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The accompanying geological map of Queensland (Pl. IX.) may be accepted as giving the approximate areas and rough outlines of the geological structure and rock-systems developed in that Colony, and is appended for that purpose only. It will necessarily be open to criticism in matters of detail; but the general features of the geological grouping may be relied on. The section (Fig. l) from Townsville to the Mackinlay range shows all the geological formations in Queensland, north of 20° S. lat. In a newly settled Colony the first object of the geologist is the determination of those districts in which the best land or available mineral wealth is to be obtained, accuracy in detail and purely scientific investigation being deferred to an often remote future. Fig. 1.– Sketch section from Townsville to the McKinlay Range. (See line on Map.) I collected the following data whilst prosecuting the search for new gold-fields, on behalf of the Queensland Government, in the northern portion of their territory, as also from the official reports of the Geologist of Southern Queensland, and other trustworthy sources. The consideration and history of the different; formations will be taken in their sequence of time, as far as the stratified or sedimentary rocks are concerned. The igneous rocks will be described under the various groups of Granitic, Trappean, and Volcanic. Alluvial. Fluviatile or freshwater deposits skirt all the present water-courses; but the accumulations are insignificant on the eastern water-shed, except near the embouchures of large rivers, such as the Burdekin

In ‘The Geology of Anglesey’ it was pointed out that little had really been ascertained concerning the laws and chronology of the foliation of the Mona Complex. A chronology was given, but the foliation of Holy Isle was therein treated as a unit, whereas it has proved to be much more than a unit. I found in 1922 that the most favourable sections for further investigation were those of the South Stack Series on the sea-cliffs of Rhoscolyn, especially under Rhoscolyn Hill, opposite the Maen-y-fran islets (G. of A., folding-plate ii). For, in the core of that major anticline, the beds are, as wholes, nearly horizontal for a quarter of a mile, which eliminates complication due to dip on major folding. The present paper is the outcome of some four weeks9 study of the section in 1922 and 1923, followed by reexamination of the thermal aureoles of the basic intrusions of Holy Isle. The original character of the rocks, their anamorphic condition, and their tectonics, have already been described. Here, therefore, it need merely be recalled that they were originally grits and shales; and that, as Rhoscolyn lies within one of the four anamorphic maxima of the Mona Complex, there are no catamorphic textures, but that all are now holocrystalline schists. Considered with regard to capacity for foliation, there are seven principal types :—(1) The massive green grits of the Stack Moor division of the South Stack Series (which are sometimes 30 feet thick); (2) the somewhat similar green grits

Having last spring paid a visit to the south side of the Alps, my principal object being to see and examine the magnificent moraines of Ivrea, and the Val d’ Aosta, which supplied the materials of which they are composed, I was led into the examination of certain Tertiary formations which this great mass of moraine material generally conceals. These Tertiary beds, exposed at a few points near Ivrea, have long since been noticed by the Italian geologists who have studied and written about this part of the country. My interest thus aroused, I afterwards proceeded to visit similar patches at Boca and Maggiora, east of the Sesia river; but it was not until I got to the Lago d’Orta, and was walking over the moraines at its southern end, that I came on the most interesting section containing the best-preserved fossils. These latter have been examined and named by Dr. Gwyn Jeffreys, and the appended list greatly increases the interest and value of this communication. I shall begin therefore by giving a detailed account of this section, referred to casually in my Address to the Geographical Section of the British Association at Southport in 1883, and I shall afterwards refer to other localities in their turn. SectionatBuccione. Those who know the Lago d’Orta will remember the old tower that stands so conspicuously on a steep point at the southern end of that lovely little lake, which, though very small when compared with its neighbour the Lago Maggiore

I. Introductory Remarks In November of last year (1911) Mr. Charles Dawson, F.S.A., F.G.S., submitted to me for examination a small collection of plants obtained by him, with the able assistance of Father Teilhard do Chardin and Father Felix Pelletier, from the Wealden Beds of Sussex, for the most part from the neighbourhood of Fairlight. Several of the specimens, although specifically identical with previously recorded types, are better preserved or larger than any hitherto found, and furnish new facts of importance. The collection includes also several new species. In accordance with Mr. Dawson9s wish, the specimens have been handed to Dr. Smith Woodward as a gift to the Geological Department of the British Museum (Natural History). With the exception of the example of Sagenopteris mantelli shown in Pl. XI, fig. 3, which is from the Ashdown Sands, the fossils in the Dawson Collection were obtained from the Fairlight Clay. In the descriptive section of this paper are included a few specimens from the Rufford Collection (collected at Ecclesbourne, near Hastings), acquired by the Museum subsequent to the publication of the Catalogue of Wealden Plants. II. Description of the Specimens. Equisetales. Equisetites lyelli (Mant.). (Pl. XI, figs. 1 a & 1 b .) (Near Fairlight, Wadhurst Clay; Dawson Collection.) 1833. Mantell, ‘Geology of the South-East of England’ p. 245 & figs. 1–3. The specimen represented in Pl. XI, fig. 1 a , though smaller than some previously figured from the Wealden Beds of Sussex, exhibits certain features worthy of notice. The incomplete internode

At the village of Midford, some three miles to the south of Bath, is a fine section of the upper beds of the Inferior Oolite rock, consisting of a cap of oolitic freestones of some 20 feet in thickness, resting upon a mass of sand, of which 25 feet are exposed at the station, and which presents all the features of the sand at Bradford Abbas and Bridport Harbour, as the sands are loose, vary in colour, and present occasional bands of hard compact stone. From these sands being so well shown at this place, Prof. Phillips was induced to name them, after the village, the “Midford Sands;” and he thus writes upon the section:— “If we wish to draw a hard limit of mineral deposits, it should probably be between the sand and its calcareous cover (which is often absent); but if we desire to study organic sequence, we shall unite the sands and their shelly cap into a transition group”*. Now as this “shelly cap” is the one so highly charged with Cephalopoda we further quote the following :— “The ‘Cephalopoda-bed,’ as Dr. Wright proposes to call the cap limestone of this sandy series, exists where the shells to which it owes its name were specially abundant, or by some natural circumstances were brought together. It is not known in the valleys of the Cherwell or Evenlode, and very partially in any of the branches of the Windrush, Coln, or Churn; but on the western front of the

I. Introduction. The area to be described is limited on the north-east by the Pass of Llanberis from near the village of Nant Peris to Pen-y-gwrhyd; on the south-east by the Vale of Gwynant down to Beddgelert; on the south-west by the Colwyn and Gwyrfai valleys to near the village of Salem; and on the north-west by the supposed line of junction between the Cambrian and the Ordovician rocks. The approximately quadrilateral area of Ordovician rocks thus defined has an extent of about 30 square miles. It is represented on portions of the 1-inch Ordnance Survey maps 106 & 119, of the 6-inch sheet, Caernarvonshire 22, and of the Quarter-sheets 16 S.E., 17 S.W., 21 N.E. & S.E., 27 N.E., & 28 N.W. It includes parts of the Quarter-sheets 75 N.E. & 78 S.E. of the 1-inch Geological Survey map (old series). The general configuration of Snowdon is represented on the map, PL. XXIX. Prof. W. M. Davis9s paper on ‘Glacial Erosion in North Wales’ [42] affords a useful guide to the topography, and is considered adequate for the present purpose. (a) Historical Review. On his first visit to North Wales in 1831, Sedgwick drew a section through Snowdon, in which he depicted the synclinal structure of the summit and the descending sequence of beds towards the north-west. From this section and from others across Y Glyder Fawr and Moel Hebog, he ascertained the general parallelism of the fold-axes in this part of Caernarvonshire. Subsequently, he determined the general succession

