bluuebunny/crossref_metadata_2025 huggingface dataset:
The Lithological Succession of the Carboniferous Limestone (Avonian) of the Avon Section at Clifton
Authors: Reynolds Sidney Hugh
Published: October 2009

Although a very large amount of information concerning the lithology of the Carboniferous Limestone is now available, that of no section has hitherto been described in detail, and it seemed that a full account of the rocks of the classical Avon Section might prove of value. The first full account of the composition or structure of one of the rocks of that section was W. W. Stoddart's description of the ‘Bryozoa-Bed’ (‘Microzoal Bed’) in 1861 and 1865. In one of his papers on the Geology of the Bristol Coalfield, he further gave a considerable amount of information concerning the Avon rocks.

Sorby, in his Presidential Address to the Geological Society in 1879, briefly alluded to some of the oolites from the Avon Section, but it was not until Mr. E. B. Wethered turned his attention to the subject that any detailed work was done. Mr. Wethered's investigations referred, on the one hand, to the chemical and mineralogical features, and on the other, to the faunal and microscopical characters. His paper on ‘Insoluble Residues obtained from the Carboniferous Limestone Series at Clifton’ dealt with the former subject, while that ‘On the Occurrence of the Genus
Girvanella
in Oolitic Kocks. & Remarks on Oolitic Structure’ contains a full description and analysis of the several oolitic bands occurring in the Avon Section. A fairly full account of the microscopical structure of many rock-types is also to be found in his paper on ‘The Building of Clifton Rocks.’ G. F. Harris also described and
An
Ottokaria
-like Plant from South Africa
Authors: Thomas Hugh Hamshaw
Published: October 2009

In the Karharbari Beds (Lower Gondwana) of Passerabhia (India), a very curious and characteristic fossil was found, to which the name of
Ottokaria bengalensis
was given by Zeiller. It is of interest, not only owing to its unusual form and problematical nature, but also on account of its association with
Glossopteris indica
and our uncertainty as to the reproductive structures of this form. Although leaves nearly allied to
G. indica
have been found in a large number of localities, not only in India but in Australia, South Africa, and Russia, fossils of the
Ottokaria
type are very rare, and, in addition to the Indian specimen, only one other example (from Brazil) has been described. The object of this note is to record the discovery in South Africa of a fossil which seems to be closely allied to, if not actually referable to, the genus
Ottokaria
.

The specimen (illustrated in fig. 1) was sent by Mr. T. N. Leslie, F.G.S., to Prof. A. C. Seward in 1913, and was recently handed to me for investigation. It occurs as an impression in a rather coarse-grained sandstone, and was derived from the Vereeniging Sandstones of the Transvaal.

The original description and figures of
Ottokaria
by Zeiller were published in 1902, and the specimen was recently refigured and described by Seward & Sahni in their revision of the Indian Gondwana plants, to which there is nothing further to add. The Brazilian specimen described by David White was called
Ottokaria ovalis
White, and was almost
The Evolution of Certain Liassic Gastropods, with special reference to their Use in Stratigraphy
Authors: McDonald Agnes Irene , Trueman Arthur Elijah
Published: October 2009

I. Historical and Introductory Notes.

Gastropods are very suitable for evolutionary studies, for the shells are frequently well-preserved in fossils; while, owing to the mode of coiling, the development may be observed in any complete individual without breakage of the shell. Such studies on fossil Gastropods have shown that they illustrate clearly many of the biological principles that have been demonstrated by investigators of other groups, such as the Ammonites.

But, although Gastropods afford excellent material for palæontological researches of this nature, it is well known that apart from, systematic work by numerous palæontologists, they have been comparatively neglected in this country. Further study is particularly desirable, since they are frequently abundant in formations where the fossils that are generally used in zoning are not common, and it is probable that a clearer understanding of the Gastropods will make it easier to correlate such rocks.

On the Continent a great deal more attention has been paid to the classification of fossil Gastropods, by E. Koken and P. Fischer, and more recently by Dr. A. E. M. Cossmann; the last-named author has produced several valuable monographs on the various groups, and his comprehensive ‘Essais de Paléoconchologie Comparée’ mark a great advance in the study of those fossils. In the course of his work that author has found it necessary to subdivide many of the genera that had been proposed by earlier workers, and has shown that many of the older names cannot be applied so broadly as has been customary.

Very
The Lower Palæozoic Rocks of the Llangollen District, with special reference to the Tectonics.
Authors: Wills Leonard Johnston , Smith Bernard
Published: October 2009

I. Introduction.

The area dealt with in the following pages forms the western half of the 1-inch Ordnance Survey Map, New Series, Sheet 121, with small contiguous strips in Sheets 120 & 137. It was mapped by us in the course of official work for the Geological Survey, in 1912 & 1913. The memoir on Sheet 121 is in preparation; but both it and the map which it accompanies have been greatly delayed by the War. This applies even more emphatically to Sheet 137. In the projected memoir on Sheet 121, special attention will be devoted to the Wrexham-Ruabon Coalfield.

In preparing the present paper, we have been influenced by a desire to publish in a concise form
1
an account of the older rocks which are more of theoretical than economic importance. We have attempted to describe the district as a geological unit, whereas the Survey Memoir must be primarily an explanation of the map and of the evidence on which it is based.

