Showing papers in "Quarterly Journal of The Geological Society in 1905"

The Palæntological Sequence in the Carboniferous Limestone of the Bristol Area

Abstract: I. Introduction. This paper deals with the fossil sequence in the Carboniferous Limestone of the Bristol area, and with the possibility of dividing that system into a series of palaeontological zones. The general geology of the area has been most luminously expounded by Prof. Lloyd Morgan in the series of papers which he has contributed to the Proceedings of the Bristol Naturalists9 Society, and to these I make constant reference. I am thus able largely to dispense with detailed accounts of topography and lithology, which would otherwise interrupt seriously the palaeontological discussion. Mr. E. B. Wethered has contributed a most instructive paper Q.J.G.S. No. 242. ‘On Insoluble Residues obtained from the Carboniferous-Limestone Series at Clifton,’ and it is with his lithological divisions that I have mainly correlated the palaeontological zones suggested in this paper. To the late Mr. W. W. Stoddart we owe the first attempt to compile a list of the fossil contents of the beds in the Avon Section. I have drawn up a complete analysis of his observations, so far only as the Corals and Brachiopods are concerned; this will, for convenience, follow immediately upon the detailed account of my own observations on the Avon section. For my purpose, it is obvious that the essential desiderata are good exposures, the relative stratigraphical position of which is unquestionable. Exposures which satisfy these two conditions are to be found in several parts of the Bristol area, and, from them, the determination of the faunal sequence is merely a matter

The Relations of the Eocene and Cretaceous Systems in the Esna-Aswan Reach of the Nile Valley

Abstract: In the autumn of 1904 I had occasional opportunities of examining the desert-margins on both sides of the Nile Valley, between Aswan and Esna. The geological information hitherto published on this part of Egypt is so scanty that no apology is needed for putting on record the following observations, which, although disconnected, have an important bearing on a somewhat vexed question of Egyptian geology, namely, the mutual relations of the Cretaceous and Eocene systems. (1) The Kom-Ombo Plain. From Aswan to Darau the valley is comparatively narrow. Immediately north of the latter place it opens out, from a narrow gorge closed in by sandstone-hills, to a broad plain bounded by an undulating sandstone-desert on the west side, and by the ordinary sandstone-hills on the east: the latter running round in a wide curve, and not approaching the river until Jebel Silsila, 30 kilometres ( miles) farther north, is reached. In the centre of this area, on the eastern bank of the river, is the temple of Kom Ombo, from which the plain takes its name. As has long been recognized, the plain is superficially an extensive alluvial deposit; in addition to the sands and clays, with fluviatile shells and occasional mammalian bones, bands of tufaceous limestone are met with in the neighhourhood of Fatira. These deposits cannot be classed with the recent Nile alluvium, as they belong to the period of the great Pleistocene lakes of the Nile Valley, and have their surface some 25 metres (82 feet) above the

On the Geology of Arenig Fawr and Moel Llyfnant

Abstract: I. Introduction. The mountains known as Arenig Fawr and Moel Llyfnant are situated somewhat to the north of the centre of the county of Merioneth, and lie immediately east of the main water-parting of Wales. The area studied lies wholly within the quarter-sheets 13 S.E., 13 S.W., 21 N.E., & 21 N.W. of the 6-inch Ordnance-Survey maps of Merionethshire. Rising from a plateau some 800 to 1200 feet high, they attain heights of 2800 and 2437 feet respectively, and, being entirely above the cultivation-zone, are practically uninhabited. The Great Western Bala-Ffestiniog Railway crosses the northern end of the district, to which Arenig Station, close under the northern slopes of Arenig Fawr, affords easy access. Although to a certain extent glaciated, the mountains are swept clean rather than Drift-covered, and it is only in the lower ground that moraines become inconveniently abundant. The adaptation of surface-forms to rock-structures is exceedingly complete, and few are the places where the ribs of harder rocks do not protrude through the scanty soil or turf. Being open to the full blast of the westerly and south-westerly gales from the ocean, the district, receives its full share of weather; and, in consequence, although the eastern slopes are often grass- or heather-covered, the steeper parts of the western slopes are rugged and bare, and afford magnificent exposures of the component rocks. Further, the structure of the district is fairly simple, and the cleavage, though present, is not so strongly developed as to prevent one from breaking the

