bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Dalradian Succession in Islay and Jura
Authors: Allison Archibald 
Published: October 2009

I. Intoduction
This paper is concerned only with rocks of accepted Dalradian age. I have, therefore, not taken into account formations lying south-west of the Loch Skerrols thrust, which include the problematical Bowmore Sandstone.
The succession, which I think may be considered as proved, is identical with that put forward by Prof. E. B. Bailey in 1917; but it has been established in the present instance mainly by consideration of current-bedding and graded bedding in several members of the sequence. The significance of certain conglomerates on Beannan Dubh, however, has again been investigated. In the following pages it is intended to retain the stratigraphical nomenclature used by Prof. Bailey, and also to discuss formations put forward by other authors in terms of this nomenclature.

The Dalradian succession in Islay and Jura, according to my determination, is as follows, the oldest rocks being at the bottom of the table :—

11.
Ardmore and Laphroaig Quartzites.

10.
Port Ellen Phyllites.

9.
Scarba Conglomeratic Group.

8.
Jura Slates.

7.
Main Quartzite.

6.
Dolomitic Group of North Islay.

5.
Power Fine-Grained Quartzite of North Islay.

4.
Portaskaig Conglomerate.

3.
Islay Limestone.

2.
Mull of Oa Phyllites.

1.
Maol an Fhithich Quartzite.

Since opinions on the geological structure of this area are many and varied, it does not seem out of place here to review and analyse very briefly
The Conglomerates and Grits of the Bala And Valentian Rocks of the District Between Rhayader (Radnorshire) and Llan-Sawel (Carmarthenshire)
Authors: Davies Kenneth Arthur , Platt John Isaac 
Published: October 2009

I. Introduction and Historical Survey
During the survey of the country between Elan Valley (Radnorshire) and Pumpsaint (Carmarthenshire) (Davies, 1926 & 1928), a collection was made of the grits and of the pebbles from the conglomerates which occur at many horizons in the district. To these have been added further specimens from the country to the north-east, so that the arenaceous deposits between Camlo Hill (Radnorshire) and Llansawel (Carmarthenshire) are described in the following paper. The whole of the sediments dealt with occur in rocks of the graptolitic facies and lie on the north-western side of the Towy anticlinorium, and they range from the upper part of the Bala stage to the lowest part of the Gala stage. Although the largest accumulations of coarse rocks are confined principally to the Upper Bala and the Lower Birkhill stages, arenaceous material occurs locally throughout the whole succession, and it is only the Monograptus convolutus zone that lacks a noteworthy amount of coarse material; even at this horizon, however, grits up to 6 inches in thickness are found in the country near Ystradffin. As the rocks of the area consist predominantly of fine-grained shales and mud-stones, the widespread occurrence in them of arenaceous and conglomeratic deposits gives to these sediments an additional importance.
Some of the arenaceous deposits appear at first sight to occur at constant horizons, and therefore to afford data for correlation purposes throughout Central Wales. Closer investigation, however, proves that they cannot be so applied, since they are only local
The Carboniferous Limestone Series in the West of the Vale of Glamorgan
Authors: George Thomas Neville 
Published: October 2009

I. Introduction and Historical Notes
The deposits that are present over the greater part of the Vale of Glamorgan consist of a more or less thick covering of Mesozoic (Triassic, Rhætic, and Lower Liassic) rocks through which extensive inliers of Upper Palæozoic strata emerge. The latter are chiefly of Avonian age, and constitute fragments of the southern arc bounding the syncline of the South Wales coalfield.
The present paper is concerned with those Lower Carboniferous inliers, lying to the west of the River Ddawan, that form the tracts of down county in the neighbourhood of Porthcawl, Bridgend, and St. Bride's Major, and which are a continuation of the series of folds comprising the Cardiff-Cowbridge anticline (see fig. 1).
The area lies wholly within the 1-inch (New Series) Geological Survey map no. 261–2, and was described by the officers of the Survey in the memoir (‘The Country around Bridgend,’ 1904, p. 13) accompanying that map. It is the purpose of this paper to supplement the information contained in the memoir with an account of the zonal sequence and of the structures elucidated by the application of the stratigraphical details obtained. It will be obvious that the work is based to a very great degree upon the publications of the Geological Survey; my indebtedness to them is considerable, especially as regards the construction of the map.
Apart from the information contained in the Survey Memoir, which almost entirely relates to the lithology, a brief note by Sibly (1920, p. 90) is the
On the Occurrence of Tremadoc Shales in the Tortworth Inlier (Gloucestershire)
Authors: Smith Stanley 
Published: October 2009