We are, therefore, greatly indebted to the Director of H.M. Geological Survey for permission to publish the following account, which is divisible into two parts. In the first, we aim at stating new facts and important modifications of the hitherto accepted ideas of the stratigraphical sequence, without traversing in detail the work of previous investigators where their conclusions have been confirmed by us. In the second part, we give a fuller description of the tectonics than the space available in the official Memoir would allow.

Our
On Certain Xenolithic Tertiary Minor Intrusions in the Island of Mull (Argyllshire)
Authors: Thomas Herbert Henry
Published: October 2009

I. Introduction.

In the years 1910 & 1911, the officers of the Scottish branch of H.M. Geological Survey, while engaged on a survey of that portion of the Island of Mull which lies south of Loch Scridain, were impressed by the great number of minor intrusions of a tholeiitic and andesitic character which penetrate the western part of the Tertiary lava-field. These rocks were described as being, for the greater part, of one type: namely, olivine-free dolerites or tholeiites, of which many have pitchstone centres, and in which a sheath-and-core structure is frequently developed.
1

Mr. E. M. Anderson noted the occurrence within them of xenoliths of apparently fused or baked sandstone, and also recorded certain nodular masses of bytownite and some ferromagnesian mineral which he compared with similar masses, collected by the late C. T. Clough and described by Dr. J. S. Flett, from a tholeiitic intrusion at Traigh Bhan an Sgoir
2
(Traigh Bhan na Sgurra, Locality 11, fig. 1, p. 230).

In 1912 Mr. Anderson discovered in the bed of a tributary of Abhuinn nan Torr (Locality 2) an exposure of a rock that contained abundant small plates of a deep-blue mineral. The rock was submitted to me for examination, and, after isolation, the blue mineral proved to be corundum of the sapphire-variety. Further work on this locality, and some excavation, yielded a series of most interesting specimens that proved clearly the abnormal and intensely xenolithic character of the rock in question; but the relation of the xenolithic mass
Shales-with-‘beef,’ a Sequence in the Lower Lias of the Dorset Coast.
Authors: Lang William Dickson , Spath Leonard Frank , Richardson William Alfred
Published: October 2009

Shales-with-‘beef’ was the name given to some 70 feet of Lias on the Dorset coast, lying above (53) Table Ledge and below (76 a) the Birchi-Tabular. The beds consist of paper-shales, marls, indurated bands, and limestone nodule-beds, with numerous, more or less impersistent, interbedded seams of fibrous calcite, called ‘Beef’ by the Officers of the Geological Survey.

Descending to the beach at Charmouth, and there forming reefs on the foreshore, the Shales-with-Beef are the most accessible Lias of that place. Yet they are, perhaps, the least known of all the beds. This is doubtless because of the generally unsatisfactory condition of the fossils found in them, and their consequent worthlessness on the one hand to the native, who finds no sale for such fragmentary and friable remains as the fossils present; while, on the other hand, the geologist seldom finds specimens more than approximately identifiable, and generally obtains completely satisfactory examples from but three or four horizons.

Sir Henry De la Beche described the Lias of this coast nearly a century ago; and, although he generally under-estimated their thickness, the subdivisions that he then made can be approximately correlated as follows, at any rate those five which lie above the Blue Lias limestones:—

(5)

Irregular bed of Limestone, with nodular concretions, frequently containing ammonites; 2 feet=Stellaris beds (87–89).

(4)

Slaty marls, with several thin beds of indurated marl; 67 feet = Black Marl series above Birchi-Tabular and below Stellaris beds (77–88).

(3)

Slaty marls containing small crystals of selenite; 32 feet Shales-with-Beef (54–76).
The Ammonites of the Shales-with-‘Beef’
Authors: Spath Leonard Frank
Published: October 2009

(A) Introduction

A list of the species of ammonites, identified by me, has already been included in Dr. Lang's stratigraphical account. It is intended here to review and amplify these identifications, and to attempt to justify the generic classification which I have adopted, also to discuss the phylogenetic relations of some of the ammonites of the Lower Lias. The development of a number of important types here dealt with, for instance,
Arnioceras, Agassiceras, Arietites, Cymbites, Xipheroceras, Microderoceras
, etc., was studied some years ago; but only brief reference can be made to this ontogenetic work, and it is also impossible at present to figure the new forms here recorded. It is a matter for regret that, in the absence of detailed stratigraphical work and careful zonal collecting for other districts, exact correlation is as yet impossible; and, for this reason, but little help was obtained from a study of the splendid collections in the British Museum (Natural History), of the genus
Arnioceras
, from Yorkshire and the Midlands, for instance. On the other hand, my
Arnioceras
material from Skye, described separately, proved of use, and confirmed what, so long ago as Dumortier's time, was surmised of the enormous range of this genus, although sufficient emphasis had not been laid upon it in previous accounts of the Dorset succession. Also, a collection made by the late Sir Henry Butlin, and recently presented to the British Museum (Natural History), contains a number of ammonites from Stockton in Warwickshire; and, since some of them were
The Geological History of the Genus
Stratiotes
: an Account of the Evolutionary Changes which have occurred within the Genus during Tertiary and Quaternary Times
Authors: Chandler Marjorie Elizabeth Jane
Published: October 2009

Stratiotes aloides
, the Water-Soldier or Water-Aloe, is a well-known monotypic European and Siberian plant of the Monocotyledonous family Hydrocharitaceæ; palæontological studies of recent years have shown this plant to be the sole survivor of an ancient genus which was living far back in the Tertiary Era.

