bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Hartfell-Valentian Succession in the District around Plynlimon and Pont Erwyd (North Cardiganshire)
Authors: Jones Owen Thomas 
Published: October 2009

The area described in this paper forms part of the hilly country some 12 to 16 miles to the east of Aberystwyth. It extends for a distance of about 9 miles, from the Plynlimon Mountains near the northern margin, to the Ystwyth Valley which forms the southern boundary; the eastern limit lies on the elevated tract which forms the divide between the coastal drainage and that of the River Wye and its tributaries, while its western margin is roughly defined by the western slope of the Rheidol Valley.
The area of 40 square miles or so included within these boundaries is given over almost entirely to sheep-grazing, and only small tracts along some of the valleys are under cultivation. In former times mining operations were vigorously carried on, but that industry is now decadent.
The small village of Pont Erwynd stands in the Rheidol Valley near the western margin of the district, and on the main road from Aberystwyth to Llanidloes which divides the area into two almost equal portions.
On the Dyke at Crookdene (Northumberland) and its Relations to the Collywell, Tynemouth, and Morpeth Dykes
Authors: Heslop M. K. , Smythe J. A. 
Published: October 2009

Of the four dykes dealt with in this paper, only one, the Crookdene Dyke, appears not to have been investigated before, although its position is marked on the Geological Survey Map, Sheet 106 N.E.
As it has many points of interest, we shall describe its mode of occurrence and properties in some detail. The other three dykes have already been investigated by Dr. Teall; what observations we have to make upon them are thus only supplementary to his work, and serve chiefly to bring out the relationships which exist among these dykes in a clearer light. It should be mentioned that Teall had already come to the conclusion that the Collywell, Tynemouth, and Morpeth Dykes fall into a distinct group, and this inference we are in a position to substantiate; the Crookdene Dyke belongs also to the same group, halving the strongest analogies to the Collywell Dyke. The field-relationships of the Collywell, Tynemouth, and Morpeth Dykes have been clearly described by Prof. Lebour. All three belong to the series which in Northumberland has a general east-and-west trend. The Crookdene Dyke also runs east and west, and for this reason, and chiefly because of its strong petrological resemblance to them, it must be classed with the dykes just mentioned.

I. T
he
C
rookdene
D
yke
.

About 16 miles west of Morpeth, in latitude 55° 8′ 35″ N., longitude 2° 2′ 45″ W., there occurs a small exposure of a basaltic dyke in the bed and banks of the Wansbeck, which is there a
Certain Jurassic (Lias-Oolite) Strata of South Dorset; and their Correlation
Authors: Buckman S. S. 
Published: October 2009

I. I
ntroduction
.

T
he
object of the present communication is to show the development and sequence of certain Jurassic strata on the Dorset coast, and to make some comparisons with strata elsewhere. The range of strata dealt with is from the top of the Middle Lias (Pliensbachian) to the lower part of the Fullers' Earth (Bathonian, Vesulian) inclusive.

The communication is laid before the Society for several reasons: it was promised many years ago; it forms a sequence to the papers on North Dorset and the Cotteswolds; it aims to give a detailed account of certain fossiliferous strata of South Dorset, to be used as a foundation for the dating of the fossils; and it offers suggestions in the matter of correlation and subdivision as a basis for the work of other investigators. With this stratigraphical paper there is also offered a palæontological paper, to describe some of the new species mentioned, and to figure some other species which are new and illustrative of strata of the same dates. That communication will be alluded to as ‘the palæontological paper.’
The investigations for this paper, which will probably be my last, so far as active field-geology is concerned, were complete in the main several years ago; it was announced in 1893 as nearly ready for publication. Since then changes of residence have involved packing of specimens, and many have not been unpacked again. As a consequence the identification of species must often be given in general terms, as they were set out
The Igneous and Associated Sedimentary Rocks of the Glensaul District (County Galway)
Authors: Gardiner Charles Irving , Reynolds Sidney Hugh 
Published: October 2009

I. I
ntroduction
.

T
he
district is a small one, having a maximum length from south-west to north-east of little more than 2 miles, and a width of about a mile. Its north-eastern margin lies about 3 miles south-west of Tourmakeady Lodge, the southernmost point in the area recently described by us. That portion of the district with which this paper deals consists of the valley of the Glensaul River, together with the hills lying to the south-west, which rise to a height of 925 feet above sea-level at Lettereeneen and to nearly 700 feet at Greenaun.

