bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Red-Rock Series of the Devon Coast-section
Authors: Irving A. 
Published: October 2009

A stay at Sidmouth during the past summer (supplemented by a second visit to the county in the Christmas holidays) has afforded me the long-wished-for opportunity of forming a personal acquaintance with the Red-Rock series of the Devon region, rocks which were described many years ago by Mr. Godwin-Austen* under the name of New Red Sandstone, and have been more fully described since by Mr. Ussher†. The paper by the latter author is of great value, as it is a very mine of facts and observations. In working along the coast-sections, however, I saw reasons for doubting the correctness of including the whole series in the Trias, and as I went on and compared what I observed with the results of the work of former years‡ in the Dyas and Trias of Germany and of the northern and midland counties of England, I was forced to the conclusion that in the Devon region we have those two systems represented.
I propose to lay before the Society in this paper an account of the observations which I have made, and to state the conclusions which (on comparative grounds) I have drawn from them.
Sidmouth(East).
(1) The escarpment of the Sid, for some 300 yards from its mouth, consists of about 50 feet of thick-bedded coarse sandstones, of a prevalent peppery-grey colour, in fresh sections, the general red colour of their weathered surfaces being due to rain-wash from above and subsequent infiltration. They exhibit magnificent current-bedding, such as we commonly meet with in
On the Gneissic Rocks off the Lizard
Authors: Fox Howard 
Published: October 2009

At Mr. Teall's suggestion, I made, during the past autumn, a methodical examination of the outlying rocks at the Lizard, and forwarded to him series of specimens from the various rocks. They may be classed under three heads:—the coarse gneisses or “Mên Hyr” type, the light banded granulitic gneisses or “Wiltshire” type, and the transition micaceous rocks of “Labham-Reefs” type. The annexed map (fig. 7, facing p. 316) shows how these rocks lie with respect to each other and the mainland. The coarse gneisses compose the outer rocks, and the fine gneisses the inner rocks. The transition rocks associate the gneisses with the typical schists of the mainland.
Beginning at the extreme west, we find the “Mulvin” composed of a dark granulitic gneiss with a strike and dip both clearly conformable with the rocks of the Lizard Head, the strike being about N.N.W. and S.S.E., the dip E.N.E.
The “Taylor” rocks are a group of three coarse gneissic rocks. The outer of these has a basic porphyritic dyke running across it from the S.W. to the N.E. with a S.E. dip. This dyke varies in width from one to four feet, and branches at the western end. The middle or main “Taylor” rock has a small gully on its southern extremity. At low-water spring-tide a basic porphyritic dyke, 18 inches wide, is seen to traverse this gully in an E.N.E. and W.S.W. direction, dipping S.S.E. The inner “Taylor” rock is mostly composed of a coarse gneiss with some basic
On the Lower Beds of the Upper Cretaceous Series in Lincolnshire and Yorkshire
Authors: Hill William 
Published: October 2009

Until recently no attempt had been made to describe the zonal divisions of the lower beds of the upper part, of the Cretaceous series in Lincolnshire. Indeed, Prof. Judd remarked in 1869, “The time has not yet come for separating the great mass of the Chalk formation in this county into zones, .... such a task not having been accomplished in the best-explored districts of the Chalk” *.
In 1876 Dr. Charles Barrois†, having been unable to visit this county, follows, in his well-known work, the description given by Prof. Judd. It was not until the publication, in the spring of 1887, of the “Geology of part of East Lincolnshire,” a memoir of the Geological Survey, that a systematic attempt was made to correlate any part of the Chalk of Lincolnshire with that of the more southern counties of Cambridgeshire, Hertfordshire, &c.
But the author of this memoir laboured under a disadvantage; for, as he remarks (p. 28), “The zones of the latter county [Cambridge] have not yet been traced northward into Norfolk, where the Chalk begins to put on what may be termed the northern or Lincolnshire facies; the data requisite for the proper correlation of the two areas are therefore incomplete.” And again (p. 31), “As yet we know nothing of the changes which the Chalk zones undergo in their passage from Cambridge to Norfolk; and in the absence of this connecting stratigraphical evidence, the correlations now suggested are not to be received as a decided expression of
On some Eroded Agate Pebbles from the Soudan
Authors: Ball V. 
Published: October 2009