II. H
history of
P
alæobotanical
I
nvestigation
.

The principal land-marks in the palæobotanical study of
Stratiotes
are as follows:—

1,

1822. The description of
Carpolithes thalictroides
Adolphe Brongniart; var.
parisiensis
(Paris Basin); var.
websteri
(Newport, Isle of Wight) (2).

2,

1833. Description of a second species,
Folliculites kalten-nordheimensis
Zenker, and the suggestion that Brongniart's fossils belonged to this genus (7).

3,

1892. Description of a third species,
Paradoxocarpus carinatus
Nehring, from Pleistocene beds (33).

4,

1892, later. Recognition that Nehring's
Paradoxocarpus
was a species of
Folliculites
of Zenker, by Potonié (36).

5,

1896. Identification of
Folliculites
as
Stratiotes
by Keilhack (54, 56),
F. carinatus
being synonymous with
S. aloides
Linn. and
F. kaltennordheimensis
being an extinct species.

Apart from these points, the whole literature of the subject is a mass of controversy. The confusion has been increased by the fact that
S. websteri
and
F. kaltennordheimensis
had been inadequately figured and described; while, owing presumably to a strong generic resemblance, shown by the figures (which failed, nevertheless, to make clear the specific distinctness), the two names were frequently used as synonyms. The disorder occasioned could not be cleared up by an appeal to type-specimens, for, in the case of
Stratiotes websteri
, these, and the type-locality too, were lost. Moreover, other species
On some Rugose Corals from the Burindi Series (Lower Carboniferous) of New South Wales; together with a Short Account of the Upper Palæozoic Rocks of the Area in which they were collected
Authors: Benson William Noel , Smith Stanley
Published: October 2009

Homœmorphy, regarding both external form and internal structures, is exceedingly common among Rugose Corals. Analogous features may occur in unrelated genera living contemporaneously in the same region or may be found reappearing in corals of different stocks in widely separated regions and epochs.

This paper describes two gener—
Amygdaloptzyllum
Dun & Benson, and
Cionodendron
, gen. nov., from the Burindi Series (Lower Carboniferous) of New South Wales; it also includes a few remarks concerning the species of
Lithostrotion
collected from the same series (and from the equivalent horizon in Queensland).

Amygdalophyllum
and
Cionodendron
are related respectively to the Carboniferous species of
‘Cyathophyllum’
(Palæosmilia) Edwards & Haime, and
Lithostrotion
; but both corals are characterized by an unusually large columella, as in Cyathaxonia.
Amygdalophyllum
and
Cionodendron
illustrate a remarkable case of parallelism.

The Australian species of
Lithostrotion
show certain small peculiarities of structure which distinguish them as a group from their British congeners.

The described material, much of which has been collected by one of us (W. N. B.), is the property of the Geological Surveys of New South Wales and Queensland, and of the Australian Museum (Sydney), and our thanks to these Institutions for the loan of the small collection is cordially tendered.

Before the corals are discussed, a short account is given of the stratigraphical succession of the region in which they were found, ‘and our reasons are stated for correlating the Burindi Series with the Viséan of Europe.

The fossils herein described come from the parishes of Moorowarra and Babbinboon, near Somerton, 20
The Petrography of the Cretaceous and Tertiary Outliers of the West of England
Authors: Boswell Percy George Hamnall , Herdman George
Published: October 2009

T
he
significance of the outliers of Cretaceous and later age resting on the Palæozoic strata of Devon and Cornwall has been frequently noted, especially with reference to the evidence yielded by them of the extent of the great marine transgressions. The details of their petrology, considered in relation to their present altitude and geographical location, are dealt with in this communication, and an attempt is made to throw light on the conditions of their deposition and the source of their constituents. Lying as they do, around and among some of the most important igneous masses in the country, they may be expected to afford evidence regarding the stability of detrital minerals and of the source of constituents in sediments of the same age, but of wider geographical distribution. A comparison of the petrography of these outliers with that of the Greensand, Eocene, and Pliocene strata farther east has therefore been instituted.

These outliers in the West Country may be grouped thus :—

Cretaceous (Upper Greensand).

Great Haldon Hills (Devon).

Little Haldon Hills (Devon).

Eocene (? Bagshot).

(?) Marazion, near Penzance (Cornwall).

Buckland Brewer, near Bideford (Devon).

Great Haldon Hills.

Little Haldon Hills.

Oligocene (Aquitanian).

Petrockstrow, near Torrington (Devon).

Bovey Tracey and Newton Abbot (Devot).

Pliocene.

St. Erth and Lelant (Cornwall).

Crouza Down, near St. Keverne (Cornwall).

St. Agnes (Cornwall),

together with certain deposits age (see p. 223).

The respective heights of the upper and lower surfaces of the deposits above Ordnance-datum are as follows :—

II. E
vidence
The Pamir Earthquake of 18th February, 1911
Authors: Oldham Richard Dixon
Published: October 2009

The Pamir earthquake of the 18th of February 1911, though of destructive violence in the central region and giving rise to long- distance records, would probably have passed without special notice had it not been for two circumstances : one, that it was accompanied by a landslip of exceptional dimensions, which dammed one of the principal drainage-valleys of the region, and gave rise to a permanent lake over 15 miles in length and 900 feet in depth; the other, that the late Prince Boris Galitzin formulated the conclusion that this landslip was the originating cause of the earthquake, and that this was an interesting and unique -instance of coincidence of epicentre and hypocentre. Attention has been recently drawn once more to this earthquake, and, although mistakes in Prince Galitzin's mathematical methods have been pointed out, the justice of his conclusion has been maintained; but this conclusion is so contrary to all other present knowledge of the character and behaviour of earthquakes, that a fuller examination of the evidence seemed desirable, and as this is not generally available, being published almost exclusively in the Eussian language, it has seemed desirable to record the facts, so far as they are available.

