bluuebunny/crossref_metadata_2025 huggingface dataset:
The Shoulders of Glacial Troughs
Authors: Cotton C. A.
Published: May 2009

The inner or immediate trough of a glaciated valley is now generally regarded as very closely related in origin to the glacier that last flowed in it, being equally a result of its erosive work whether vertically excavated or laterally opened by it. This is the Trog of Richter (1900), which he regarded as more or less exactly containing the glacier of the last glaciation during at least a great part of the period of trough-development, though signs of overflow at the height of the ice flood are found above the “shoulders” which bound the trough. Rarely does the trough comprise the whole valley: more commonly shoulders distinctly separate steep trough walls from gentler upper valley-side slopes. In addition to the inner trough-side shoulders, however, higher benches are in many cases unmistakably present, though they may be poorly defined and are always discontinuous, so that their correlation and restoration as a definite number of actual upper shoulders is by no means certain.
The Ordovician Rocks of the Builth District A Preliminary Account
Authors: Jones O. T. , Pugh W. J.
Published: May 2009

The Builth district was visited by one of us (O. T. J.) in the spring of 1939 with a view to arranging an excursion for the International Geological Congress which was to have been held in London in 1940. Amongst other places the magnificent range of quarries in the Ordovician volcanic rocks of Llanelwedd, near Builth, was examined. Beyond the western end of the quarries a striking boulder bed was observed which promised to give an insight into a remarkable episode in the history of the district. This bed is shown on the I in. Geological Survey Map, Old Series, Sheet 56, S.W.
“Algal Dust” and the Finer-grained Varieties of Carboniferous Limestone
Authors: Wood Alan
Published: May 2009

Certain of the Lower Carboniferous algae are preserved as moulds in a fine-grained calcareous matrix precipitated by their own life processes. The cell walls of the alga are not preserved. This observation applies to the genera Ortonella, Mitcheldeania, Bevocastria, and Girvanella. In the case of Mitcheldeania the filaments are so close together and so parallel that an impression of a definite wall may be obtained, but occasional irregularities and a comparison of the microstructure with that of other forms leaves no doubt that this too is a precipitate.
The Malignite of Poohbah Lake, Ontario
Authors: Shand S. J.
Published: May 2009

In an article on “Limestone and the Origin of Feldspathoidal Rocks”, which appeared in the Geological Magazine ten years ago, I referred to the malignite of Poohbah Lake, Western Ontario, and was so bold as to predict that “further work at Poohbah Lake … will eventually furnish evidence of the presence of limestone in contact with the alkaline eruptives”,1 In August, 1939, I found myself at last in a position to visit the locality and see how far my prediction could be verified.
Icelandic Tectonics—Graben or Horst ?
Authors: Hawkes L.
Published: May 2009

The younger rocks of Iceland (Pliocene to Present Day) occupy the broad median zone shown in Text-fig. I; the boundaries are only approximate in places, and information is lacking with regard to the eastern one particularly. Outside this zone early Tertiary basalts predominate but (I) the uppermost basalts are regarded by some authors as Quaternary, (2) Quaternary and Recent volcanic rocks occur in the Snaefells Peninsula and in Skagi. The thickness of the early Tertiary series has been estimated at 3,000 m.; it may well be more, and it is reasonable to suppose that originally these basalts extended over the site of the median zone. Hitherto all workers in Icelandic geology have considered the zone to be a graben where the older rocks have been faulted or tilted downwards, but recently R. A. Sonder (1, 2) has put forward the startling idea that it is a horst, a view which is discussed, and not unfavourably, by H. G. Backlund (3). Before considering this new conception attention will be drawn to evidence in the neighbourhood of the north-western boundary of the zone, evidence which is not mentioned by Sonder and which, although it has been known for over 70 years, is often ignored or forgotten by writers on Icelandic tectonics.
The Coal Veins of British Malaya
Authors: Richardson J. A.
Published: May 2009

So far as the writer has been able to ascertain, the occurrence in British Malaya of coal in vertical veins, as distinct from coal interbedded with sediments, was first recorded in 1908 by Mr. J. B. Scrivenor, who described an example in a tin mine in alluvium at Siputeh, west of Batu Gajah, Perak.
Statistical Methods in Sedimentary Petrology. Part II. Grain-Size Measurements and their Graphical Study
Authors: Smithson Frank
Published: May 2009

It is proposed in the present paper to discuss certain micrometric methods applicable to the minerals of sedimentary rocks and to suggest how their graphical study may be used for the elucidation of certain problems in sedimentary petrology. The examples used are taken chiefly from the Triassic and Jurassic rocks of Yorkshire as described in Part I.1
Note on the Occurrence of Dayia navicula (J. de C. Sowerby) in the Lower Ludlow Rocks of Shropshire
Authors: Shirley J.
Published: May 2009