During Lower Old Red Sandstone times the district of Glen Coe furnished an arena wherein terrestrial disturbance and igneous activity combined to produce effects of imposing magnitude and, as we believe, of some theoretical importance. The paper now presented embodies an account of a cauldron-subsidence which affected an area roughly oval in shape, and measuring not less than 5 miles from side to side. We show that the subsidence took place in at least two stages, and that it was accompanied in a complementary fashion by the uprise of a series of marginal intrusions. In the first instance the nature of the volcanic succession in Glen Coe will be dealt with, its variations from point to point will be described, and evidence will be adduced to illustrate the marked inequalities of the floor of Highland Schists upon which these volcanic rocks accumulated. The second portion of the paper is devoted to the evidences of the cauldron-subsidence, and treats in some detail of its tectonic features and the accompanying plutonic intrusions. In a final section we have added a theoretical discussion of our results.

I. History and Literature of the Worms-Heath Outlier The occurrence of outliers of the Lower London Tertiaries far away from the main mass, in the Chalk-tract of Surrey, was known to Prestwich, and the sites of some of them were noted by him, though not in his papers read to the Society. 1 But, presumably because he was then dealing with distance from the main mass and not with size, these sites included only small patches, at the top of the Chalk-escarpment of the North Downs and not the much larger outlier with which we are especially concerned, roughly a square mile in area and some way inward from the Chalk-escarpment. All these outliers consist wholly of the uppermost of the three divisions of the Lower London Tertiaries, to which the name Blackheath Beds has been given, the underlying Woolwich Beds and Thanet Beds being absent. This was not mentioned by Prestwich, who was dealing with the Lower London Tertiaries as a whole and not with the divisions thereof, the details of which, moreover, had not been then fully worked out, his third paper on the Series not appearing until 1854. The first recognition of the Tertiary tract of Worms Heath was on Sheet 6 of the Geological Survey Map, published in 1864, though the Surveyor (who need not be named) was mistaken as to the age of the deposit when he first saw the place, some years before that date, the pebble-beds being taken as a peculiar kind of Drift

I. Introduction. This paper deals with the geological structure of a part of the South American Andes, as illustrated by a horizontal section drawn from the port of Arica in the extreme north of Chile (formerly Peruvian territory), across the mountain-ranges or ‘Cordilleras,’ to the ‘Montana,’ or forested region of the Amazon basin, known as the Bolivian Yungas. It is the partial result of two years9 geological exploration in Peru, undertaken on behalf of Mr. W. E. Balston, F.G.S., who, being impressed during his travels by the geological features of the country, was good enough to send me out for the Oxford University Museum to study them in greater detail. I was accompanied for fifteen months by Mr. J. R. Thomas of Montana (U.S.A.), who, after his valuable help in the field, I much regret, has been unable to assist me further in the study and publication of our results. At Mr. Balston9s suggestion, we commenced work in the south of the district, following the route of the new Arica-La Paz railway, which at the time of our visit was in course of construction. Unfortunately, the line passes for the greater part of its length over igneous rocks and barren sediments, furnishing little in the way of palaeontological evidence, and thus compares somewhat unfavourably with the more fossiliferous sections of our northern traverses. This southern section, however, has a particular interest on account of its historical associations, since it is practically coincident with a section first described in 1842 by

Problems connected with the sampling, interpretation and visual appraisal of till fabrics are discussed. Methods of statistical analysis are reviewed and a methodology for till fabrics presented. Fifty till fabrics from closely controlled sites allow a discussion of within- and between-site variability for this section of the Yorkshire coast. It is suggested that all the glacial deposits are of Newer Drift age. The till sequence can be divided into a basal shale-charged deposit and an upper dark red/brown till. Englacial or sub-glacial water-lain sands are also common and varved clays locally separate till sheets. Results indicate that till fabrics are characterized by low within-site precision, i.e. there is a considerable degree of orientation scatter, although dips are more compact. Between-site variability is moderate and is greater vertically within a deposit than laterally. Rotation of the data allows the typically bimodal distribution to be concentrated and analysed in the most efficient manner. A series of models are proposed for a rational description of fabric types and are linked to fabric genesis. Ice-flow, as revealed by the till fabrics, was north-south except in the vicinity of Robin Hood9s Bay where an east–west component predominates. The reason for this difference is discussed. Distinct orientation and dip directions are more likely caused by flow within the till matrix rather than the ice/till contact.

The threefold division of the great north-western drift, established by Professor Hull, extends into the peninsula of Wirral, if not further south, in Cheshire; and I have found it strongly marked near Padeswood station, Flintshire. To the south of the Mersey, the Lower Boulder-clay becomes very attenuated or patchy, while the upper or brick-clay becomes thicker or more generally diffused. In many places the upper clay is underlain by extensive and persistent deposits of non-glacial sand and gravel (attaining at Gresford a thickness of 150 feet), which rest on rock, excepting where they are underlain by a few remnants of the lower clay which escaped denudation. In other places the upper and lower clays coalesce. One of the best instances of the two clays in contact, with their distinctive characteristics still preserved, may be seen at Dawpool, on the N.E. side of the estuary of the Dee. From Parkgate the lower clay (with large boulders), under a thin covering of the upper clay, may be traced nearly all the way to the Dawpool cliff-section, which reaches about 50 feet in height, and extends for a distance of three miles. In the part of this section S.E. of Dawpool cottage, where it has not been obscured by talus or the effects of rain, the upper may be seen to be separated from the lower clay by a line (either winding or straight), which in some places is so sharply defined as to indicate that the top of the lower clay had

The present paper is the result of continued search for Corals in the Great Oolite, and must be taken as supplementary to the one I have already published in the Journal of the Geological Society. As the information it contains is wholly supplementary, I do not deem it necessary that a systematic classification of the species should be very closely observed. A section will be given of the Great Oolite at Milton, Oxfordshire, where a coralliferous bed is exposed, and one also of the quarry near Cirencester, from which the late Mr. Brown obtained most of the Oolitic Corals which were given by him to the Oxford Museum. These sections, accompanied by an enumeration of the corals obtained from them, and some sections in the neighbourhood of Bath, with the species they have yielded, constitute the principal part of the paper. To this will be added notes and descriptions of some of the species. The genus Bathycœnia , and its allies, I have already shown to be characteristic of the Cornbrash ; but three specimens of Bathycœnia Slatteri have lately been found at Combe Down, Bath; and its presence there, taken in connection with the prevalence of the well-known Bradford-clay Encrinite in the corresponding coral-beds of Farley Down and Hampton Down, would scem to point to a higher geological level for the coralliferous deposits around Bath than I have hitherto attributed to any of the Oxfordshire coral-beds. At the same time it is desirable that I should mention the occurrence of

Overlying the profitable portion of the Fifeshire Coal-measures there is a series of red barren beds, of which we have not seen any description. Possibly Mr. Howell refers to similar measures, as occurring in Mid Lothian, in the Edinburgh memoir of the Geological Survey (pp. 110, 111); and since the date of that memoir an upper series of beds, evidently identical with that of Fife, has been recognized by the Geological Survey in Lanarkshire, and described as a separate subdivision ( d 5′) of the Coal-measures. The best exposure of these red measures in Fife is on the coast from the mouth of the Leven to East Wemyss. Having somewhat carefully examined this section, we shall notice it briefly in detail —first as to the succession of strata, and afterwards as to the fossils found in them—and so give some account of the series. The section in question forms part of the Wemyss coal-field, which, with the smaller adjoining fields of other lairds, is the most northerly piece of true Coal Measures existent in Britain. The dip of the strata is easterly, rarely exceeding 10°, generally less; and as the trend of the coast is north-east and south-west, a section in descending order is to be observed by traversing the shore from the Leven westward.

