bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Effects of Artificial Heating on Fluorite-Bearing Albite-Granite from St. Austell, Cornwall
Authors: Weymouth J. H. , Williamson W. O.
Published: May 2009

The granite consisted chiefly of albite, quartz, muscovite, microperthite, fluorite, and topaz; zircon was very rare. The low to high quartz transition enhanced thermal expansion and porosity. Heating was continued step-wise to 1,300°C. and caused an irreversible increase in porosity at all temperatures investigated. The changes undergone by the various minerals, separately or through interaction, were noted. Fluorite began to melt against muscovite or alkali-feldspar between 800° and 900°C. Muscovite developed brownish pleochroism at the lower, and was replaced by mullite at the higher, temperatures. The gradual melting of feldspar, the development of cleavages and cracks in quartz, and the invasion of these cracks by feldspathic glass resembled phenomena in certain xenoliths.

The conditions that produced glass when powdered granite was heated unconfined or in a bomb are described.
Namurian Goniatites in the U.S.S.R.
Authors: Ramsbottom W. H. C.
Published: May 2009

Goniatite faunas characteristic of the principal Namurian stages are reported in many areas of the U.S.S.R. The faunas are listed, and a brief account of some recent systematic work is given.
On the Significance of Metamorphosed Calcareous Concretions in Lower Birrimian Schists of the Gold Goast
Authors: Conybeare C. E. B.
Published: May 2009

Nodules of “pseudodiorite”, i.e. metamorphosed calcareous concretions, occur in the Lower Birrimian (Pre-Cambrian) quartz-biotite schists which are interpreted as having been calcareous muds and silts. The probable metamorphic history of these nodules is traced.
The London Clay of Coastal Suffolk and Essex
Authors: Davis A. G. , Elliott G. F.
Published: May 2009

The London Clay exposures on the coasts of Essex and Suffolk are described and their fossils listed. Correlation is made with similar strata in Germany and Denmark, and the significance of all these beds in relation to the Lower Eocene palaeogeography of North-Western Europe is indicated.
Quantitative Measurement of Available Relief and of Depth of Dissection
Authors: Dury G. H.
Published: May 2009

Simple arithmetical techniques are set out whereby planimetric data, of the kind used in constructing area-height diagrams, can be made to yield additional quantitative information useful in description and comparison of relief. The most useful is an expression for mean available relief, which takes account of the form as well as of the height of interfluves. It is also shown how the depth of dissection of a datum surface can be mapped and measured.
Some Holothurian Spicules from the Upper Bathonian of the Dorset Coast
Authors: Hampton John S.
Published: May 2009

Six species (one new) of holothurian sclerites, representing the genera Achistrum, Rhabdotites, and Etheridgella, from the Upper Bathonian of the Dorset coast are figured and described, and are the first of such organisms to be recorded from the Great Oolite of England.
Movement of Sand by Wind
Authors: Carroll Dorothy
Published: May 2009

During last winter (1937) at Cottesloe, a seaside suburb of Perth, Western Australia, a large sand-dune was being levelled. This provided the writer with an excellent opportunity for observing the movement of sand grains by wind.
The Cambridge Collection of Rock-slices
Authors: Barker Alfred
Published: May 2009

It has been suggested that petrologists may be interested in a brief account of the Cambridge University collection of rock-slices, comprising at present some forty thousand slides. It had its small beginning sixty years ago, when microscopical petrography was still something of a novelty. Among the first in this country to use the new method of research was Dr. T. G. Bonney, then in residence at Cambridge; but the large collection which he gradually amassed came to us only at his death, and the earliest slides in our cabinets were made for E. B. Tawney, at that time Assistant to the Woodwardian Professor. The preparation of thin slices of rocks was not the comparatively easy and rapid process. that it is to-day (emery was the only abrasive used), and it was not unusual to give credit to the practitioner in published papers. The best known, if not the only one, in England was F. G. Cuttell; later it was customary to get the slicing done in Germany.
Notes on the Geology of the Lizard Peninsula. No. 5. Porthallow and Neighbourhood: Folding: Tourmaline-bearing Rocks
Authors: Scrivenor J. B.
Published: May 2009

Anyone who studies the relation of the rocks of the Lizard Peninsula to those immediately to the north must realize that Porthallow, the little village in a sheltered cove near St. Keverne, is a critical locality in the problem, and one indeed that may hold the key to the solution of the relative ages of the rocks on either side of the sinuous line called the Lizard Boundary. Porthallow is at the eastern extremity of that line. The western extremity is on Polurrian Beach, near Mullion, where a very clear fault with a breccia about 22 feet thick separates two totally distinct formations, sandy and argillaceous killas on the north from hornblendegneiss on the south. At Porthallow, however, although there are cliffs on either side of the cove washed by the sea, the geology is far from having the textbook clearness of Polurrian Beach and there is room for much difference of opinion. Text-fig. 1 is a sketch-map of the locality based on the Ordnance Survey 25 in. to the mile map, and first the main features of the geology will be described. For the neighbouring country the reader is referred to the Survey 1 in. map (Sheet 359) and to the 6 in., Sheet lxxxi N.E.
The Consolidation of Muddy Sediments
Authors: Jones O. T.
Published: May 2009