In the type area the Ludlow Rocks generally have been divided into Lower Ludlow Shales, Aymestry Limestone, Dayia Shales and Whitcliffe Flags in upward sequence. The Dayia Shales are characterized by the presence of enormous numbers of Dayia navicula (J. de C. Sowerby). This preponderance of D. navicula in the shales immediately above the Aymestry Limestone has caused a tendency to regard beds in other localities containing this fossil as being on the same stratigraphical horizon in spite of the character of the accompanying fauna. In two recent papers on the Ludlow Rocks of the Welsh Borderland (Straw, 1937, and Earp, 1938) it has been shown that D. navicula ranges through at least 3,000 feet of strata, occurring commonly throughout this great thickness and outlasting more than one change of fauna. Although, in this area, the brachiopod ranges from the zone of Monograptus nilssoni into the Upper Ludlow it has not hitherto been recorded below the Aymestry Limestone in Shropshire. This gap in our knowledge is now filled by the discovery of specimens in Lower Ludlow Shales exposed in a small quarry 40 yards north-east of Stokewood Cottage, which is on the west side of the railway line a little over a mile south of Craven Arms. The quarry shows about 15 feet of nodular shales with thin limestone seams. The commonest fossils are Chonetes laevigata (J. de C. Sowerby), C. minima (J. de C. Sowerby), and Stropheodonta filosa (J. de C. Sowerby) which occur in large numbers on some of the bedding surfaces. Other fossils are Stropheodonta euglypha (Dalman), Delthyris sp., Orthoceras sp., Dalmanites sp., and a plectambonitid. Dayia navicula seems to be confined to a thin layer on the north side of the quarry. Graptolites referable to Monograptus cf. chimaera occur fairly commonly. About 400 yards in a south-easterly direction another small quarry exposes Conchidium Limestone which is about 170 feet stratigraphically above the beds in the first quarry.
Some new Species of Proetidae and Otarionidae from the Ashgillian of Girvan
Authors: Begg J. L.
Published: May 2009

The genus Proetus is present at three horizons in the Girvan district. The first appearance is at Balclatchie in the highest beds of the Barr Series of Lapworth (Bala); next it occurs in the Drummuck Trinucleus Shales (Ashgillian), now usually referred to as the Drummuck Group; and its final occurrence is at Newlands in the Saughhill Group (Mid-Valentian).
The Landscape Cycle under Semi-Arid Conditions
Authors: Cotton C. A.
Published: May 2009

It is difficult to draw the line between aridity and semi-aridity, just as it-is difficult to differentiate between humid and semi-arid climates as they affect the development of landscape forms. No hard and fast divisions based on rainfall figures can be adopted. Evaporation, in part controlled by temperature, and the seasonal distribution of rainfall are also important factors. “The rainfall regime is divisible”, according to. Bryan, “into the episodic and the periodic. In the episodic type rain falls in storms that are highly variable in intensity and are scattered through the year; in the periodic type precipitation is concentrated in one season, either summer or winter. In areas having the periodic type vegetation is adjusted to the wet season, and a relatively greater vegetative cover is possible with low rainfall. The Mediterranean region and California have the periodic type of rainfall, with winter maximum and mild temperatures. Thus in many sub-areas the land forms under mean annual rainfalls of 15 to 20 inches are very similar to those of humid regions, although the soils … are quite like those of other arid regions. The episodic rainfall, because of its variability in time throughout the year, is less effective in promoting growth, and the vegetative cover may be so scant with rainfalls of 5 to 7 inches that geomorphologically the region is essentially a desert. Episodic rainfall as high as 15 to 20 inches may produce steppe conditions. … In general the warmer areas have a relatively scantier vegetation with the same rainfall regime. Including this relation all varieties of hot and cold deserts or semi-arid climates are possible (2).”
Reddened Carboniferous Beds in the Carlisle Basin and Edenside
Authors: Trotter F. M.
Published: May 2009

The origin of the West Cumberland haematites is one of those unsettled problems that have exercised the minds of geologists and miners for more than half a century. Theories have been evolved, but not one can claim general acceptance. It is not my purpose to discuss these theories here, but the consideration of one of them was directly responsible for the examination of the reddened Carboniferous rocks that form the subject of this paper. This theory, first advocated by J. G. Goodchild and later supported by Dr. B. Smith, may be stated briefly thus: The New Red Sandstone rocks were the immediate source of the haematites. From these rocks the iron was carried in solution to lower levels by the downward percolation of meteoric waters. The theory had the merit of explaining, not only the haematite deposits of the Carboniferous Limestone of West Cumberland, many of which occur beneath the New Red Sandstone Series, but also the reddened Carboniferous strata frequently found in North-Western England, beneath and fringing the base of the Permo-Triassic rocks.
Quaternary Sea-Levels in the Northern Hemisphere
Authors: Anderson W.
Published: May 2009

The investigation of the possibility of late-glacial sea-levels at 190 feet (58 m.) and 140 feet (42 m.) has entailed the reading of a vast quantity of literature dealing with glacial observations. The following is an account of some facts gathered and some ideas arising from these readings.
Rhynchonellids of the Boueti Bed of the Great Oolite Series of Langton Herring, Dorset: A Study in Variation
Authors: Aitken W. G. , McKerrow W. S.
Published: May 2009

(1) The range of variation in the external characters of the rhynchonellids examined is illustrated by means of graphs and scatter-diagrams.

(2) The three-variable scatter compares directly the proportions of thickness, breadth, and length, and defines the assemblage as adequately as several scatters which relate only pairs of variables. A close relationship is shown to exist between the three-variable scatter in which the positions of specimens are mathematically determined and the scatter in which the specimens are placed according to general appearance.

(3) The three-variable scatter, when considered with size-groups, indicates that with growth, breadth and thickness increase more rapidly than does length. All the scatters indicate that proportionate thickness Varies to a greater degree than does proportionate breadth or proportionate length.

