bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Higher Silurian Rocks of the Kerry District, Montgomeryshire
Authors: Earp John Rowland 
Published: October 2009

The north-western part of the upland tract of Clun Forest is shown on the Geological Survey maps (sheets 56 and 60) to be composed of a wide belt of rocks of Ludlovian age, overlain to the south-east by a roughly circular outlier of “Old Red Sandstone” known as the Bettws-y-crwyn outlier. The area dealt with here includes the north-western part of that outlier and a considerable part of the Ludlovian belt to the north and west, forming the borderland of the counties of Radnorshire, Shropshire, and Montgomeryshire. The district has been studied on the six-inch scale: namely, on the Ordnance Survey maps, Montgomeryshire XLIV NW. and SW., XLIII NE. and SE., Radnorshire IV NE., and Shropshire LXVIII NW.
Like all the Clun Forest district, the general elevation of the ground is from 1000 to 1500 feet, and the southern and eastern sides of the hills are mostly gentle dip-slopes, while the northern and western sides are steeper scarp slopes. The main ridge of high ground, Kerry Hill, forms the watershed between the streams flowing north-eastwards into the Severn, and the south-easterly flowing Teme and its tributaries. The south-westward extension of Kerry Hill and the high ground around Gorddwr Bank form the watershed between these two drainage systems and the south-westerly flowing tributaries of the Ithon. The valleys are mostly filled with drift, and the glacial geology of the district has been discussed by Dwerryhouse and Miller (1930).
Murchison (1839) gave a general description of the “OuTliers of Old Red Sandstone
The Tertiary Volcanic Rocks of Central Victoria
Authors: Edwards Austin Burton 
Published: October 2009

The Tertiary era in Victoria was marked by two extensive periods of intermittent vulcanicity; one ranging from the Oligocene to the Middle Miocene (Older Volcanic Series), the other from the Pliocene to the Recent (Newer Volcanic Series). The Older Volcanic Series, now greatly eroded, occurs mostly south and east of Melbourne. The Newer Volcanic Series, which has suffered much less erosion, extends north-west and west from Melbourne as a broad plain of about 10,000 square miles in area, and forms the floor of the Great Valley of Victoria. This paper is concerned with lavas of the Newer Volcanic Series lying between longitudes 144° E. and 145° E. (Fig. 1).
The Geological Survey of Victoria generously provided facilities for cutting 500 thin sections, and lent to me another 500 slides on my departure for England, besides putting at my disposal maps, literature, and unpublished analyses.
Mr. D. E. Thomas, of the Survey, in conjunction with whom the detailed field work was done, generously withdrew from the work.
Fifty chemical analyses were prepared in the Geochemistry Department, Imperial College of Science and Technology, London, under Dr. H. F. Harwood. Much helpful criticism was received from Professors Boswell and Brammall, and my thanks are due to Dr. G. W. Tyrrell of Glasgow and Dr. E. S. Hills of Melbourne for reading the manuscript, and to Professor Brammall for seeing the paper through the press.

P
revious
L
iterature

A bibliography of references to Victorian basalts is provided in Professor Skeats's Presidential Address, on the volcanic
Slip-Planes and Breccia Zones in the Tertiary Rocks of Peru
Authors: Baldry Robert Ashley 
Published: October 2009

The Peruvian oilfields lie on the coast about 4° south of the Equator, where South America juts out farthest west into the Pacific. At Ancon, in the Santa Elena peninsula of Ecuador, is another oilfield with rocks of the same age.
The Tertiary rocks on the coast are cut off by the Amotape mountains on the south-east, about 20 to 25 miles inland. These mountains are a complex of Carboniferous slates and quartzites metamorphosed by intruded granites, with small outcrops of unmetamorphosed Cretaceous rocks. The range runs north-east and south-west, and most of the main tectonic features are parallel to this axis.
The oil-bearing strata are Middle and Upper Eocene at Negritos, Talara, Lobitos, and Cabo Blanco in Peru, Upper Oligocene or Lower Miocene at Zorritos, 70 miles farther north, and Middle and Upper Eocene again at Ancon in Ecuador.
A north-east and south-west section through Cabo Blanco shows the following features (Fig. 1) : a geofault five miles off-shore, where the sea-bottom drops to 2000 fathoms; a flat coastal shelf; a narrow belt of deeply dissected Tertiary rocks; the Mancora Tablazo (a flat tableland of Quaternary deposits 15 miles wide and 1000 feet above sea-level); foothills of Tertiary rocks; and the Amotape mountains of metamorphic rocks.
The geology has been well described by Bosworth and again by Olsson and Iddings.
The most striking feature, the slip-planes and breccia zones, have been described only in my private geological reports during the last twelve years. I have to thank the directors
On a theory of Gravitational Sliding applied to the Tertiary of Ancon, Ecuador
Authors: Brown Charles Barrington 
Published: October 2009

