bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Occurrence in British Carboniferous Rocks of the Devonian Genus
Palæoneilo
, with a Description of the New Species P.
carbonifera
Authors: Hind Wheelton
Published: October 2009

The genus
Palæoneilo
was established by Hall for certain Nuculiform shells from the Devonian beds of New York. He selected as the type
Palæoneilo constricta
, which had hitherto been referred to the allied genus
Nuculites
by Conrad. The diagnosis of the genus was as follows:—

‘Nuculiform shells, transversely ovate or subelliptical, the posterior end often subrostrate, with a more or less defined sulcus along the umbonal slope. Cardinal line arcuate. Surface marked with striæ of growth, which are often lamellose and elevatel into concentric ribs. Hinge furnished with a row of regular small transverse teeth, which is sometimes interrupted beneath the beak by a change in the direction of the teeth, or by several oblique teeth. Ligament external, contained in a shallow and narrow groove along the cardinal border. Muscular scars not strongly impressed, situated below the extremities of the hinge–line. Pallial line simple.’ Hall referred twenty species to this genus.

The Nuculidæ are represented in Carboniferous rocks by the genera
Nucula, Nuculana
, and
Ctenodonta
, and to these must now be added Palæoneilo, Two fine examples of this genus are in the Museum of Practical Geology, Jermyn Street, labelled ‘Carboniferous Shale (bottom of Yoredale Shale), beck south of Hammerton Hall, Slaidburn, Yorkshire,’ which I think means that the shells occur above the massif of Mountain Limestone, at which horizon the allied genus
Ctenodonta
also occurs.

It is therefore curious that a genus so well developed in Devonian times should appear at the top of the Carboniferous Limestone Series, there being
The Silurian Sequence of Rhayader
Authors: Lapworth Herbert
Published: October 2009

I. Introduction.

(1) The Ordovieian and Silurian Complex of Central Wales. I
f
an examination be made of any general geological map of Wales, in which the outcrops of the various formations are marked with the colours habitually used by the Geological Survey, the attention is certain to be arrested by the broad spread of pale pink or purple colour which occupies the central portions of the map. It will be seen that this tint spreads over an area representing some 1800 square miles, or nearly one-fourth of the area of the Principality: stretching from Machynlleth to Caermarthen, and from the shores of Cardigan Bay nearly to the town of Builth.

Round this unbroken field of pale tint upon the map sweep mere strongly–coloured bands which mark the outcrops of the bordering formations; but within the central field itself little or nothing is given which would enable one to gather an idea of the sequence or distribution of its rocks. Even upon the latest Index Maps ot the Geological Survey, we find merely a few scattered reference–letters,— b
2
, b
3
, b
4
, b
5
,—which indicate that within this great region rocks are known to occur belonging to the Llandeilo, Caradoc, and Llandoverv formations; but no attempt is made to mark out the boundaries of the various groups.

The reasons are not very far to seek: we need only refer to any published description of the rocks themselves. In the words of the late Walter Keeping, 'Central and West Central Wales is made up almost
On a Particular Form of Surface, apparently the Result of Glacial Erosion, seen on Loch Lochy and Elsewhere
Authors: Blanford W. T.
Published: October 2009

There is a form of surface, the result, I believe, of glacial action and subsequent subaerial denudation, of which I have now seen examples in widely–separated areas. I first noticed it on Lake Como, then in the Great Glen of Scotland, and again in British Columbia.
1
These are the only striking instances that I have seen, but smaller and less conspicuous examples appear to be common in valleys that have been traversed by glaciers.

The surface in question consists of an almost even plane, sloping at a moderate or high angle, and cut at intervals by small ravines or channels, along which rain drains on.

I think it probable, indeed almost certain, that this peculiarity must have been noticed by other geologists. I have not succeeded in finding any description of it, despite some search, but I shall not be surprised if it has attracted the attention of some among the many eminent observers who have studied the glacial phenomena of Scotland, and if it has been fully described, perhaps by more than one. I do not call attention to the peculiar surface because I think it new to geologists, but because I believe, for reasons that will appear in the sequel, that this combination of glacial and freshwater erosion is worthy of further examination and record. I should perhaps have published some notes on it before, had I been able to obtain photographs or figures of the locality, but until recently I have been unable to procure any. Last
Contributions to the Geology of British East Africa.—Part II.The Geology of Mount Kenya
Authors: Gregory J. W.
Published: October 2009

I Introduction.

Mount Kenya, the greatest mountain in British East Africa, was discovered by Ludwig Krapf, 2 when on December 3rd, 1849, he saw its two-horned summit from a hill above the Wakamba village of Kitui. No suggestion as to the structure of Kenya was made until 1883, when Joseph Thomson, after a view of the mountain across the Laikipia plateau, described it as the denuded remnant of an old volcano. ‘The peak,’ he tells us, ‘without a doubt represents the column of lava which closed the volcanic life of the mountain . . . . The crater has been gradually washed away.’ The first definite geological information about Kenya we owe to Count S. Teleki, who was the first European to reach the mountain; in 1887 he climbed the western slopes to the height, of about 13,800 feet, and brought back some rock-specimens which have been described in detail in a valuable memoir by A. Rosiwal. This petrologist determined the specimens as augite-andesite, andesitepitehstone (hyalo-andesite), and phonolite, and thus proved the volcanic nature of the mountain.