I. Introduction
The presence in South Gloucestershire of rocks older than the Old Red Sandstone was made known more than a century ago by the researches of W. Buckland and W. D. Conybeare (1824, p. 216) and T. Weaver (1824). Murchison included them in his Silurian system (1839, pp. 447–9, 454–62, and map separately issued), utilizing, in addition to his own observations, notes and sketches made by the Rev. George Cooke, Rector of Tortworth at that time.
The area was mapped by D. Williams, J. Phillips, A. C. Ramsay, and H. W. Bristow of the Geological Survey during the directorship of De la Beche, and the information was published in 1845 (Geological Survey 1-inch Map, Sheet 35). Bristow revised this part of the sheet in 1865, and further information was added to the map in 1866.
John Phillips (1848, pp. 190–8 & pl. i) gives a good account of the Palæozoic inlier, and H. B. Woodward includes a shorter and less accurate description of the beds in his memoir on the Bristol coalfield (1876, pp. 9–11 & pl. i).
Within recent years, S. H. Reynolds, partly in collaboration with C. Lloyd Morgan and F. R. C. Reed, has written a series of papers dealing with the geology, petrology, and palæontology of the southern part of the outcrop, and has summarized the results in his ‘Geological Excursion Handbook for the Bristol District’ (1912 & 1921, pp. 200–9). Nothing, however, has been published about the northern part (that is, the country north
The Corallian Rocks of the Howardian Hills (Yorkshire)
Authors: Wilson Vernon 
Published: October 2009

I. Introduction
In north-eastern Yorkshire, the gritstones and limestones comprising the Corallian sequence occur flanking the greater part of the Vale of Pickering. From the coastal districts about Filey and Scarborough they extend westward, forming a broad belt of flat-topped hills, the Tabular Hills, and terminating in the magnificent escarpment of the Hambleton Hills overlooking the Vale of Mowbray. To the south-west, the continuity of outcrop is broken by the Coxwold-Gilling rift which intervenes between the Hambleton Hills and the Howardian Hills, the latter lying to the south-east. It is the area of the Howardian Hills which forms the subject of the present communication.
The lower ground between the rift faults is occupied by low hills of Kimeridge Clay, covered to varying degrees by glacial drift, but an area of Corallian rocks forms a prominent ridge between Coxwold and Kilburn.
About 3½ miles east of Coxwold, the Corallian appears in Gilling Park, and from thence extends as a low ridge in an east-south-easterly direction through Malton to the vicinity of North Grimston, where it becomes lost under the Cretaceous overstep. The strata in this area have commonly a low dip to the north, but the presence of an intricate system of faults causes local modification in the dip and distribution of the rocks and complicates the stratigraphy. The northern boundary of the Corallian is determined by the main Gilling fault, though for the most part its course is obscured by drift. Besides the main line of outcrop, areas of Corallian
Report on some Fossil Plants Collected in Tanganyika Territory
Authors: Robertson Lesley Stuart 
Published: October 2009

The plant impressions described below were collected last year by Mr. G. M. Stockley from the Karroo formation in the Upper Gombati River, just below the Lukensi Mountain, Tanganyika Territory. They were sent to Prof. J. Walton for identification, and by him were kindly given to me to describe. The collection includes several specimens of
Glossopteris
fronds and equisetaceous stems, and is now included in the Hunterian Museum Collection in the University of Glasgow.

Glossopteris

Specimens of pale clay shale from the Kidodi area were found to contain several fragmentary impressions of fronds of
Glossopteris
, among which two different species have been identified.