In the study of the structures acquired by sediments in the process of slumping, a knowledge of the probable state of consolidation of the materials is of some importance in forming correct views regarding submarine sliding and the conditions under which it occurred.
Factors Controlling Graptolite Successions and Assemblages
Authors: Elles G. L.
Published: May 2009

The Lower Palaeozoic rocks of Britain afford the most complete succession of graptolite faunas as yet known, but these successions are not always of uniform type, since they are controlled by different factors.
Filtering appendices on the branchial arches of Coelacanthus lepturns Agassiz
Authors: Demanet F.
Published: May 2009

Recently, in describing the fauna of the passage-beds between the Dinantian and the Namurian, I pointed out, for the first time, the presence of some Conodonts1 in the Carboniferous of Belgium. Since the discovery of this first series of specimens, I have picked up several hundred Conodonts in various localities, included either in the passage-beds, or in the lower levels of the Namurian. It is to be expected that other localities may shortly be discovered.
On Granitization and Associated Processes
Authors: MacGregor Malcolm , Wilson Gilbert
Published: May 2009

A review of the literature, and our own observations have led us to the conclusion that granitization, widely defined as the process by which solid rocks are converted to rocks of granitic character, has been an important process in the evolution of many subjacent masses of granite and allied rocks, such as granodiorite and diorite, in erogenic regions.

Granitization of pre-existing rocks seems to involve two processes: (a) Metasomatism under the influence of permeating highly energized fluids—emanations—ahead of advancing magma; and (b) Mechanical penetration by magma. During the first process metasomatic exchanges take place between the minerals of the country-rock and its pore fluid: the reactions tend towards the achievement of equilibrium under the existing physico-chemical conditions. This metasomatism is selective, and promotes the convergence, in bulk and mineral composition, of rocks which were originally different, towards a common end-product. During the early stages conditions are essentially those of thermal metamorphism, but with rising energy level and increasing magmatic contributions the final conditions are dominantly “igneous”.

The mechanical penetration of the altered rocks and their mixing with magma may follow the first process without a break. Alternatively, intrusion may occur before metasomatism is completed, or has even had appreciable effect. The mixing or intrusion stage is accompanied by reactions, which tend towards the attainment of equilibrium, under magmatic conditions, between the magma and the foreign material. In terms of bulk composition the products will be intermediate between that of the magma and that of the incorporated material.

The metasomatism trends of the various examples that we have discussed are plotted together in Text-fig. 8. The diagram brings out the convergence of the curves from the normal sedimentary field to the rhyolite-diorite line, which is itself the locus of mixtures between metasomatized products and acid parental magmas.

Granitic rocks may originate as the result of either or both these processes. That which predominates in any particular case depends on the supply of emanations and the local physico-chemical conditions. In the deeper parts of the granitic layer complete or selective fusion is to be expected, and the magmas so formed may rise and granitize the overlying rocks: firstly, by metasomatism, and at higher levels chiefly by mechanical penetration. At still higher levels, owing to loss of energy, rising magma is unable to cause extensive modification of the pre-existing rocks, and forms true intrusions.
Statistical Methods in Sedimentary Petrology. Part I. Percentage Composition of Assemblages and their Graphical Study
Authors: Smithson Frank
Published: May 2009

In recent years much work has been done in determining the quantitative—or more strictly “numerical”—composition of heavy mineral residues from sedimentary rocks in the hope of obtaining evidence as to whence the detritus was derived. It is clear that the petrological characteristics of the land mass whose erosion provides the detritus must always be an important factor in predetermining the percentage composition of the residue as we now find it. Yet the sorting action of the transporting agents (which tend to separate the heavy from the less heavy minerals) and of chemical agents (which, both before and after deposition, destroy some minerals and introduce new ones) may often be suspected of having a great or even a dominating influence upon the final composition of the residue. It is proposed in this paper to investigate by simple mathematical methods the probable effect of these processes and to do so along lines which have been suggested by the study of actual heavy mineral assemblages.
Possible Late-Glacial Sea-levels at 190 and 140 feet O.D. in the British Isles
Authors: Anderson W.
Published: May 2009

Almost twenty years ago the writer mapped the series of late-Glacial drainages in the area immediately south-west of Newcastle-upon-Tyne (1).
Kyanite-Gedrite Parageneses
Authors: Tilley C. E.
Published: May 2009

Discussion of the genesis of kyanite-amphibole associations in amphibolites has so far been limited to assemblages involving common hornblende (1). Striking examples of an association of kyanite with rhombic amphibole (gedrite) now known from the Archaean gneisses of the White Sea area, Russia, visited by the Northern Excursion of the International Congress in 1937, probably provide one of the first records of this paragenesis in the literature.1The rocks of the region include coarse-grained garnet and kyanite rich gneisses associated with amphibolites in the Shueretsky district of Karelia, and have been described by Ignatiev (2).
The Periods of Coal Formation represented in the British Coal Measures
Authors: Trueman A. E.
Published: May 2009