The object of the following communication is to give an account of a short geological excursion through parts of the counties of Berkshire and Wiltshire, by several members of this Society. The party consisted of Prof. E. Forbes, Mr. Sharpe, Mr. Prestwich, Mr. Tylor, and the author of this memoir; they were joined for the first day by Mr. Cunnington of Devizes, and they again had the advantage of that gentleman9s knowledge of detail in their visit to his neighbourhood and Calne. I propose to confine the account to the localities and sections actually visited: the line of country was selected by Mr. Prestwich, and it may be as well to state briefly in the outset, the points of geological interest which mainly influenced the choice. Those who are acquainted with the memoir of Dr. Fitton on that portion of the cretaceous series which occurs in this country below the chalk, are aware that the author clearly establishes that the several deposits of upper greensand, gault, and lower greensand are clearly distinguished, and developed in great thickness along the S.W, coast of the Isle of Wight. Subs.equent observers, by greatly extending the knowledge we had of the lowest cretaceous fauna of this region, and determining the range of the various forms, have rendered it necessary that the base of this series should be everywhere re-surveyed. From the Isle of Wight westwards, the next section of the beds below the chalk is that presented at Swanage Bay, being thirty miles due

Those geologists who hold that the quartz-felsites between Llanberis and Caernarvon are of Pre-Cambrian age, rest their belief mainly on the fact that the conglomerate which they take to be the base of the Cambrian rocks in that district contains numerous pebbles of this felsite. It would be very desirable to have this inference confirmed by direct evidence of stratigraphical unconformity between the two rocks; but I do not know that any one has been able to point to a section where that conglomerate is seen actually resting on the felsite, and where there is an unconformity at the junction. The section which I wish to describe, and which seems to have escaped the notice of the geologists who have from time to time during the last few years reexamined the district, does show the conglomerate resting with the most marked unconformity on a lower group of rocks; and it is for this reason that I call attention to it. I saw the section first in the summer of 1880, and visited it again during the summer of the present year. The section is found in one of the cuttings of the railway which runs from the Dinorwig quarries along the north-eastern shore of Llyn Padarn; to show its position with respect to the adjoining rocks, I have plotted, in fig. 1, the section along the railway from some distance on either side of it. We start at the south-eastern end in the bottom beds of the slaty series which

I. Introduction. This paper contains the results of a detailed examination of the Carboniferous Limestone in the Mendip area. The object of my work has been the complete investigation of the faunal sequence in the Carboniferous-Limestone Series, following on the lines laid down by Dr. Arthur Vaughan, in his great paper on ‘The Palaeontological Sequence in the Carboniferous Limestone of the Bristol Area.’ Detailed work in the Mendips has shown that the system of zones and subzones, established by Dr. Vaughan in the Bristol sequence, requires only very slight modification to co-ordinate accurately the faunal sequence in the Mendip area. The correlation of the Mendip and Bristol areas is treated fully in the present paper, my comparison being based on Dr. Vaughan9s paper, to which I make frequent reference. I am indebted to Mr. H. B. Woodward9s Geological Survey-memoir on ‘The Geology of East Somerset & the Bristol Coalfields,’ published in 1876, and to a paper by Prof. C. Lloyd Morgan, entitled ‘Mendip Notes,’ published in the Proceedings of the Bristol Naturalists’ Society, for much valuable information and guidance. To my recent paper on ‘The Carboniferous Limestone of Burrington Combe,’ which deals fully with the Burrington section, I refer frequently. The Carboniferous Limestone presents more or less complex structural features in several parts of the Mendip area, and it is to be hoped that the application of palaeontological study to these problems will furnish correct solutions. The time at my disposal has not permitted me to pay much attention to

I. Introduction. This paper deals with the geological structure of the Andes of Central Peru, as represented by a horizontal section drawn from the island of San Lorenzo off the Pacific coast at Callao to the River Perene, a tributary of the Apurimac, one of the headwaters of the Ucayali. It is a third contribution to a series of papers written as the result of a two years9 expedition to South America (1910–12) undertaken on behalf of the late Mr. W. E. Balston, F.G.S. The district traversed is one of the best-known and most populous in Peru, for through it passes the northern Transandine route from Lima, the capital of the country, to the port of Iquitos on the Amazon, whence steamers sail direct to Europe. The first half of the section follows the line of the central railway of Peru. This is the well-known Oroya line, famous not only as the highest railway in the world, but also as a wonderful feat of engineering, rising as it does to an altitude of over 15,000 feet in a course of 100 miles. The line ascends the steep-sided valley of the Rimac by means of a series of sinuous curves and zigzag ‘switchbacks,’ cut for the greater part in the face of the solid rock. After passing through no fewer than 65 tunnels it reaches the summit of the watershed between the Atlantic and the Pacific river-systems at Ticlio, 15,665 feet above sea-level, and thence descending to 12,000 feet terminates at

The well here described was sunk in the garden of Dallinghoo Post-Office, near Wickham Market (Suffolk). Dallinghoo is about 4 miles north-west of Woodbridge, and about 161 feet above Ordnance datum. The well is one of three bored by a water-finder9s advice. His counsels were successfully acted upon in two out of the three cases, and this result will probably help to keep the superstition alive in that district. In this Post-Office well water9 was found at a depth of 79 feet. The section shows:— Below this the boring was not continued. Mr. George R. Allen, of Wickham Market, the borer and builder of the well, has carefully collected the fossils from the Boulder-Clay, and has given me the boring measurements. Besides Gryphaea incurva and Ichthyosaurus sp. (vertebra) the following fossils were found and were kindly identified for me by Mr. E. T. :Newton, F.R.S. :— In addition to these there is a concreted mass of indeterminable Lima and Ostrea , too young for identification, probably assignable to the Lower Lias. There are also large pieces of a dull-green bituminous shale, containing numerous fossils, showing young ammonites and brachiopoda ( Discina sp.), and black shining objects, possibly fish-scales. This shale burns with a bright yellow flame, and gives off a disagreeable pitch-like odour. A mass of quartz-grains, cemented by a dull-brown ferruginous material, is thought by Mr. Newton to be most probably Carstone. The fragment of Ammonites rarivostatus is very much worn at the upper (dorsal) surface and striated. Belemnites abbreviatus also is