Glossopteris Conspicua Feistmantel
(Nos. 1205-1208)

This relatively uncommon species has a wide-meshed venation; the network formed by the secondary veins is very large and open. The meshes are polygonal, very much longer than broad, and of approximately the same size throughout the lamina. Figure 1 shows a fragment of the lamina, 5 cms. in length, in which the midrib is distinctly visible. The largest of the fragments shows that the lamina is at least 7 cms. broad. In Fig. 2 the regular form of the venation can be seen. On comparison with other known species of
G. conspicua
, these fragments are found to agree very closely with those from the Damuda Series of India figured by Feistmantel (1881, pl. xxviii A, fig. 5), and also with one from the Orange River Colony figured by Arber (1905, pl. iii, fig. 3).
Glossopteris conspicua
has also been recorded from
The Lower Palæozoic Rocks of Austwick and Horton-in-Ribblesdale, Yorkshire
Authors: King William Bernard Robinson , Wilcockson William Howson 
Published: October 2009

I. Introduction
The area dealt with in this communication is one of the small exposures of Lower Palæozoic rocks forming part of the edge of the rigid block which, near the Craven faults, appears from beneath the great spread of almost horizontal Carboniferous strata of the Mid-Pennine area. The late Prof. J. E. Marr suggested that this rigid block was formed in the main of Pre-Cambrian rocks with a fringe of Lower Palæozoic strata deposited against its flanks, the whole having been compacted in pre-Carboniferous times. In the Austwick-Horton area, therefore, we may expect to find evidence of successive transgressions with special marginal fades and signs of numerous breaks in the succession, which features are absent or not well defined in the more central parts of the Lower Palæozoic trough of the Lake District and southern Scotland. It is with the hope of throwing some light on these matters that we venture to add yet another to the long list of papers on this district of Yorkshire.
The mapping and collecting of material has been carried out by both authors. The detailed mapping was begun in 1920 by Mr. Wilcockson, and he also collected the greater part of the fossil material.
Professor King took the Cambridge field-mapping classes here from 1920 to 1931 inclusive, and during that time examined many of the exposures and determined certain fossil localities. Trenches were dug by Mr. Wilcockson in 1920 with the aid of grants from the British Association, and two trenches were dug
The Pre-Cambrian and Lower Palæozoic Rocks of the Eastern end of the St. David's Pre-Cambrian Area, Pembrokeshire
Authors: Williams Thomas George 
Published: October 2009

I.Introduction
This paper describes the geological structure of a strip of country lying between four and 12 miles east of St. David's, and occupying the central portion of the small peninsula of north-western Pembrokeshire. Although in a district made classical by the researches of many famous geologists, this tract has received but passing notice, and, up to the present, has remained practically unknown geologically. The area is about 30 square miles in extent, measuring rather more than seven miles from east to west and four miles from north to south. It is bounded on the east by the G.W.R. main line to Fishguard, where the line runs along the Western Cleddau valley, between Welsh Hook and Mathry Road (Heathfield). On the north it adjoins the Abereiddy-Abercastle area (Cox, 1915, p. 273) and the Pen Caer area (Cox, 1930, p. 274), while to the south is the Brawdy-Hayscastle area (Thomas & Jones, 1912, p. 374). The St. David's area (Green, 1908, p. 363) and the Trefgarn area (Thomas & Cox, 1924, p. 520) lie respectively a few miles to the west and south-east.
The country here described is represented on the Ordnance Survey six-inch quarter-sheets, Pembrokeshire 15 N.E., S.E., N.W., S.W., 16 N.W., S.W., 8 S.E., and 9 S.W., and it comprises a portion of the area embraced by the Geological Survey one-inch maps, Sheet 40 (Old Series) and Sheet 209 (New Series).
The district forms part of the Pembrokeshire 400-foot peneplain, and shows the monotonous topography typical of the in
The Younger Intrusive Rocks of the Kudaru Hills, Nigeria
Authors: Bain Alexander David Neil 
Published: October 2009

