
2
and includes beds of Yoredale facies of the Middle and Upper Limestone groups, overlain by Millstone Grit.

The tracing of the marine members of the Yoredale rhythmic units or cyclothems has established correlations between the successions of the Alston Block to the north and the Askrigg Block to the south. These show that marine conditions frequently persisted longer to the south and east of the area than elsewhere. Millstone Grit facies enter at a lower horizon on the east and west of the Cotherstone area than they do in the centre, the lower horizon corresponding with the Tan Hill Grits to the south, which, it is suggested, pass laterally into the Coalcleugh Transgression Beds of the north. This is demonstrated by equating the Upper Felltop Limestone of the Alston Block with the Hearne Beck Limestone of Upper Swaledale. The upper horizon, of grit facies, is subjacent to the Botany Limestone and is considered to be the equivalent of the First " Millstone Grit " of Durham and the Water Crag Grit of Upper Swaledale, the Botany Limestone corresponding with the Shunner Fell Limestone.