(4) The sample, being random, is probably nearly representative of the goniorhynch rhynchonellid fauna of the Boueti Bed at Langton Herring. The stratigraphical value of the work, however, can only be proved by examination of assemblages from other localities and horizons.

(5) Since the scatters show that all gradations occur between the extreme variants, the forms behave as though belonging to a single homogenetic community. It is recognized that internal characters may in due course be found to show discontinuity in their variation, but on present evidence it appears that only one species is present.
The Plio-Pleistocene Boundary and Mammalian Correlation
Authors: Cooke H. B. S.
Published: May 2009

The problem of the boundary between the Pliocene and the Pleistocene is still very far from satisfactorily settled both from a geological and from a faunal viewpoint. It becomes increasingly apparent that the two aspects of the problem require different definitions and in consequence there has been very great confusion in the application of the terms “Pleistocene” and “Quaternary” both in geological and in palaeontological literature. The original definitions of these terms, too, seem very largely to have been forgotten and they have been used by a variety of writers for various purposes.
The Lower Ordovician Cryptolithids of the Llandeilo District
Authors: Williams Alwyn
Published: May 2009

The following description of new genera and species of Lower Ordovician Cryptolithids is the result of a stratigraphical and palaeontological investigation of the rocks in the Llangadock-Llandeilo district, Carmarthenshire.
Stratigraphical Nomenclature of Scottish Metamorphic Rocks
Authors: Anderson J. G. C.
Published: May 2009

Among the most controversial problems of British geology are those concerning the metamorphic rocks which make up the greater part of the Scottish Highlands. The writer, in common with many geologists whose work has brought them into contact with the region, has long felt that the discussion and solution of these problems would be greatly facilitated by a nomenclature less involved and more consistent than that at present in use. A simplified nomenclature, moreover, would do much to stimulate and hold the attention of students and general readers.
Twelve Years' Measurement of Accretion on Norfolk Salt Marshes
Authors: Steers J. A.
Published: May 2009

In this magazine for January, 1938, there appeared a short note on the rate of sedimentation in the salt marshes of Scolt Head Island. The records then only covered two years. In a note in the Trans. Norfolk and Norwich Nat. Soc., 15, 1939, 41, some additional readings, covering four years, were published and analysed. This summer (June, 1947) I was able to measure the accretion again after a further interval of eight years, so that we now have rates and averages for two, four, and eight years. Unfortunately the line on Aster Marsh was partly destroyed during the war when it regrettably formed part of the target area for artillery fire.
Dolomite Contact Skarns of the Broadford Area, Skye: A Preliminary Note
Authors: Tilley C. E.
Published: May 2009

The metamorphism of the Durness dolomite horizons in the aureole of the Beinn an Dubhaich granite of Skye has long provided one of the best known examples of dedolomitization and progressive thermal metamorphism of siliceous dolomites recorded in the literature. Harker's study (1904) concerned itself primarily with assemblages regarded as derived without notable accession of material during metamorphism and the occurrence of products of metasomatic origin at the contact of the granite has hitherto received but little notice in print. Yet as long ago as 1897, Geikie had written of this contact: “… the most abundant and interesting deposits are metalliferous. Fragments of a kind of ‘gossan’ may be noticed all along the boundary line of the boss, and among these are pieces of magnetic iron ore and sulphides of iron and copper. The magnetite may be seen in place immediately to the south of Kilbride. A mass of this ore several feet in diameter sends strings and disseminated particles through the surrounding granophyre and is partially coated along its joints with green carbonate of copper” (Geikie, 1897, p. 384). It is of interest to note further that a record of “a mineral resembling humite” from this same contact is made in the Annual Report of the Geological Survey for 1896 (1897).
Notes on the Geology of Killary Harbour
Authors: McLaren D. J. , Miller T. G.
Published: May 2009

The Rosroe Peninsula, on the south side of Killary Harbour, Co. Galway, is formed of the Rosroe Grits, mapped by the Geological Survey of Ireland (1875) as “Lower Silurian”. Kilroe (1907) in a rapid revisionary survey of Galway and Mayo, described the succession on Rosroe as inverted (op. cit. p. 154, n. 3):—

“ Mr. McHenry informs me that the fossils (graptolites) on the south side are indicative of Upper Llandeilo, while those on the north side are Lower. This being the case, the order of the beds is inverted, as they dip northerly.”
The Distribution of the Kordofan Sand (Anglo-Egyptian Sudan)
Authors: Edmonds J. M.
Published: May 2009

The Kordofan Sand is a deposit of unconsolidated surface sands covering large areas to the west of the White Nile in the central part of the Anglo-Egyptian Sudan and especially in the province of Kordofan. In character, it is a typical winddeposited sand of well-rounded quartz grains, with a colour varying from pale buff to deep red. The colour is due to iron staining on the surface of the quartz grains, but only extends to a very shallow depth, sometimes as little as 4 to 5 feet, below which depth the sand is colourless. The absence of colour in the deeper parts of the deposit appears to be due to absence of iron rather than to its presence in a reduced state, and it is thought therefore that the iron must represent a concentration in the upper portion of the deposit. As far as investigation has been made there is no evidence of a downward leaching of iron-bearing solutions with penetration to underlying deposits.
A Note on Pleistocene Deposits near Lake Manyara, Tanganyika
Authors: Kent P. E.
Published: May 2009