As a result of recent work on the correlation of the Coal Measures in the various British coalfields it is now possible to determine the relative ages of the chief productive measures in the different areas. Some aspects of this work were summarized in 1933 but much further work has been done since that time, especially with reference to the Scottish coalfields (Weir and Leitch, 1936). The results of these investigations may be expected to throw considerable light on the physiography and other factors controlling the deposition of the Upper Carboniferous rocks, but in the present note attention is drawn only to the zonal distribution of the more important coals in various British coalfields.
The Brachiopod family Parastrophinidae
Authors: St-Joseph J. K. S.
Published: May 2009

Biconvex to plano-convex usually partly costate Protremata, without pseudodeltidiuin or chilidium so far as known. Of the two valves the dorsal is considerably the larger and more convex. The delthyrium is closed by the incurved dorsal umbo. Dentition simple; strong teeth developed on dental-plates fit into sockets between the brachial-processes and the valve margin. The dental-plates unite to form a duplex spondylium. In the dorsal valve the alate cardinalia consist of short brachial-processes supported on outer-plates, which may remain parallel or converge to form a sessile cruralium or cruralium duplex. The muscles are attached within the spondylium in the ventral valve, while dorsally there is a central grouping of the adductor muscles on the inner surface of the valve below the cruralium.
The Geomorphology of British Guiana
Authors: Bracewell S.
Published: May 2009

(1) There is no evidence of the alignment of the Essequibo with the edge of a deep ocean basin.

(2) The Essequibo River is not a well-defined dividing line between two geological provinces.

(3) The Essequibo River does not mark the former locality of a coast line; it is not parallel to a tectonic depression.

(4) The “fault-line coast” criteria described are not restricted to the area west of the Essequibo, and even if they were, this would not necessarily be evidence of a tectonic break along die Essequibo.

There are a number of other controversial statements in the paper. I have attempted to deal only with the chief points raised in the four arguments referred to.
The Start-Dodman-Lizard Boundary-Zone in Relation to the Alpine Structure of Cornwall
Authors: Hendriks E. M. Lind
Published: May 2009

Previous opinion sums up in favour of the continuity of the three boundaries, the entire line being one of dislocation in the east, dislocation and intrusion in the west. Previous opinion also favours the view that, inside the boundary-zone, not only are the Start-Lizard schists continuous, but they have features comparable with some of the Alpine “Schistes lustrés”, with recumbent folding at the Lizard.

The boundary-zone is defined as a belt of variolite (ophiolite), exotic blocks, and serpentine intrusive in, and contemporaneous with, a great thrust.

Recent work by the writer has shown that some of the beds outside the boundary-zone are a “facies flysch”. Younger beds come in towards the west, in association with the westerly pitch visible in the older beds in South Devonshire; geanticlines occur in the Lower and Middle Devonian respectively, of South Devon and South Cornwall. In an area further north some of the beds show an accumulation of folds comparable with those of the “autochthonous sedimentary” in front of some of the great Alpine nappes; recumbent folding is prevalent in both Devon and Cornwall. The Cornish Flysch was deposited under conditions such as might have preceded a great nappe movement; it is described in relation to the exotic blocks and serpentine in the fracture.

The much younger Alpine Flysch also includes ophiolites and exotic blocks, with serpentine intrusive in the fractures upon which the great nappes advanced. According to some authors, the nappes arose from recumbent folds based on geanticlines.

The similar direction of both the Cornish (Variscan) and the Alpine movements makes possible a comparison in certain effects as, for instance, the southward increase in albitization and metamorphism, between the great Alps and the similar but older, comparatively tiny, flattened, and denuded relic in south-west England.

These cases are also strikingly paralleled by a zone of basic igneous rocks and exotic blocks which overlies the Himalayas.

The evidence appears sufficient basis for the suggestion that the Start-Dodman-Lizard boundary-zone may be the relic of a great Variscan nappe, associated with the fan-structure of Cornwall.
The Microflora of the Upper and Lower Estuarine Series of the East Midlands
Authors: Murray Nesbitt
Published: May 2009

The Upper and Lower Estuarine Series in the East Midlands contain a number of layers of carbonaceous shale or clay and in many cases roots can be seen extending downwards in the underlying deposits. Except for plant-remains these carbonaceous layers are for the most part barren. Samples supplied by Mr. Linsdall Richardson were examined by Professor Harris and found to contain small fossil plants of types which appeared determinable and thus of possible stratigraphic value. Mr. Richardson collected other samples which he sent together with stratigraphic notes; Professor Harris handed me the material for investigation.
On Permian and Triassic Tetrapods
Authors: Watson D. M. S.
Published: May 2009

During the past few months some papers on early amphibia and reptiles have reached me from America, Russia, and China. These have afforded me much pleasure as a change from my present unaccustomed work, and I therefore feel that I can usefully express my thanks to their authors by writing a criticai summary of their conclusions. And such a review is justified because collectively these papers add very greatly to our knowledge and understanding of the evolution of early Tetrapods. Reference will be made to a list of these papers at the end of this review. It is most convenient and logical to discuss firstly the individual animais and then their distribution in time.
The Lower Limit of the Pleistocene in Europe and Asia
Authors: Pilgrim Guy E.
Published: May 2009