Amond a large number of pebbles and rock specimens collected by Surgeon-Major Greene in the Soudan, and recently presented by him to the Science and Art Museum in Dublin, I found that the majority of the former were of very similar character to the Agate and Jasper pebbles derived from the basalte of India. Upon closer examination I observed that a certain proportion of them are eroded in a manner unlike anything I have ever noticed in India, though, if the cause of erosion is what I believe it to have been, it is most probable that similarly eroded pebbles would be found in certain localities there also. Inferentially we may conclude, from the nature of these pebbles, that they originally came from a region in which basaltic rocks occur to a considerable extent. That this conclusion is of no little importance will presently be seen.
Throughout India, wherever there is deficient subsoil drainage on the one hand, or excessive evaporation and limited rainfall on the other, saline matters make themselves apparent, either in saturated subsoil solutions, or by crystallizing out in the soil itself, in the latter case, during wet seasons, being sometimes the cause of saline lakes and pools.
The nature of these salts varies with that of the minerals constituting the rocks from which they have been derived; and in reference to the distribution of the various salts of sodium, potassium, and magnesium, extensive observations have been made, both in India and America, in connexion with the
Report on the Recent Work of the Geological Survey in the North-west Highlands of Scotland, based on the Field-notes and Maps
Authors: Peach B. N. , Horne J. , Gunn W. , Clough C. T. , Hinxman L. , Cadell H. M. 
Published: October 2009

Introduction.

I
n
November 1884 a brief notice or report was published of the results of the work of the Geological Survey in Sutherland. The object of that report was mainly to announce that the detailed mapping of the region had convinced us that the views entertained by our former chief, Sir Roderick Murchison, were no longer tenable. It was then intended that an official Report should soon be published, embodying the details of the survey work and containing a full digest of all that had previously been done by other observers. But the complicated structure of the region and the necessity of continuing the mapping southward along the great line of disturbance have hitherto delayed the publication of this Report. It is felt, however, that instead of further postponement until the conditions of official publication are fulfilled, it will be of advantage to publish a
résumé
of the chief results which the Survey has up to the present time obtained, and hence the present communication is laid before the Society.

Previous Literature.
In fulfilment of the promise made in the preliminary notice above referred to, we now offer an outline of the work of previous observers, chiefly with the view of showing how far our own labours have been forestalled by theirs.
In 1819 Macculloch described a remarkable development of red sandstone, quartz-rocks, and limestones among the gneiss and schists of the North-west Highlands and Islands. He maintained that the red sandstones and conglomerates rest unconformably on the western gneiss
Notes on some of the Auriferous Tracts of Mysore Province, Southern India
Authors: Attwood George 
Published: October 2009

During the end of the winter of the year 1886 and a portion of the spring of 1887 I was employed in Southern India inspecting a large area of mineral lands supposed to be auriferous (see Map, fig. 1), and during my travels by train, bullock-carts, and on foot (the latter about 600 miles), I collected some rock specimens and made notes and sketches of my observations, which I now submit for the consideration of the Society.

My notes are divided into three parts, namely:—

1.
1. The Melkote Area.

2.
2. The Seringapatam Area*.

3.
3. General observations on some of the auriferous tracts of Mysore Province from numerous traverses.