The Rhætic and Contiguous Deposits of Glamorganshire

Abstract: I. Introduction. In the autumn of 1904 I made, in company with my friend, Mr. E. Talbot Paris, a detailed examination of the Rhaetic and contiguous deposits of Monmouthshire and GLamorganshire. The results of my investigations in the former country have already been made known, and it now remains to record those in the latter. Less than four years have elapsed since the officers of the Geological Survey completed the re-survey of the Secondary rocks of Glamorganshire; and that part of the memoir on ‘The South-Wales Coalfield ’ which deals with the Bridgend district was only issued to the public last January. This being the case, it might be thought that but little of interest would have remained to be noticed in the present communication. However, whereas the officers of the Survey were mainly concerned in the mapping of the deposits, my attention was directed ill most cases to the accumulation of facts bearing upon the physical geography of the Rhaetic Epoch. On a previous occasion I communicated to this Society a theory, to account for the geographical distribution in North-West Gloucestershire and Worcestershire of certain beds at the base of the Rhaetic Series. I then stated that, ‘there is evidence to suggest that there were earth-pressures at work at the close of the Keuper Epoch, which caused the deposits to be thrown into slight synclinal and anticlinal flexures. In the depressed areas the earlier deposits of the Rhaetic were laid down, and successive overlap on to the marls seems

The Marine Beds in the Coal-Measures of North Staffordshire

Abstract: I. Introductory Remarks. The North-Staffordshire Coalfield offers exceptional facilities for the study of Coal-Measure geology. It is remarkably rich in deposits of coal, ironstone, and marl, which are being worked by means of a comparatively-large number of mines and quarries; and, by reason of the excessive folding and faulting of the Measures, the whole sequence is exposed within a moderate area. The number of these exposures is further increased by the shaft-sinkings and cross-measure drifts which are rendered necessary by the disposition of the strata, and are constantly in progress in some part of the district in the process of mining the different beds. Each of these operations, therefore, not only reveals a section of the strata, but also provides a large quantity of material for search and examination. In order, however, to reap the fullest benefit from such opportunities, it is necessary to inspect the excavated debris almost day by day, so that the stratigraphical position of each fossiliferous band may be located in situ , with exactness. It is obvious that this can only be performed by local workers; and, during the past six years, I have taken advantage of these opportunities for minute and careful examination of the individual beds of the Coal-Measures, chiefly with the purpose of establishing a more satisfactory correlation of the seams in the different areas of the Coalfield. Fortunately, the work has added to our knowledge of the prevalence of marine conditions during the period of deposition in the Midlands of those Measures

On the Divisions and Correlation of the Upper Portion of the Coal-Measures, with special reference to their Development in the Midland Counties of England

Abstract: While working out the flora of the British coalfields, I have found no group of rocks more interesting than the group of sandstones and marls, frequently of a red, purple, or mottled colour, and their associated limestones, which lie above the Middle Coal-Measures of the Potteries Coalfield. When preparing my paper on ‘The Fossil Flora of the Coalfield of the Potteries,’ the classification which I adopted was that used by Mr. John Ward, but at that time little was known about the thickness and stratigraphical relationship of the beds forming this group. The classification adopted by Mr. Ward is as follows:— In the present paper my remarks will be restricted to the rocks here called Permian and Upper Coal-Measures. Any reference that may be made to the underlying group will be merely incidental. At the time when my paper on the fossil flora of the Potteries Coalfield was written, I had seen no plants from the so-called ‘Permian’ of that area, and, in regard to these rocks, Mr. John Ward says, in the work already mentioned:— That these rocks were Carboniferous and not Permian, I felt quite certain: for, apparently, the same so-called ‘Permian’ rocks were passed through while sinking the shaft of the Hamstead Colliery at Great Barr, near Birmingham; they contained a typical Upper Coal-Measure flora; and with this series I classed them at the time. Messrs. F. G. Meachem & H. Insley had previously referred these rocks to the Upper Coal-Measures. I shall have occasion to refer

On the Sporangium-like Organs of Glossopteris Browniana, Brongn

Abstract: I. Introduction. Glossopteris is now among the most familiar of all fossil plants. The tongue-shaped fronds of this genus, with their reticulate lateral nervation, are exceedingly charactcristic of the Permo-Carboniferous rocks of India, Australasia, and Southern Africa, and occur also in the Permian of Russia, and in beds of Rhaetic age in Tongking and China. So great is the abundance of these fern-like leaves in the Lower Gondwana Series of India, and its homotaxial equivalents in the Southern Hemisphere, that this plant has given its name to the flora of that former continental region. Although a very large number of Glossopteris-fronds have been described by different authors, it is only within the last few years that we have learnt, anything as to the general habit of this plant. We are chiefly indebted to the researches of Prof. Zeiller, of Paris, for progress in this respect. It has now been ascertained that this plant was heterophyllous,—a fact which was first suggested by M9Coy in 1847. In addition to the larger and often tongue-shaped fronds, much smaller leaves, generally spoken of as scale-fronds, were borne on a rhizome-like stem, which has been long known under the name of Vertebraria. The nervation of the scale-fronds resembles that of the larger leaves, except that there is no midrib. In shape they are, as a rule, ovately triangular, pointed at the apex, and strongly concave. An average specimen measures centimetres or more in length. Up to the present time we are without any definite