Theline of demarcation between the Pliocene and the Pleistocene systems is of more importance than would at first sight appear, if for no other reason than because when stratigraphers and palaeontologists are forced by one consideration or another to use the system in preference to the stage names it is often impossible to gather the actual age which they attribute to the deposit or fauna which they are describing. This paper aims at explaining my own point of view, by which I hope to incline adverse scientific opinion towards a definite predilection for the division which I myself favour. Perhaps this may eventually lead to a pronouncement on the question by an authoritative international committee.
Laminar Moulds in Cellulose Acetate for the Study of Rock and Mineral Structures
Authors: Dollar A. T. J.
Published: May 2009

The preparation and utility of laminar collodion moulds for recording relief features in natural surfaces of fossil plants is well known from the writings of Professor A. G. Nathorst (1). Equally familiar is the technique of Professor J. Walton (2) for making cellulose acetate “peels” from ground and etched surfaces of rocks containing carbonized remains of vegetable tissues. More recently, similar methods have been adopted by Dr. S. Leclercq (3) for studying fossil corals, by Professor A. E. Trueman (4) for examining ammonites, and by Dr. J. K. S. St. Joseph (5) and Dr. J. Weir for the analysis of fossil brachiopods. In these several cases, ground and etched specimens were prepared, from which cellulose nitrate or cellulose acetate moulds were taken. Hitherto, however, no corresponding technique appears to have been used either for research upon inorganic rock-structures or for the investigation of surface relief-characters of minerals.
The Roots of Mountains
Authors: Hills G. F. S.
Published: May 2009

The two Palaeozoic ranges, the Caledonian and the Hercynian, were comparable in size with the Alps. In his chapter on the European Altaids, F. E. Suess1 says “Recent investigations have brought evidence that the original Variscan mountain chain of which now only scanty remains are left, was once not inferior in size and extension to the Alps to-day”. The remains of both ranges are now at a low level, and it was for some time tacitly accepted that that low level was due to denudation through the long period since they were formed. That low level is not, however, consistent with isostatic theory. Isostatic theory requires that a mountain must have strong roots immersed in a heavier plastic medium so that in effect the chain and its roots float “hydrostatically” in that medium. Accordingly if a layer h km. thick and density p is removed from the top of the range, the level of the range will fall by h (1 − /σ) where σ is the density of the plastic medium. If p = 2·6 for granite, and σ = 2·85 for the intermediate layer, the level will fall by − km.
Crozzle and Hussle
Authors: Cope F. Wolverson
Published: May 2009

Description of an intraformational contorted shale in the Middle Coal Measures of the Potteries Coalfield. The contorted bed occurs immediately below the Winpenny Coal in thin argillaceous measures between thick sandstones. It shows strongly slickensided contacts, and consists of black carbonaceous shale, folded, sheared, and burnished. Deformation is ascribed to shearing stresses operating during folding. This shale is called “hussle” by the miners, whilst a similarly contorted, but non-carbonaceous, shale was termed “crozzle” by old miners of the Staffordshire-Derbyshire moors.
Supposed Commensalism of Carboniferous Spirorbids and certain Non-marine Lamellibranchs
Authors: Trueman A. E.
Published: May 2009

In the course of examination of the non-marine lamellibranchs from British Carboniferous rocks I have for several years noted all instances of the attachment of the tubes of Spirorbis. The observations which have been made confirm the conclusions of Pruvost (1919, p. 32; 1930, p. 257) that Spirorbis in the Coal Measures is frequently found attached to plants, occasionally to marine shells, and more commonly to non-marine lamellibranchs. Of the latter, Naiadites and Anthraconauta show the greatest number of attachments; attachments to Carbonicola are not uncommon, but Spirorbis is rarely, if ever, attached to Anthracomya. Over 80 per cent of the attachments recorded by the writer from the Lower Westphalian relate to Naiadites, practically all the remainder relating to Carbonicola; in many instances, however, there were great numbers of Spirorbis attached to individual specimens of Naiadites whereas the numbers in the case of Carbonicola were generally much smaller. In the Upper Westphalian attachment to Anthraconauta is very common, and the similarity of Anthraconauta and Naiadites in this respect was urged by Pruvost as one evidence of their presumed relationship and as justification for separating Anthraconauta from Anthracomya (1930, p. 223). These conclusions I am able to endorse from these observations.
Notes on the Upper Devonian Trilobites in the Whidborne Collection in the Sedgwick Museum
Authors: Reed F. R. C.
Published: May 2009

The collection of Upper Devonian trilobites which Whidborne studied and described or figured is a small one, but most of the figured specimens are in the Sedgwick Museum, and though generally they are in poor preservation he was able to determine the species to his satisfaction. However, since his Monograph appeared (1896) a considerable amount of work on Devonian trilobites has been published, and the whole question of the Devonian or Carboniferous age of part or all of the beds from which they came is still unsettled. The evidence of the trilobites is somewhat contradictory, the genus Phacops and its subgenera being usually considered to range up no higher than the Devonian, while Brachymatopus has been regarded in the past as restricted to the Carboniferous. Whidborne recorded also a species of Phillipsia from the Upper Devonian, but as will be pointed out in this paper the evidence of the specimens is against this generic reference. The precise horizon and exact locality unfortunately were not given by Whidborne in the case of his figured specimens, the name of the town, village, or road only being stated, and this is unsatisfactory, particularly in those instances where it is of great importance to know the definite horizon or bed from which they were obtained, for the lithological characters of the matrix or mode of preservation is usually insufficient to determine it.
Lineation in Moinian and Lewisian Rocks of the Northern Highlands of Scotland
Authors: Phillips F. C.
Published: May 2009