Before dealing with the local observations and records of the earthquake, it will be well to refer briefly to Prince Galitzin^s paper.2 His conclusions were based primarily on the survey conducted in 1913 by Col. Spiiko, from which it was computed that the mass of the landslip amounted to between 7
The Jurassic Rocks of New Zealand
Authors: Trechmann Charles Taylor
Published: October 2009

The Jurassic in New Zealand comprises a thick series of deposits, important both stratigraphically and structurally. In every locality where the sequence is well seen they follow closely the Triassic rocks with apparent perfect conformity. Compared with the underlying Trias, however, they exhibit contrast in a number of characters, among which are the following:—

(
a
) They are, generally speaking, less steeply inclined and enter less, so far as is at present known, into the structure of the Alpine mountain-ranges. No instance is known to me where rocks with recognizable Jurassic fossils occur in a slaty or semi-metamorphic condition as do the Triassic rocks in some places on the eastern fringes of the Southern Alps: for example, at Mount Potts and Mount St. Mary.

(
b
) The Jurassic, in contrast with the Trias, exhibits a much greater vertical range of marine fossiliferous deposits throughout its thickness, including horizons ranging from the lowest Lias to the Kimmeridgian and Tithonian. The Trias, on the contrary, is fossiliferous only in the higher beds, ranging from the Ladino-Carnic to the Rhaetic.

(
c
) Jurassic rocks apparently occur over a rather greater length of the two islands than the Trias, although this is probably due merely to accidents of outcrop and exposure, since Trias much resembling that in New Zealand recurs in New Caledonia. The Jurassic rocks at Waikawa occur at the extreme south-eastern corner of the Soufch Island, and near the northern extremity of the North Island at Cape Maria van Diemen and Spirits Bay Mr. A.
Further Researches on the Succession and Metamorphism in the Mona Complex of Anglesey
Authors: Greenly Edward
Published: October 2009

S
ince
my return to North Wales, the proximity of Anglesey has made it possible (in intervals of my survey of the country about Bangor and Carnarvon) to seek further light on the unsolved problems of the Mona Complex; and some of the results are embodied in the present paper.

I. T
he
A
ge of the
M
ona
C
omplex
.

Pebbles derived from the Mona Complex had already been found in Cambrian rocks ranging from the Bron-llwyd GS-rit down to the basement conglomerates of Carnarvonshire. Fragments have now been obtained from much lower horizons. For the massive conglomerate of Bangor cannot be later than Cambrian, and it is certain that, at any rate, the lower portions of the Bangor Volcanic Series (with which portions alone we are concerned in this paper) must be much older than that conglomerate. The Volcanic Series being essentially pyroclastic, fragments other than those of the contemporaneous volcanic rocks are rare. The agglomerates, however, have yielded a few fragments of Gwna quartzite and jasper. These fragments are not schistose. But in a slide [E 1539], cut from an agglomerate between the Workhouse and Hendre-wen Lane, there is a beautiful oval fragment (fig. 1, p. 335), about ⅛ inch long, of undoubted Penmynydd-Zone mica-schist, well-foliated and holocrystalline, with sphene, zircon, and a pale epidote. It is, therefore, certain that, before the eruption of this ancient volcanic series, the Penmynydd anamorphism of the Mona Complex was complete.

II. T
he
G
wna
B
eds
.

New Analyses of the Quartzite.

At the time of the issue
The Glaciation of North-Eastern Ireland
Authors: Dwerryhouse Arthur Richard
Published: October 2009

The region to be described covers the counties of Antrim and Down, with parts of Armagh, Londonderry, Tyrone, Monaghan, and Louth, in all about 3200 square miles, and is included in sheets 6, 7, 8, 12, 13, 14, 18, 19, 20, 21, 26, 27, 28, 29, 34, 35, 36, 37, 47, 48, 49, 59, 60, 61, 70, and 71, of the maps of the Ordnance Survey of Ireland on the scale of 1 inch to the mile.

The area is also covered by Bartholomew's ' ‘Quarter-inch to the mile map of Ireland’, Sheet 2, which contains most of the place-names used in this paper.

References to the previous papers on the subject are collected in a (‘ Bibliography of Irish Glacial & Post-Glacial Geology ’ by R. LI. Praeger, Proc. Belfast Nat. Field-Club, App. (1896), and in a Summary of Recent Glacial Investigations by the B.N.F.C., ibid. App. vii (1905–1906).

The area is naturally divided into four geographical units—the basaltic plateau of County Antrim, the Trias-filled valley of Belfast, the undulating Palaeozoic area of Down and Monaghan, and the igneous areas of the Mourne Mountains, Slieve Croob, and Carlingford.