1. Melkote Area.
The first section (see Plan, fig. 2, and Section, fig. 3) which I will describe is in the Hassan District of the Province of Mysore, starting about one mile west of the sacred Hindoo city of Melkote, and extending in a north-easterly direction to about half a mile beyond the Lokapavani River.
A gneiss of a highly schistose character was first observed dipping sharply to the west and in it numerous small bands of flaky mica are found, which in places, has weathered and decayed, forming a sort of white plastic clay.
The shcistose gneiss is followed by a hard, coarse-grained gneiss, which forms the elevated portions of the Melkote hill- or mountain-range (3550 feet aboe sea-level at Madras), and has a general strike of north 20° east, dipping at angle of about 40° to the west.
Large
On the Law that governs the Action of Flowing Streams
Authors: Oldham R. D. 
Published: October 2009

Of all the agents which Nature employs in her great and ceaseless work of change, of destruction and construction, of removal and renewal, probably none have been less studied, few are less understood, by geologists, than water in the form of streams and rivers.
In a general way it is known that, with sufficient velocity, a stream will erode its bed, and that if the velocity be reduced sufficiently it will deposit part or all of what solid material it may be carrying down its course. But, while mathematicians and engineers have been investigating, in all their details, the laws which govern the flow of water, geologists have done little to investigate the laws under which it acts in shaping the surface of the world we live in.
Rain, glaciers, and the sea; these seem almost to have limited the horizon of the geological view, and, without forgetting the researches of Prof. Hull, the essay of the late Mr. Greenwood, or the application of the principles enunciated by him to a special case by the late Mr. Fergusson, we may almost say that the intermediate link in the chain—the flowing stream—has either been regarded as unworthy of notice, or the vague general ideas and statements of the textbooks have been regarded as a complete and satisfactory account of the problem.
Yet in the whole range of physical geology there is no subject which will better repay a detailed investigation or open a wider field of intricate and interesting problem than
On Perlitic Felsites, probably of Archæan Age, from the Flanks of the Herefordshire Beacon; and on the possible Origin of some Epidosites
Authors: Rutley Frank 
Published: October 2009

In a previous communication to this Society a rock was described (No. 20) in which faint indications of a perlitic structure were discernihle. It occurred on the side of the Herefordshire Beacon, overlooking Castle-Morton Common, and a short distance in rear of the well-known cave.
The specimens now under consideration were derived from the Rabbit Warren near the above-mentioned locality; No. 1 from a point about thirty yards above the path, where it touches a small beck which runs between the higher portion of the Beacon and the Warren ; while No. 2 was procured a little above and to the east of this spot, and about halfway up the steep bank of the Warren.
The first is a rather deep greenish-grey to brownish-grey rock, which, on a smoothly-cut surface, shows a meshwork of very delicate veins, darker than the material of which the rock is mainly composed.
The second specimen is of paler colour, a yellowish-green or buff tint predominating.
It was difllcult at the time to procure better samples, and both of these must be regarded as in a considerably advanced stage of alteration. They were, however, kept, as they seemed to show faint indications of perlitic structure, and although, in sections cut from them, the structure is somewhat obscure, there is nevertheless sufficient proof that it is present.
A section taken from specimen No. 1 appears by reflected light, under a low power, to consist of greenish-white to greyish-white matter, broken by small dark specks and curved
On a Hornblende-biotite Rock from Dusky Sound, New Zealand
Authors: Hutton F. W. 
Published: October 2009

This rock was collected in Dusky Sound by Mr. W. Docherty, and given to the late Sir J. von Haast, who gave it to me. I do not know its field relations, but undoubtedly it is of eruptive origin and is associated with the Archœan gneisses and schists of that district. As I am not aware of any similar rock having been described, I think that some account of it may be interesting.
The rock is compact, crystalline, of a dark green colour, weathering reddish brown, and the specific gravity varies between 3·00 and 3·07. With a lens it is seen to be composed of two minerals in nearly equal proportions. One is a black mica, the plates of which are sometimes collected into masses 0·1 to 0·2 inch in diameter, but generally scattered through the other mineral. Cleavage-flakes of this mica can be easily detached, and, under the polariscope, prove to be biotite, in which the two optic axes nearly coincide. When thin, these cleavage-laminæ have a greenish tinge by transmitted light
Under the microscope, in thin sections of the rock, the biotite has the usual brown colour and strong dichroism. It often contains crystals of apatite, which is, I think, not usual.
The other mineral, in thin sections, is of a pale bluish-green colour and dichroic, but not strongly so, passing from a pale brownish green to a pale bluish green, some portions being more strongly dichroic than others. With ordinary light very little structure is apparent, but
On the Eozoic and Palæozoic Rocks of the Atlantic Coast of Canada, in Comparison with those of Western Europe and of the Interior of America
Authors: Dawson J. William 
Published: October 2009