It has recently been reaffirmed, on the basis of evidence derived from published maps, that in the Moine schists the south-easterly plunging lineation appears to increase in intensity as the Moine thrust area is approached. This statement is not in accordance with facts observable in the field and is a false premise on which to base the conclusion that thrusting and lineation are related. A further fact of vital significance in relation to such a conclusion is the widespread development of a similar lineation, plunging south-easterly and likewise expressive of a girdle fabric, in unmoved Lewisian rocks of the foreland.
A Restudy of the Ingletonian Series of Yorkshire
Authors: Leedal G. P. , Walker G. P. L.
Published: May 2009

A description of the Ingletonian Series is given, with special reference to the sedimentary structures which occur and their use in determining the nature of the folding of the beds; this is shown to be isoclinal. The age of the series is discussed, and it is considered to be in all probability Pre-Cambrian.
A Deep Bore in the Cleveland Hills
Authors: Fowler A.
Published: May 2009

This bore, a recent trial for oil, is situated on the high moorland, rising to just over 1,300 feet above sea-level, in the south-western corner of the Cleveland Hills, where the imposing Jurassic escarpment overlooking the Triassic lowland between Thirsk and Northallerton, suddenly forsakes its northern trend to strike eastwards for about nine miles, before resuming a more northerly course towards Guisborough and the North Sea.
A Deep Borehole at Formby, Lancashire
Authors: Kent P. E.
Published: May 2009

Discovery of a shallow oilfield in Triassic rocks in a fenland area west of Formby, as described by Lees and Taitt (1946, pp. 307–11), led to an attempt to determine the nature of the local Carboniferous rocks, which were regarded as the most likely primary source of the oil found in the Trias.
Resemblances between Moine and “Sub-Moine” Metamorphic Sediments in the Western Highlands of Scotland
Authors: MacGregor A. G.
Published: May 2009

In this paper the writer deals with certain mineralogical and textural features found in the Moine and Sub-Moine Series of western Scotland, viz. garnet-zoisite calc-silicate ribs, non-garnetiferous epidotic calcsilicate ribs, sutured (crenulate) quartz-mosaic, foliation oblique to folded bedding, and the presence of abundant yellow epidote and of spots of haematite. The garnet-zoisite calc-silicate ribs have been claimed by Dr. Richey and Professor Kennedy as diagnostic of parts of the Moine Series. For the non-garnetiferous epidotic calc-silicate ribs, which have not previously been described, the name “calc-silicate ribs of Arnipol type” is suggested. These ribs occur in adjacent groups of rocks that have been mapped with the Lower Striped Schists and the Lower Psammitic Group of the Moine and with the outermost psammitic zone of the Sub-Moine.
The Chalky Boulder Clays of Norfolk and Suffolk
Authors: Baden-Powell D. F. W.
Published: May 2009

In the past there have been two main lines of approach to the glacial problems of East Anglia:—

(1) Attempts to find out the number of. glacial and interglacial deposits; and

(2) The direction or directions of ice-movement as shown by the constituent materials.

A fresh investigation of the boulder clays has been undertaken, combining as far as possible these two points of view, with special attention (so far) to the varieties of “Chalky Boulder Clay” (see Baden-Powell, 1948, pp. 287–8).
The Cleveland Axis
Authors: Rastall R. H.
Published: May 2009

Among the most notable features of the geology of Yorkshire are two parallel structures known as the Cleveland and Market Weighton anticlines. Although they are parallel and not far distant, it has often been pointed out, and especially by Kendall and Lamplugh that these structures differ in almost every possible way. The Market Weighton axis has now no topographical expression at the surface, whereas the Cleveland axis forms the watershed of one of the most clearly developed river-systems of the country. The first and most obvious meaning of this is that the Cleveland axis moved during the Tertiary, while the Market Weighton axis did not. But the real fundamental difference goes much further back than that.
Problems of Ammonite Nomenclature
Authors: Spath L. F.
Published: May 2009

The International Rules of Zoological Nomenclature aim at the “elimination of all possibilities of discussion”; and in troubled times like the present, when it is impossible to secure decision on a knotty problem by the International Commission, automatic solution of any nomenclatorial difficulty should be particularly welcome. We all know of certain genera that have caused trouble to revisers because they were based on several species, subsequently found to belong to more than one genus; likewise species have often been based on a number of differing specimens, some of which have in course of time been relegated to other species or genera. Now Opinion 88 claims that the procedure to be followed in such cases is well known, but on this point there appears to be some doubt, and I therefore propose to discuss the two species mentioned in the above title1.
The Tectonics of Holland Arms
Authors: Greenly Edward
Published: May 2009

A distinction is drawn between the gneisses above the Craig, excessively shattered, and those of the Gaerwen country, now regarded as autochtonous and on a different tectonic horizon.
Note on the Sandstone Injections of Eathie Haven, Cromarty
Authors: Waterston Charles D.
Published: May 2009