The Blea Wyke Beds and the Dogger in North-East Yorkshire

Abstract: I. Introduction. The exact stratigraphical position of the Blea Wyke Beds and their relations to the beds above and below them have given rise to a great deal of discussion, but no very satisfactory conclusion seems to have been reached by any of the writers on the question. Many attempts have been made to assign these beds to the Lias or to the Inferior Oolite, but hitherto there has always been some objection to drawing a hard-and-fast line at any particular horizon; and in these days, when less importance is attached to arbitrary divisions of geological time, and more to broad questions of physical geography, it seems worth while to study the question afresh from a more modern standpoint. These beds are also noteworthy for another reason, because a study of them seems to throw some light on the history of the Peak Fault, perhaps the greatest and most important dislocation in North-East Yorkshire. Before beginning the detailed study of the Blea Wyke Beds, it will be necessary to say a few words concerning the general structure of the district in which they are developed. The southernmost exposure of the Lias on the Yorkshire coast is in the cliffs below what was formerly known as Peak, but now called Ravenscar. At this point the beds have a rather steep dip to the south, and by proceeding northwards from Staintondale, we pass in succession over a fine series of Oolitic and Liassic strata. The Oolites form the cliffs as far north

On the Chemical and Mineralogical Evidence as to the Origin of the Dolomites of Southern Tyrol

Abstract: I. Introduction. The country of the ‘Dolomites’ has long been classic ground to geologists. The researches of Dolomieu at the end of the eighteenth century, and of L. von Buch early in the nineteenth, first aroused the interest of geologists in the district. Their attention at first was mainly directed to speculations concerning the mode of origin of the mineral, named after the French geologist, of which the mountains are so largely composed; this question, even at the present day, is far from settled. The stratigraphy of the district has always presented many points of difficulty. The earlier observers, struck by the contrast in scenery and composition between the bold, precipitous, dolomite-masses and the marls and stratified tufts of the green pasture-lands or ‘Alpen,’ were at a loss to explain their mutual relations, especially as very few fossils were at first discovered in any of the deposits. In 1834, however, Graf Munster, who had examined the strata near St. Cassian, enumerated, and (inpart) described and figured 400 species of fossils from them, and subsequent observers have added largely to the number. The precise age of these deposits, which had till then been a matter of discussion, was settled by the examination of their fossil contents. It was shown not only that the beds were of Triassic age, but that, unlike the Trias of most of the European areas, they had been deposited under marine conditions. In 1845 Bronn suggested that the St. Cassian fauna had inhabited a shallow sea where

On the Igneous Rocks occurring between St. David's Head and Strumble Head (Pembrokeshire)

Abstract: I. Introduction. The area with which this paper deals adjoins the strip of coast lying between St. David9s Head and Strumble Head in Pembrokeshire. No detailed account appears to have been given hitherto of the igneous rocks of the greater part of this district, but the Strumble-Head rocks have been described by Mr. F. R. Cowper Reed in his paper on the geology of the Fishguard District. Adjoining parts of the county have also received attention: Mr. John Parkinson has discussed the Prescelly area, and the district south of St. David9s, including Skomer Island, has been described by various writers in considerable detail. The granitic rock of St. David9s, of classic interest by reason of its disputed igneous origin, has been the subject of exhaustive discussion by Henry Hicks, and has been described petrographically by Thomas Davies, E. B. Tawney, Prof. Bonney, Sir Archibald Geikie, the Rev. J. F. Blake, and Prof. C. Lloyd Morgan. Murchison made some reference to the trap-rocks of Pembrokeshire in his well-known memoir, and these rocks were mapped on the 1-inch scale by the Geological Survey in 1845, under the superintendence of Sir Henry de la Beche, the igneous rocks being re-surveyed in 1855-56 by W. T. Aveline. Of the stratigraphy of this portion of Pembrokeshire there is still much to learn. Hicks mapped the outcrops between St. David9s and Abereiddy Bay, and Mr. Cowper Reed has done the same for the neighbourhood of Fishguard. These lines are approximately shown in the accompanying sketch-map (P1.