The great plateau of County Antrim is formed of Tertiary basalts lying unconformably upon various older rocks, including Dalradian schists, Carboniferous,Triassic, Liassic, and Cretaceous rocks. The present surface of the basalt country forms a trough with its axis running north and south. The central valley is occupied by Lough Neagh, the waters of which stand at 52 feet above, and the
The Geology of the Schists of the Schichallion District (Perthshire)
Authors: Anderson Ernest Masson
Published: October 2009

The district studied, extends from the northern slopes of Carn Mairg across Strath Tummel, and includes a part of the valley of the Errochty Water. Except for some later intrusions, it is occupied entirely by crystalline schists. These belong in part to the series of Struan Flags—the probable equivalents of the Moine Gneisses of the more northern Highlands—and in a greater part to the so-called Dalradian Series, which here projects along a north-and-south axis for about 7 miles into the flags. The area includes the best development of the well-known Schichallion Boulder Bed, and has a historical interest from its association with Maskelyne's Schichallion experiment, which in itself led, at an early date, to a certain study of the geology.

The district was mapped about the year 1900 by the late Mr. J. S. Grant Wilson, of the Geological Survey. Although a succession not previously recognized forms the basis of the map now presented, the latter follows Wilson's in many of its main features, and the investigation of the area would have been a task of far greater difficulty without the guidance of his previous work.

I am to a great extent indebted to Mr. E. B. Bailey for the inspiration which led me to take an interest in the problems of the Southern Highlands. Mr. Bailey, in a previous traverse of the ground here described, had anticipated that part of the conclusions of this paper which concern the divisions of the Quartzite Group, and the relations of the rocks
The Petrology of the Arnage District in Aberdeenshire: A Study of Assimilation
Authors: Read Herbert Harold
Published: October 2009

In the Buchan, Formartine, and Strathbogie districts of Aberdeenshire, the plutonic rocks of lounger Granite age include half-a-dozen large gabbro-masses the approximate positions of which are shown in fig. 1 (p. 447). These gabbros are later than the regional folding, but antedate the local Middle Old Bed Sandstone. They possibly form one huge sill.

In 1914, Mr. W. R. Watt described the geology of the southern part of the Huntly Mass, and announced the discovery of gabbros modified by the incorporation of sedimentary material. These endomorphic gabbro-derivatives were shown to be similar in character and origin to rocks recorded from Le Pallet (France) by Prof. A. Lacroix and from Snowbank Lake (Minnesota) by Prof. A. N. Winchell. After the War it was my good fortune to revise for the Geological Survey the country around Huntly and Banff (Sheets 86 & 96 of the 1-inch Geological Survey Map of Scotland), and 1 was then able to investigate the distribution, nature, and origin (in the Huntly Mass) of the abnormal rock-types discovered by Mr. Watt. Later, similar rocks were found in the Insch Mass.

As their importance in the field increased, it was felt desirable to have some handy term for rocks resulting from the incorporation of sedimentary material in a magma, and, in 1921, the name contaminated rock was suggested. The term hybrid of Dr. A. Harker was considered to have a more specialized meaning, since it has come to denote rocks formed either 'by the mixture of two magmas, or
The Upper Ordovician Rocks of the South-Western Berwyn Hills
Authors: King William Bernard Robinson
Published: October 2009

The area to be described is part of North-Western Montgomery- shire. All place-names mentioned will he found on the 1-inch Ordnance Survey Map, Sheet 136 (Bala). or on the accompanying sketch-maps (figs. 1, 2, & 3, pp. 488, 493, & 496).

Geologically, this area is the western part of the southern flank of the great Berwyn dome of Ordovician strata; hut a glance at the geological map shows that in this south-western portion the beds are pinched up so as to form a wedge-shaped south-westerly extension, one flank of which runs with remarkable straightness for several miles. The reason for this straightness of outcrop lies in the fact that in this belt of country the strata are vertical, or have acquired a slight reversal of dip from the south-eastward overfolding.

To this cause must also be attributed the parallel arrangement of hill and valley, each band of hard rock standing out as a straight ridge, and each soft bed forming a parallel depression. Thus the sandstones of the Caradocian and the grits and massive mudstones of the Salopian stand out as ridges, while the softer Ashgillian and the sliales of the uppermost Caradocian form the marked valley which is followed by the old pack-road connecting the Upper Vyrnwy valley with that of the Tanat. This strike-valley is drained by various streams. In its northeastern part to Pen-y-garnedd (Sheet 137 it is drained by a tributary of the Tanat, then for a short distance the headwaters of the Cain drain the
The Geology of the District around Corris and Aberllefenni (Merionethshire)
Authors: Pugh William John
Published: October 2009

The area described in this paper lies south-east of the main mass of Cader Idris, about the villages of Corris and Aberllefenni. The north-western boundary is the great fault-valley of Tal-y-llyn, lying at the foot of Cader Idris, and along which runs the road from Towyn to Dolgelly, over the picturesque pass called Bwlchllyn-bach. The south-eastern boundary lies parallel, at a distance of some 3 or 4 miles. The area extends from the high ground about Taren y Gesail in the west to Mynydd Dolgoed and Waen Oer in the east, a distance of about 6 or 7 miles.

The district lies mainly within the county of Merioneth, but a part extends over the border into Montgomeryshire. It is included in the 1-inch Ordnance Survey Maps, Sheets 149 & 150, in the 6-inch maps of Merionethshire, Sheets XLII, N.E. & S.E., XLIII, N.W., XXXVII, S.E., XXXVIII, S.W., and in the Geological Survey Map, Old Series, 1-inch Sheet 59, N.E.