I. Introduction
A Preliminary account of the geology of the Kudaru Hills was published in 1927 (Bain), but a more detailed study of the group has since been completed and is now presented. The discovery of fayalite in certain rocks has necessitated a modification in the terminology and order of intrusion given in the first account.
The hills are in the Zaria Province of Nigeria, lying midway between the towns of Zaria and Jos on the railway (Fig. 1). The area is about 65 square miles and has an oval outline with the longer axis running north-east and south-west. The axes measure 11 miles and 7½ miles respectively. To the south, near Munchira, joined to the main mass of the hills by a low neck, is a prolongation of the main intrusion which rises to a considerable height in D. Nasalwa and which measures 2½ miles by 1 mile. Bordering the group on the north and east sides is a curved ridge containing some high peaks (Pl. VIII). Separating this ridge from the main part of the group is a crescent-shaped plain divided into two by a number of low hills west of Babinda village. This plain is underlain by various gneisses, while the rest of the district consists of later members of the Younger Intrusive series of the Northern Provinces of Nigeria (Falconer, 1923).
The highest peaks are in the interior but not in the centre of the group, and bare massive ridges of solid granite are there developed,
New Forms from the Insect Fauna of the British Coal Measures
Authors: Bolton Herbert 
Published: October 2009

I. Introduction
The present paper contains the results of an examination of a suite of fossil insect wings discovered by Dr. Emily Dix, Prof. A. E. Trueman, Mr. W. Hemingway, and officers of the Geological Survey, to all of whom I would acknowledge my indebtedness for the generous loan of the specimens.
The work has been done by means of a Government Research grant from the Royal Society.
The specimens comprise about half the series discovered, the remainder including a number of wings whose structure has as yet defied analysis.
One species is referred to a family of the Palæodictyoptera, the most archaic group of fossil insects; two others are clearly palæodictyopteroid but, owing to their fragmentary character, cannot be assigned to any known group; three wings are referred to genera of the Protoblattoidea not previously recorded from Great Britain; whilst the list of Blattoidea from British Coal Measures is increased by two new species of the family Archimylacridæ and two species of Mylacridæ. Two forms are referred to the provisional order Hapalopteroidea, hitherto known only from the Anthracitic series of Sharp Mountain Gap, Vermont, Pennsylvania, U.S.A. Five specimens are indeterminable. Diagnosis.—wings twice as long as wide, and thin. Costal margin distally curved inward. Secondary branching abundant, and dividing by regular bifurcation. Diagnosis.—Wings thin, two to three times as long as wide, coastal margin curving inward into a small rounded apex. Inner margin almost straight. Veins branching by regular bifurcation. Diagnosis.— Wings at least two and a half times as
A Granite-Schist Contact in Stewart Island, New Zealand
Authors: Williams Gordon John 
Published: October 2009

I. Introduction
Stewart Island is a rugged and almost uninhabited island lying off the southern coast of New Zealand. It is densely forested, but along the summits of the bleak wind-swept highlands, which are constantly buried in cloud, the thick bush gives way to scrub and tussock, and some bare rock-surfaces are exposed.
The granite peaks of Stewart Island expose sections of an extensive granite batholith, which makes up the greater part of the island and probably extends 60 miles south to the desolate Snares Islands and 70 miles north-west to the fiord country of the South Island of New Zealand. The granite invaded a biotite-muscovite-schist with interlaminated quartzite, a chloritized kyanite-amphibole-schist, and a calc-silicate-hornfels. All these rock types occur as small pendants in the granite (see map, Pl. XI), but the mica-schist predominates.
The object of the paper is to discuss the origin of the mica-schist, the manner in which it was dispersed to give place to magma, and the mineralogical changes produced in both the granite and the schist by reaction between these rocks and the fugitive constituents of the magma. Where relevant, passing mention will be made of the calcareous rocks.
The fugitive substances were reactive at two periods: (1) prior to the ascent of the main intrusion, when gases passed into the roof of the batholith and either contributed to the formation of the micas of the schist or were responsible for the persistence of the micas into the innermost aureole; and (2) subsequent to the
West Highland Tectonics: Loch Leven to Glen Roy
Authors: Bailey Edward Battersby 
Published: October 2009