On Certain Genera and Species of Lytoceratidæ

Abstract: I. Certain Lytoceratidae from the Norhthampton Sands (Aalenian). Some time ago Mr. Beeby Thompson, F.G.S., sent to me for identification certain species of Lytoeeratidae from the Northampton Sands. As one is new and remarkable for its homœomorphy to Phylloceras , and the others are interesting, I desire to offer the following notes to the Geological Society. In order to classify the series of Toarcian-Aalenian Lytoceratidae, to which these species belong ( jurense and allied groups), it is necessary to note that there is ontogenetic evidence that they have passed through a more or less definite sequence of phylogenetic stages. In regard to ornament, there is a sequence of development—first some elaboration, but, later, simplification from a costate (or corrugate) to a completely-smooth stage. In regard to whorl-shape, there is a constant tendency to pass, more or less in pace with the decline in ornament, from the Lytoceratan to the Phylloceratan form—that is, from an evolute to an involute whorl, the umbilicus constantly contracting. Conjointly with such change there is a further tendency, to pass from stout to coustantly more compressed whorls. Now, Lytoceras originally took its name from the evolute character of its whorls (λυτός); Phylloceras from the character of its lobe-line (φύλλον). But the whorl-character of Phylloceras is the opposite of λντός: it is involute; and that is what is implied by saying ‘phylloceratan whorl-shape.’ The main difference between the Lytoceratidae and the Phylloceratidae may be expressed in this way: the first have the whorl-shape more primitive and the lobe-line

The Microscopic Structure of Minerals forming Serpentine, and their Relation to its History

Abstract: I. Introduction. Althoughso much has been written about serpentine during the last thirty years, a few points, as we think, still require to be cleared up. So we propose to describe in this paper, though it will mean some repetition of details already in print, the changes by which that mineral, or group of minerals, is produced from certain magnesian or ferromagnesian silicates. One of us published his first paper on this subject in the beginning of 1877, and since then he has been able to do some field-work on the rock on an average at least once a year. Of the specimens thus procured a number have been sliced for microscopic study, and others acquired by gift or purchase, so that his collection now includes about 180 sections of peridotites and serpentines, besides a large number containing more or less altered single grains of the parent-minerals. From the study of these, and of other specimens in the cabinets of friends, the opinions expressed in this paper have been independently formed, and it would have been written half a dozen years ago, if his arrangements had permitted him to visit certain localities, concerning which, as he believed, incorrect statements had been made. That task was kindly undertaken by the other contributor to this paper, who, in the summer of 1904, supplied the last link by visiting Sprechenstein and the Brenner district. Prior to this she had made a special study of the serpentines of Anglesey and of the Voges,

On an Ossiferous Cavern of Pleistocene Age at Hoe-Grange Quarry, Longcliffe, near Brassington (Derbyshire)

Abstract: I Introduction In April 1902, the south-south-eastern end of a cavern in the Hoe-Grange Quarry was broken into, in the course of the quarrying operations (P1 VI) The discovery was first made known to us by Mr J Ward, Curator of the Cardiff Museum, who was formerly a resident in Derby, and has worked out several caverns in the neighbourhood One of us visited the quarry on April 26th, 1902, and subsequently, through Messrs Holland & Rigby, solicitors (of Ashbourne), obtained leave from Major Nicholson, the owner of the quarry, to work the deposits on behalf of the Derbyshire Archaeological & Natural History Natural History Society The owner stipulated that the cavern should be worked in such a manner as would secure the largest amount of evidence possible under the circumstances In company with Mr C Fox-Strangways we visited the quarry, and found that the cavern had been indiscriminately worked in the upper part, above the line AB in the horizontal section (Pl V, fig 1), for a distance of 34 feet north-north-west of the point where the quarrymen had first broken in at the south-south-eastern end Our thanks are due to Messrs Shaw&Lovegrove, the lessees of the quarry, who did their best, before we took the work over, to secure and retain, as far as they could under the circumstances, specimens which had been obtained By this means they supplied us with 1577 specimens, and we subsequently recovered other 679 specimens from the tip-heaps Some of these were obtained

Sarsen-Stones in a Claypit

Abstract: Midway between High Wycombe and Princes Risborough, above Bradenham, 630 feet above sea-level, there is a plateau which is deeply entrenched by transverse valleys running to the Thames, towards which the plateau is inclined in accordance with the dipslope. On riding from Lacey Green to Nap Hill through cultivated country plastered by the usual ‘Clay-with-Flints,’ it appears surprising to find suddenly in the corn-fields a row of brick-kilns in full operation, among heaps of white stones symmetrically cut into kerbstones and paving-setts, with scattered mounds of white debris, pointing clearly to some features of great geological interest. The principal pit from which these materials are taken exhibits a structure in remarkable contrast with the surrounding country, as will be seen from the accompanying photograph, which shows a large sarsen-block measuring more than 10 feet across, embedded in a fine, clean, tenacious, grey and reddish clay. On the opposite side of the pit, which is about 40 yards across and roughly circular, another large stone (half uncovered) lies near the surface, and slopes towards the centre of thc pit. In the foreground is seen what the workmen call the ‘rock’, forming a containing-wall for the clay in which the sarsens are embedded. There is no gradation from the ‘rock’ to the fine clay, and the line of demarcation is clear and hard, the large unworn flints in the ‘rock’ never protruding into the sarsen-clay, which free from the admixture of any kind of pebble. It cuts as clean as a

On some Gasteropoda from the Silurian Rocks of Llangadock (Caermarthenshire)