The area is drained almost entirely by tributaries of the River Dyfi. (Dovey), which lies some 4 or 5 miles south of Corris. The most important stream traversing the area is the River Dulas, which passes through the villages of Corris and Aberllefenni. It is along this valley that the main road from Machynlleth reaches Corris and Aberllefenni, and it is also followed by a light railway which affords alternative communication between the abovementioned localities. The regoin is one of some economic importance, and contains important slate- and slab-quarries, which have
The Miocene of Ceylon
Authors: Wayland Edward James , Davies Arthur Morley
Published: October 2009

It has long been known that fossiliferous limestones occur in the Jaffna peninsula in the extreme north of Ceylon, but until recently they have received little attention, and nothing approaching a detailed account of them appears to have been published.

At various times between 1914 and 1916 (inclusive) in the capacity of Assistant Mineral Surveyor for Ceylon, I carried out geological investigations over a stretcli of more than 800 miles of the coast-line of the island. During the progress of this work sedimentary beds were frequently met with; and the best-developed group of these—the Miocene—is dealt with in this paper. It will be shown that the Jaffna limestones are of Miocene age, that similar limestones occur elsewhere in Ceylon, and that Miocene rocks of other fades also occur.

I am at a disadvantage in that all my field-notes, being the property of tlie Mineral Survey, remain in Ceylon ; but sufficient information is contained in private note-books to allow of a general description.

Prior to Dr. Davies's determination of the contained fossils the age of the Jaffna limestones was very uncertain; for, while I recognized them as Tertiary, and regarded them as probably Eocene, a previous author believed them to be of Cretaceous age. Sir Emerson Tennant regarded them as a recent coral-formation, and this view is still held by engineers and others who have occasion to deal with them; while Mr. J. S. Boake, in a very ingenious, if entirely imaginary, representation of Ceylon geology, depicted them as covering
The Late-Glacial Stage of the Lea Valley (Third Report)
Authors: Warren Samuel Hazzledine
Published: October 2009

Shortly after the publication of the later of the previous papers on this subject, I discovered another exposure of the Late-Glacial deposits of the Lea Valley. It was found under rather unsatisfactory stratigraphical conditions, during some small secondary digging in a practically abandoned gravel-pit of large size. The sides of the pit are sloped down and overgrown, and in part built over, so that the stratigraphical relations of the deposit in question are obscure.

The site is on the higher margin of the 50-foot, or Taplow, Terrace, immediately below the 100-foot contour, east of the New River, and north of the road which runs through Barrowell Green, between Winchmore Hill and Palmers Green, Edmonton.

On the first visit, I noticed a bed of clav, about a foot thick, of which several yards could be seen. As it was clearly in place, and had been left as unprofitable during the digging, I took a sample home, and found it to yield seeds, but comparatively little vegetable debris apart from the seeds, so it was unusually easy to work for the purpose in hand.

A few days later I spent an afternoon in the pit, washing out as much of the clay as I could in the time, and forwarded the results to the late Mr. Clement Reid. He sent me a preliminary list and statement, which were not intended for publication until the identifications had been checked; this work Mrs. E. M. Eeid & Miss M. E. J. Chandler have now
The Fossil Flora of Clacton-on-Sea
Authors: Reid Eleanor Mary , Chandler Marjorie Elizabeth Jane
Published: October 2009

The investigation of the fossil flora of Clacton was first begun by the late Clement Reid in 1916, from material collected by Mr. S. Hazzledine Warren. The work was never completed, and, at the further request of Mr. Warren, it was taken up again in the spring of 1922 by ourselves, when we re-examined the whole material. By far the greater number of Mr. Reid's 111 determinations remain unaltered; but, in the case of a few, we consider that he was mistaken, and further research has revealed a considerable number of unrecognized, or undetermined, species, bringing the total up to 135, a list of which is appended (facing p. 622).

Before making any comments of our own, the conclusions to which Mr. Reid's work had led him must be stated. These may be gathered from his letters to Mr. Warren as the work progressed, between February 4th and April 5th, 1916. A few extracts from these follow here.

‘March 2, 1916 … The flora is most interesting, and is well worth further work, as it ought to throw much light on climatic conditions. Have you been able to make out where the stream came from, and what were the deposits that lined its banks? The flora does not agree with that of a stream flowing through London Clay; it points either to a dry climate or to dry gravelly stream-banks: I cannot say which.’

‘March 16, 1916 … These 58 species point clearly to a small stream (not estuarine), bordered
Note on a Mandible of a very Young
Elephas antiquus
from Clacton-on-Sea
Authors: Andrews Charles William
Published: October 2009

Some time ago Mr. Hazzledine Warren sent to me for examination the anterior portion of the lower jaw of a very young elephant, collected with numerous other Proboscidean remains from Clacton-on-Sea. Unfortunately, the teeth are missing; but, since all the other elephant-remains from the same horizon in this locality are referable to
Elephas antiquus
, it may be regarded as almost certain that this mandible is that of a fœtal or newly-born member of the same species.

Only the anterior portion of the jaw is preserved, the symphysial region being in an excellent condition: posteriorly the bone is broken away on both sides, a little behind the level of the anterior wall of the alveolus for the penultimate milk-molar. The symphysis is remarkable for its strongly developed beak, the upper surface of which seems to have made a very obtuse angle with the line of the alveolar border of the jaw: but, since this is much broken, the exact relations are not clear. Laterally, the sides of the beak are considerably pinched in; ventrally, it passes by a concave curve into the rounded and thickened posterior portion of the symphysis, the posterior face of which forms a broad, nearly vertical, spout-like channel.