The sandstone injections which penetrate the Kimmeridgian strata of Eathie are described, the presence of sill-like injections being particularly noted. It is considered that the occurrence of “sandstone-sills” at Eathie is of importance in ascertaining the mode of origin of the injections of the locality. It is further suggested that the sills support the hypothesis that the injections are the result of infilling of fissures from below by sand and water.
On the Normal Faulting of Rift Valley Structures
Authors: Busk H. G.
Published: May 2009

Much has recently been written about the compressional theory for the origin of Rift Valleys in Africa, and the supposed reversed faulting of their sides, and so little has been published about the evidence for their normal faulting, that those who have not had the opportunity of working in rift valley areas may possibly obtain a rather one-sided view of the problem. It seems fair, therefore, to ask for space in the Geological Magazine to reflect on the case against the compressional theory, and to bring forward in general some of the evidence in support of normal faulting.
Darwin and the forgotten Mr. Lonsdale
Authors: Tasch Paul
Published: May 2009

William Lonsdale's associations with Sedgwick, Murchison. and Darwin are noted and his inference that the “transition series” was Devonian age, derived in 1837 from a study of fossil corals, is interpreted as an unique contribution to the belief that “species undergo modification”. As the first applied evolutionist, it is argued that he belongs on the list of important early contributors to the theory of evolution.
Sandy Gypsum Crystals from Berbera, British Somaliland
Authors: Macfadyen W. A.
Published: May 2009

Gypsum crystals containing 62 per cent by volume of sand are described from a late Raised Beach, where they were found by digging shallow coastal wells. An account is given of their crystallographic form and of the circumstances in which they have been produced. Gypsum has not only been deposited in the voids of the sand but has even moved the individual grains apart. A review is given of earlier records of sandy gypsum crystals, sometimes called “desert roses”, and comparison is made.
The Lamprophyre Problem
Authors: Smith H. G.
Published: May 2009

Judd was one of the early workers to recognize that changes in the mineral constitution of an intrusive igneous rock, changes affecting the earlier minerals, may take place prior to the completion of crystallization. He points out that minerals, since their first crystallization, may have undergone several series of changes, totally dissimilar in kind, and resulting from causes altogether different, and that the dissolved material may be carried away from a crystal and deposited within the cavities of neighbouring crystals of different species. This process must result in the blending together in the most inextricable manner of material derived from different crystallized minerals, and the whole characters of the rock may be completely altered.
An Augitite from S. Vicente, Cape Verde Islands
Authors: Part Gerald M.
Published: May 2009

Two specimens of Augitite (Nos. 64613–4) in the British Museum (Natural History) were collected during the voyage of H.M.S.Challenger (1872–6) and acquired by the Museum in February, 1890, through the Director of the Challenger Office, Dr. (later Sir John) Murray. The rock was briefly described by Renard,1 who noted the fibrous texture and unusual elongation of its pyroxene, as “related to the pyroxenites”.
The Micro-fabric of the Moine Schists
Authors: Phillips F. C.
Published: May 2009

Some years ago (Phillips, 1937) I published the results of a preliminary survey of the fabric of some Moine schists by the methods which have been evolved in that branch of the study of rocks now generally known as structural petrology. This survey showed that the quartz, muscovite, and biotite in all the specimens of Moine schist examined have the girdle-arrangement characteristic of a B-tectonic; that the b−axes of these girdles, over a large area of outcrop, plunge in a south-easterly direction; and that the direction of the b−axis of a given specimen is frequently marked by a visible lineation on the foliation-surface of the schist. Study of the fabric of Moine schists visibly affected by the dislocation-phase of the post-Cambrian movements was shown to afford support for the view, already advanced by others on the basis of petrographic study, that the ultimate effect of these movements on the Moine schists is to break down the previously existing fabric; there is a dislocation-metamorphism “undoubtedly superposed upon the general Moine metamorphism” (Read, 1934, p. 307).
Nick Points and the Curve of Water Erosion
Authors: Lewis W. V.
Published: May 2009

Increasing attention has been paid in recent years to the reconstruction and interpretation of stream profiles. It might therefore be well to examine a little more closely the way in which the curve of water erosion and the polycyclic valleys are produced. In this paper these problems are considered in the light of some preliminary experimental work recently described in this Magazine (1).
On the Chloride Waters of Great Britain
Authors: Anderson W.
Published: May 2009

Formerly there were several surface brine springs in the North-East Coalfield; to-day there are none. From the many accounts of their occurrence nothing has been learned of their exact position, and very little of the composition of their waters. The earliest record, made in 1684, described the Butterby spring (Todd, 1684), and then at various times during the next two centuries brine springs at Framwellgate, Lumley, Birtley, Walker, Wallsend, Hebburn, and Jarrow were noted. In particular the Birtley salt spring is often mentioned, and on the 6-in. Ordnance map, Durham No. 13, 1862 edition, it is sited to the south-east of the village. Although no record has been found there must have been either a brine spring or well at Gateshead, for the name of the present-day suburb, Saltwell, is very old, and brine springs are still active in the coal workings of that area.
Synthetic Quartz Crystals
Authors: Van Praagh G.
Published: May 2009

War-time requirements for untwinned quartz focused attention on the laboratory production of quartz crystals. Both the Germans and ourselves devoted considerable effort to this project with the result that, by the end of the German war, both countries were in a position to begin large scale manufacture. The fact that quartz crystals can be grown from aqueous solution in a short time is of considerable significance for geologists, and the method will therefore be described in some detail.
The Hinge of certain Non-Marine Lamellibranchs from the Lenisulcata Zone of the Coal Measures
Authors: Eagar R. M. C.
Published: May 2009

(1) The Carbonicola fallax group of shells, which characterize the Lenisulcata Zone of the Coal Measures, is an extremely variable one comprising a wide range of forms, between which there appears to be perfect gradation.