Teleki's account of the structure of Mount Kenya differed, however, from that of !Fnomson. The former climbed through the forest-belt from Ndoro and entered a valley, which I have named the Teleki Valley (see map, P1. X); he followed this eastward until it suddenly bent northward and expanded into two great glacier-filled valleys, on the southern and south-western sides of the central peak. The high western wall of the Tyndall Glacier, the main
Contributions to the Geology of British East Africa.—Part III. The Nepheline-Syenite and Camptonitic Dykes intrusive in the Coast Series
Authors: Gregory J. W.
Published: October 2009

I. Introduction.

The interest of the great volcanic series of British East Africa is lessened by one drawback. The sequence of the lavas evidently extended over a prolonged period; a vast interval must have intervened between the eruptions that poured out the materials which form the rolling plains of Laikipia and the Athi, and those that built up the existing craters of Longonot and the Kyulu Chain. But this long series of volcanic rocks is not associated with contemporary sedimentary deposits whereof the age is known. The lacustrine beds interstratified with the volcanic rocks will no doubt some day yield up the vertebrate fossils which probably occur in them. Until then, however, the evidence for the correlation of the volcanic series of British East Africa remains deplorably scanty.

Accordingly I was much interested when, as I was passing through Mombasa in 1893, Mr. C. W. Hobley told me of some dykes intrusive in Jurassic rocks at the back of Wasin, an island south of Mombasa, where the British East Africa Company then had a station. Mr. Hobley showed me a specimen of the rock forming Mount Jombo, which he regarded, no doubt correctly, as the massif whence the dykes were given off. As I was unable myself to visit the locality, Mr. Hobley most kindly procured for me specimens of the dykes, and gave me three specimens of the rock from Mount Jombo itself. This material forms the basis of the present paper.

Mr. Hobley
1
has himself referred to the
Fossils in the Oxford University Museum.—III.
Ichnium Wattsii
, a Worm-track from the Slates of Bray Head: with Observations on the Genus
Oldhamia
Authors: Sollas W. J.
Published: October 2009

The abundant literature which has been evoked by certain curious markings in the ancient rocks of Leinster since they were discovered by Oldham in 1844 (1)
1
is illustrative of the interest aroused by an unsolved problem. Its solution would appear to be still incomplete, and the present communication, while adding to our knowledge, at the same time adds to the facts to be explained. Of late years the subject has acquired additional importance, since the recognition of specifically identical markings in similar rocks of other parts of Europe (12, 13, 14, 21) and America (23) has led some geologists to regard them as guides to the ‘identification of strata.’ Without expressing any opinion as to their value for this purpose, it may yet be noticed as a very remarkable circumstance that hitherto
Oldhamia
has not been recorded from younger rocks than the Lower Palæozoic; according to most writers, indeed, it is confined to the Cambrian System. Thus in the Ardennes
Oldhamia antiqua
is found associated with
Nereites cambrensis
in the greyish-green phyllades of Fumay; and in the Devillo-Revinian of Stavelot
O. radiata
occurs together with an
Agnostus
and
Arenicolites didymus
. In Brabant
O. radiata
is met with in the middle member of the series of phyllades and quartzites which are there supposed to represent the Cambrian. At one time De Lapparent
2
cited
Oldhamia
as present in Ordovician strata; his words are as follows:— ‘A la base [of the Silurian System] s'observent à Boutoury les couches à
Bellerophon
(
Ehlerti
et à
The Bunter Pebble-beds of the Midlands and the Source of their Materials
Authors: Bonney T. G.
Published: October 2009

I. Introductory.

Until the summer of 1895 I spent at least a month in every year in the immediate neighbourhood of the northern end of Cannock Chase. In 1880 I published
1
a short note on the pebbles in the Bunter Conglomerate, so largely developed on that moorland. A second appeared in 1883,
2
and the subject was mentioned in my address to Section C at the meeting of the British Association in Birmingham in 1886.
3
In 1890
4
I replied briefly to certain criticisms on the hypothesis which I had adopted in regard to the origin and history of these pebbles. Besides this, I published in 1888 some observations on the action of rivers in forming pebbles, the results of a journey planned with a view of obtaining the necessary facts, and in 1895 a note on the Budleigh Salterton pebbles which I had examined for comparative purposes. Since that year, when my close connexion with Staffordshire was broken, the pressure of other work has kept me from putting together information acquired after 1886, drawing up a summary of the whole evidence, and pointing out its bearing on the hypotheses which have been advanced as to the origin of the pebbles.

Throughout my work, though it was rather desultory, I have gathered facts for myself, and so shall not attempt to burden these pages with an elaborate list of the ‘literature of the subject.’ That prior to 1869 is enumerated in the memoir of the Geological Survey on the Coal Measures, Permian,
The Rocks of La Saline (Northern Jersey)
Authors: Parkinson John
Published: October 2009

The rocks of La Saline, an indentation of the larger St. John's Bay, resemble very closely those from Sorel Point, a little less than a mile to the west. Around the latter headland we find that a porphyritic granite has forced its way into a diabase, shattering and breaking it up, softening and locally melting it. Hence changes can be readily traced in the acid magma, which is rendered basic, and in the diabase which is impregnated by it. M. Noury mentions and maps
1
an outcrop of ‘diorite’ at one point in the bay of La Saline and surrounded by granite, but clear evidences of intrusion are wanting.