While with the East African Archaeological Expedition in 1935, the writer had the opportunity of examining certain lacustrine deposits located by Dr. L. S. B. Leakey in the Mkujuni Valley of the Manyara basin.
The Pleistocene Beds of Kanam and Kanjera, Kavirondo, Kenya
Authors: Kent P. E.
Published: May 2009

Pleistocene deposits near Homa were first visited by Dr. F. Oswald (1914), who described the exposures at Kanjera. Dr. L. S. B. Leakey and his colleagues of the 1931–2 East African Archaeological Expedition located human remains while collecting the fauna of the beds, and the importance of this discovery led to resumption of work on the area by the 1934–5 expedition to which the writer acted as geologist, and to a special study of the geology of the area and provenance of the human remains, for which Professor P. G. H. Boswell joined the expedition at Dr. Leakey's invitation, his visit being facilitated by the Royal Society. Mr. E. J. Wayland, of the Uganda Geological Survey, also spent a short period with the expedition before Professor BoswelPs return. It was a sad disappointment to ali concerned that the early date of the human remains could not be established with certainty (Boswell, 1935), but in tne present note it is proposed to describe the geology of the deposits, which is itself of considerable interest.
Metasomatism and Intrusion in Jamaica
Authors: Trechmann C. T.
Published: May 2009

The nearest known pre-Cretaceous rocks to Jamaica are Jurassic in Western Cuba, and Carboniferous in Colombia, Venezuela, and Honduras, all about 500 miles away. The evolution of Jamaica seems to have been somewhat as follows. Andine (?) orogenesis on or near the site took place, accompanied by magmatic invasion; the rocks are nowhere seen “in situ”, but they have supplied pebbles of granite, granodiorite, porphyry, hornfels, vein stuff, and limestones, more or less foliated or marmorized, but not gneisses nor schists. There is no evidence that any of them are older than Cretaceous, but they go to form the oldest beds of the island, the massive Blue Mountain purple conglomerates whose composition varies from place to place and of which no natural base is seen. Interbedded with these conglomerates are fossiliferous shales and Rudist limestones of Upper Senonian to Maestrichtian age. Low down, however, there is in Eastern Jamaica a bed of algal and foraminiferal limestone, without Rudistae, which was partly torn up and incorporated as rolled pebbles in the conglomerate. Some of these pebbles contain Camerina dickersoni Palmer, a foraminifer of Upper Cretaceous age, so the pebbles are but little older than the conglomerate containing them. Laramide orogenesis took place and this series was invaded by granodiorite and other intrusions. The uplifted area was eroded and some of the igneous and associated Cretaceous rocks exposed to denudation. Depression occurred and Lower or Lower Middle Eocene Carbonaceous shale or Richmond Beds, a Flysch-like series of limestones, shales, and conglomerates, were deposited.
The Pseudodeltidium of the Strophomenid Brachiopods
Authors: Arber Muriel A.
Published: May 2009

The term pseudodeltidium was proposed by Bronn (1862, p. 242) for the shell-plate covering the delthyrium, or triangular opening between the teeth, in the ventral cardinal area of those brachiopods now assigned to the order Protremata. It is typically developed among the “family” Strophomenidae, of which it is a diagnostic feature, as a convex arch overhanging the interior of the ventral valve (Text-fig. 1A). In the embryo, the pseudodeltidium is secreted as a single unit when the shell is first formed, and is therefore not homologous with the deltidium (von Buch, 1834, p. 15) of the order Telotremata, since this is formed in the post-embryonic period as two separate plates which may subsequently coalesce (Beecher, 1892)
The Age and Tectonic Relationships of East African Volcanic Rocks
Authors: Kent P. E.
Published: May 2009

The great volume of extrusive rocks which has accumulated during and since the Tertiary period is one of the most important geological features of East Africa, and one which various people have related to the formation of the Rift Valley System.
Rainfall, Rivers, and Erosion
Authors: Rastall R. H.
Published: May 2009

Although there are in existence numberless books, many of them of great excellence, dealing with the effects of denudation (Geomorphology) nevertheless long experience and much reading seem to show that the more descriptive side of the subject, the result of the processes, has received more attention than the actual mechanism by which the results have been brought about. This applies more particularly to river erosion. In most books there is at the outset a tacit assumption that rivers do erode and the matter is left at that. Now rivers and running water generally certainly do perform the work of denudation somehow, as is proved beyond doubt by the large amount of material sometimes carried in suspension. But a careful consideration seems to show that the subject is not quite so simple as would appear from most textbooks.
The Geology of the Zanzibar Protectorate and its relation to the East African Mainland
Authors: Stockley G. M.
Published: May 2009

An interesting zoo-geographical study of the islands and the mainland of the East African coastal region, has just been completed and the results have been published as a paper in the proceedings of the Zoological Society of London (1941). Messrs. Moreau and Pakenham in this study have raised the question of the age of the faults, which played such a large part in causing the separation of the island of Pemba. They quote Sir Edmund Teale and C. Gillman: “ There is no reason why land connections should not have persisted long after the Miocene, and probably right into the Pleistocene.” The purpose of the following article is to restate the facts and to discuss the above conclusion. In the view of the writer no new geological evidence has arisen to cause him to change his original estimate, that Pemba Island dates from the late Miocene or early Pliocene (1928).
Five New Ordovician Trilobites
Authors: Reed F. R. C.
Published: May 2009