I wish to make it quite clear from the beginning that the conception of large-scale sliding due to gravitation within the mass of Tertiary sediments of North-West Peru is entirely due to Mr. Robert Ashley Baldry. My work and conclusions upon the structure of the Tertiary of the Santa Elena peninsula, Ecuador, are the result of the inspiration of that thesis, which I have extended to accord with the evidence as I read it. Mr. Baldry does not necessarily agree with all my conclusions, because he has not so far examined my evidence in the field.
The earliest workers in North-West Peru—J. Grzybowski, C. Maddocks and E. R. Blundstone—described the coastal structure as a series of folds parallel to the trend of the Amotape mountains. Only Grzybowski published an account (1899), and showed in diagrammatic sections some block-faulting at Grau and folding in the Amotapes.

The first published works of real importance were those of T. O. Bosworth, in the form of two papers read before this Society (1920
a, b
) which were later expanded into a book (1922). He described the structure as a mosaic of faulted blocks, the faults having throws up to 5000 feet, and considered folding to be negligible.

Up to 1925, Mr. Baldry and I had examined a considerable part of the tract from the Pariñas valley to Tumbez, between the Amotape mountains and the sea, and had realized its complexity. Further detailed mapping of the Cabo Blanco region by Mr. Baldry presented such difficult
The Fauna of the Baton River Beds (Devonian), New Zealand
Authors: Shirley Jack 
Published: October 2009

Research into the geology of New Zealand has shown the existence of rocks containing faunas of Silurian or Devonian age in not widely separated localities in the north of South Island. These faunas were named, after the localities, the Reefton and the Baton river faunas. The Reefton fauna has been studied in detail by Dr. R. S. Allan (1935), who proved conclusively that it was of Lower Devonian age with great similarity to the Upper Siegenian and Lower Emsian (= Lower Coblenzian) faunas of western Europe. The Baton river fauna is the subject of the present study.
The collection upon which the work is based consists of three parts. First, the collections of the New Zealand Geological Survey under J. Hector from locality 128 (Baton river); second, the collections of a more recent survey; and third, a series of specimens from Auckland University College. The collections were brought to England by Dr. R. S. Allan, together with that from Reefton. He was unable to make a detailed study of the Baton river fossils, which he left with Professor O. T. Jones, at that time at the University of Manchester. With the consent of the Director of the New Zealand Geological Survey, Professor Jones asked me to take up the study of the fauna.
The earliest detailed account of the stratigraphy of the Baton river and Wangapeka districts is by Mackay (1879, pp. 121–31). He mentions (pp. 125–6) that a large collection of fossils was made from the Baton river series
The Geology of the Country around Pwllheli, Llanbedrog and Madryn, South-West Carnarvonshire
Authors: Matley Charles Alfred 
Published: October 2009

A number of papers have been published in recent years dealing with the geology of the southern part of the Lleyn peninsula. Mr. T. C. Nicholas in 1915 described the eastern horn, known as St. Tudwal's peninsula; papers by myself (1902, 1913, 1925, 1928, 1932) dealt with the western coast from Bardsey Island to Nevin and inland to Rhiw and Sarn, and one in 1930 by Dr. Heard and myself with the Bodfean tract. The purpose of the present communication is to describe the remaining area (about 42 square miles), which extends from Porth Neigwl (or Hell's Mouth) northward to Bodfean and eastward to the coast between Abersoch and Pwllheli, and thence to the neighbourhood of Four Crosses.
This country is built of Ordovician sediments accompanied by members of the “Bala Volcanic Series” and its associated intrusives. Glacial drift covers large areas, but the igneous rocks often project as prominent ridges and hills, of which the dominant peak is Carn Fadryn, 1217 feet high. The southern part of the area is a plain of thick drift which has filled up the head of the wide-mouthed bay of Porth Neigwl. The western horn of the bay at Rhiw and the eastern horn south of Llanengan are prolonged inland as pre-glacial cliffs and slopes, and the glacial deposits between them, which must have once extended farther south, are being removed by sea-erosion; yet at their truncated southern margin they still extend below sea-level.
The Afon Sôch, with its tributary the Afon Horon,
Eddies in Mountain Structure
Authors: Bailey Edward Battersby 
Published: October 2009