I. Introduction
The present paper is a sequel to my paper on the “Recumbent Folds in the Schists of the Scottish Highlands”, published in this journal in 1910, and expanded with certain corrections and discussions in a Geological Survey Memoir on the “Geology of Ben Nevis and Glen Coe”, 1916. The existence of these two publications allows of concentration on new features of interpretation.
The Loch Leven referred to in the title is the salt-water loch of that name, between Argyll and Inverness-shire. The coastal parts of the district are well served by roads, railways, and steamers. There are also inland roads through Glen Etive, Glen Coe, Glen Spean, and Glen Roy. The main villages or small towns are Ballachulish, Kinlochleven, Onich, Fort William, and Spean Bridge. Accommodation is easy to get.
The geological facilities include good exposures, high relief, and wonderfully definite lithology. Some of the mountains are carved out of Devonian igneous rocks, as at Ben Nevis and around Glen Coe, but much the greater number consist of the schistose rocks which concern us here. These peaks include a large number rising well above 3000 feet in height, and one, Aonach Beag, surpassing the 4000-foot level.

When I described the Ballachulish stratigraphical succession in 1910, and again in 1916,1 was careful not to suggest an original
order of superposition
. I described recumbent folds, but left it to the future to decide which set of limbs was normal and which inverted. In 1922, however, I attempted a comprehensive treatment
The Metamorphic Geology of Unst in the Shetland Islands
Authors: Read Herbert Harold 
Published: October 2009

I. Introduction
The Shetland Islands occupy a critical position in the Caledonian mountain area. They lie about 200 miles north-east of the post-Cambrian dislocations of Durness in Sutherland, the same distance north of the Dalradian outcrops of the Banffshire coast, and the same distance west of the metamorphic region of Bergen in Norway. The investigation of their tectonics and metamorphism is required in any synthesis of the Caledonian front.
The island of Unst is the most northerly of the group. Its size is about 50 square miles. Its coastline reaches the great length of nearly 70 miles, and, though formed of cliffs usually hundreds of feet high, is for the most part readily accessible. Inland exposures are good, while even where peat partly obscures the solid rocks, as happens with some of the politic gneisses, outcrops are sufficient for the mapping of small divisions.
During the field-seasons of 1929 and 1930, I mapped the island on the scale of 6 inches to a mile while a member of H.M. Geological Survey. Since then the material has been worked out at the University of Liverpool. In 1933 I spent three weeks in the island in order to test certain points that had arisen during the laboratory study. I desire to express my thanks to Sir John Flett, Director of the Survey, for permission to complete the Unst work and to present this account.
Unst consists entirely of rocks that have undergone one or more metamorphisms under markedly different physical controls. The
The Rocks below the Red Chalk of Lincolnshire, and their Cephalopod Faunas
Authors: Swinnerton Henry Hurd 
Published: October 2009

I. Introduction
Though the rocks below the Red Chalk of Lincolnshire are of peculiar interest, the absence of exposures along the coast, together with the rarity and transitory character of inland excavations, have made it exceedingly difficult to build up a body of information that approaches, even approximately, that standard of detail and accuracy which characterizes modern stratigraphy. Any information that can be culled from borings is, therefore, of especial value.
In the early summer of 1932 the Alford Town Council sank a boring in search of water from the Spilsby Sandstone. After piercing a thick covering of boulder-clay, the boring entered the lower part of the Red Chalk and then passed through 200 feet of other strata before entering the Spilsby Sandstone. Fortunately, a long spell of dry weather preserved the core from that rapid disintegration which would have been produced by rain, and also enabled me to make the requisite number of journeys from Nottingham to Alford for effecting a careful examination of the core. My heartiest thanks are due to Mr. R. Bentham and to Mr. P. E. Kent, who accom- panied me on most of the journeys and helped me with the laborious task of breaking up the rock and of making a thoroughly representative collection of specimens from all portions of the core.
Other borings have subsequently been put down at Maitbyle-Marsh, Fordington, and Skegness, but the use of the percussion method of boring, and other circumstances, have prevented me from obtaining more than fragmentary