(2) The hinge of the group is also a highly variable feature, bearing little relation to the outline of the shells. Its variation, however, is more fully known in small forms than in large ones.

(3) Evidence submitted in the present paper indicates that, although the hinge pattern of the C. aquilina group may not be as constant a feature as has hitherto been supposed, the group is distinct from that of C. fallax. There is no evidence suggesting genetic relationship. A basis for the distinction between internal moulds of C. aquilina and C. fallax is fully described.

(4) The basic features of the hinge of the C. fallax group are essentially those which characterize the Carbonicola pseudorobusta–C. communis group of the Ovalis Zone. While certain of the hinges of the larger shells appear typical of the latter group there are a number of other patterns which have not previously been described in the Carbonicolidae.

(5) The hinge features of the C. fallax group appear less specialized than those of shells from the Ovalis Zone, especially Carbonicola pseudorobusta Trueman (MacLennan, 1944).

(a) Large strong teeth have not been seen. Definite small teeth are not commonly developed. It is usual to find gentle swellings on the hinge plate corresponding to depressions in the opposing valve. Some forms are quite edentulous.

(b) Only one tooth has been found in either valve, although more than one swelling or depression may be present. There is no approach to the more complicated patterns figured by MacLennan (1944).

(c) In most cases engagement of the dental apparatus would only take place as the valves opened. Notches or sockets in the hinge plate are not necessarily opposed by teeth or swellings, but they would have been more or less filled as the opening continued, when the hinge plates apparently rolled against one another.

(d) In a community of small shells there is evidence to suggest that in several cases the hinge margin of the left valve slightly overlapped that of the right for a short distance anterior to the umbo.

(6) The range of variation of hinge characters in a community is very large. Collections from different horizons, however, may indicate individual peculiarities or tendencies in the variation. Whether these owe their origin to local conditions or evolution is not yet clear.

(7) The hinge of Anthracomya from the Lenisulcata Zone is as yet little known. What evidence there is points to a hinge similar to that of small Carbonicola showing the same type of variation.
Some Grits and Associated Rocks in the Etruria Marls of North Staffordshire
Authors: Williamson W. O.
Published: May 2009

The grits and conglomerates in the Etruria Marls of North Staffordshire include types with a chamosite-rhombohedral carbonate cement containing interesting spherulitic and concentric structures. Manganese appears in this cement and in certain calcareous bands in the argillaceous fades of the Marls. The clastic fragments suggest derivation from Pre-Cambrian and Cambrian rocks. The heavy mineral suite resembles that listed by Fleet for similar horizons in the Midlands, but staurolite is recorded also.

There is no new evidence bearing on Robertson’s hypothesis that basic igneous rocks of Carboniferous age have contributed to the formation of the Etruria Marls.
A Seismic Investigation of the History of the River Rheidol in Cardiganshire
Authors: Coster H. P. , Gerrard J. A. F.
Published: May 2009

In its upper reaches the River Rheidol flows south, parallel to the coast of Cardiganshire, and about ten miles inland. At Devil's Bridge it turns sharply to the west (Text-fig. 1) and enters the sea at Aberystwyth. Due to rejuvenation the river has, in its southward course, incised the floor of its old mature valley the form of which is still clearly visible, and which continues to the south beyond Devil's Bridge to Pontrhyd-y-groes and Tregaron. This part of the valley now contains only small streams.
The Carbonaceous Shale or Richmond Formation of Jamaica.
Authors: Trechmann C. T.
Published: May 2009

The Carbonaceous or Black Shale or Richmond Formation of Jamaica is a deposit of considerable importance in connexion with the geological history of the Greater Antilles. R. T. Hill1 correlates provisionally the Richmond Formation, as he calls these beds, with the Scotland Series of Barbados, the oldest formation in that island, and also with certain of the Tertiary beds of Trinidad. In the present communication I shall endeavour to present some observations on the Carbonaceous Shale Series of Jamaica, together with a description of the fossils I collected in it. This series of deposits consists of a sequence of ferruginous sandstones both coarse and fine-grained, some of them very hard, others when weathered extremely friable; of impure carbonaceous limestones of a very unfossiliferous nature; of grey nodular friable shales often with carbonaceous plant-like remains in them, but scarcely any other fossils; and of coarse conglomerates which seem to occur chiefly in the lower part of the formation.
On some Arthropod Remains from the Rhynie Chert (Old Red Sandstone)
Authors: Hirst Stanley , Maulik S.
Published: May 2009

Since writing the first report on the arthropods of the Rhynie Chert beds (see Ann. Mag. Nat. Hist. (9), xii, pp. 455–74, 5 pls., and 13 text-figs.) some additional specimens of Palaeocharinus have been collected. A few examples are fairly complete and well preserved, showing a considerable amount of structural detail, such as the chaetotaxy, claws of the legs, ornamentation of the chitin, eyes, etc. An account of the lateral eyes is given below. We also include notes on a supposed insect and another fossil arthropod which we refer with doubt to the aquatic Merostoma. All the illustrations in this little paper have been drawn by Miss Violet Borrow, A.R.C.A., with the aid of a camera lucida under our personal supervision.
The Bala-Silurian Succession in the Llangranog District (South Cardiganshire)
Authors: Hendriks E. M. Lind
Published: May 2009

The area examined occupies about 12 square miles in South Cardiganshire bounded inland by a line joining the hamlets of Sarnau and Nanternis, and extending along the coast from the stream crossing Penbryn Sands in the south to New Quay in the north.
The Formation of Rock Basins
Authors: Kendall J. D.
Published: May 2009

In 1880 I communicated to the Manchester Geological Society a short paper, on the above subject, which endeavoured to show that Ramsay's suggestion of glacier erosion cannot explain the origin of Rock Basins. I have often since considered the facts and arguments advanced by different writers on the subject, but am more convinced than when I previously wrote that our Lake Basins were not formed by glacier erosion. The arguments herein are additional to those employed in my communication to the Manchester Geological Society.
Subterranean Penetration by a Desert Climate
Authors: Bailey E. B.
Published: May 2009

The subject matter of the present note is furnished by the abnormal redness of many parts of the Arran Carboniferous. W. Gunn, in his invaluable memoir, records this colouration without particular comment; but, as Scottish geologists are aware, B. N. Peach, under whose supervision Gunn carried out his survey, has long claimed that the Arran Carboniferous is stained by solutions that have percolated down from overlying New Red Sandstone. After a careful consideration of the exposures, I feel convinced that two features of Peach's proposition are secure:—

(1) The red colour of much of the Arran Carboniferous is not original.

(2) It must be in some way connected with the New Red Sandstone.
The Kailpot, Ullswater
Authors: Marr J. E.
Published: May 2009

In my work on The Geology of the Lake District, p. 162, I suggested that this pothole was a “giant's kettle” formed by water flowing down a crevasse in the ice.
The Vulcano-Glacial Palagonite Formation of Iceland
Authors: Peacock Martin A.
Published: May 2009

The geological feature which strikes the traveller in Iceland perhaps most forcibly is the complete contrast afforded by the well-ordered, level, or gently dipping basalt sheets with almost negligible tuff intercalations which constitute the Pre-glacial Kainozoic Plateau and the Late-glacial and Recent volcanic formations, and the enormous, chaotic, rarely-bedded accumulations of the Palagonite Formation in which lava flows are subordinate in amount; and he is at once presented with the question: Why did igneous action which produced lava sheets in Pre-glacial times result in dominant tuffs and breccias in the period which followed, and then revert to the production of lavas in later times ? This question has not yet been fully answered.
The Massive Chert Formation of North Flintshire
Authors: Sargent H. C.
Published: May 2009

In the Geological Survey Memoir, “The Geology of the Coasts adjoining Rhyl, Abergele, and Colwyn,” Mr. (now Sir Aubrey) Strahan most truly observes (p. 18): “There is in scarcely any part of this country a more remarkable development of chert than that which overlies the Carboniferous Limestone of North Flintshire.”
Domes in Scotland and South Africa: Arran and Vredefort
Authors: Bailey E. B.
Published: May 2009

Hall and Molengraaff have recently produced a memoir of outstanding importance dealing with the Vredefort Mountain Land on the border of the Transvaal and the Orange Free State (1925). Their account, which is a model of lucidity, is accompanied by a map and sections, and is copiously illustrated with photographs, mainly of rock slices. It includes a chapter on the History of Research, and another that introduces tectonic comparisons with the Black Hills of Dakota and Wyoming and the Ries Kessel near Nördlingen. The features of the Vredefort district that command most attention in this country are its tectonics and its flinty crush-rocks, or pseudotachylytes, to use Shand's alternative designation. Hall and Molengraaff's memoir supplies much new information on these two subjects, and also in regard to other topics, stratigraphical and petrographical, that are of rather more local interest. In the present notice, only one aspect of the memoir will be discussed, namely the tectonics of the Vredefort Dome.
Notes on British Dinosaurs. Part VI: Acanthopholis
Authors: Nopcsa Baron Francis
Published: May 2009

Fifty years ago, when Professor Seeley gave his masterly description of the Dinosaurs of the Cambridge Greensand, so little was known of these animals that it was naturally impossible to co-ordinate the different remains and to fix their systematic position. Up to 1902 scarcely any attempt was made to review Professor Seeley's conclusions. In that year I tried myself, in a paper, to determine their systematic position, but I find I was mistaken in some points. In 1917 Mr. Bajazid Elmas discovered at Szentpéterfalva some remains of Struthiosaurus that throw much fresh light on the position of this genus, and thus also on the allied genus Acanthopholis. Owing to the war the utilization of these discoveries had to be postponed, but now an attempt can again be made to group the Dinosaurs of the Cambridge Greensand.