In regions of compression it is common to find some stratigraphical group or groups broken up into a multitude of minor thrust-slices, which are packed in characteristic imbricate fashion. The slices, so arranged, are called
schuppen
, a German word meaning scales. Individual schuppen incline steeply towards the direction from which overthrust has occurred. Their relative movement is trivial, as concerns adjacent members, but may in the aggregate lead to impressive telescoping of the affected zone.

Schuppen structure is generally attributable to the passage overhead of some major thrust-mass. It is abundantly represented in the North-West Highlands of Scotland (Fig. 1). I well remember how B. N. Peach in conversation would compare the advance of a thrust-mass, riding upon schuppen, to the launching of a ship, carried upon rollers (the idea is expressed in print [Home 1907, p. 472]). It is the purpose of the present paper to show that Peach's simile finds much closer illustration in some of the deformations characteristic of the metamorphic sediments which constitute the interior of the Scottish Highlands.
The word “thrust” is to be found in the earliest British writings on tectonics: for instance, in those of James Hall of Edinburgh. This probably influenced Peach and Home in their application of the term to the great fold-faults of the North-West Highlands. Study of Peach and Horne's writings makes it clear that their more important thrusts are covered by the following definition, which with verbal modifications, I have repeatedly given:—
A thrust is a fold-fault which
The Petrography and Petrology of the Lower Cambrian Manganese Ore of West Merionethshire
Authors: Woodland Austin William 
Published: October 2009

The Cambrian manganese ore of the Ardudwy district of Merionethshire occurs interstratified in that series of rocks which locally forms the lowest Cambrian and which is known as the Harlech Grit series. This series crops out in a broad, irregularly oval, mountainous tract, with the long axis alined north and south. It extends from Barmouth in the south to within about one mile of Ffestiniog in the north and from the coast on the west to the Ganllwyd valley on the east.

Ramsay (1881, p. 19) first described these rocks, but no attempt was made to classify the series until in 1893 Good-child grouped them as follows (Dewey and Dines 1923, p. 59):—

4.
Upper Mudstones (Lingula Flags and Menevian) with Upper Manganese Bed at base.

3.
Upper or Moelfre Grits.

2.
Lower Mudstones; Lower Manganese Bed near base.

1.
Lower Grits.

He thus recognized two manganese horizons separated by at least 850 feet of rocks.

Charles Lapworth and T. Stacey Wilson, recognizing only one ore bed, divided the Harlech Grit series of the Survey as follows (Andrew 1910, p. 161):—

5.
Gamlan Shale group: grey, greyish green, and sometimes purple shales, slates and flags with occasional grit bands increasing in number eastward. 750–1200 feet.

4.
Barmouth Grits: massive grits and conglomerates. 600 feet.

3.
Hafotty or Manganese Shale group: grey and green mudstones with rare grits in west, becoming more frequent
The Early Cretaceous Valley-floor Pene-Plain of the Lake Nyasa Region and its Relation to Tertiary Rift Structures
Authors: Dixey Frank 
Published: October 2009

On the floor of the upper Luangwa Valley of North-Eastern Rhodesia there are early Cretaceous Dinosaur Beds closely comparable with those occurring on the north-western floor of the Nyasa rift, and in recent papers (1937) I have given evidence to show that at least the northern ends of these two features, apart from the basin actually occupied by Lake Nyasa, had attained their present dimensions as far back as the early Cretaceous. Furthermore, having shown that the post-Karroo pebble beds of the upper Luangwa Valley belonged to the Dinosaur Beds, I suggested that the pebble beds of the lower Luangwa Valley were similarly assignable. On this and other grounds I suggested that the great system of troughs developed in this part of Africa, namely, those of the Luangwa and the middle and lower Zambezi, and the Nyasa-Shire rift, had attained to much of their present form in the early Cretaceous, and that the Dinosaur Beds and comparable formations filling these troughs had been base-levelled with the adjacent plateau during the Miocene peneplanation.
Also, in a recent paper (1937c) on the early Cretaceous and Miocene peneplains of Nyasaland I described the secondary early Cretaceous peneplain on which rest the Dinosaur Beds and the Lupata series. I now adduce evidence to show that this secondary peneplain was an important feature in the early Cretaceous geology of this region, and that it extended as a great valley-floor surface of erosion, still recognizable, throughout the length of the system of troughs referred to. This
Further Notes on Lower Devonian Plants from South Wales
Authors: Heard Albert 
Published: October 2009

In 1926 I recorded the occurrence of a Lower Devonian flora from the Senni Beds near Brecon, and described one new genus,
Gosslingia
, in detail. In 1931 a “thalloid-like” plant,
Thallomia
, from the Lower Downtonian of the Llandovery district, was recorded (Heard and Jones 1931).

Other fragmentary plant remains are present in both the above localities, and it is the object of this communication to place on record some of the more interesting of these fossils. Most of the material is badly preserved, and has proved unsuitable for examination by transfer or “film-pull” methods.

As previously recorded (Heard and Jones 1931, p. 552), the plant
Thallomia
occurs with a few fragments of dichotomously branched stems and obscure carbonaceous material at Capel Horeb near Llandovery. The fossil plants are associated with a lenticle of mudstone which is intercalated with the flaggy sandstones (Tilestones) of Lower Downtonian age.

Only one fairly complete specimen was obtained by Mr. J. F. Jones, who found the plant bed (Pl. XII, fig. 1). This consists of a slender stem, about 4–5 cms. long and 0–8 mm. wide, which shows two dichotomous branchings. Each of the two upper and equal divisions of the stem is terminated by a capsule-like body (5 mm. by 2 mm.), which tapers at the base and has an obtuse end. This is regarded as a sporangium.
A “film-pull” from these sporangia shows only a broken carbonaceous margin to the sporangium. No spores are to be seen. The greater part of the fossil
Explanatory note on the Block Diagram of the Great Rift Valley from Nakuru to Lake Magadi (Plate XIV)
Authors: Busk Henry Gould 
Published: October 2009

This diagram was constructed during an examination of the Rift Valley region on behalf of the D'Arcy Exploration Company and the Anglo-Saxon Petroleum Company. The author is greatly indebted to these companies for permission to publish this work, and acknowledges with gratitude the assistance rendered during the examination by the Department of Mines, Kenya Colony.
It is difficult to give an effective picture of the Great Rift Valley by contour maps, and in those that exist the topographer has tended rather to round off his contour lines in the conventional manner, so that, where in nature there exists bold ruggedness, there appears on the map only flowing curves. An attempt has been made in this projection to bring out the steepness of the fault scarps, and the colouring has been progressively deepened to show the increasing depth to which the plateau has been faulted down. Thus the plateau round Nairobi, lying on the Kapiti plains, is coloured lightly, and the depth of colour increases northward from Limuru along the Kainankop plateau, and then down to Naivasha. Yet Naivasha is at a greater height above sea-level than Nairobi, the sides and bottom of the Rift Valley having together been raised to the northward relative to sea-level. There is a considerable slope of the whole of the Rift Valley and its sides towards the south. Thus, Lake Magadi lies at the lowest point in the diagram, though the difference between the level of this lake and the sides of the valley is
The Geological Structure of the Kings-Clere Pericline. The Eocene Succession between Kingsclere and Ecchinswell
Authors: Hawkins Herbert Leader 
Published: October 2009

The Vale of Kingsclere is in north Hampshire, about five miles south of Newbury, and just beyond the southern border of Berkshire. Geologically it is a periclinal crest on the anticline that forms the southern limit of the London Basin. It may be considered as the “type-specimen” of a “valley of elevation”, for in 1826 Buckland used it in illustration of the features to which he gave that name; and it, alone of his examples, was mentioned in the somewhat diffuse title of his memoir. There could hardly be a more suitable type selected to represent a pericline, whether considered from a tectonic or geomorphological standpoint.
The floor of the Vale, scoured out by the headwaters of northward flowing streams, is composed for the most part of the Upper Greensand, which occurs as an inlier 4¾ miles long and 1 mile from north to south at its greatest breadth. The southern boundary of the Vale is a steep escarpment of the Chalk, partly breached near the south-west end, and deeply embayed by picturesque coombes at two other points. From the crest of this escarpment, which attains a height of over 850 feet in the west and is only 100 feet lower in the east, a rolling downland is seen sweeping southwards to Winchester and beyond; while to the north the heather-clad commons of the western end of the London Basin form the foreground to a view that comprises Reading, Oxford, the White Horse Downs and glimpses of the Cotswold Hills.
The Interglacial Formation in Viðidal, Northern Iceland
Authors: Lindal Jakob H. 
Published: October 2009

The rocks to be described occur within an Icelandic remnant of the North Atlantic Tertiary basalt plateau extending from the Skjálfanda river in the east to Breiðafjord in the west. It is a plateau from 800 to 1100 metres in height, incised by fjords and valleys, and some of the quasi-horizontal surfaces between the valleys may be the but little eroded remnants of the original surface. Two series of Tertiary basalts are recognized, the upper one being in general marked off from the lower in that in the former the rocks are more coarsely crystalline, the flows thicker and often with columnar jointing, whilst veins and amygdales are less common. The sediments found in places between the two series contain fossil plants which are believed to be Lower Eocene in age and to indicate a southern temperate climate. The upper series, designated by Dr. H. Pjeturss the “Grey Stage”, resembles the dolerites of the Palagonite Formation, which latter, however, is much younger. To the south, the plateau descends through the “Heath Plateau”, from 300 to 600 metres in height, to the region of the Palagonite Formation, a thick series of sediments and lavas laid down in the graben of central Iceland. The Palagonite Formation is seen to succeed the southerly dipping basalts of the northern tract, and the view advanced by Pjeturss that this formation is of Quaternary age is now generally accepted.
Between the Vatnsnesfjall (900 metres) on the west and the Viðidaisfjall (1000 metres) on the east is
The geology of the Colwyn Bay district: a study of submarine slumping during the Salopian period
Authors: Jones Owen Thomas 
Published: October 2009

The area described in this communication is bounded on the north in part by the coast of Colwyn Bay and farther west by the base of the unconformable Carboniferous rocks. It extends southwards for nearly five miles and westwards to the estuary of the River Conway near Llansantffraid Glan-Gonway. It is included in the area recently described by Professor Boswell (1935).
The town of Colwyn Bay stands at the foot of a steep crescentic scarp which marks an old cliff-line, the base of which is concealed by boulder-clay. The upper edge of the scarp is nearly 500 feet above sea-level, and southward of it extends an undulating plateau culminating on Mynydd Du, 4½ miles to the south, in low twin summits at 1133 and 1139 feet above sea-level. The plateau is traversed by steep-sided valleys eroded by streams which flow northwards towards the bay or westward into the estuary of the River Conway. The watershed between the Conway and the bay drainage pursues a zigzag course in a general north-west and south-east direction across the centre of the area. It runs for long distances through the high ground occupied by the slumped beds described below.
The plateau is mainly upland pasture diversified by rocky knolls and ridges usually covered by gorse and bracken. In some cases the trends of the ridges indicate broadly the general structure of the area, which in others is revealed by long scarps of bare rock, alternating with narrow strips of cultivated ground or pasture. The
The geology of the south-western part of Clun Forest
Authors: Earp John Rowland 
Published: October 2009

In my recent paper on the Kerry district (
Q.J.G.S.
xciv, 1938, p. 125) a map of the highly contorted strata in the western part of Clun Forest was published, and the characters and origin of the beds were discussed. Over the southern part of the district which they occupy, however, no account of the related strata was given. The associated beds occupy the area described here, and the description completes the stratigraphical account of the whole region occupied by the contorted beds.

The stratigraphical subdivisions adopted are similar to those in the Kerry district, but, as in the southern part of that district, the Leintwardinensis Shale group cannot be separated. The thickness of strata included between the base of the Wilsonia Grits and the base of the Dayia Beds is here about 3500 feet. This is 500 feet greater than that estimated for the equivalent beds in the Kerry district. The difference may be due to actual thickening, but it is possible that the thickness in the latter district was rather under-estimated. In the Kerry paper, also, it was mentioned that the Platyschisma Beds are never more than 40 feet, and are usually about 25 feet thick. In this district they are even thinner, and seldom exceed 15 feet in thickness.
I. Detailed description of the beds
(a) Ludlovian

(i)
Graptolitic Lower Ludlow Shales
.—Only the upper three or four hundred feet of these have been examined. They are chiefly dark grey, thinly bedded shales, sometimes nodular in character, but seldom