In a quarry on the cliff-top, and cropping out on a sloping path which leads towards the eastern end of the bay, is a rather coarse granite containing some quantity both of hornblende and mica, a fair amount of quartz, and large flesh-coloured orthoclases
sometimes ⅘ inch long. At the eastern end, and forming the crags on the shore, occurs a redder rock, less markedly porphyritic and inclining as a rule towards an aplite, though occasionally some quantity of black mica is present; its specific gravity is 2·60. At Sorel Point
2
two distinct intrusions of the acid magma are found: an earlier, porphyritic, which has melted and partly incorporated fragments of the diabase; and a later, non-porphyritic aplite which took the same course as did the first, but without its effect on the diabase. These two have kept
Further Evidence of the Skeleton of
Eurycarpus Oweni
Authors: Seeley H. G.
Published: October 2009

In 1876
1
Sir Richard Owen figured a fossil from the Sneeuwberg which was referred to a young or small Dicynodont reptile, and described as showing impressions of the neural arches and ribs, of cervical and dorsal vertebræ, and of bones of the left fore-limb. Eight ribs are shown and described. It is stated that ‘the distal end of the humerus is much expanded; the radius and ulna are distinct and in a prone position; the palm of the fore-paw has impressed the surface of the slab.’ The hand is briefly described, and the author remarks upon the agreement with the mammalian formula of phalanges, seen in its five digits. This underside of the hand was figured again in 1880
2
in illustration of the foot of
Platypodosaurus
. Owen mentions no evidence of the Dicynodont characters of the specimen, though it was doubtfully referred to
Dicynodon
. It was afterwards named
Eurycarpus Oweni
and more carefully figured in 1889.
3
The original specimen was presented to the British Museum in 1872 by Mr. Thomas Bain, through Sir Henry Barkly, who was then Governor of Cape Colony.

One of my objects in visiting South Africa in 1889 was to recover, if possible, the remainder of this specimen, which was the only skeleton then known with the limbs in natural association with the vertebral column. A visit to Graaf Reinet, however, was not possible. But I ascertained that the skull was found with the complete skeleton, and that a short memorandum on its characters was made
On an Intrusion of Diabase into Permo-Carboniferous Rocks in Frederick Henry Bay, Tasmania
Authors: Stephens T.
Published: October 2009

The most striking features in the geological structure of by far the greater part of Tasmania are the lofty mountain-ranges, which, to the casual observer, appear to consist solely of diabasic greenstone, or dolerite, as it is variously termed. Tasmania is in extent nearly as large as Ireland, and this rock occupies the summits of all the mountains in the eastern half of the island, extending well into the western half in the central and southern districts, and reaching a maximum altitude of 5069 feet above sea-level. But the diabase is not confined to the mountain-ranges. It crowns almost every considerable hill within the area described; it is exposed at numerous points in the river-beds and valley-bottoms; it fringes the margin of basaltic lava-flows of Tertiary age; and its presence has been detected elsewhere by boring through overlying sedimentary strata.

The oldest sedimentary rocks exposed in the south-eastern quarter of Tasmania belong to that division of the Upper Palæzoic Series which in Eastern Australia and Tasmania is classed as Permo-Carboniferous. The question of the relations of these sediments to the diabase has often been raised. Were they quietly deposited during a long unbroken period against and around vast masses of igneous rock previously cooled and denuded? Or is the diabase an intrusive rock, the existence of which in the shape of vast dykes and sills has been disclosed through the removal of overlying strata by the ordinary processes of denudation? The former theory seems to have been widely accepted as
Notes on the Geology of Gilgit
Authors: McMahon C. A.
Published: October 2009

Part I.—Introduction.

My son, Capt. A. H. McMahon, C.S.I., C.I.E., Y.G.S., Political Agent, Malakand, when stationed at Gilgit, made field-observations and collected rock-specimens for me in the course of numerous traverses through the Gilgit area.

I have not had an opportunity of visiting the region covered by this paper; but I have seen much of the neighbouring Himalaya, and I have had the advantage of correspondence not only with my son, but also with Capt. J. R. Roberts, I.M.S., regarding the geology of Gilgit. I am greatly indebted to Capt. Roberts for much valuable information, for field-observations undertaken on my behalf, for careful drawings of sections, and for numerous additional specimens supplementing those sent by my son. I cannot overrate the obligations under which I am to him.

A sketch-map (see p. 344) has been prepared to accompany this paper, compiled mainly from the map of the Pamirs (1896) by H. Sharbau and the Right Hon. G. N.—now Lord—Curzon; and from the map of Astor and Gilgit (1883) by the Surveyor-General of India.

The geology of the neighbouring parts of Kashmir has been described by Mr. R. Lydekker, Y.R.S., in vol. xxii (1883)of the Memoirs of the Geological Survey of India, and in papers published in the Records of the same Survey. The map published with the above-mentioned Memoir shows the geology of Kashmir as far as Astor, at which place this paper takes up the geology.