The area of Ordovician rocks, with which this paper is concerned, is roughly quadrilateral in shape. It is bounded by peat and drift on its southern side, partly by peat and drift and partly by grit and conglomerate of ? Bala age on its northern side, while its western and its eastern sides are bounded by faults.
The western fault, very clearly seen along a stream-course that runs northwards down the slope of Lettereeneen, brings a fairly coarse quartzose conglomerate, forming the actual summit of the hill, against the Ordovician rocks. This conglomerate contains large felsite pebbles and smaller ones of quartz, and of red and black chert, and is quite different from the coarse conglomerate of Arenig age, to be described below (p. 255). We have found no fossils in it, and an account of it is beyond the purpose of this paper, but we class it with the grits and conglomerates found on
The Tourmaline-Corundum Rocks of Kinta (Federated Malay States)
Authors: Scrivenor John Brooke 
Published: October 2009

I. I
ntroduction
: P
revious
L
iterature
.

I
propose
in the following paper to describe and discuss the origin of certain rocks, remarkable alike in mineral composition and in structure, found in the Kinta Valley of Perak, the premier tin-field of the Federated Malay States. The two chief ingredients of these rocks are tourmaline and corundum; and it is evident, from the geological structure of the district, that they are the result of extreme metamorphism in beds associated with schistose rocks found chiefly on the west side of the valley, and perhaps also in thin beds intercalated with the crystalline limestone that generally forms the bed-rock of the tin-mines.

The previous literature dealing with the Kinta Valley, or, indeed, with Perak as a whole, is very scanty, and does not take long to review.
In 1882 M. J. Errington de la Croix described the geology of the Malay Peninsula (pp. 9–20), noticing the Kinta limestones as being widely developed.
In 1884 the Rev. J. E. Tenison-Woods said that the granite ranges of Perak are flanked by ‘Lower Limestone ridges’ forming detached hills about 1500 feet high.
‘The limestone is crystalline, without a trace of organism[s], though lines of stratification can still be traced.... There is a Palæozoic sandstone, clayslate, or gneissose formation lying between the limestone and [the] granite. It is much decomposed, and gives rise to a red clay which generally goes by the name of laterite.’
In the same year the same author mentioned an instance of a recent volcanic rock
The Gneisses and Altered Dacites of the Dandenong District (Victoria), and their Relations to the Dacites and to the Granodiorites of the Area
Authors: Skeats Ernest Willington 
Published: October 2009

I. I
ntroduction
.

T
he
rocks with which this paper deals occur about 25 miles distant from Melbourne, in a direction a little south of east. The area is all included within the parish of Narree Worran, in the counties of Evelyn and Mornington. The oldest rocks in the district are sediments of Lower Palæozoic age, either Silurian or Ordovician; but with these the paper is not directly concerned.

Intruded into these sediments is a mass of granodiorite, which is now exposed at the surface in the southern part of the area. To the north of the granodiorite lies an extensive area of hypersthene-biotite-dacite and quartz-porphyrite, which forms the Dandenong Hills. This rock series is also younger than the Older Palæozoic sediments, for in some places it appears to rest upon them, and in others to be intrusive into them. The boundary between the granodiorite and the dacite runs in an easterly direction, and while examining this junction in 1905 I discovered a belt of gneissic and altered rocks which for several miles come between the normal development of the granodiorite and of the dacite. It is with these rocks and their relations to the plutonic and volcanic series adjoining them that this paper deals.
Hitherto gneissic rocks have been recognized in Victoria only in certain parts of the Western District and in North-Eastern Gippsland. These, however, are probably of Archæan age, and certainly have nothing in common with the foliated rocks described below.