The railway from Ashbourne to Buxton, when completed, will cover a distance of about 20 miles. It runs nearly due north, passing near the villages of Fenny Bentley, Thorpe, Tissington, Parwich, and Alsop-en-le-Dale, and will enable visitors from the north to reach conveniently some interesting parts of the limestone-district, besides rendering the beauties of Dovedale more accessible to the tourist. For the first 6 miles the railway runs on the Bunter Beds, Boulder Clay, and Yoredale rocks, and for the remaining 14 miles on the Mountain Limestone. The northern section, from Buxton to Parsley Hay, was completed several years ago, and I believe that no geological description of it was published. The southern section is now in progress of construction. The cuttings as far as Crake Low, about 6 miles from Ashbourne, are practically completed, but farther north there are several through which a passage has not yet been made. For this reason, I confine myself in the present paper to a description of the geology of the line from Ashbourne to Crake Low. Undoubtedly the most interesting portions are the three cuttings near Tissington, Highway Close Barn, and Crake Low. Sir A. Geikie, speaking of the latest traces of volcanic activity in Derbyshire points out that ‘though no contemporaneous tufts have yet been found among the Yoredalo rocks, coarse agglomerates do traverse the Yoredalo group at Kniveton.9 A careful examination of these cuttings has enabled me to fill this gap in our geological knowledge. The railway-excavations bring to view

The county of Cumberland, in which the city of Sydney is situated, and parts of the adjacent counties, are composed almost entirely of a palaeozoic formation of great thickness and extent. The principal materials of this formation are certain shales and sandstones, with a few associated beds of coal. In the close of the year 1845 I made a short excursion across a portion of this district, in company with the Rev. W. B. Clarke. We carried with us a mountain barometer, and by taking the means of the two sets of observations made in going and returning, got such an approximate estimate of the heights of the ground and the thickness of the rocks, as to enable us to construct a section with a sufficient approach to accuracy to be relied on for my present purpose. This section runs from Liverpool (a town just at the head of the tidal waters of George9s River, which falls into Botany Bay) by a slightly winding line, first S.S.W. for about twenty miles, through Campbelltown to Appin, and then about S.S.E. for about eighteen miles to Wollongong in the Illawarra district. Wollongong is on the coast about forty-five miles to the northward of Sydney. From Paramatta by Liverpool to Campbelltown the country is low, gently undulating, and composed (P1. VII.) almost entirely of (No. 1) black and brown shales, with a few thin interstratified beds of sandstone in their lower portion. From Campbelltown to Appin the country rises into bolder undulations, and

The object of this communication is to amplify and correct certain descriptions and sections of the Junction-Bed of the Middle and Upper Lias near Eypesmouth on the coast of Dorset, which I contributed as an appendix to Mr. S. S. Buckman9s recent paper on Jurassic chronology. On the Dorset coast the long time-gap between the top of the Domerian, in the Middle Lias, and the base of the Yeovilian, or Bridport Sands, in the Upper Lias, is represented by only a few feet of strata, and these vary greatly from section to section and even within a few yards. These few feet constitute the Junction-Bed, and fossils collected inch by inch in the different exposures show that, although all the hemerae recognized by Mr. Buckman as filling this gap have not been found, yet representatives of many hemerae occur, some in one exposure and some in another, and always in their appropriate order; so that it is fair to assume that the period was one of continual oscillation and penecontemporaneous erosion, and that the strata present a succession of non-sequences. At least in one exposure, at Watton Cliff, a considerable non-sequence can be directly demonstrated in a single block; here a bed belonging to a definite horizon thins out completely between two beds of respectively earlier and later dates. In order to make clear how much of the supposed complete sequence is represented and when the non-sequences occur, the following table is given, showing all the horizons of this date

Although a very large amount of information concerning the lithology of the Carboniferous Limestone is now available, that of no section has hitherto been described in detail, and it seemed that a full account of the rocks of the classical Avon Section might prove of value. The first full account of the composition or structure of one of the rocks of that section was W. W. Stoddart9s description of the ‘Bryozoa-Bed’ (‘Microzoal Bed’) in 1861 and 1865. In one of his papers on the Geology of the Bristol Coalfield, he further gave a considerable amount of information concerning the Avon rocks. Sorby, in his Presidential Address to the Geological Society in 1879, briefly alluded to some of the oolites from the Avon Section, but it was not until Mr. E. B. Wethered turned his attention to the subject that any detailed work was done. Mr. Wethered9s investigations referred, on the one hand, to the chemical and mineralogical features, and on the other, to the faunal and microscopical characters. His paper on ‘Insoluble Residues obtained from the Carboniferous Limestone Series at Clifton’ dealt with the former subject, while that ‘On the Occurrence of the Genus Girvanella in Oolitic Kocks. & Remarks on Oolitic Structure’ contains a full description and analysis of the several oolitic bands occurring in the Avon Section. A fairly full account of the microscopical structure of many rock-types is also to be found in his paper on ‘The Building of Clifton Rocks.’ G. F. Harris also described and

I. Introduction. The old ‘sea-cliff’ theory of Wealden denudation, which regarded the escarpments as the direct result of marine action, has long disappeared, and no one now doubts that the main physical features of this district have been produced by subaerial agencies. Beyond this, however, there is but little unanimity. Whether the subaerial process has been continuous since early Oligocene times; whether it can be divided into two cycles, with a peneplain between; or whether the removal of the top of the dome has been assisted by marine planation, are questions so undecided that, except on the one point already mentioned, geologists are perhaps in no closer agreement as to the physical history of the Wealden area than they were thirty years ago. In the second section of this paper the older lines of evidence are reviewed, and in places supplemented by new arguments, tending to show that the theory of marine planation is the one which, on the whole best, embodies the observed facts. In the third section the history of the four western rivers (Wey, Mole, Arun, and Adur) is examined, and the same inference drawn. Whether this explanation holds good for other parts of the Wealden area must be left to future investigation. The expression ‘plane of marine denudation’ is said by Foster & Topley (5, p. 473, footnote) to have been first used by Ramsay in 1847; but the words themselves are not to be found in the abstract of his paper to which they refer

I have on former occasions described the eocene strata of White-cliff Bay and of Alum Bay*. The sections of these two localities show in a remarkable manner the changes there undergone, in the comparatively short distance of twenty miles, by the series of sands and clays forming the Bracklesham Bay beds, and included between the London clay and the Barton clay. I also gave the commencement of the section of the Barton clays at Barton, to show their connection with the upper part of the section at Alum Bay. I have recently had the opportunity of further examining the coast-sections from Barton Cliff to Poole Harbour, with a view to continue the sequence of superposition lower in this more westward portion of the series. This part of the coast was described by Sir Charles Lyell in a paper read before this Society in March 1826. I need not therefore enter into a detailed description of the strata, but will confine myself to the question of the exact position which they bear with reference to the Barton clay, and to a few general observations on their physical conditions. The progress made by the sea in the destruction of the cliffs has also, I believe, brought to light some new features. In the first place I have, I think, obtained evidence of the existence of the Barton clays to the westward of Christchurch Harbour ; consequently the section downwards from them, which I had discontinued at Muddiford, can now be taken up

1. Introduction. The area of Avonian rocks with which this paper deals, and which I term the Midland Area, includes the large, irregularly-shaped periclinal mass of Carboniferous Limestone, forming the southern termination of the Pennine anticline, south of the Peak, and comprises also a few small inliers adjacent to this main outcrop. (See map, fig. 1, p. 35.) The main part of this area is included in Derbyshire, but a small, south-western portion lies in Staffordshire. In the Geological-Survey Memoir on North Derbyshire, the Carboniferous-Limestone succession of this area, as shown by the extensive section between Buxton and Monsal Dale, is briefly described; details of a few other sections are given; and the nature of the junction between the Carboniferous Limestone and the overlying shales, as seen at various points, is discussed. An account of the elementary tectonics of the area, and of the general features of the Carboniferous Limestone, is contained in a paper by Mr. H. H. Arnold-Bemrose, entitled ‘A Sketch of the Geology of the Lower Carboniferous Rocks of Derbyshire,’ published in the Proceedings of the Geologis9ts’ Association, vol. xvi (1899–1900) p. 165. Details of a new sections in the area are given in papers by Mr. Arnold-Bemrose and by Dr. Wheelton Hind, published in the Quarterly Journal of the Geological Society and elsewhere: I refer to these in the course of the present paper. The tectonic structure of this area has not yet been adequately investigated. However, the detailed mapping of the igneous rocks associated with