An account of the geology of Yárkand, Káshgar, Wákhan the Great and Little
On Longmyndian Inliers at Old Radnor and Huntley, Gloucestershire
Authors: Callaway Charles
Published: October 2009

I. Introductory.

The rocks of the Longmynd Hills, in Western Shropshire, originally supposed to be Lower Cambrian, are now admitted to be of pre-Cambrian age. In the following pages evidence will be offered which will enable us to extend the distribution of the Longmyndian system to a considerable distance from the typical area.

I. The Longmyndian Inlier at Old Radnor.

The village of Old Radnor is situated on the western slope of an
isolated ridge, about ¾ mile long, striking north-east and south-west. The mass of the hill is composed of grit, but there are some associated slaty bands, and on both sides of the ridge the Woolhope Limestone is largely exposed. Murchison
1
considered the grits to be May Hill Sandstone, and the Woolhope Limestone was supposed to be in conformable succession with it. He perceived, however, that neither grits nor limestone possessed the normal characters of the groups to which he believed them to belong, and he attributed their peculiarities to the metamorphic action of intrusive igneous masses. On the Geological Survey map, the arenaceous series is described as ‘altered sandstone,’ and identified as May Hill Sandstone.

Many years ago, I was struck with the close lithological resemblances between the Old Radnor Series and some parts of the typical Longmyndian, and I could not acquiesce in the view that he rocks were ‘altered’ in the sense of being truly metamorphic; but it was not until the summer of 1897 that I ascertained the existence of
On an Anomodont Reptile,
Aristodesmus Rütimeyeri
(Wiedersheim) from the Bunter Sandstone near Basel
Authors: Seeley H. G.
Published: October 2009

I. Introduction.

Dr. Robert Wiedersheim, of Freiburg-im-Breisgau, has described a remarkably perfect skeleton of a small reptile, which is known as
Labyriuthodon Rütimeyeri
. The remains are a natural mould of the bones, in friable sandstone contained in two slabs, so divided as to display in many cases the under and upper surfaces of the cavities from which the bones have been dissolved away. The fossil was found at Riehen, near Basel, in the Bunter Sandstone ; and is preserved in the Museum of the University of Basel. Prof. Wiedersheim made a restoration of the skeleton, which was published in 1878, with figures of both slabs, by the Swiss Palæontological Society.

The animal is said to show no trace of abdominal armour, such as characterizes
Archægosaurus
and most Labyrinthodonts. It does not possess the breast-girdle of median and lateral sculptured bones, found in Labyrinthodonts ; and the skin is inferred to have been naked. The external surface of the skull, which would have demonstrated its form and structure, is not available, having been, as Prof. Wiedersheim states, chipped away to expose the internal mould of the head. The bones are said to have been smooth and free from sculpture ; and on that account the skull is compared to
Hylonomus
of the Coal Measures.

It was regarded us an Amphibian, in opposition to Von Meyer's view that the Labyrinthodontia are true Reptilia.
1
The type is unique in Europe. The original figures were unsatisfactory, and I applied to the late Prof. Rütimeyer
The Igneous Rocks of the Coast of County Waterford
Authors: Reed F. R. Cowper
Published: October 2009

I. Introductory.

In a former paper on the Waterford coast
1
the Ordovician sedimentary beds and the contemporaneous lavas and tufts were described.- It is now proposed to give an account of the other igneous rocks which occur along the coast, on which I have been at work for the last seven years during repeated visits.

The great complexity of their relations has been noticed by many observers, and while the following account does not claim to be exhaustive, an attempt is here made to determine the order and relations of the principal outbursts of volcanic energy and to describe some of t~he characters of the rocks.

The bibliography of the Lower Palæozoic rocks of County Waterford has been given in detail in my previous paper. With regard to the igneous rocks, however, the papers by Weaver,
2
Jukes,
3
and Haughton
4
may be referred to, and the accounts by Mr. McHenry & Prof. Watts,
5
and Sir Archibald Geikie
6
may be specially mentioned The Geological Survey Memoir for Sheets 167, 168, 178 & 179 is a fund of information; and further reference to the igneous rocks will be found in papers by Haughton,
7
A. von Lasaulx,
8
and Dr. Hatch,
9
and in Mr. Teall's ‘British Petrography’ (pp. 248, 348).

The description of the igneous rocks is here given in the first place according to the main petrological types. After having examined the available information as to the relations of these types, we shall be in a position to determine their age and the sequence
The Geology of Mynydd-y-garn (Anglesey)
Authors: Matley Charles A.
Published: October 2009

I. Introductory

Above the village of Llanfair-y'nghornwy, in the north-west of Anglesey, stands a hill known as Mynydd-y-Garn or The Garn. Although rising to a height of less than 600 feet above Ordnance datum, it is one of the highest hills in the county, and is so well elevated above the surrounding country that from its crest the view embraces the greater part of the island, the Caernarvonshire mountains, and large expanses of sea.

Ramsay in his memoir on the ‘Geology of North Wales’ makes but slight mention of the Garn,
1
merely noting that it lies in a much-faulted district. Prof. Blake gave a brief notice of the geology of the hill in his ‘Monian System of Rocks’;
2
and the present writer gave, incidentally, a further short account in a recent paper.
3
The results of a more detailed examination of the geological structure made during the past summer seem to warrant a more extended description than any hitherto made.