Since the year 1845 the author has contributed from time to time to the Journal of this Society more than forty papers on the geology of Nova Scotia, New Brunswick, and Prince Edward Island, in which frequent comparisons were made between the rocks and fossils of the Atlantic coast-region and those of the inland plateau of the North-American continent on the one hand, and those of Europe on the other. Many additional details bearing on the more uncertain parts of these subjects have been accumulated in unpublished notes in recent years, while large additions to our information have resulted from the extension of the Geological Survey of Canada, under Logan and Selwyn and their assistants, to those provinces, and from the Geological Survey of Newfoundland under Murray and Howley, while new facts have been accumulating with reference to the continuation of the Atlantic rocks southward on the coast of the United States, and also with regard to the intermediate or “inner marginal” series observed on the Lower St. Lawrence and thence southward. The time seems thus to have arrived when some further and useful comparisons may be made, as well as corrections and amplifications of previous statements; and these seem to be the more necessary, inasmuch as it is evidently difficult for geologists who have not personally studied these districts to correlate with accuracy the geological features of the marginal belts of the two sides of the Atlantic.
The subject is, however, so extensive that within the limits of this
Second Note on the Movement of Scree-Material
Authors: Davison Charles 
Published: October 2009

The first results of the experiment described in this note, namely, those relating to the period from May 5 to September 22, 1887, have already been recorded in a paper read before the Geological Society on February 29, 1888.
After a brief interval the experiment was continued under the same conditions as before, from October 4, 1887, to May 5, 1888, with the object of comparing the rates of descent in the winter and summer halves of the year, and also of determining the effects on creeping of rain and snow.

Allowing a
distance of ½ mm. for the interval of 12 days during which the experiment was suspended, the total descent during
the year was 13⅙ mm. (
i. e.
a little more than half an inch), the mean rate of descent being therefore ·00140 inch per day.

Comparison of the Rates of Descent during the Winter and Summer Months
.—Dividing the year of the experiment into winter, from October 4, 1887, to April 3, 1888, and summer, from May 5 to October 4, 1887, and April 3 to May 5, 1888, we have :—

Had the creeping movement been proportional to the range of temperature, the average daily descent during the winter, compared with that during the summer, would have been rather less, namely ·00095 inch per day. Not only, however, is the heat of the sun more intense in summer than in winter, and consequently the effects produced by passing clouds
Directions of Ice-flow in the North of Ireland, as determined by the Observations of the Geological Survey
Authors: Kilroe J. R. 
Published: October 2009

The field observations of the Geological Survey, Ireland, being completed, it was considered desirable by the Director to represent those bearing on glacial phenomena in the northern half of the country on a general map, scale ten miles to one inch. Data for this were amply furnished by the one-inch sheets already published, and by those in course of preparation, upon which the usual map-indications of glacial striæ are numerous and distinctly shown. These indications consist of circles denoting the places of observation, lines crossing those circles giving the trends of striæ, and arrowheads attached thereto indicating the directions of ice-fiow when these are determinable.
In carrying out this transfer a remarkable circumstance became apparent, namely, that the striæ were capable of being resolved into two distinct sets, nearly at right angles to each other; which rendered it convenient to appropriate two copies of the general map to the two sets of striæ. The striæ thus transferred have been further connected by continuous lines about three eighths of an inch apart, or have served as guides when the lines do not happen to pass through the exact points of observation. So constant in direction are the striæ of each set over an area of some 16,000 square miles, that they maintain an almost unswerving parallelism to those continuous, though slightly waved lines. Comparatively few deviate more than a few degrees to one side or the other of the general direction, such deviation being adequately accounted for by local inequalities of
Notes on two Traverses of the Crystalline Rocks of the Alps
Authors: Bonney T. G. 
Published: October 2009