The following descriptions are based on specimens recently collected in the Ordovician rocks of the Girvan area by Mr. James L. Begg and Mr. R. Tripp, and are all new species of interest.
Unrecorded Inliers of Silurian Rocks, near Wickwar, Gloucestershire, with Notes on the Occurrence of a Stromatolite
Authors: Whittard W. F. , Smith Stanley
Published: May 2009

The Upper Palaeozoic rocks at Wickwar pass eastwards below Mesozoic strata, but about half a mile farther to the east the pre-Triassic surface is laid bare in places in the floor of the Little Avon River for a distance of 1,300 yards between Stmt Bridge and a point some 360 yards below Horse Bridge. The rocks found here are of Silurian age. Exposures are small and discontinuous since the stream has covered the valley floor with its own deposits and only at intervals does it flow on, or cut laterally into the solid rock. Moreover, the base of the Trias, which is nowhere many feet above the thalweg, sinks twice below stream level, dividing the Silurian outcrop into three inliers. The first two, conveniently styled the northern and southern Sturt Bridge Inliers, are separated by only 40 yards of Triassic deposits, but between the more northerly of these and the Horse Bridge Inlier 330 yards of Triassic rocks intervene.
The Arenig Rocks of Arran, and their Relationship to the Dalradian Series
Authors: Anderson J. G. C. , Pringle J.
Published: May 2009

The existence of pillow lavas, black shales, and cherts in North Glen Sannox, Arran, has been known since W. Gunn carried out the detailed mapping of this part of the island for the Geological Survey in 1899. A description of these rocks, in which that author makes the suggestion, not since seriously disputed, that they are of probable Arenig age (Gunn, 1900) was first published in the Summary of Progress for 1899. Full accounts, to which the reader is referred for details not repeated in the present paper, were later given by Gunn (1903, 1905) and by Tyrrell (1928).
A Revised Terminology and Subdivision of the Middle Jurassic Rocks of Yorkshire
Authors: Hemingway J. E.
Published: May 2009

It is suggested (1) that the term “Estuarine Series”, as applied to the Middle Jurassic rocks of Yorkshire, should be abandoned and that “Deltaic Series” should be substituted; (2) that the boundary between the lower and middle divisions of this series should be revised and that the persistent Eller Beck Bed should be substituted for that boundary in place of the wedging Millepore Series of the Scarborough district and its inland equivalent, the Whitwell Oolite.
An Alkali Facies of Granite at Granite-Dolomite Contacts in Skye
Authors: Tilley C. E.
Published: May 2009

The development of an alkali pyroxene-bearing fades of granite at the contact of the Beinn an Dubhaich granite of Skye with Durness dolomites is associated with a skarn formation involving magmatic transfer of alumina. The significance of the processes at work in this and related examples is discussed.
Notes on the Nile Valley in Berber and Dongola
Authors: Sandford K. S.
Published: May 2009

Low-lying physiographical features in the northern Sudan are associated with Lower Tertiary “lake beds”. Some undulation may have been imposed, e.g. in the Dongola bend of the Nile. There has been little vertical river erosion below the level of the lake beds in the northern Sudan, whereas in Egypt there were long successions of Tertiary sediments, uplifts, folding, and faulting. Neither late-Tertiary marine flooding nor successive regradings of the Nile in Egypt reached the Sudan. With reference to the present flood plain the summit level of some silts of Palaeolithic age rises in a striking manner from the country around Atbara (and probably a wider area) downstream into the Dongola bend, reaches a maximum (so far as known) around Wadi Haifa, and then falls again.
Accuracy in Geological Place-names
Authors: Rastall R. H.
Published: May 2009

In the interests of accuracy and practical convenience, a detailed account is given of several instances well known to the author where vague or badly chosen place-names have given rise to uncertainty or even definite errors, in the position of geological localities, including one recent description of an important deep boring in N.E. Yorkshire. Attention is also drawn to an increasing looseness in the definition of the ancient local name of Cleveland. Trouble has also been caused by the recent invention of a new place-name, Ravenscar, which is synonymous with the ancient name, Peak (not The Peak, as often written by geologists). When an author is not himself thoroughly conversant with the place-names of his district it is recommended that some local authority, not necessarily a geologist, should be consulted.
A “Luxullianite” from East Dartmoor
Authors: Blyth F. G. H.
Published: May 2009

A dyke-like mass of luxullianite type is emplaced along a line of fracture which crosses granite in a zone of pneumatolytic reddening, and is exposed in a quarry face. Extensive tourmalinization is related to post-emplacement fractures which traverse both the luxullianite and the adjacent rocks.
The Pediment Landform: Some Current Problems
Authors: King Lester
Published: May 2009

The pediment is a widespread and fundamental landform adapted to and moulded by sheet-flow of surface water. The usually abrupt transition from hillslopes to pediments corresponds to a change in surface water flow from linear- to sheet-flow. A cut-rock surface is an essential feature, and where this is buried beneath a detrital mantle some climatic change is to be suspected.
A Xenolithic Minor Intrusion at Slievenagriddle, County Down
Authors: Patterson Edward M.
Published: May 2009

Examination of a xenolithic minor intrusion of Caledonian age at Slievenagriddle, County Down, has shown the existence of felspathic replacement rims and rheomorphic veins associated with the xenoliths, and derived from them by metasomatic action of the magma.

Chemical and spectrographic analyses of the main rock of the intrusion, and of a rheomorphic vein, establish an order of geochemical migration for the metals of the alkali series.

In conclusion I wish to express my thanks to Mr. J. J. Hartley, of Queen's University, Belfast, for valuable advice and help in the field work; to Dr. J. E. Richey and other members of the Geological Survey for much useful criticism and assistance; to Dr. D. L. Reynolds for reading this communication in MS., and to Dr. R. L. Mitchell, of the Macaulay Institute for Soil Research, for performing the two spectrographic analyses.
Recent Tectonic Progress in India
Authors: Bailey E. B.
Published: May 2009

It is so easy these days to overlook recent advances of science that I venture to draw attention to two particularly important papers on Indian tectonics by W. D. West, published in 1939 and 1936, both carrying self-sufficient maps. The 1939 paper deals with Alpine tectonics displayed in the Shali Window of the Himalayas, north of Simla; its partner, with a recumbent fold and slide in the Nagpur district of Peninsular India.
On the Fringe of Tretaspis
Authors: Begg J. L.
Published: May 2009

This paper is an endeavour to demonstrate a development in the fringe of the Trinucleidae, which attained its acme in the Upper Ashgillian as exemplified by the Girvan species Tretaspis cerioides (Angelin) var. sortita Reed.
A Note on the Gneisses of Rum
Authors: Tilley C. E.
Published: May 2009

The recent reinterpretation of the structure of Rum presented by E. B. Bailey (1944) involves a revision of the age of the gneisses of that island. Harker's description of these banded and foliated rocks had referred them to a late date in the Tertiary igneous sequence of the plutonic centre (Harker, 1908). This interpretation had been arrived at in face of the earlier belief of Geikie that they formed part of the Lewisian Series and it is now known that Harker's contemporaries on the Geological Survey who had opportunity of examining his collections dissented from his conclusions though this opinion had until recently not been committed to print (Flett, 1944).
Stratigraphical Classification and Nomenclature
Authors: Henson F. R. S.
Published: May 2009

The subject of stratigraphical classification and nomenclature has given rise to much controversy in the literature.
Geology of the Aust-Beachley District, Gloucestershire
Authors: Whittard W. F.
Published: May 2009

The folds and many of the faults in the Keuper Marls of the Aust-Beachley District are claimed to be compaction phenomena. The distribution of almost vertical sheets of alabaster in the Keuper Marls is attributed to infilling of contraction cracks. The palaeontology of the Carboniferous rocks, particularly of the seldom-visited islands of the Severn, is used to determine the structure. Several post-Triassic faults of tectonic origin have been mapped and others predicted; the age of the faulting is unknown.
The Influence of Water Films adsorbed by Mineral Grains upon the Compaction of Natural Sediments and Notes on Allied Phenomena
Authors: Sugden W.
Published: May 2009

The mechanism of the compaction of sediments is discussed, with special reference to the rôle played by adsorbed water, under both normal conditions and conditions of erosion and tectonic force. The effect of adsorbed water on the migration of oil and gas, and the possible relation of sediment-compaction to submarine slumping and sedimentary volcanism are also reviewed.
The Age of the Ore Deposits of the Lake District and of the Alston Block
Authors: Trotter F. M.
Published: May 2009

Thereis a lead-zinc (with subsidiary copper) metallogenic province on each side of the Vale of Eden. To the east the veins of the Alston Block are found in Carboniferous rocks and a Hercynian age is the generally accepted date of the mineralization. To the west the veins lie in the Lower Palaeozoic rocks of the Lake District. Within the latter area ore-veins associated with the Shap Granite are, by common consent, regarded as of Caledonian age. But these apart, there is a regional mineralization in the Lake District, best developed in the northern part of that topographical unit, which has also been regarded as of Hercynian age.
The Age of the Neptunian Dyke at Hazler Hill
Authors: Strachan Isles , Temple John , Williams Alwyn
Published: May 2009

During the Easter Field Meeting of the Sedgwick Club, portions of the Neptunian dyke at Hazier Hill, near Church Stretton, were collected and brought back to Cambridge for further examination. The material consisted of a buff-coloured, sandy mudstone with scatters of facetted pebbles of quartzite and igneous material, including weathered rhyolite, up to a centimetre in diameter. The material proved to be richly fossiliferous and the following fauna was obtained which, we believe, throws some light on the age of these sand-filled fissures :—
FasciculophyllumThomson and other genera of the “Zaphrentis” omaliusigroup of Carboniferous corals
Authors: Hudson R. G. S.
Published: May 2009

British Carboniferous corals belonging to theFasciculophyllum omaliusigroup are usually erroneously referred to the generaZaphrentisRafinesque & Clifford andDensiphyllumDybowski. None of the species usually attributed toDensiphyllumis congeneric with that genus: some, such asD. bradbournenseWilmore, have been shown to belong to the genusRhopalolasmaHudson (Hudson, 1936, and in press); for others, such asD. rushianumVaughan, a new genus,Rotiphyllum, is here erected.
The Structure of the Dendroid Graptolites
Authors: Bulman O. M. B.
Published: May 2009

In 1938 Roman Kozlowski published a preliminary account of a collection of dendroid graptolites and allied forms from the Upper Tremadoc of Wysoczki, Poland, upon which he had been working for many years. All of the thirty-eight species listed were new to science, as were twelve of the seventeen genera, for the reception of which he erected three new orders, Tuboidea, Camaroidea, and Stolonoidea, in addition to Nicholson's Dendroidea. Presumably, no long delay in the publication of the full monograph was anticipated; but the names have remained nomina nuda, and the only clues we have at present to the characters of the new orders themselves are slight.
A Further Examination of Organic Remains in Rhyolite-Ash in Malaya
Authors: Scrivenor J. B.
Published: May 2009