The outer face of the mandibular ramus is strongly convex from above downwards; its upper alveolar border is so much broken that the anterior of the two mental foramina has come to lie at the upper edge of the jaw, and at first sight resembles an alveolus for a
Ostracoda from the
Elephas-antiquus
Bed at Clacton-on-Sea
Authors: Withers Thomas Henry
Published: October 2009

The freshwater Ostracoda submitted to me by Mr. Hazzledine Warren from the Elephas-antiquus Bed at Clacton, and now presented by him to the Geological Department of the British Museum, number well over five hundred specimens. An examination of these shows that four species only are represented, and, although the shells are extremely fragile, quite a large number of specimens have the two valves attached. All four species are still found living in the ponds and rivers of Europe, and two species,
Erpetocypris reptans
and
Ilyocypris gibba
, are quite common forms, with a very wide European distribution: they, moreover, occur fossil in the Weybourn Crag and in numerous Pleistocene deposits (including Grays, Clacton, and Whittlesey), while
I. gibba
is recorded from the Middle Hamstead Beds (Oligocene) of the Isle of Wight. Of the two remaining species,
Scottia browniana
is known living only at Lake Fadd (Bute), and
Potamocypris trigonalis
is known from Pegwell Bay; but T. Rupert Jones was of the opinion that this latter form was probably derived from the River Stour, which empties itself into the bay.

The numbers of specimens representing each species are, approximately:
E. reptans
, 200;
I. gibba
, 100;
S. browniana
,200; and
P. trigonalis
, 50.

E
rpectocypris reptans
(Baird).

1836.
Candona reptans
Baird, Hist. Berwicksh. Nat. Club, vol. i, p. 99 & pl. iii, fig. 11.

1857.
Candona reptans
Baird: T. R. Jones, Pal. Soc. ‘Monogr. Tert. Entomostraca’ p. 16 & pl. i, figs. 7a-7e.

1874.
Cypris reptans
(Baird): Brady, Crosskey, & Robertson, Pal. Soc. ‘Monogr. Post-Tert.
The Non-Marine Mollusca of Clacton-on-Sea
Authors: Kennard Alfred Santer , Woodward Bernard Barham
Published: October 2009

An account of the non-marine mollusca of Clacton based on the known collections was published by us in 1897,1 when we were able to record sixty-one species; but of these fifteen were unconfirmed records. Since then Dr. Frank Corner has kindly sent us a small series principally obtained from the estuarine bed, while the extensive collection of the late Dr. Henry Woodward has passed into our keeping. From this additional material we were able to raise the total number of known species to sixty-seven.

We are greatly indebted to Mr. S. Hazzledine Warren for placing at our disposal the results of his systematic exploration of these beds. The number of known species is now eighty-two, the longest list from any English Pleistocene deposit. One species,
Vertigo pusilla
Miiller, although recorded by S. V. Wood, we have omitted, since there are no examples extant. In the following table we have indicated in the first column the results of previous work, while the remainder show the frequency of each species in the various layers recognized by Mr. Warren.

From the estuarine bed three species were obtained, namely:—

Paladilhia radigueli
(Bourguignat) common,

Vivipara diluviana
(Kunth) rare,

Corbicula fluminalis
(Müller) rare,

as well as two marine species, namely:—

Scrobicularia plana
(Da Costa).

Cardium edule
Linn.

Thus sixteen new records are added to the list, while eight known species were not represented in Mr. Warren's collection.

Notes on the Species.

L
imax
.—Hitherto no species of
Limax
has been recorded from Clacton. Why this genus should be so rare
Les Gisements de Mammifères Paléocènes de la Belgique
Authors: Dollo Louis , de Chardin P. Teilhard
Published: October 2009

Nous avons, actuellement, quatre gisements de Mammifères paléocènes, en Belgique. Ce sont, en les énumérant dans l'ordre de leur découverte:

1.

Erquelinnes (Hainaut).

2.

Orsmael (Brabant).

3.

Leval (Hainaut).

4.

Vinalmont (Liége).

L'un de ces gisements (Orsmael) ayant fourni, dans ces derniers temps, d'abondants matériaux, le moment paraît opportun pour jeter un coup d'oeil sur ce qu'ont produit les quatre localités, en attendant l'apparition, dans les Mémoires du Musée royal d'Histoire naturelle de Bruxelles, de la monographie que prépare l'un de nous (P. Teilhard) sur les Mammifères paléocènes de la Belgique.

En 1880 M. A. Gravis, aujourd'hui Professeur de Botanique à l'Université de Liége, découvrait, dans les sabliéres d'Erquelinnes, les premiers restes de Mammifères paléocènes du pays, et il s'empressa d'en faire don au Musée de Bruxelles.

L'année suivante (1881), M. A. Rutot, alors Conservateur au Musée, les signala à l'Académie sous le nom de
Pachynolophus Maldani
. Il donna, en outre, une coupe du terrain, qu'il rapportait au Landénien supérieur.

Longtemps après (1909), l'un de nous (L. Dollo) y ajouta le
Coryphodon eocænus
. Et, tout récemment, il fit entreprendre de nouvelles recherches dans le gisement, qui amenèrent la découverte, au même niveau, d'une faune de petits Mamimifères. L'étude de ces restes, qui consistaient essentiellement en dents isolées, étant très délicate, ne pouvait être entreprise utilement que par quelqu'un s'étant déjà beaucoup occupé de ces formes sur de meilleurs matériaux (P. Teilhard).

C'est ainsi qu'il y reconnut, notamment, les genres
On a New Form of Blattoid from the Coal Measures of the Forest of Dean
Authors: Bolton Herbert
Published: October 2009

I am indebted to Dr. A. Morley Davies, F.G.S., for the opportunity of examining and describing a blattoid forewing or tegmen collected upon the spoil-heap of the Harrow Hill Mine, Drybrook (Forest of Dean), during the course of a visit to that place by a party of students from the Imperial College of Science & Technology in 1921.

The wing is a right forewing or tegmen, and lies upon a block of grey shale containing plant-remains.

The tegmen is somewhat large for a blattoid, having a length of 44 mm., and a greatest width (across the anal area) of 19 mm: it is thus a little over twice as long as wide. The surface is densely chitinous and lustrous, with sunken veins, while the wing presents structures not hitherto seen, so far as I know, in any other British or European blattoid.

The outer (costal) margin is moderately convex along the proximal two-thirds, and then curves more abruptly inwards over the distal third, so that the wing-apex is carried backward towards the inner margin, to which it is joined by a short curve. The inner margin is convex over the anal area, concave in the middle, and a little convex over the distal cubital area, where it passes by the short curve mentioned into the blunt apex.

The double curvature of the inner margin imparts to the wing a somewhat humped appearance.

The costal area is very wide basally, somewhat triangular, and terminates in an acute angle beyond the middle
The Structure of the Bowmore-Portaskaig District of Islay
Authors: Green John Frederick Norman
Published: October 2009

The island of Islay occupies a peculiarly critical position in connexion with existing controversies regarding the Highland metamorphic rocks.

The history of the various opinions held on the North-West Highlands is given somewhat fully in the Geological Survey Memoir (2, pp. 11–32). In brief, it was generally believed for many years that the geology of the Highlands was comparatively simple. The apparent succession in the north-west was accepted as the true one, and, as Cambrian rocks there underlay the gneisses and schists which covered the greater part of the Highlands, these were supposed to be Palæozoic rocks, regionally altered by post-Silurian movement. Although Nicol had argued that the succession was deceptive, and in 1860 had in reality indicated the correct solution of the main structural problems, Murchison and his supporters long maintained their position. The chief point at issue was settled by the work of Lapworth, published in 1883, after which the ‘upward succession’ was abandoned.

But the unidentified gneisses and schists at the top of the apparent succession: that is, those above the Moine Thrust, covering most of the Highlands, were still regarded as largely altered Palæozoic rocks, although the original evidence for this view had disappeared. Lapworth held the ‘eastern schists’ to be, unlike the Lewisian Gneiss, of post-Silurian dynamical manufacture from Archæan and later rocks.

The Geological Survey, mapping down the west coast of Scotland along the great thrusts, accepted, generally speaking, the theories of Lapworth, the tendency being to treat the schists that spread over the
The Igneous Rocks of the Tortworth Inlier
Authors: Reynolds Sidney Hugh
Published: October 2009

In a paper published in 1901 by the present writer, in collaboration with Dr. C. Lloyd Morgan, an account is given of the igneous rocks of the Tortworth Inlier, the divergent views of previous writers as to the contemporaneous or intrusive character of the rocks are summarized, and the occurrence of fossiliferous calcareous tuffs is proved, leading to the conclusion that the associated ‘trap’-rocks are lava-flows of Silurian age. The exposures of ‘trap’ in the neighbourhood of Woodford and Middlemill are considered to belong to the lower of the two trap-bands.

A second paper by the present writer, in this case in collaboration with Dr. F. R. Cowper Reed, published in 1908, was concerned only with the fossiliferous Silurian rocks. The work, however, led to the conclusion that the trap of Woodford and Middlemill does not belong to the lower band, but is really part of the upper band shifted northwards by a fault (see fig. 3, Q. J. G. S. vol. lxiv, 1908, p. 518). Further information relative to the igneous rocks, obtained when working at the above paper, was published in 1908 in the report of a committee of the British Association, appointed to investigate the pre-Devonian rocks of the Mendips and Bristol area. In this report reason is given for doubting whether the lower trap-band may not, after all, be intrusive. The rocks are exposed:—

(1)

by the stream about 300 yards south-east of Charfield railway-station;

(2)

in two old quarries, one
The River-Gravels of the Oxford District
Authors: Sandford Kenneth Stuart
Published: October 2009

The object of this paper is to investigate the contents and mutual relations of the Pleistocene fluviatile deposits associated with the headwater streams of the Thames, and to find what bearing they have on the history of the river and of Quaternary times.

The paper is rather of the nature of a first report, and contains much introductory matter, for the district to be considered has not received the amount of attention which has been paid to other parts of the same river.

The district in which the work has been carried out may be defined under two headings:—

(i)

Area of detailed work and close observations.

(ii)

A wider area which has come under observation, but which I have not been able to keep under careful scrutiny day by day.

(i) Roughly, the country lying within the bounds of the Oxford Special Sheet, Geological Survey Map, 1908.

(a)

The Thames from Newbridge to Culham.

(b)

The Evenlode from the upper end of its gorge near Chadlington by Charlbury, to its junction with the Thames at Cassington.

(c)

The Cherwell from Kirtlington to Oxford, where it joins the Thames. Ot Moor (Ray Valley).

(d)

The Thame as far up its course as Ickford.

(ii) The country enclosed by a line drawn on the map through the following places:—Banbury, Buckingham, Thame, Cholsey, Didcot, Marcham (near Abingdon), Newbridge (about 4 miles south