II. P
revious
L
iterature
.

The origin, age, and field-relations
The Natural Classification of Igneous Rocks
Authors: Cross Whitman 
Published: October 2009

I. I
ntroduction
.

I
n
how far may the systematie classification of igneous rocks, the basis of their petrographic description and nomenclature, be constructed by the application of truly ‘natural factors’? This question has long been debated, but petrographers have not reached agreement as to the answer. Meanwhile petrographic system has become greatly confused through varying views as to what are ‘natural relations,’ and by the illogical or inconsequent use of arbitrary factors. It seems useless to hope for agreement in this matter until the petrographers of different schools have come to understand thoroughly each other's points of view, which are based largely on experience in widely separated fields of work. It is with the idea of promoting in some measure this mutual understanding, that I offer this discussion to the Geological Society of London.

The rocks of the earth exhibit a great variety of relationships of geological importance, as to their origin, their mode, form, and place of occurrence, and possess, in many groups, a complex and often obscure character. The rock is usually defined with emphasis on its geological importance, and it is considered as a geological unit. But there has not always been the desirable clear distinction between the rock-mass, of certain relations of form or position with regard to the earth, and the substance of the mass, the rock proper.
From various standpoints of geology classifications of rocks have been set up, more or less refined, for special or general purposes. All of these classifications are of use
Dedolomitization in the Marble of Port Shepstone (Natal)
Authors: Hatch F. H. , Rastall R. H. 
Published: October 2009

I. I
ntroduction
.

While on a visit to the marble quarries of Port Shepstone, the attention of one of the authors was attracted by a block of granite, included in the dolomite and surrounded by a dark banded border, which was succeeded in order by a pale brown and a pale green zone. On closer examination these coloured rings were found to consist of a portion of the marble, containing a number of interesting minerals in zonal arrangement. Among these minerals a brown mica and a coal-black substance were the most conspicuous to the unaided eye, although a pale mica and a green serpentinous mineral could also be distinguished. On account of its obvious interest a photograph of the occurrence was taken (see fig. 3, p. 512), and a number of specimens were collected for microscopic examination.
The Port Shepstone marble is well known in Natal, on account of its beautiful white appearance and coarsely crystalline (saccharoidal) texture. Unfortunately for those interested in its commercial exploitation, it does not possess the uniformly fine and even grain of the celebrated marble of Carrara, a fact which militates against its employment for statuary purposes. It is first mentioned in geological literature by C. L. Griesbach, who notes the occurrence of a ‘crystalline limestone of enormous thickness, [but] whose position relative to the neighbouring strata is not clear.’ In the year 1894, David Draper described it in somewhat more detail, and stated that he had no doubt ‘that the calcareous matter of which the
On the Evolution of
Zaphrentis delanouei
in Lower Carboniferous Times
Authors: Carruthers Robert George 
Published: October 2009

I. I
ntroduction
.

A
n
attempt is made, in the following communication, to demonstrate the evolution of a small Zaphrentid coral, belonging to a gens of common occurrence in the Lower Carboniferous rocks of Scotland.

The simple rugose corals seem to have been strangely neglected by workers on phylogenetic problems. Although suggestions as to the lines of evolution of certain species have been advanced from time to time, no direct proofs have, apparently, been forthcoming.
Yet, in some respects, few of the Invertebrata are so well adapted for investigations of this nature. In most of these corals, all the growth-stages of the skeleton are retained intact, and can be studied by means of serial sections cut across the corallum. The one serious difficulty arises from the remarkably sporadic distribution of such fossils or, indeed, of the Rugosa in general —a fact only realized to the full after one has engaged in the systematic examination of a wide area, in search of some particular gens. As a matter of fact, the corals here dealt with are the only ones that range through most of the Lower Carboniferous rocks of Scotland. Even then, they are found on horizons often somewhat widely separated in time and unproductive for long distances. Fortunately, the stratigraphy of the Scottish rocks is so well known, that collections can be made all over the country, from horizons the position of which in the sequence is fixed more or less definitely. Although, therefore, section after section of some particular limestone may
Recumbent Folds in the Schists of the Scottish Highlands
Authors: Bailey Edward Battersby 
Published: October 2009

I. I
ntroduction
.

T
he
district discussed in this paper includes a considerable portion of two typical Highland counties, Inverness-shire and Argyllshire. It lies in the main between Loch Linnhe, on the north-west, and a chain of granitic intrusions which, on the south-east, connect the Moor of Rannoch with the upper portion of Loch Etive. It extends northwards to the River Spean, and southwards to Appin and Loch Creran.