II. Stratigraphy, and Description of the Rocks

The mass of the hill consists of an inlier of sericitic and chloritic schistose phyllites, usually green, surmounted by a massive conglomerate, and surrounded by black slates and shales. The slates, apparently of Upper Llandeilo age, form, a strip about a mile in width, and are bounded both on the north-east and south-west by fractures which bring them against older rocks.

A geologist making a traverse from Craig-y-gwynt over the hill in a north-north-westerly direction (see fig. 1, p. 22) and then north-north-eastward to
On some Tufaceous Rhyolitic Rocks from Dufton Pike (Westmorland)
Authors: Rutley Frank
Published: October 2009

The specimens which form the subject of this paper were selected for examination on account of their peculiar appearance, and because it was thought probable that they might afford some evidence of solfataric action on British rhyolites of considerable geological age. Through the kindness of my friend Mr. H. B. Woodward, F.R.S., I have been able to learn a few particulars concerning the geology of Dufton Pike. From these it appears that the central portion of the Pike consists of volcaninc rocks of the Borrowdale Series, bounded by four faults, those on the east and west being approximately parallel and running in a north-north-westerly direction. The rocks faulted against this central mass of volcanic rocks are of Lower Silurian age on the north, south, and east; while those on the west are Upper Silurian, consisting of Stockdale Shales and Coniston Flags.

The specimens about to be described were collected by the late Prof. A. H. Green, F.R.S., and Mr. J. G. Goodchild, F.G.S., and were evidently procured from the Borrowdale Volcanic Series which constitutes the central mass of Dufton Pike. The specimens were given to me many years ago, so that, never having visited that part of Westmorland, I am ignorant of the precise spots from which they were derived. The chief interest which attaches to them lies in the peculiar character of the alteration that they have undergone: an alteration which appears to me to have been probably due to solfataric action.

For the careful analyses which accompany this
On the Corallian Rocks of St. Ives (Huntingdonshire) and Elsworth
Authors: Wedd Charles Bertie
Published: October 2009

I. Introductory Remarks

Lately while mapping the Ampthill Clay, I have been able to trace the Elsworth and St. Ives Rock for a considerable distance. I propose to give here a sketch of its outcrop and some account of exposures not previously noticed. The district here treated of is contained in the 1-inch quarter-sheets of the Geological Survey, Nos. 51 north-west & south-west (western part) and 52 north-east & south-east (eastern part), and in the New Series Map Sheet 187 (not yet published).

From Prof. Seeley's
1
papers the following description of the Elsworth Rock at Elsworth may be extracted:—

It is known to occur throughout the village of Elsworth, passing southward under Ampthill Clay with three whitish-grey stonebands.

Prof. Seeley (
op. cit.
) also recorded rock-beds of type similar to the Elsworth Rock from wells at Bourn (3 miles south-south-west of Elsworth), Papworth Everard, and Conington ; but he considered that the rock at the latter two places belonged to a lower horizon than that of Elsworth.

In a brickyard west of St. Ives a like rock has long been known (the St. Ives Rock); in other brickyards north and north-east of St. Ives beds of rock were noticed by Prof. Seeley as dipping eastward, and these he was inclined to think were continuous with the Rock west of the town.

A collection of fossils in the Woodwardian Museum, agreeing closely with the fauna of the Elsworth and St. Ives Rock, was supposed to have come from Holywell, but the occurrence of the limestone
The Unconformity in the Coal-Measures of the Shropshire Coalfields
Authors: Clarke William James
Published: October 2009

This unconformity, locally known as the Symon ‘Fault,’ has received so much attention from geologists in the past, that it would almost seem superfluous to attempt any new study of the subject. So far back as 1861 it was brought by the late Marcus Scott before the notice of the Geolgical Society
1
in a very valuable paper, of the facts contained in which I shall here make use, though my inferences will be somewhat different from his.

In 1863, Mr. John Randall, in a joint paper with Mr. George E. Roberts, read by Sir Andrew Ramsay before the Geological Society,
2
showed that the same agency which created the Symon or Great East ‘Fault’ in the Coalbrookdale Coalfield had removed the whole of the older or lower beds of coal and accompanying seams of ironstone from the Devonian rocks several miles south of the above field, and that they had been replaced by two beds of inferior coal. Between the upper two of these seams was a bed of limestone containing
Spirorbis carbonarius
of sufficient thickness to repay burning for lime, the whole dipping apparently beneath the Bunter Sandstone, and reappearing in the same order, as Sir Roderick Murchison showed, a mile farther south at Cantern Bank and Tasley near Bridgnorth. Mr. Randall, in subsequent papers read before various scientific societies, and more particularly in his work on ‘The Severn Valley,’ published in 1882 (Madeley), showed that the same phenomenon of the Symon or Great East ‘Fault’ was observable all the
Note on the Occurrence of Corundum as a Contact-Mineral at Pont Paul near Morlaix (Finistère)
Authors: Coomára-Swámy A. K.
Published: October 2009

In the neighbourhood of Morlaix the schists and quartizites of the Lower Devonian are extensively developed. They are much altered, and often injected by intrusive granite. The altered rocks are described by Prof. Barrois as quartzites micacés and leptynolithes. The minerals found in the latter include biotite, muscovite, andalusite, sillimanite, quartz, iron-oxide, chlorite, garnet, staurolite, zircon, graphite, and rarely felspar. The quartzites micacés contain large grains of irregular quartz (not clastic), with flakes of dark and white mica, zircon, iron-oxide, graphite, and garnet.