In a letter published in the March–April, 1942, number of this magazine I said I hoped to continue working on the problematical bodies found in rhyolite-ash in Malaya and first described by me in 1930. Further work has been done, but before giving the results I must mention the unusual sequence of events that has led up to the present paper. My identification of “rods, spheres, and club-shaped objects” as spongeremains in 1930 (the work was chiefly done in 1928) was then supported by Dr. M. Burton, who thought they came from marine sponges; but in February, 1942, he withdrew this support. In Annual Reports for 1937–1940 Mr. E. S. Willbourn, Director of the Geological Survey, Federated Malay States, recorded more outcrops of this ash and mentioned the discovery by Mr. H. D. Collings of stone axes in gravel of probably Mid-Pleistocene age below the ash. Supported by Dr. K. P. Oakley, Mr. H. D. Willbourn queried the problematical bodies being sponge-spicules.
The Association ofNaiaditesandCarbonicolain a part of the Central Coalfield of Scotland
Authors: MacLennan Rhona M.
Published: May 2009

The material to be described was collected in the Shotts-Newhouse area (Sheet 31) of the Central Coalfield from the mussel bands above the Shotts Gas and presumed Lower Drumgray Coals. These horizons are within the Ovalis Zone (Weir and Leitch, 1936, pp. 704, 707). Fossils from above the presumed Lower Drumgray Coal were collected from the waste tip of South Langridge Colliery; material from the Shotts Gas was obtained from the tips at Fortissat, Hassockrigg, and Hirstrigg collieries.
Pimlicocrinus gen. nov. and two new species of Amphoracrinus from the Carboniferous Limestone
Authors: Wright James
Published: May 2009

In a recent paper (Geol. Mag., lxxix, 1942, 272), a single specimen from Coplow Knoll, Clitheroe, which differed from the commoner forms found there, was referred to the genus Amphoracrinus under the name of A. clitheroensis. Some time after sending this paper to the editor I found in my collection a smaller specimen belonging to the same species and still later another one, together with seven specimens belonging to a distinct though closely allied species. This additional material shows that both species differ in several respects from Amphoracrinus and the new genus Pimlicocrinus is now proposed for their reception.
The Pre-Karroo Stratigraphy of Tanganyika
Authors: Stockley G. M.
Published: May 2009

The purpose of this paper is to discuss certain aspects of pre-Karroo (unfossiliferous) stratigraphy of Tanganyika and to make certain proposals, which are considered desirable in order to further geological research in East Africa and to aid in regional and detailed mapping. A summary of the unfossiliferous rocks, together with these proposals, changing the names of certain systems, is systematized in Table I. The suggestions embodied in this scheme are as follows:
The Portencorkrie Complex of Wigtownshire
Authors: Holgate Norman
Published: May 2009

The Portencorkrie igneous complex, a trapezoidal area of plutonic rocks intrusive into Silurian sediments, is situated in the Rhinns district of Wigtownshire some sixteen miles south of Stranraer and about four miles north-west of the Mull of Galloway. It appears on the Geological Survey (Scotland) 1-inch Sheet 1, and lies within the Ordnance Survey 6-inch quarter-sheets Wigtownshire 33 S.W. and 37 N.W. To the north and south the igneous margin can be followed with fair accuracy, while to the east the boundary is obscured by drift. Westwards, the rocks pass beneath the Irish Sea.
The Yorkshire Dogger: III. Upper Eskdale
Authors: Rastall R. H. , Hemingway J. E.
Published: May 2009

1. A sequence of strata is determined in the Dogger of Upper Eskdale and its tributary valleys. The rocks fall into three main series, which are subdivided into groups.

2. The underlying Yeovilian sediments, originally included with the Dogger, are mapped and briefly described. The unconformity between them and the Dogger is emphasized.

3. The Dogger is marine throughout but only the oldest yields an adequate faunal assemblage, similar to that of the Glaisdale Oolite Series (upper opalinum). The greater part of the Dogger of this area is therefore younger than that of the Yorkshire Coast.

4. Chemical changes in the sea-water caused the deposition of siderite to characterize the earliest phase (Glaisdale Oolite Series). This was succeeded by a phase of dominantly chamosite deposition (the Chamositic Series) followed by a reversion to siderite deposition (the Ajalon Series).

5. Earth-movement controlled sedimentation over the area. During the first phase an eastern tilt to the region held the centre and west above or near sea-level, where it received no sediment. The second phase saw general depression with the accumulation of shallow water sediments. This was followed by uplift and erosion when a broad shallow valley was cut. Partial depression then flooded the valley with derived marine sediments.
Notes on Actinocrinites elephantinus Austin and Amphoracrinus brevicalix Rofe
Authors: Wright James
Published: May 2009