The region thus defined is dissected by an intricate system of deeply cut glens, flanked by some of the loftiest mountains of Great Britain, including the giant Ben Nevis itself, 4406 feet high. The rock exposures on the mountain sides are remarkably clear, owing to the comparative absence of morainic material.
The detailed mapping of this district has recently been completed by the Geological Survey, and the results of the work will shortly be published in an official memoir. In the present paper an outline is given of the complicated tectonics of the crystalline schists.
Before entering on this description brief reference may be made to the results obtained by other workers along similar lines of enquiry.

(
a
) Historical Review.

Geologists are now familiar with the researches of James Nicol [l] , who showed that the gneisses, which Sir Roderick Murchison had described as conformably overlying the fossiliferous strata of the North-West Highlands, are in reality separated from the latter by a powerful dislocation.
Dr. Callaway was the first, however, to appreciate clearly that this dislocation is of the nature of a gently
The Relationship of the Permian to the Trias in Nottinghamshire
Authors: Sherlock Robert Lionel 
Published: October 2009

I. I
ntroduction
.

T
he
Permian System is generally considered to be represented in England by two distinct divisions, corresponding to the Zechstein and the Rothliegende of Germany. The English Rothliegende is further regarded as of two types: that of the Midland Counties, or Salopian type, and that of Collyhurst (Lancashire). The Zechstein is supposed to be represented by the Magnesian Limestone Series of the North-Eastern counties, together with some scanty deposits near Manchester above the Collyhurst Sandstone, and in Cumberland. The red beds of Devon, which are of doubtful age, need not be considered here.

In recent years the Permian age of many of the deposits of Salopian type has been called in question, and it has been shown that, in many cases, they are united to the Carboniferous System below and are unconformable to the Trias above.
In the case of the English Zechstein the beds are magnesian limestones, marls, and sands, and the limestones contain fossils which have been recognized as Permian. This division is chiefly represented by the long belt of strata which stretches continuously from the Northumberland and Durham coast, through Yorkshire, as far south as Nottingham. The Permian in this region differs from the English Rothliegende, not only in lithological character, but in its relationship to the beds below; for it has been known for a long time that it is markedly unconformable to the Carboniferous upon which it rests.
The nature of the upper boundary of the Permian is, however, less clear. It is usually
The Effects of Secular Oscillation in Egypt during the Cretaceous and Eocene Periods
Authors: Hume William Frazer 
Published: October 2009

I. Introduction.

I
n
the year 1878 Prof. Zittel laid the foundations of modern Egyptian sedimentary geology on a broad basis, since which period the Cretaceous and Eocene strata of that country have aroused much interest. The problems which have especially appealed to investigators are:—

(1) The age of the Nubian Sandstone.
(2) The changes of the fossiliferous Cretaceous strata when traced from north to south.
(3) The nature of the junction between the Eocene and the Cretaceous.
(4) The distribution and variation in the Eocene beds.
(5) The nature of the changes which have marked the passage from the Eocene to the Oligocene Period.
The work carried out by the Egyptian Geological Survey has, since 1896, widened our knowledge of the facts on which the broader theoretical conclusions will have to be based; and, in the present contribution, I shall endeavour to set forth the new data which have been obtained by me in connexion with each of these questions, only referring to the results of other investigators where these are necessary to complete the consideration of areas which have not been personally investigated. The portions of Egypt which have thus come under personal study are:—
(1) Eastern Sinai.
(2) A longitudinal region bordering Wadi Qena.
(3) The area between latitudes 25° N. and 28° N. covered by the Eastern Desert Survey Memoirs of 1903 and 1906.
(4) The districts bordering the Nile between Esna and Aswan.
(5) A series of traverses across the Western Desert between the Oases of
Notes on some of the Brachiopoda from the
Paradoxides
:Beds of Comley
Authors: Cobbold Edgar Sterling 
Published: October 2009

L
ingulella
Cf.
ferruginea
Salter.