Among the intrusive masses, that of Pont Paul is of especial interest. The rock is a granite rather poor in quartz; the minerals include orthoclase, microcline, oligoclase, quartz, hornblende, biotite, apatite, zircon, sphene, and allanite (the last two not noticed by myself). The granite is much decayed for a depth of many feet. Included fragments of dark micaceous rocks are to be found in it: they are about the size of a man's fist, and not very abundant. Some may be found
in situ
, and dug out of the crumbling granite, others by searching the floor of the shallow quarry. These included fragments resemble the Devonian leptynolithes of the district. They contain abundantly small tabular hexagonal crystals of blue corundum, first noticed by Prof. Barrois in 1887.

Examination of thin sections of the included fragments shows that the minerals certainly present are biotite, muscovite, corundum, plagioclase, andalusite, pyrite, magnetite, sillimanite, green spinel, and zircon. Orthoclase and quartz may possibly occur.

The corundum is very abundant, forming conspicuous
On the Origin of the Dunmail Raise (Lake District)
Authors: Oldham Richard Dixon
Published: October 2009

Every visitor to the English Lakes, who has travelled by coach from Windermere to Keswick, must know the Dunmail Raise, that deep-cut wind-gap through the mountains which forms, if properly understood, one of the most remarkable natural features that it has been my lot to see one of the most difficult of satisfactory explantion, and one which has not by any means attracted the attention that it deserves.

Cut down to a height of 782 feet above sea-level, the gap lies between the masses of Helvellyn (3118 feet) on the one hand, and High Raise (1500 feet) and the Sea Fell Pikes (3210 feet) on the other; it forms a typical instance of the lückenpass of Richthofen, or wind-gap of the Americans, but differs from the majority of such in one important point which will be brought out in the sequel.

Approaching the pass from the north, there is seen a deep-cut valley, broad and open at the bottom, from which the sides rise steeply in, what Mr. Marr has named, the curve of erosion; it is; in fact, a typical stream-valley, and a valley properly belonging to a volume of water to which the term river is applicable; yet when this gradual ascent is traversed the road, after a short steep rise over a moraine, crosses an insignificant little streamlet, the Birkside Gill, which is utterly out of proportion to the valley down which it now flows, and is a very glaring instance of what Prof. W. M. Davis
The Hollow Spherulites of the Yellowstone and Great Britain
Authors: Parkinson John
Published: October 2009

I. Introduction

In a paper which I had the honour of presenting to the Geological Society some time ago on the Pyromerides of Boulay Bay, I explained the formation of these nodules by supposing the extrusive magma in which they were produced to be imperfectly mixed and in a somewhat viscous state, a conclusion which facts in the field appear amply to justify. These, and other nodules which I studied in North Wales and near Wrockwardine, led me to suppose that the dominant characteristic of these peculiar structures was not that of spherulitic growth, which rather was secondary, and that the principal cause operating in their formation, as just remarked, was a clotting in the magma by a process of flow-brecciation. At the same time, I did not suggest that this was the sole means by which pyromerides were produced, and moreover I purposely left some of the structures which are found, notably the not infrequent concentric arcs of quartz, for later consideration and discussion. Recently, in crossing the American continent, I made a detour to the Yellowstone Park with the object of studying the obsidian there, and it is the result of this excursion which has led to the putting together of the following notes. Since the paper above referred to was written, I have examined the rocks of Boulay Bay and Wrockwardine for the third and second times respectively, and have studied those of Pontesford Hill.

The general features of the National Park of the United States are
Recent Geological Changes in Northern and Central Asia
Authors: Wright George Frederick
Published: October 2009

There are so many points of resemblance between Northern and Eastern America and the corresponding areas of Asia that one would naturally expect to find that the Glacial history of the two evidence is abundant and unmistakable, that in post-Tertiary times Glacial ice extended along the Atlantic coast southward from Labrador and the Hudson-Bay region as far as New York City in lat. 40°, and in the Mississippi Valley to Carbondale in Southern Illinois, about lat. 38°. North of an irregular line connecting these points the whole country was, at a very recent period, covered with Glacial ice as deep as that which mantles Greenland at the present time. In all, about 4,000,000 square miles were brought under the direct influence of Glacial ice in America.

Being familiar with nearly the whole of this North American field, and somewhat so with the glaciated portions of Europe, I set out, a little more than a year ago, in company with my son, Mr. Frederick B. Wright, to examine those portions of the Asiatic Continent which most nearly correspond in general superficial conditions to the glaciated portions of America. Sailing from San Francisco in February 1900, we spent six weeks in Japan, and satisfied ourselves that lofty as the mountains are, there have never been extensive glaciers among those on Nippon, the largest of the islands. From the verbal reports made to us by Prof. Jimbo, of the University of Tokyo, it seems equally clear that the more northern island of Yesso
On the Use of a Geological Datum
Authors: Thompson Beeby
Published: October 2009