Introduction
In the address which I delivered at the Anniversary Meeting of the Society in 1886, I gave a brief outline of some investigations into the petrology and structure of certain districts of the Oberland, Pennine, and Lepontine Alps. These had led me to conclusions which were then stated, and had further indicated to me the principal types of rock recognized by the Swiss geologists, and enabled me, as it were, to translate into stone one of their maps. I then determined to make two traverses of the Alpine chain at distances remote from the central portion (the scene of my previous work) and from each other, so as to acquire a knowledge of the rock-types employed in mapping by geologist outside the Swiss Republic, and compare the crystalline schists or gneisses of these regions with those already known to me. The points, I may again mention, on which I was specially seeking for light were (1) the relation of foliation to pressure, stratification, &c., or, in other words, the history of the genesis of gneisses and schists; (2) the value of the apparent stratigraphical succession which I had observed over a considerable district of the Swiss Alps.

For these purposes it was rerquisite that any section examined should fulfill, as nearly as possible, the following conditions:—

(1)
It should run in a fairly straight line as nearly as might be at right angles to the apparent strike of the rocks.

(2)
It should exhibit a seeming succession as extensive as possible.
On a new Genus of Siliceous Sponges from the Lower Calcareous Grit of Yorkshire
Authors: Hinde George Jennings 
Published: October 2009

Nearly forty years since, Dr. H. C. Sorby, F.R.S., communicated to this Society a paper on the microscopical structure of the Calcareous Grit of the Yorkshire coast, in which reference was made more particularly to the nature of certain microscopic reniform bodies with which the rock ill places was largely filled. In mineral constitution some of these bodies were of calcite, others of chalcedonic silica, whilst ill others both these minerals were present, and the question as to their original constitution was decided by Dr. Sorby in favour of the calcite, since it was thought extremely iml;robable that, if originally of silica, this material would have been dissolved and replaced by calcite, whereas the substitution of silica in place of calcite was a well-known phenomenon. The definite tbrm and outline of these bodies left no doubt that they were of organic origin, and Dr. Sorby recognized their resemblance to the small siliceous globules which form an outer crust to many existing sponges, but rejected this view on the ground of their supposed calcareous nature, trod he finally concluded that they were small shells, possibly Foraminiferal, in whose inteiior calcareous or siliceous materials had been infiltrated, in the same manner as in the chambers of the Ammonites occurring in the same rock.
Subsequently, in 1876, Prof. J. F. Blake, F.G.S., discovered similar minute bodies in rocks of nearly the same age in Dorsetshire and Wiltshire, and noticed that some of them were hollows enclosed by thin crusts or shells, which dissolved
The Propylites of the Western Isle of Scotland, and their Relation to the Andesites and Diorites of the District
Authors: Judd John W. 
Published: October 2009

I. I
ntroduction
.

There exists in the Western Isles of Scotland a great series of lavas which, for the most part, underlie the ophitic olivine-basalts, and constitute the oldest of the ejections of the great Tertiary volcanoes of that district. These rocks were distinguished by me in 1874 under the old English field-name of “Felstones,” and it was stated that they “vary in colour from black, through various shades of green and grey to white; but in almost all cases their surfaces acquire a white crust in consequence of weathering action”
In attempting, at that date, to define more exactly the characters of these lavas, by studying them microscopically in thin sections, I was confronted by two difficulties. In the first place, it soon be became manifest that these more acid lavas of the Western Isles include a great variety of types--differing widely from one another in mineralogical constitution and in structure; and in the second place it was found that the minerals of which those rocks were built up were in a remarkably altered condition.
In both these respects, the “felstones” present a very striking contrast to the overlying series of ophitic olivine-basalts. The latter, as I have shown, are remarkable for their uniformity of composition and character, and, except where influenced by surface-agencies, seldom present any great signs of alteration; they are indeed, as a rule, singularly fresh and unchanged in their appearance.
But in the “felstones” which underlie the basalts the most extreme metamorphism is seen to have