1867. Cf
Lingulella ferruginea
et var.
ovalis
Salter, Q.J.G.S. vol. xxiii, p. 340 & figs. 1–3.

1868 & 1971. Cf
Lingulella ferruginea
Davidson, Geol. Mag. vol. v, p. 306 & pl. xv, figs. 1-8; ‘ Monogr. Brit. Foss. Brach. ’ (Pal. Soc.) vol. iii p. 336 & pl. xlix, figs. 32–35.

1876. Cf
Lingulella(?)
sp. indet., Linnarson, ‘ Brachiopoda of the
Paradoxides
Beds of Sweden ’ Bihang K. Svensk. Vetensk.-Akad.Handl. vol. iii, No. 12, p. 15 & pl. iii figs 27–28.

1883. Cf.
Linguealla ferruginea
Davidson, ‘ Monogr. Brit. Foss. Brach.’ (Pal. Soc.) vol. v, pl. xvii, fig 35.

Shell corneous, small, slightly convex, ovate; widest about a third from the front, length about one and a half times the breadth ; broadly rounded in front; sides tapering to the beak, which in the pedicle-valve appears to have been acutely pointed. Numerous concentric growth-lines. Pedicle-slit narrow.
Dimensions.—Length = 4 millimetres, breadth = 2 to 2½ mm.

Locality and horizon,.½The upper section on the Shoot-Rough Road, Comley; from a band of the Shoot-Rough-Road Flags with
Paradoxides davidis
, and also from a band with
Paradoxides rugulosus
at the top of the Shoot-Rough-Road Sandstone.

Note.— Three examples of this small
Lingulella
have been collected, and they agree fairly well with the Menevian species from St. David's, although the Shropshire form seems to be rather more acuminate at the beak.

The
Lingulella(?)
figured by Linnarsson from the
Paradoxides-forchhammeri
strata of Sweden may be identical.

L
ingullella
(?) spp.indet.

An imperfect single valve (fig. 7)
The Stratigraphy and Tectonics of the Permian of Durham (Northern Area)
Authors: Woolacott David 
Published: October 2009

Abstract
These beds, which vary much in thickness, lie in North Durham in the general form of a syncline beneath Sunderland.
The unfossiliferous Yellow Sands are probably a deltaic formation reassorted by wind, the other beds being the result of deposition in an inland sea undergoing desiccation. The magnesium carbonate existed in the waters of the sea, and was either deposited along with the calcium carbonate, or introduced by seepage when the beds were being laid down.
Great changes in the amount and distribution of these carbonates have, however, taken place since deposition. The cellular structures that occur in the limestone can be classified as follows:—(1) Concretionary-cellular; (2) negative breccia; (3) solution-cavities; and (4) fractured cellular. Most of them have been produced by the leaching-out of the magnesium carbonate (dedolomitization), or of both that and calcium carbonate. In some cases the rock has been rendered crystalline, as well as more calcareous, and the fossils have been obliterated. They do not afford any proof that the rock has been dolomitized subsequent to deposition. The percentage of calcium carbonate is sometimes over 99, while that of magnesium carbonate is occasionally as much as 50.
The fauna of the Magnesian Limestone is very restricted (about 140 species) and most peculiarly distributed. The marked paleontological features are the profusion of individuals in the Middle Fossiliferous Limestone (which appears to have formed a shell-bank in the Middle Magnesian-Limestone sea) and their sudden disappearance in the Upper Limestone. No corals, echinoderms, polyzoa, brachiopods., or cephalopods have ever