In June last Mr. Emile F. Guiton, a member of the Geological Section of the Societe Jersiaise, drew my attention to a raised beach which had been exposed in the course of some building operations on the southern coast of the island. It is on the east side of the ridge between Le Hocq and Pontac, and the section showing it runs from under the surface of the eastern slope about 25 feet westwards: here it is terminated by the rock, fine red granite, which makes a steep descent, and passes under the bed of pebbles. It is nearly at right angles to the main axis of the ridge, and faces northwards. The ridge here bends somewhat inwards, so that there was ground sloping to the north-east covering the beds before they were laid bare, and the underlying rock seems also to slope in the same direction. The middle of the section shows the following succession of beds, from above downwards:— At the western end of the

The relations of the rocks on the western border of Ross and Sutherland have long been a subject of controversy. Into the details of this it is needless to enter on the present occasion, as they have been recently recapitulated to the Geologists′ Association and published in their Proceedings*. The materials for this sketch are mainly contained in our own Journal; and the last contribution to the subject was a paper read by Dr. Hicks on May 22, 1878†. After listening to the ingenious theory put forward by that author, it occurred to me that the question was one on which the testimony of the microscope ought to be especially valuable. According I spent some days last summer at Kinlochewe, in order to examine the rocks in the field and to obtain specimens for microscopic work. I have now the honour of laying before the Society the results of these investigations. (1) Syenite of Glen Laggan. Previous writers on the above section have agreed in stating that a mass of igneous rock makes its appearance on the floor of Glen Laggan, about two miles from Kinlochewe, and extends for some distance up the bed of the stream, apparently cutting off the quartzite from the newer group. This rock is called diorite by Nicol, syenite by Murchison, Geikie, and Hicks; it is shown by the last author upon a section‡ as intrusive among the calcareous series which overlies the quartzites. Almost immediately on reaching the spot where the “syenite” first appears

During a recent rearrangement of the fossils from this limestone in the Woodwardian Museum my interest was especially aroused by the number of peculiar and unnamed specimens amongst them; and I was thus led to examine them with particular care, and subsequently to visit Keisley myself and collect more in the field, as well as to inspect Prof. Harkness9s collection at Carlisle, and the specimens in some small private collections. The following descriptions have therefore been based on the examination of as large an amount of material as was available. Prof. Harkness9s collection at Carlisle and that of Prof. Nicholson and Mr. Marr at Cambridge are those upon which the well-known lists of Keisley Limestone fossils have been founded; the last list was published by Prof. Nicholson and Mr. Marr in 1891. By carefully removing the matrix I have been able to bring out many minute characters previously invisible, and have also discovered several entirely new species, which make an important addition to our knowledge of the bed. Many thanks are due to Mr. Marr, Prof. Nicholson, Mr. Goodchild, Chancellor Ferguson, of Carlisle, Mr. E. T. Newton, and others for help and information. In this first past of my communication the tribolites alone are dealt with, being the largest and most characteristics section of the fauna. In the second and concluding part the rest of the fossils will be described, and the general relations of the fauna discussed. Crustacea—Trilobita A list of fossils from the Keisley Limestone was published in

In a former communication I described “The Rhaetic and Lower Liassic Rocks of the neighbourhood of Belfast”*, and I now propose to continue the subject with a description of the strata which surmount the Liassic series, namely, the Upper Cretaceous rocks in part. An incentive to study these formations was the knowledge that the results of the labours of the late Robert McAdam, Esq., F.G.S., had been anxiously looked for by many geologists†, who hoped that the true relationship of the Irish Cretaceous beds would have been satisfactorily determined by him from the study of his own collection of local fossils. That geologist has passed away from amongst us without having accomplished these researches; and as his collection has not been applied to the furtherance of the much-desired object up to the present time, I have undertaken the task he may have intended to perform. During a residence of two years and a half in Belfast, I have worked assiduously in collecting fossils from the Irish Cretaceous strata, and in studying their lithology and stratigraphical characters, with the hope that these materials would enable me to correlate them satisfactorily; and I shall now endeavour to show that they belong to the so-called Upper Greensand and to the Upper Chalk. The general features of the disposition of the Neozoic rocks in the neighbourhood of Belfast may be understood by reference to the accompanying section. II. Absent Formations. 1. Oolitic Strata .—In the foregoing section, the Cretaceous beds

I. Introduction. [C. A. M.] Although Carboniferous rocks form the rock-floor of the greater portion of the County of Dublin, they are so much concealed inland by Glacial Drift as to render their structure and relationships usually obscure. On the coast, however, they crop out in several very good sections, especially near Malahide, about 4 miles north of Dublin Bay, and at Rush, about 6 miles still farther north. The latter is the more extensive and interesting of these two. From the shore south of Rush village, extending northward past Loughshinny to within a mile of Skerries—a distance in all of about 5 miles—the Lower Carboniferous rocks are splendidly exposed: the outcrops being only interrupted occasionally, where the shore is covered by sand, or the Glacial Drift descends to sea-level. At the suggestion of Mr. G. W. Lamplugh, F.R.S., and tempted by the interesting character of the rocks themselves, I was induced (during a temporary residence in Ireland) to make a detailed examination of these beds. In order to understand the coast-section in full detail, a horizontal section of the beds, as shown in the cliffs and along the rocky shore, has been prepared for the whole distance on the scale of 1 inch to 10 feet. As, however, fossils have up to the present been collected only from the rocks near Rush, that is to say at the southern end of the line of section, the present communication will be restricted to that part of the area; but account

A section at Wolvercote, a village miles north of Oxford, has been open for the past ten years, and-will reward study by geologists interested in the phenomena of Pleistocene time, whether their object is to study the ehanges of laud and elimate, or whether, as was the ease with the writer, they seek for some detail in the fragmentary story of Palaelithic Man. The section eontains four parts, which may thus be named in the order of their age: (1)the Oxford Clay beneath, which is largely quarried for bricks; (2)an old surface, in which pits or troughs chiefly filled with gravel are seen enveloped in weathered clay; (3) a river-bed, containing gravel at the base, and layers of variouslyeoloured clay above; and (4)a surface-layer of humus over all, about 2 feet thick, containing h9eolithie remains. The relation which the various paris bear one to the other is also plain. The old Pleistoeene surface lies upon eroded Oxford Clay; the river-bed has worn a channel in the old Pleistocene surface; between the river-bed and the Neolithic surface is the trail usually named ‘warp,’ which, however, is not discussed in this paper. The river-bed first attracted my attention : it lies on the summit of land between the Isis and Cherwell, at an equal height above either river. There seems to be no reason to doubt that it represents the deposits of a stream whieh contained the united waters of both rivers, at a time before they became

I. Previous Knowledge of the Underground Geology. The first investigation into the underground geology of Northamp-tonshire, or the strata lying immediately beneath the thick deposit of the Liassic series, consisting of limestones and clays, which covers the county to a large extent, was made in the year 1836. A company was then formed and a shaft sunk near the village of Kings-thorpe, about miles N.E. of the town of Northampton, for the purpose of reaching the Coal-measures, which, upon the advice of practical men, it was thought could be found at no great depth below the surface, ”though competent scientific individuals, as Mr. Smith, the father of English geology, and Mr. Richardson, then of the British Museum, expressly denounced it as a mistaken enterprise“. An account of this shaft (fig. 4, p. 496) has been given by the late Mr. S. Sharp, F.G.S., in the ‘Geological Magazine,’ from which I extract the following passage t :— “No accurate detailed section of the shaft was taken at the time; but at a depth of 210 feet from the surface, a water-yielding ‘Limestone rock’ in the Middle Lias (Marlstone)was pierced, which produced 36,000 gallons of water per hour. At a depth of 880 feet (as is stated in pencil-notes on a diagram in my possession, which notes are said to have been made by Dr. William Smith, F.R.S., F.G.S., &e.) the New Red Sandstone was reached, and a flow of brackish water of a like volume

The short paper which I have to lay before the Society has been suggested by several previous communications on the subject of rocks older than, and unconformable to, the Cambrian Slates of North Wales. In the year 1867 I brought before the British Association at the Dundee meeting the accompanying section on the Llanberris and Carnarvon Railway, then for the first time exposed in a new cutting near Llanberris. The section was subsequently published in the ‘Geological Magazine’ for March 1868, to which I must refer the reader. Up to this time no suspicion existed of the occurrence of an unconformable series of ancient rocks in North Wales older than the Cambrians. Previous to this the researches of Dr. Hicks in Pembrokeshire established in that district the fact of the occurrence of great series of beds unconformable to the overlying Cambrians; but during the succeeding seven or eight years no fresh observations were made in the Llanberris district. At the reading of Dr. Hicks9s paper on December 2, 1874, I pointed out an apparent analogy between the Pembrokeshire series and that at Llanberris; and this, I believe, induced Professor Hughes and Dr. Hicks to visit Llanberris, and their observations on that district were recently communicated to the Society (Q. J. G. S. vol. xxxiv. pp. 137 & 147). Rather singularly, they disagree with me in the conclusion 1 arrived at, that there was a visible break in the series of rocks exposed in the Llanberris railway-cutting, but admit that such

The object of my present communication is to call attention to an interesting section that has lately been exposed in a quarry on the eastern side of Tideswell Dale in Derbyshire. The locality is exactly pointed out by the words “Tideswell Dale” in the Ordnance Map No. 81, S.E. At this spot it will be seen, by a reference to the map of the Geological Survey, that an outcrop of toadstone occurs. Another outcrop of toadstone is also exposed by the railway-cutting on the right bank of the Wye, opposite Litton Mill; this rock is fully described in the recently published memoir of the Geological Survey relating to this county. Above this are found thinly-bedded limestones; whilst lower down the river the loadstone is wanting, and a considerable thickness of fossiliferous limestone occurs with “thin lenticular partings of shale and red clay.” At the bottom of Miller9s Dale a toadstone, capped by about 150 feet of limestone, is seen running along the roadside on the left bank of the river; this bed is hard and massive in part, with calcareous veins and haematite; and is also amygdaloidal except where it has been exposed to the atmosphere; it is then vesicular and in places much decomposed. An upper bed immediately beneath the limestone is very green and soft, is veined with calcite, and has also here and there a little iron pyrites; the limestone above is very hard, and also has specks of pyrites in it. Going on now up Tideswell

1. Introduction [C.A.M.]. Loughshinny, a tiny fishing-village on the coast of County Dublin, about midway between the larger villages of Rush and Skerries, is well known to Dublin geologists for the fine exposures of contorted strata exhibited in the neighbouring cliffs. These exposures form part of an extensive coast-section of Carboniferous rocks which may be followed, with a few interruptions, for about 5 miles from Rush on the south to Skerries on the north. A description of the rocks in the southern portion of this coast section, from Rush as far north as a small cove called Brook9s End, was given by us in 1905, together with an account of the faunal succession and correlation of the beds. The present paper continues the description northward from Brook9s End, and is intended to be read in conjunction with our previous paper. The references given to former literature and maps in that paper apply equally to the ground now to be described. Before, however, describing in some detail the rocks around Loughshinny, it seems desirable to recapitulate very briefly the sequence of the rocks in the Rush portion of the coast-section. At Rush the lowest beds are a thick mass of dark slates (Rush Slates), with intercalated limestone-bands; they pass up into the Rush Conglomerates, and the latter into a calcareous group (Supra-Conglomerate Limestones and Carlyan Limestones). The ascending succession is as a whole from south to north, and the beds mentioned appeared, from the palaeontological evidence available at the time, to

I. Introduction. About miles east of the Severn Tunnel the South Wales branch of the Great Western Railway, in passing through the Patchway Tunnel, crosses the western margin of the Bristol Coalfield, and in the railway-cutting immediately to the west, Lower Carboniferous rocks are exposed. Here only the highest beds of the series are present, the Dibunophyllum Zone (D 2 and probably D 1 ), the main part of the sequence being cut out by the Cattybrook Fault, which brings in the Coal Measures. These are seen in the western end of the cutting, and are well exposed in the adjacent Cattybrook Brickworks. The Carboniferous Limestone has a general eastward dip—that is, towards the middle of the coal-basin; but, near the Cattybrook Fault, the beds are thrown into folds, and are much overthrust and broken by minor dislocations. The Coal Measures which are nearly vertical are ill-exposed near the line of fracture, and are seen in the adjacent brickworks to be intensely disturbed. The disturbance, in fact, on both sides of the fault is unequalled elsewhere in the Bristol district. The only published accounts of these exposures are (1) a brief reference by C. Richardson in the Report of the British Association (Manchester), 1861; (2) a somewhat fuller account in the Report of the Royal Coal Commission, 1871; (3) a short summary of the latter by H. B. Woodward in the Geology of East Somerset & the Bristol Coalfield and (4) an allusion by C. Lloyd Morgan to

In my former paper I took for the basement-limit of the Keuper what we might fairly call the base of the ‘ building-stones’ Prof. Hull, on a visit with me to Sidmouth in the summer of 1891, suggested that the bed of breccia below the footbridge over the Sid would make a better basement-line for the Keuper formation, and bring the classification more into harmony with the lines of demarcation adopted by himself and others for the Midlands and elsewhere. Though I had noted this bed and referred to it in my paper, its character as a distinct basement-breccia had not impressed itself upon me, since I regarded it as nothing more than one of the intercalated lenticular masses of the Bunter Sandstone. A closer examination reveals, however, its true character. It contains angular and subangular fragments of grit and quartz, enclosed in a dull brick-red matrix. What mainly deterred me from adopting this breccia as a basal line for the Keuper was the very marked current-bedded structure of the 10 to 15 ft. of coarse Bunter-like sandstone, which follows the breccia in the upward succession on the face of the cliff. This, however, is not a real difficulty, because— as Prof. Hull pointed out to me on the ground—this structural character is not at all uncommon in the basement-beds of the Keuper below the Waterstones in other areas. On looking into the literature of the subject a little more closely since my visit to Devon with Prof. Hull, I

The use of ‘Rhaetic’ as an international lithostratigraphical term is rejected in favour of a national terminology. The establishment, type-region and a possible standard section for the Rhaetian, and a marker point for its base are discussed. A critical examination is made of the evidence involved in the suggestion that the Norian and Rhaetian are contemporaneous and that the latter cannot be used as a chronostratigraphical unit. World-wide reinterpretation of faunal and field observations does not support this proposition. Alterations to the lower boundary of the Rhaetian are found to be unnecessary and the suggestion that the Germanic facies should be split from the remainder of the stage and placed in the Jurassic is rejected. The Rhaetian is reaffirmed as the final stage of the Triassic, and the base of the Pre -planorbis Beds supported as the lower boundary of the Jurassic.

Having in a former communication to this Society* endeavoured to prove that the great series of purple and green grits and slates which form the southern highlands of Ireland belong to the Uppermost Silurian period, and that between them and the succeeding beds of the Old Red Sandstone there occurs everywhere a wide hiatus (a gap of unrepresented geological time), indicated not only by visible unconformities but also by absence of intervening beds at various points, it now becomes desirable to inquire, and, if possible, to determine what formations in other districts may be supposed to fill up the hiatus above referred to, and then, having determined this point, to see what inferences may be drawn concerning the physical geology of the regions referred to at the various stages indicated both by the presence and the absence of consecutive strata. This inquiry naturally leads one to cast a glance at the neighbouring coasts of England and Wales as the districts where light may be looked for on these questions; and I propose in the following pages to make a comparison of the series of beds in both countries, namely the South of Ireland and North Devon, and adjoining districts north of the Severn†. It will also be desirable, with a view to a fuller investigation, to refer, when necessary, to the Devonian and Carboniferous series as it occurs in Belgium and Scotland, and to see how far it is comparable with, and sustains our observations of, the Devonshire section. Views

Descriptions of the coast-section between Highcliff and Bourne-mouth, with which the present paper deals, have already appeared in the publications of the Society. That by Sir Charles Lyell, in 1826, was written when the strata included in this section were still supposed to belong to the Plastic Clay underlying the London Clay. In it the different beds forming Christchurch Head are carefully distinguished, and their superposition illustrated in a somewhat idealized section. The description of the eight miles of cliff from a mile beyond White Pits to Poole Harbour is, however, dismissed in a very few words:—The “section presented by the cliffs is continued so precisely in the line of bearing of the strata, that no new beds rise up, and it is unnecessary to describe them in detail..... The prevailing character of the strata throughout this extent of coast is line white sand; but yellowish and pinkish beds of sand occur, and thinly laminated clays in great abundance, resembling in appearance many of the light-coloured argillaceous marls of Montmartre near Paris; but in none could I discover any organic remains, except vegetable impressions, and these very indistinct.” The proofs of origin, whether marine or freshwater, are considered equivocal. The total thickness of the series, nowhere exposed to view, is put down at “not less than 150 feet.” It is also suggested that the argillaceous strata with shells of Alum Bay “are probably concealed here at some of the interruptions of the section.”

The well at Rock Mills (Messrs. Joseph Sykes & Co.) is situated in the mill-grounds in the valley of the River Hohne at Brockholes, about 4 miles south of Huddersfield. According to the Geologiqal Survey-map (Quarter-Sheet 88 S.E.), the alluvimn in the valley at this point rests on shales which underlie the Rough Rock, the uppermost member of the Millstone Grit. The shales appear to vary considerably in thickness in this district. Green states that 100 feet of shales are present between the Rough Rock and Grit A about Holmfirth, which lies 2 miles south of Brockholes; while on Holestone Moor, west of Huddersfield, he estimates that thev are 200 feet thick between the same horizons. Spencer has shown that in the district embraced in the next sheet to the north (Quarter-Sheet 88 N.E.) the shales contain a marine fauna; and the discovery of Edestus should stimulate the efforts of the local geologists to further work on this horizon. During the excavation of the well no record of the various strata passed through was made by the sinkers; but it appears, from notes supplied by Mr. J. R. Simpson, of Banks, Honley, that the rocks were mainly shales, with some thin beds of sandstone. At the depth of 120 feet the specimen of Edestus was obtained by Mr. H. H. Freer in a bed of rock—rather friable shale,—which also contained numerous fragments of marine shells. Among the specimens the following have been identified:—Posidoniella lœvis (Brown), Gastrioceras sp., Glyphioceras reticulatum (Phill.)

Previous work in the area.—The Meifod district was visited by Sedgwick on various occasions in 1832, and again in 1842 and 1843, in the last-mentioned year in company with J. W. Salter. It was from this district that several of the types described by McCoy were collected, and also many of the fossils recorded in Salter9s catalogue were obtained during these visits. It seems strange, since this district was in many ways a connecting link between Sedgwick9s Bala succession and Murchison9s Shropshire succession, that no further work has been published since Salter9s catalogue in 1873. The general succession was established by Sedgwick, but the exact horizons of some of the beds and the relationship between them needs revision in places: thus Sedgwick attributed the absence of the May Hill Sandstone to the unconformable overlap of the Wenlock Series, whereas, as will be shown in the sequel, the succession is complete at this horizon. It is also unfortunate that the beds in the Mathrafal section were placed by Salter in the Upper Bala (Llandovery rocks = Lower Llandovery of the Geological Survey), since it would now appear that they belong to the base of the Upper or top of the Middle Llandovery of the type area. The Caradocian deposits on the whole occur in the northern part of the area under discussion, where they form the folded southern flank of the Berwyn dome and the cores of the series of anticlines which run off south-westwards from the main dome. The strata

I. Introduction. In describing the clays which underie the Chalk at Speeton on the Yorkshire coast in a paper communicated to this Society in 1889, I attempted to show the necessity for a fresh classification of these deposits.Further investigation of this section has fully confirmed the views then advanced. It has also indicated the desirability of a corresponding revision of the inland exposures of the rocks of the same age in Yorkshire and Lincolnshire, since it is only by means of the knowledge of the full sequence to be acquired on the coast-section that the true relationship of the limited and isolated exposures of the interior can be unravelled. Using such opportunities as have at intervals occurred, I have therefore more or less closely examined the base of the Chalk escarpment throughout its whole length in Yorkshire and Lincoln-shire, and desire in this paper to put on record the result of my investigation. It will be shown that the divisions proposed for the Speeton section are readily applicable to the inland exposures, and indeed afford the most convenient and natural means of palae-ontological classification, albeit some modification of the systems, usually applied is thereby required. It may be well at once to state that, while my chief aim will be to establish the correlation of the deposits by means of their palaeontology, no attempt will, for the present, be made to carry the palaeontological research further than is necessary for this purpose. Hence the fossils dealt with herein will only

On the opposite side of the Severn to Aust Cliff, and 2 miles north-north-west of that section, there is a corresponding elevation known as Beachley, Aunard9s, or Sedbury Cliff. Chepstow lies to the west-north-west, and in a direct line is distant about miles, but by road about miles. I have distinguished the cliff-section as that of Sedbury, since Sedbury Park, the country-seat of Sir William Marling, Bart.—to whom, and to Mr. S. S. Marling, I am indebted for permission to examine the cliff and for kind assistance—is situated on the Rhaetic and Liassic outlier. The literature relating to the section is not voluminous. In that which has come under my notice I find it incidentally mentioned in several papers,1 and briefly noticed in two other communications. The earliest account is that given by the Rev. P. B. Brodie, but it is based upon information supplied by Mr. Higgins. This account may be summarized as follows. There is a development of true ‘Insect-Limestone’ above the ‘Landscape-Stone,’ and although they are separated one from the other by 4 feet of shale at the eastern end of the section, at the western they thin out and blend as at Aust. The ‘Landscape-Stone’ contains a great variety of insect-remains, some of which are tolerably perfect. The ‘ Cypris - and Plant-Bed’ is seen in its proper position, and in every case possesses a true ‘Landscape’ character. Sir W. V. Guise observed that this section closely resembled the exposure at Aust, yet presented differences which

I. Introduction. This paper is a condensation of a longer memoir, the parts omitted being chiefly lists of fossils and remarks on the same. It embodies the results of some five years9 study of the Rhaetic Series, chiefly in the Bristol district, maple easier by the fact that I reside in that district. II. Descriptionoffournew Rhaetic Exposures. (A) Redland, Bristol. A number of exposures have been recently made here in cutting a new road. One of these has already been briefly dealt with in a local memoir by Mr. W. H. Wickes (46), and again by Mr. Parsons (47). I give, with slight modifications, Mr. Wickes9s classification of the beds, and his list of fossils, enumerating those that I have found in addition. The lettering corresponds to that used by the late Edward Wilson for the Pylle-Hill section (36). The fossils are not obtained solely from the exposure originally described, but from the newer exposures as well. It is impracticable to separate them, as the material thrown out has been mixed. Such is the original exposure, which furnished the material for Mr. Wickes9s paper. The next section to be opened, about a quarter of a mile or less away, displayed upturned beds of Upper Carboniferous Limestone, cut off flat, with the Rhaetic Beds deposited on them unconformably. The limestone-beds are very massive, and dip at 35° south 80° east. Between these beds little pockets of yellow clay pass down for a variable distance, due to greater erosion

The object of this paper is not so much to give a minute description of the district I am about to review, as to promote a discussion amongst the members of the Society here present on some of its phaenomena, which seem to be singularly illustrative of the superficial changes that have been effected in the south of England by dynamic forces of comparatively modern date. The district is to be found in the ninth section of the Ordnance Map, and extends from near Portsmouth to Shoreham, or that flat country which is to be seen from any part of the tops of the South Downs from Portsdown Hill eastward to the Shoreham River.

This paper introduces a simple method for objectively analysing the arrangement of beds in sequences of alternating rock types. The number of times that different lithologies overlie one another in a section may be recorded in a table, termed the data array. The probability of one lithology overlying another in a section is a function of their frequency (i.e. the number of times that they occur), and the 9memory9 of the depositional process. Since their frequency is known, from the data array, it is possible to calculate the number of times that different lithologies should be interbedded with one another if they were arranged at random. Comparison of these figures with the observed number of transitions (shown in the data array), picks out lithological transitions which occur more often than expected if they were randomly arranged. In such cases it can be said that one lithology has a good 9memory9 for another. For example in the Coal Measures coal may have a good 9memory9 for seat-earth. The results of these studies are presented on facies relationship diagrams. These record the most probable upward and downward transition for each lithology in a section and can be used to detect the modal and composite sequences. After testing for memory a corrected facies relationship diagram may be constructed showing those transitions which occur more often than expected assuming a random model. It is these transitions which must be considered when postulating the sedimentary process which controlled the deposition of a rock sequence. This method is applied to stratigraphical sections of the Paradox salt basin, U.S.A., Libyan Miocene shoreline deposits, fluviatile Torridonian (Pre-Cambrian) rocks of Scotland, and Yoredale (Lower Carboniferous) beds of northern England. All four cases show signs of memory in the vertical arrangement of their beds. The simplest examples show simple oscillatory motifs, both rhythmic (in the sense ABCABC) and cyclic (in the sense ABCBA). The more complex examples show arrangements due to up to three intertwined oscillations. The geological significance of these results is discussed.

The great extent of bare and clean-denuded chalk hills forms a very striking feature of the scenery around Salisbury. But, although the more prominent parts of the country are so free from drift, the small valleys which traverse these great undulating downs contain, scattered along their base and often extending for a short distance up the slopes of the adjacent hills†, a considerable quantity of gravel, flint- and chalk-rubble, and brick-earth. This drift is, in greater part, of local origin, and is very irregular in its structure and distribution; one material predominating at one spot, and another taking its place close by. Flint-rubble and sandy clays preponderate usually in the lower parts of the valleys, chalk-rubble being more common on the hill-slopes, whilst the brick-earth is irregularly and only occasionally patched on the base of the hills, alternating with and replacing the flint- and chalk-rubble. Three of these small valleys are confluent at Salisbury. It is on the north-easteru side of the one through which the Willey flows that one of the best exhibitions of the Drift is obtained. The following section shows the prevailing relation and structure of this deposit, which here rises about 30 to 40 feet above the level of the Willey*. The railway-cuttings between Salisbury and Wilton expose some good continuous sections, whilst several brick-fields give a few deeper excavations. In a cutting adjoining Wilton, large subangular gravel, chalk-rubble, and coarse rubbly brick-earth alternate and pass laterally one into the other. The following section of a

The zonal subdivisions of the Cambridgeshire Chalk were first described in 1880, and more fully in the Memoirs of the Geological Survey, in 1881, the outcrops of the Totternhoe Stone and the Melbourn Rock having then been traced as far as Burwell and Newmarket respectively; but the survey of the Suffolk Chalk having been previously completed, the lines were not continued on the Survey map. The section exposed in the cliffs near Hunstanton has often been described, but the beds there seen are very different from those which occupy a similar stratigraphical position near Newmarket; it was evident, therefore, that between these two places the beds forming the lower part of the Chalk underwent a considerable amount of lateral change, and that, until more was known of the manner in which one facies of the Lower Chalk passed into the other, no correlation of the Norfolk and Cambridge sections could be more than suggestive. Moreover, in the absence of this information, one of us has found much difficulty in correlating the subdivisions of the Lincolnshire Chalk with that of the Midland counties, and he felt that when once the constitution of the Norfolk Chalk was properly understood, that of Lincolnshire, which bears great resemblance to it, would no longer offer any difficulty. It being clear, therefore, that important issues depended upon an investigation of the changes that take place in the Cretaceous rocks as they pass from Suffolk into Norfolk, it was with the object of exploring this terra incognita

The locality to which I would draw attention this evening is the extreme north-west corner of the county of Lincoln—the district, in short, as the rough map (fig. 1) will show, bounded by three rivers, the well-known Humber and Trent and, eastwards, the little Ancholme—this last a strange name to modern ears, but one which has been honoured by the mention of that old English classic, Isaac Walton. It is a corner of the land unknown to fame; but we are now becoming celebrated commercially by the recent discovery of a most extensive and valuable deposit of iron-ore, respecting which I shall have something to say by and by. But, besides this commercial importance thrust upon us, the district has a special value in the eyes of the geologist as being a middle link in the chain of the Jurassic strata, between their development in the south and their somewhat dissimilar appearance on the Yorkshire coast. The labours of Mr. Judd and Mr. Sharpe, in the southern portion of the county, have brought into clear light the commencement of this variation. But the state of things in this northern corner has not as yet been brought before your notice. The accompanying section (fig. 2) gives a general idea of the district. Three escarpments are represented, and two long sloping plains between them. The westernmost scarp is capped with Lower Lias (Bucklandi–zone), the middle one with Lincolnshire Limestone; and the easternmost is the Chalk Wold. Both these latter elevations are characteristic