Abstract: Prof. Groom has sent me some pieces of rock of Silurian age, from Llangadock, containing a number of gasteropoda. These fossils occur almost entirely in the state of internal and external moulds. The former rarely show much structure, but by pressing wax into the latter the original form and ornamentation of the shells are frequently reproduced, in such a manner as to give a tolerably-good idea of the original. By this means I have been able to make out ten distinct forms, which are referable to seven different genera, but only seven are sufficiently well preserved to be specifically determined with any degree of certainty. They may be enumerated thus:— Plethospira [Ulrichospira] similis , sp. nov. Bembexia (?) Groomii , sp. nov. Bemhexia (?) sp. nov. Bembexia (?) Lloydii (Sow). Murchisonia [Goniostropha] Cambria , sp. nov. Murchisonia [Cyrtostropha] torquota (?) M9Coy. Loxonema sinuosum (?) Sow. Loxonema Grindrodii (?) Don. Gyronema Octavia (d9Orb.). Polytropina globosa (Schloth.) Two small external moulds from the Upper Ludlow Beds, of which the wax-impressions bear some resemblance to Cyrtostropha torquata (M9Coy) are too imperfect for certain identification. The same may be said of the much-worn internal mould from the Wenlock Beds, which possibly represents Loxonema sinuosum (Sow.). Besides these doubtful ones, there are three other species from Llangadock which have been previously described by other palaeontologists, namely, Bembexia(?) Lloydii (Sow.), Gyronema Octavia (d9Org.), and Polytropina globosa (Schloth.). They all have a wide range, and cannot be considered characteristic of any particular horizon. Cyronema Octavia (d9Org.) is by

On the Order of Succession of the Manx Slates in their Northern Half, and its Bearing on the Origin of the Schistose Breccia associated therewith

Abstract: I. Introduction. Among the slates of the Isle of Man some strata have been found which represent, in the opinion of Mr. G. W. Lamplugh, so distinct a type of phenomenon that he assigned thereto a special name—that of a ‘crush-conglomerate.’ In the earlier announcement of this result in 1895, he defined the rock as ‘made up of scattered fragments set in a slaty matrix,’ and considered it ‘due to the breaking-up under pressure of alternations of flaggy slate and thin grit-bands’ ( op. cit. p. 565). So far as this general statement goes, we shall find it included in the description, of many fragmental rocks; but when we seek further information, and enquire concerning the fragments whether they be angular or round, scattered or crowded, uniform or various, composed of neighbouring rocks or of remote ones, and of the pressure, whether it be shearing or otherwise, metamorphosing or not—then our troubles begin. The paper in the Quarterly Journal was only a preliminary account of what had been observed, and a full statement was promised when the Geological Survey-Memoir on the island should: be published, which took place in 1903. I had early, however, taken an interest in the question, owing to the inclusion by Sir Archibald Geikie of some rocks in Anglesey in the same category. But I had not to wait so long as 1903, for, with the greatest kindness, Mr. Lamplugh lent me some advance-proofs of the principal passages involved, and thereby enabled me to spend portions of

Observations on some of the Loxonematidæ, with Descriptions of Two New Species

Abstract: The genus Loxonema was founded by Phillips in 1841, and was thus described by him:— ‘Spiral, turriculated; whorls convex, their upper edges adpressed against the next above; without spiral band; mouth oblong, attenuated above, effused below, with a sigmoidal edge to the right lip; no umbilicus (?); surface covered by longitudinal threads or ridges, generally arched.’ He further states that these observations are merely provisional, until the form of the aperture is more perfectly known. In noting the number of species, he writes that most of them are probably ‘varieties of three or four types having L. sinuosa for one extremity and L. Hennahii for the other; a second related to L. tumida and L. lincta ; a third to L. rugifera .‘ [ Loc. cit. ] Later researches show that this description is correct for the group of shells having Loxonema sinuosum for the type, and the generic name must be restricted to them. The essential characteristics are the possession of whorls adpressed at the suture and the presence of strongly-sigmoidal lines of growth. Shells having more convex whorls, or less sigmoidal lines of growth, must be placed elsewhere. Prof. Koken and other palaeontologists have created several new genera for some of these latter. The type, Loxonema sinuosum , is the first species described by Phillips: it is a Devonian form from South Petherwyn, which he identifies with Terebra (?) sinuosa , Sow. from the Aymestry Limestone. They are probably distinct species, although Mr. Whidborne thinks them correctly identified. The striae on the Devonian form