Before the Austins published their Monograph on Recent and Fossil Crinoidea, they issued to prospective subscribers an illustrated circular intimating the forthcoming publication of the work. Through the kindness of Professor W. T. Gordon, of King's College, London, I have a copy of this circular. It is in one sheet, printed on one side only and measures 7¼ in. by 9½ in. Over one-third of the upper part of the printed page is occupied by two specimen illustrations, “Platycrinites laevis (Miller)” on the left, and “Actinocrinites elephantinus (Austin)” on the right hand side. The genus Platycrinites was later fully described in parts 1, 2, and 3 of the Monograph, and a facsimile of the drawing of P. laevis of the circular is given on pl. i, fig. 1e of the Monograph. The illustration of Actinocrinites elephantinus Austin, however, does not seem to have been published in any work by the Austins prior or subsequent to part 8 of the Monograph, which was the last number to appear.
The Chalk Rock at Winterborne Abbas, Dorset
Authors: Robbie J. A.
Published: May 2009

An abnormal lithological development of the Chalk Rock occurs in the neighbourhood of Winterborne Abbas, South Dorset, where it contains pebbles of Upper Greensand material. Two exposures of this rock have previously been recorded but further information regarding this variant of the Chalk Rock was obtained during the resurvey of the area in 1936. A possible source of origin for the derived material is suggested.
Two Early-named Valid Species of English Upper Jurassic Ammonites
Authors: Arkell W. J.
Published: May 2009

Perisphinctes listeri (de Haan). 1825. from the Corallian Beds, and Titanites cingulatus (de Haan), 1825, from the Portland Beds, are valid species that have been overlooked. The original figures on which they were based are reproduced.
The Nomenclature of Lower Carboniferous “Reef” Limestones in the North of England
Authors: Bond Geoffrey
Published: May 2009

Various ways in which Lower Carboniferous reef limestones have accumulated are described, and terms defining them are introduced. Regional sedimentation, lithology, structure, fauna, and erosion history are kept separate in the discussion. The reef limestones of Northern England are briefly reviewed in the light of this classification.
Basement Carboniferous in Upper Teesdale, N. Yorks.
Authors: Harry W. T.
Published: May 2009

Excavations in Upper Teesdale, N. Yorks, exposed basement Carboniferous at its unconformable contact with underlying shales of probable Silurian age. The lowest basement beds are tough conglomerates cut by compression joints. The constituent pebbles are unsorted, locally derived, and mainly andesites and rhyolites, with vein quartz and shale pebbles. A dreikanter outline is common. The conglomerate is contrasted with others also between the Carboniferous and Lower Palaeozoic in England.
Depth of Burial of South Wales Coals
Authors: Wellman H. W.
Published: May 2009

Metamorphism of the South Wales coals is considered to be due to depth of burial and not to a thrust. Dr. Trotter's data are used to calculate the metamorphic gradients at different places. The differences in these gradients, which are calculated in two different ways, are discussed. The South Wales gradients together with data from New Zealand are used to estimate 18,000 feet as being the total depth to which the 4 per cent anthracite was buried. Maximum depth of burial is considered due to cover unconformable to the coal measures except in the southern part of the coalfield.
Note on Two Lineated Tectonites from Strathavon, Banffshire
Authors: McIntyre Donald B.
Published: May 2009

The principal tectonic terms employed are defined. A specimen of sheared quartzite from Corshellach is described. Shear-planes, drag-folds, and lineation are syngenetic. Their geometric relations show that the lineation is in b. Also described is a specimen of folded marble and graphite schist from Urlarmore. Elongated bodies of graphite schist represent tectonic thickening along the antiform hinges. Their maximum dimension, which is much greater than any other, is parallel to the lineation, but they have not suffered extension in this direction. The form of folds and rotated bodies shows that the lineation is again in b. The sense of the movement was towards the south-west. It is believed that throughout mid-Strathspey and Strathavon similar lineations bear the same relations to the kinematic directions.
Some Features of the Lower Carboniferous Reef Limestones of Clitheroe, Lancashire
Authors: Parkinson Donald
Published: May 2009

The Clitheroe Limestone of Coplow, Salt Hill, and Bellman quarries is redescribed, particularly from the point of view of the origin and structure of the reef knolls and their relation to the surrounding deposits. Coplow knoll is considered to be the exposed part of a lenticular mass of upper C1 reef limestone which originally sloped steeply east. An earth movement within the C2 zone is marked by limestone breccias and a boulder bed, but there seems no evidence of pronounced erosion. A later uplift preceded the deposition of the Worston Shales. Slickensiding in the reef limestone is briefly discussed and possible effects of compaction of the sediments are considered. Three growth stages in reef formation are postulated.
Rejuvenation in a Rhabdosome of Dictyonema flabelliforme
Authors: Bulman O. M. B.
Published: May 2009

An abnormal specimen of Dictyonema flabelliforme showing close-set bifurcation of the branches in a portion of the distal mesh is described and figured, and possible interpretations are considered.
Some Large Felspar Augen from near Ilorin Town, Nigeria
Authors: King Basil C.
Published: May 2009

Large augen, composed principally of single crystals of potash felspar, are sporadically distributed in certain banded gneisses. It is inferred from structural and textural evidence that the augen have formed by metasomatic processes.
Note on Lineation, Boudinage, and Recumbent-folds in the Struan Flags (Moine), near Dalnacardoch, Perthshire
Authors: McIntyre Donald B.
Published: May 2009

Present knowledge of the tectonics of the Struan area is summarized. Recumbent-folds and incipient boudinage are recorded in the Struan Flags. The different types of lineation present are described; it is pointed out that all types present are mutually parallel. Simple kinematic analysis of an exposure north-west of Dalnacardoch, demonstrates that the lineations coincide more or less closely, with the axis of rolling; they are therefore b-lineations. The need for further field-work is stressed, and the type of data required is indicated.