A proper interpretation of geological phenomena frequently requires that allowance shall be made for differential earth-movements that have taken place since the period under consideration. Present differences of level in rocks of the same age may be due to actual differences in depth of the sea-floor on which they were deposited; but they may also be the result of subsequent differential earth-movements. The rock selected as a datum should combine as far as possible the following characteristics :—It should be thin, of considerable horizontal extension, having similarity in physical characters and palaeontological contents over a large area, and situated as near as possible, in vertical sequence, to the reference-deposit. In Northamptonshire three formations meet these requirements—the Rhætic Beds, the Marlstone Rock-bed, and the Cornbrash. The Author applies the Marlstone Rock-bed as a datum to the study of the five chief deep explorations in Northamptonshire, with the following results:—While the old land-surface (below the Trias) now varies in height by more than 250 feet, the variation in thickness of the rocks between it and the Middle Lias
only reaches 56½ feet; and although the old land-surface is actually lowest where the Rhætic rocks have not been detected, when compared with the position of the Marlstone it is found to be the highest. The further application of the same method enables the Author to recognize Rhætic rocks at Northampton, to correct the record of the Kingsthorpe shaft, and to explain the presence of Triassic saline water in the Marlstone. A revised section of the Kingsthorpe shaft is given. Another point proved is that a general levelling-up process was going on just before the beginning of the Lower Liassic Period, and another at the close of the Middle Liassic Period.
The Geological Succession and Palæontology of the Beds between the Millstone Grit and the Limestone-Massif at Pendle Hill and their Equivalents in certain other Parts of Britain
Authors: Hind Wheelton , Howe John Allen
Published: October 2009

I. Introduction

The following paper is an attempt to define the geographical extent, stratigraphical sequence, and palæontological horizon of the beds which lie between the top of the Mountain Limestone and the series of grits known as the Millstone Grits. We have taken as the type-section that on Pendle Hill (Lancashire), where these beds attain their maximum development; and as the term Pendleside Limestone has already been employed by the officers of the Geological Survey to designate the calcareous member of the group, we propose to extend the term to the whole group defined above and call it the Pendleside Group.

It will be observed that this term includes the ‘shales-with-limestones’ that rest on the Mountain Limestone of the Derbyshire and North Staffordshire area, to which the name ‘Yoredale’ has been frequently applied; but one of us has already demonstrated the fact that the Yoredale Series of Wensleydale is totally different from the Pendleside Group, and that the former is the equivalent of the upper part of the Carboniferous Limestone massif, both on palæontological and stratigraphical grounds.

The present paper is divided into six sections: the first being a brief introduction; the second describing in some detail the various occurrences of the beds with their fossils; the third embodies a general account of the palaeontology; the fourth is a sketch of the probable physical conditions of the period; the fifth describes some of the chemical and physical characters of the rocks; while the sixth deals with the petrology and micropalæontology.
The Influence of the Winds upon Climate during the Pleistocene Epoch: a Palæometeorological Explanation of some Geological Problems
Authors: Harmer Frederic William
Published: October 2009

I. Introductory

The progress of meteorological science during recent years has given us much information as to the causes of the constant, and to a superficial observer the apparently capricious, changes of weather which obtain over certain portions of the earth's surface. We understand now, not only why, in Great Britain for example, one day is dry or cold, and the next rainy or warm; but also why the general character of the seasons often differs so widely from the normal, the climate of spring being experienced at one time in January, and the conditions of winter in May or June. The scientific meteorologist, equally with the unlettered peasant, still looks, however, to the vane on the church-tower for his first explanation of anomalous weather, though the meteorologist shows us that the direction of the winds is due to the relative position, and to the form and alignment, of areas of high and low barometric pressure. The winds must necessarily blow, as is well known, in a direction more or less parallel to the isobaric lines, moving in the Northern Hemisphere outward from, and round the centre of, an anticyclone in the direction of the hands of a watch, and towards and round a cyclone in the opposite direction. To use the old formula (Buys Ballot's law), ‘if you stand with your back to the wind, you have the higher barometer on your right hand.’

The comparatively genial climate of Great Britain during the winter is attributed to the Gulf
On the Geological and Physical Development of the St. Christopher Chain and Saba Banks
Authors: Spencer Joseph William Winthrop
Published: October 2009

I. Introduction

The islands of Saba, St. Eustatius, St. Christopher, Nevis, Redonda, and Montserrat form the interrupted extension of the mountain-district of Guadeloupe, constituting a succession of volcanic ridges, surmounting the Caribbean side of the eruptive belt, which is seen to have a breadth, at sea-level, of 35 miles.

The Saba Banks, situated upon the south-western side of the eruptive backbone of the Antillean chain, correspond to the sunken areas of the St. Martin-Anguilla and Antigua-Barbuda banks, upon the eastern side.

William Maclure's contributions in the early part of the nineteenth century refer to some of these islands. Mr. P. T. Cleve's paper is, however, the most valuable geological publication on the subject. Locally, Dr. Christian Branch and his father have given much attention to the natural history of St. Kitts, and they kindly conducted me to many points of interest.