On the Age and Relations of the Phosphatic Chalk of Taplow

Abstract: I. Introduction. In the course of an investigation of the Upper Chalk in the western part of the London Basin, we had occasion, last autumn, to examine the pit at the South Lodge of Taplow Court, to which so much attention was attracted twelve years ago by Mr. A. Strahan9s discovery of the richly-phosphatic character of some of the beds therein exposed. It was originally intended to devote no more than a few paragraphs to this section, in a short account of the highest beds of the Chalk and their relations with the Lower Eocene sediments in the whole area, which we have in preparation; but the difficulties in the way of a satisfactory interpretation which presented themselves at the preliminary inspection referred to, and seemed, for a time, but to increase with succeeding visits, compelled us to undertake a minute examination of the beds, and the results of this work now appear to be of sufficient interest to merit the more detailed discussion obtainable in a separate paper. In dealing with the phenomena of a single exposure of a rock having so wide a lateral range as the Chalk, some loss of the sense of continuity and of proportion is usually inevitable; but a separate treatment of the Taplow-Court section appears to be justified, no less by the remoteness of the beds from any visible Chalk of a similar age, than by their exceptional lithological character. References to the Phosphatic Chalk of Taplow are numerous and widely scattered, but

The Superficial Deposits and pre-Glacial Valleys of the Northumberland and Durham Coalfield

Abstract: I. Introduction. Nearly the whole of the rock-surface of the Northumberland and Durham Coalfield is covered by superficial deposits of an extremely variable thickness. After I had made some study of the thickness of these deposits and the pre-Glacial contour of the north-east of County Durham, Prof. Lebour suggested to me that results of some importance might be obtained from a thorough investigation of all the borings and sinkings made in the Northern Coalfield, and the working out of this subject has occupied the greater portion of my leisure-time for the last three or four years. Nicholas Wood & E. F. Boyd, in a paper on the ‘Wash’ published as long ago as 1864 (1) first clearly showed that the deposits covering the rock-surface of this coalfield were not arranged in an irregular manner, but were found along valley-like depressions. Since then, little has been done towards the thorough elucidation of the Glacial and superficial geology of this area. Indeed, little of a detailed character could have been attempted until the publication in 1897 of the final volume of the ‘Account of the Strata of Northumberland & Durham, as proved by Boring & Sinkings’ (4). The six volumes published by the North of England Institute of Mining & Mechanical Engineers give details of 2,353 borings made in the Northern Coalfield, or in its immediate neighbourhood. A large number of these are useless for our present purpose, because their exact position is not known, many of them are vague and indefinite

Notes on the Palæontology

Abstract: Introduction. It has been known for some time that thin bands containing marine shells occur in several coalfields, and from time to time figures and descriptions have been published. Among the earliest of these publications were Sowerby9s descriptions and figures of the marine mollusca from the Pennystone Ironstone of Coalbrookdale, in Prestwich9s memoir. Perhaps the other most important publication is that by Mr. George Wild, in which a large number of marine mollusca were figured. So well known was the occurrence of marine fossils, as distinct from the bands of Carbonicola, Anthracomya, and Naiadites, that Prof. Hull, in his paper on ‘The Upper Limit of the Essentially-Marine Beds of the Carboniferous Group of the British Isles’, included the Gannister Series or Lower Coal-Measures with the Millstone Grits and the series of shales and black limestones below them, which he erroneously correlated with the Yoredale Series of Wensleydale. This classification is obviously unsound; (1) because the Gannister Series is not wholly marine in origin, for it contains beds in which the marine fauna is absent; and (2) a marine fauna is not limited to the Gannister Series, but recurs at several horizons in the middle portion of the Coal-Measures, which are therefore not ‘essentially freshwater or estuarine beds.’ Indeed, there is an unbroken succession from the base of the Pendleside Series to the top of the Coal-Measures, at times marine, at times estuarine, or of freshwater origin. This thick series contains two distinct molluscan faunas, which recur with irregular alternations. One

The Rhætic Rocks of Monmouthshire

Abstract: I. Introduction. In Monmouthshire the Rhaetic does not extend over a large area, and occurs only in the neighbourhood of Newport. Here it has attracted very little attention until quite recently, when the resurvey of the South-Wales Coalfield necessitated a fresh examination of the deposits, in order to complete the geology of Sheet 249 (New Series). Certain sections which came within the area were described, but hardly in sufficient detail, as the only lamellibranch recorded was Modiola minima . In the present paper four new sections and three new exposures are described: the Goldcliff and Lis-Werry sections being included in the former category, because hitherto comparatively little was known about them. II. Decription of the Sections. (A) Goldcliff. About miles to the south of Llanwern Station, and rising from the alluvial flat called Caldicot Level, is the little inlier of Keuper, Rhaetic, and Lower Liassic rocks denominated Goldcliff. Although the occurrence here of Rhaetic and Lower Lias has long been known to geologists, details of the section have been difficult to obtain; and, until the present time, it has been possible to investigate only the basement-beds of the Rhaetic and those at the base of the Lower Lias. This is due to the fact that the cliff had to be faced with masonry, in order to continue the sea-wall. About the year 1824 Buckland & Conybeare noted the occurrence here of Lias and Red Marl, but remarked that the section ‘ is now almost entirely concealed by a high sea-wall

On the Occurrence of Elephas Meridionalis at Dewlish (Dorset). Second Communication: Human Agency suggested

Abstract: In June 1888 I read a paper before the Society on the occurrence of Elephas meridionalis at Dewlish in Dorset. Subsequent excavations were made by the late Mr. J. C. Mansel-Pleydell, of which he gave accounts in two articles in the Proceedings of the Dorset Natural History & Antiquarian Field-Club, vol. x (1889) pp. 12 et seqq. & vol. xiv (1893) pp. 139–41, the second of these being illustrated by photographs of the deposit. Mr. Clement Reid also, in the latter part of 1888, spent four days in investigating the locality, and described it in the Geological Survey Memoir on the geology of the country around Dorchester, 1899. This memoir contains a drawing (p. 35) copied from one of Mr. Pleydell9s photographs. The photographs themselves are now reproduced (Pls. III & IV). It is not necessary to describe the locality afresh, as that has been done already by Mr. Pleydell and by myself, and subsequently very clearly by Mr. Reid. The distant fence shown in Pl. III is on the brow of the hill, and the early finds were made just beyond it. The deposit was then opened on the opposite side of it, where the pelvic bone lies, the fence being left intact. The trench was afterwards followed for about 103 feet, until it suddenly terminated in a smooth ‘apse-like’ end. The photograph showing the pelvic bone (Pl. III) was taken from the farther end, looking about due north-west towards the brow of the hill. Both the views seem

The Tertiary Fossils of Somaliland, as represented in the British Museum (Natural History)

Abstract: I. Introduction. Since the publication in the fifty-sixth volume of this Journal (1900) of Prof. J. W. Gregory9s paper on the Geology of Somaliland, which was founded upon specimens in the British Museum (Natural History) mostly collected and presented by Mrs. Lort-Phillips, the National Collections have been enriched by two further series of fossils from the same country—that obtained by Dr. Donaldson Smith from the neighbourhood of Berbera, and presented by His Highness the Gaekwar of Baroda; the other presented by Major R. G. Edwards Leckie (of the Canadian Mounted Rifles), and collected by him during an exploration-tour, from Upper Sheikh and Garrasgooi in the Golis-Range district, and also from the Eilo Range of mountains. In the course of my official duties at the British Museum, I have been entrusted with the examination of these new collections, with the view of describing the individual specimens, as well as of ascertaining their importance with regard to the stratigraphy of the country. In carrying out this work, a large amount of comparison with species already known from Somaliland and elsewhere has been imperative, while the limestone-matrices surrounding the different specimens have been microscopically examined in several cases, in order that the best confirmatory evidence should be obtained as to geological horizons. This examination has rendered necessary a revision of some of the geological and palaeontological conclusions referred to in Prof. Gregory9s memoir, for which I am largely responsible in connection with the determination of certain molluscan remains therein mentioned. The new material

The Carboniferous Limestone of the Weston-super-Mare District (Somerset)

Abstract: I. Introduction. Weston-super-Mare lies miles W. 25° S. of Clifton Suspension Bridge. The Carboniferous Limestone in the neighbourhood forms two ridges which stand up prominently from the surrounding alluvial flats. The southern ridge, which I term the Weston-Worle ridge, runs a little north of east from the coast, at Weston, to Worle, and is about 3 miles in length. The northern and smaller ridge, known as Middle Hope (the Woodspring ridge), lies 2 miles farther north, is about 2 miles in length, and runs almost parallel to the Weston-Worle ridge. The occurrence of contemporaneous igneous rocks associated with the Carboniferous Limestone both at Weston and at Middle Hope, lends especial interest to the district. The igneous rocks have been described by Sir Archibald Geikie and Mr. Aubrey Strahan, and also, more fully, by Prof. C. Lloyd Morgan & Prof. S. H. Reynolds. The Spring-Cove lava (Weston) has, further, been fully described by Prof. W. S. Boulton. The present paper is devoted chiefly to a detailed description of the Weston-Worle ridge. My object in examining the district was an investigation of the coral- and brachiopod-succession in the Carboniferous Limestone, in connection with my work in the Mendip area, and in continuation of the work accomplished by Dr. Arthur Vaughan in the Bristol area. In order to accomplish this with thoroughness in the Weston-Worle ridge, much detailed stratigraphical work has been necessary, owing to the fact that faulting and resultant folding have complicated the structure of the ridge. Both the stratigraphy

An Experiment in Mountain-Building: Part II.

Abstract: In 1903 the Society did me the honour of publishing a short paper on this subject. I may, perhaps, just repeat that Sir James Hall many years ago, and others since, have illustrated the formation of folded mountains by placing layers of cloth under a weight, and then compressing two of the sides so that the cloth was thrown into folds. Since then, other and more complete, experiments of the same kind have been made by Favre, Cadell, Daubree, Willis, Ruskin, and others. In these investigations the compression was from two sides only. If, however, folded mountains are caused by contraction due to the cooling of the earth, the compression must take place from all sides. With the view of illustrating this, I requested the Cambridge Philosophical Instrument Company to make for me an apparatus consisting of four square beams of wood, resting upon a floor, which by means of screws could be moved nearer to, or farther from, each other. The beams left between them a space 2 feet across and 9 inches in depth. In this square central space 1 placed layers of cloth, baize, oil-cloth, cement, etc., separated by layers of sand. The machine was then set in motion, and compressed so that the central space was reduced from 24 inches square to 22. Since last year I have made other experiments, changing the arrangement in various ways. The results differ in details in almost every case, the initial movements being probably determined by slight differences in

On the Occurrence of Rhætic Rocks at Berrow Hill, near Tewkesbury

Abstract: Berrow Hill (184·8 feet above Ordnance-datum) is a small outlier of Lower Liassic and Rhaetic deposits, distant about 2 miles in a south-easterly direction from Chase-End Hill, the southern end of the Malvern Range. It occurs in the centre of a basin-shaped area formed by the Keuper Sandstone, which in this district comes about 215 feet below the base of the Rhaetic. By means of this sandstone-deposit, it is possible to trace with very great accuracy the amount of flexuring that these Keuper beds have undergone. The causes and effects of this flexuring have been dealt with elsewhere, but it may be of interest to mention that at Berrow the sandstone is arranged so as to form a basin; and at Eldersfield—immediately to the south—the numerous exposures show the dip to be quaquaversal. In the past there was a complete ellipsoidal dome, but now the sandstone is much denuded, capping a central boss, while the main mass is at distances varying from a quarter to three-quarters of a mile away. East of the Eldersfield district the rocks are necessarily disposed synclinally: on the northern extension of this axis lies Berrow Hill, and on the southern Berth Hill. This hill, according to Symonds, is capped with Rhaetic Black Shales. On the east again the Keuper Sandstone reappears to form an anticline, and then disappears, dipping gently eastward or south-eastward. A reference to the map (fig. 1, p. 425) and sections (figs. 2 & 3. p. 426) will explain much more lucidly

Notes on the Geological Aspect of some of the North-Eastern Territories of the Congo Free States

Abstract: I. Introduction. In 1902 I had the honour of being commissioned by the Government of the Congo Free State, as mining-engineer and geologist, to accompany an exploratory mission sent to their north-eastern territories, and I had the opportunity of taking a few notes on the geological aspect of that part of Africa, which is as yet little known to the geologist. It has occurred to me that the observations recorded during nearly two years spent in that region, although no doubt very incomplete, might possibly be found of some interest. The Government of the Congo Free State have given me in Africa in a very generous way, through all their officials, every assistance to carry out the investigation of that large tract of country: and I beg to be allowed here to mention my debt of gratitude towards them, as also to thank the Secretary-General of the Interior, Commandant Liebrecht, for the kind permission which he has granted me to bring these notes before this Society. I am also greatly indebted to Mr. J. Allen Howe, who has kindly undertaken the petrological description of the rocks, for his valuable assistance and advice. The Uelle district and the Lade Enclave are the north-eastern-most provinces of the Congo Free State. They cover an area at least six times as large as Belgium, and the Uelle district alone extends over 72,000 square miles. On the map it presents the shape of a long and broad belt of country nearly parallel to the Equator,

The Derby Earthquakes of July 3rd, 1904

Abstract: Between the Derby earthquakes of March 24th, 1903, and July 3rd, 1904, there exist several points of intimate resemblance. The isoseismal lines of the two shocks, when drawn on one map, are so closely related that they might be the isoseismals of a single earthquake; both earthquakes were twins; the two epicentres in 1904 were nearly or quite coincident with those in 1903; and both earthquakes were followed by an after-shock, originating for the most part in the interfocal region of the fault. The points in which they differ are of little consequence. The intensity of the shock of 1903 was greater than that of the shock of 1904; the impulses at the two foci were approximately of the same strength in 1903, and of unequal strength in 1904; they occurred at the same instant on the former occasion, while, on the latter, they were separated by a brief interval of time. The principal shock of 1903 occurred on a weekday at 1.30 P.M., that of 1904 at 3.21 on a Sunday afternoon. Thus, although of less intensity, the recent earthquake was felt and heard over a much wider area than its predecessor. There was at the time practically no traffic in the streets, and many of the observers (especially of those at a great distance from the centre) were lying down—conditions that favoured the observation of the earthquake in places at which, on an ordinary occasion, it would have passed totally unperceived. There were at least three earthquakes in