St. Christopher, everywhere in the West Indies called St. Kitts, with St. Eustatius, called Statia, on one side, and Nevis on the other, form a trisected ridge, fringed by a narrow submarine coastal plain, sunk to a depth of between 80 and 140 feet, which last rises above the floor of the submarine Antillean plateau to a height of between 2000 and 2700 feet or more. Saba is an isolated volcanic cone rising out of equally deep water; and Montserrat, to the south-east, is another island of more varying character along the same axis. This submarine chain, which is about 100 miles long, does not exceed a breadth of
On the Clarke Collection of Fossil Plants from New South Wales
Authors: Arber E. A. Newell
Published: October 2009

The earliest scientific descriptions of fossil plants, from the rocks of New South Wales, are those by Brongniart of the genera
Glossopteris
and
Phyllotheca
, published in his ‘Prodrôme’ in 1828. In his ‘Histoire,’ published in the same year, figures and specific descriptions of these, and other genera, are to be found. It was not, however, until some years later that the first systematic collections of fossil plant-remains from this region were begun by the Rev. W. B. Clarke, Count Strzelecki, and by Dana. In 1845 Morris published an account of Strzelecki's collection; and two years later McCoy examined the Clarke Collection, made between 1839 and 1844, which he described in a paper in the Annals & Magazine of Natural History, in 1847. Dana's specimens were described in 1849. The Clarke Collection, numbering nearly 2600 specimens of all kinds, including some 80 fossil plant-remains, was, by the great generosity of its owner, presented to the Woodwardian Museum, Cambridge, in November 1844.

As already stated, the more important paleeobotanical specimens in this collection were described by :McCoy in 1847, twelve being regarded as new types. It has been thought, however, that a reexamination of this early collection, in the light of the recent advancement of our knowledge with regard to the structure and affinities of fossil plants from Australia, India, South Africa, and elsewhere, might not be without value, especially as the more modern memoirs on the fossil flora of Australia, by Feistnnantel and Tenison-Woods, contain in several instances only the original
Notes on the Genus
Lichas
Authors: Reed Frederick Richard Cowper
Published: October 2009

I. Introductory.

During 1901 a boring was made near Lyme Regis in search. of coal, and was carried to the depth of 1300 feet without reaching the base of the Upper Triassic marls.

The story of this endeavour to find coal at a place where no geologist would have recommended the attempt, is one which has often been repeated at different places. The undertaking was promoted by a ‘practical man’ who had experience of coal-mining in South Wales, and who had convinced himself that coal was likely to be found at no great depth near Lyme Regis. He obtained permission to bore, and induced a certain number of persons to form a syndicate, for the purpose of making a boring to ascertain the depth at which the expected Coal-Measures were to be found.

The results of the boring have a twofold interest: first, to all people in the South-west of England they should be a warning against the folly of expecting to find Coal-Measures at a depth of less than 2000 feet below any part of Western Dorset; secondly, they are of interest to geologists, for the information which is thus afforded as to the great thickness of the Keuper Marls in Devon and Dorset.

It was anticipated that coal would be reached at a depth of less than 600 feet, and when this limit was passed without success it was decided to continue the boring to 1200 feet. At this depth it would have been abandoned, had it not
On
Polyphyma
, a New Genus belonging to the Leperditiadæ, from the Cambrian Shales of Malvern
Authors: Groom Theodore
Published: October 2009

I . Occurrence.

The number of lobulated ostracoda at present recorded from the Cambrian formation is very small, and the species are still very imperfectly known. Forms referred to
Beyrichia
have long been known from the Cambrian beds of Scandinavia, Stockingford, and South Wales. The writer some time since detected in the lowest portion of the Malvern Black Shales a species identical with the Stockingford form, which latter had been provisionally identified with the Swedish
Beyrichia Angelini
, Barr. The specimens obtained from the Stockingford Shales were few and imperfect; the Malvern examples are far more abundant and, though for the most part imperfect, are better preserved. They present characters which serve to separate the species from those now placed under the genus
Beyrichia
. Many of the specimens have been submitted to Prof. T. Rupert Jones, who (after an examination kindly made of much of the material) considers it impossible to refer the form to any known genus, and recommends the stablishment of a new genus and species. I would propose to describe the species under the name of
Polyhyma Lapworthi
.

The specimens were obtained from the Black Shales (M 257) at the northern extremity of Chase End Hill, in the Southern Malverns, where they were associated with
Acrotreta
sp.,
Kutorgina pusilla
, Sars,
Protospongia fenestrata
, Salter, and other fossils. The shales are nowhere actually exposed, and can be reached only by excavation. Some two days' work with the pick and spade produced perhaps a hundredweight of the shale in small pieces.
The Sequence of the Cambrian and Associated Beds of the Malvern Hills
Authors: Groom Theodore
Published: October 2009

In a former communication
1
the disposition of the older Palæozoic beds in the Southern Malverns was described, but few stratigraphical details were given. It is proposed on the present, occasion to complete the description of these rocks, with the exception of the lithology. Further research has strengthened the conclusions formerly drawn, and has afforded some additional evidence as to the succession; while diligent collecting, and examination of the specimens previously collected, has added many fossils to the small stock hitherto known. A number of these are new ; they have already been described in part by Mr. Frederick Chapman,
2
and by the author,
3
and descriptions of the remainder by Mr. C. A. Matley and the present writer will be found towards, or at the close of this paper, together with some notes on certain trilobites for which Mr. Philip Lake and myself are jointly responsible.

The following subdivisions of the strata may now be recognized: