bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palæontological Notes on the Silurian Inlier of Woolhope
Authors: Reed Frederick Richard Cowper 
Published: October 2009

Shell ovate, with sides subparallel and very slightly arched; anterior end broadly rounded, subtruncate. Pedicle-valve with umbonal edges diverging at about 110°. Interior of pedicle-valve with a large, elongated, subrhomboidal, thickened area extending for nearly half of the length of the valve and produced in front into a long, tapering point reaching to about three-fourths of the length of the valve; area defined by narrow raised ridges which arise near the beak, and run outwards and forwards on each side with increasing strength and slight curvature to the widest part of the area, thence curving inwards and converging, at first at about 60° and finally at a rapidly diminishing angle, to meet in a sharp point in the middle line. Concrete laterals narrow, triangular, extending for more than half of the length of the area, forming an elongated, subrhomboidal scar divided by a rather broad, rounded median groove continued forwards to the anterior point of the area; centrals transverse, oval, oblique, large, lying in front of and alongside of the concrete laterals, separated anteriorly by the median groove. Cardinal margin of valve somewhat thickened and flattened internally.
Dimensions.—Length of valve = 26 mm. Width of valve = 19 mm. Length of area to tip=17 mm. Width (maximum) of area = 9 mm.
Horizon and locality.—Woolhope Limestone, Littlehope.

Remarks.—The internal characters of this shell are closely similar to those of
L. lewisi
Sowerby, from the Aymestry Limestone; but the internal area is more developed as a platform, the median ridge is
The Stratigraphy and Geological Structure of the Cambrian Area of Comley, Shropshire
Authors: Cobbold Edgar Sterling 
Published: October 2009

The object of this paper is to record the exact position of the excavations which I carried out at Comley between 1906 and 1915, and to describe the stratigraphy and tectonics of the Comley area as revealed in the natural and artificial exposures.
With a few exceptions, the fossils found have already been described (11) (12) (13) (14),1 the faunal assemblages have been tabulated, and the strata assigned to some twenty faunal horizons
The excavations were undertaken with financial assistance from the Committee of the British Association for the Advancement of Science appointed ' for the excavation of critical sections among the Palaeozoic rocks of Wales and the West of England,' and the results were reported to the Association as the work proceeded. A few additional excavations have been made during 1926, notes on which will be found below (p. 555).
The Comley Cambrian area, with the sub-area of the Cwms, is barely one-third of a square mile in extent. It is bounded (see map, PI. XLIII) on the west by the pre-Cambrian rocks of the Caradoc range; on the south by red grits and conglomerates that are referred in this paper to the Torridonian (?), and correlated with the Western or Wentnor Series of the Longmyndian, (17) pp. 327 & 334; on the east by the Uriconian of the Hope Bowdler and Cardington mass, and by the Caradocian of Hoar Edge and the Chatwall Ridge; northwards the boundary is ill-defined. The Shineton Shales {Dictyonema and higher beds) occur in
Description of
Camarotœchia
crebrilineata
sp. nov.
Authors: Reed Frederick Richard Cowper 
Published: October 2009

Shell transversely subpentagonal, rounded, subglobose, unequally biconvex. Pediele-valve shallower than the brachial valve, with a broad, weak, undefined, median sinus, widening anteriorly; beak high, rounded, incurred, pointed; interior of valve with the walls and floor of the umbonal cavity thickened, with thin low dental plates fused to the sides and supporting small short teeth ; umbonal cavity sharply separated in front from the base of the deeply sunk subpyriform muscular area, extending about half the length of the valve, and composed of a pair of elongated flabelliform diductors enclosing very narrow shorter adductors.
Bmchial valve deeper and more convex than the opposite valve, with a low, median, undefined, rounded fold; the interior of the valve has a long, lanceolate, well-defined muscular area extending fully three-fourths of the length of the valve, and composed of a pair of narrow adductors separated by a low, thick, median septum; hinge-plate thick, large, with a concave semicircular face divided by a narrow median slit into a pair of triangular areas; erura stout, rod-like, cylindrical, closely placed in the middle line.
Posterior margins of both valves slightly thickened internally. Surface of valves covered with regular rounded fine thread-like riblets, 40 to 50 in number, 9 to 12 lying in the sinus.
Dimensions.—Length=10 to 12 mm Width=12 to 14 ram.
Remarks.—The material consists of several more or less perfect internal casts of complete shells, or single valves with impressions of the external surface of a few of the same specimens. The internal characters are well preserved,
The Serpentines and Associated Rocks and Minerals of the Shetland Islands
Authors: Phillips Frank Coles 
Published: October 2009

The Shetland Islands consist largely of a foundation of metamorphic rocks—schists and paragneisses, with associated limestones and quartzites—upon which rest, with marked unconformity, patches of sediment of Old Red Sandstone age. In the north of Mainland is a magnificent development of igneous products of this same age. Earlier than the Old Red Sandstone however, there was injected into the older rocks a series of intrusions, rolled pebbles of which occur in the basal conglomerates of the Old Red. These older intrusions range from granites to the ultrabasic rocks which, more particularly form the subject of the present investigation.
Shetland has so far received scant attention from geologists; hence very little previous literature can be noted. So far as petrographical investigations are concerned, the field is practically untouched. The earlier writings of Jameson (1) and Hibbert (2) are of historical interest only. Heddle (3, 5, 7, 19), who carried out an exhaustive study of the mineralogy of the islands, seems to have given less attention to the geology He does devote some space, however, to the question of the origin of the serpentines, and concludes that they were produced by the metamorphism of the associated gabbro (3, p. 12). This view was accepted at a later date by Peach & Home (4, p. 782), but to these authors belongs the credit for most of the really sound work contributing to our knowledge of the geology of the area. Sir John Flett mentions the serpentines and pyroxenites in a discussion on a
The Kateruk Series and Associated Rocks of the Northern Suk Hills (Kenya Colony)
Authors: Glenday Vincent G. , Parkinson John 
Published: October 2009

The district where these completely metamorphosed sediments, temporarily termed the Kateruk Series, occur lies on the extreme north-eastern flank of the Chemerongoni or Northern Suk Hills, an important if but little-known range, reaching elevations of 5000 to 5500 feet, and having a total length of about 55 miles, in the north-western portion of Kenya Colony.
Geographically, it is terminated on the south by the Swam or Turkwal River, on the north by the Turkana Plains.
The route taken by one of us [V. G. G.], from Kacheliba in Tranz-Nzoia, was past the south-eastern face of Chau or Kapchok (6870 feet), a rugged hill of the typical granitoid gneiss of the district, thence eastwards to the Ngoron or Murwon River, before turning northwards along the eastern escarpment of the hills.
On the Murwon River the rocks seen consisted of the same gneiss and compact hornblende-schists.
The planes of foliation dip slightly to the south of west at high angles, and are frequently cut by bands of a pink felspar-pegmatite, containing white mica and having a fairly constant trend to north 60° east. These veins vary from half an inch to 6 inches across. On the Kasey Pass, dividing the southward from the northward flowing tributaries of the Swam, the dip of the planes of foliation changes to almost due east.
Crossing the summit of the Pass, we find a precipitous descent to the Chepurwa River, rising on the south-eastern slopes of Tarikot. Here the principal rock is a quartz-mica-schist, associated with
Geology of the Naparima Region of Trinidad, British West Indies
Authors: Illing Vincent Charles 
Published: October 2009

In the middle of the Island of Trinidad, south of the Central Range, is a broad undulating lowland. It stretches across the Island at its narrowest part, practically in the latitude of San Fernando. Towards the west it is the heart of the sugar-cane industry; towards the east it merges into the low ground of the Nariva, a derelict lowland of forest and swamp. It is to the western portion of this lowland that the name Naparima is usually applied. The present paper is concerned with the area extending from the Gulf of Paria on the west to Princes Town on the east. Its northern boundary is formed by the foothills of the Central Range, while on the south it extends practically to the Oropuche lagoon, a total area of approximately 35 square miles.
The Naparima area includes a large portion of the famous black soils of Trinidad, which have been utilized extensively for sugar-cane plantations. From it almost every vestige of the primitive forest has long been removed, and the undulating lowland is now one broad expanse of cane-fields, while in places a less fertile patch is given over to grass or guava scrub. From the distance it looks like one broad plain, but actually it is covered almost entirely by a complicated valley-system, leaving the intermediate high ground as a ‘fingering’ system of hog-backed ridges. These practically all attain the same general height, and are the remnants of an uplifted and partly dissected peneplain, tilted gradually westwards to
The Stratigraphical Distribution of the Cornbrash: I. The South-Western Area
Authors: Douglas James Archibald , Arkell William Joscelyn 
Published: October 2009

The detailed investigation of the stratigraphical distribution of the Cornbrash which has resulted in the present paper was commenced in 1921 by Mr. R. W. Segnit, who, however, left this country in the following year for Australia after completing little more than the study of the sequence in the immediate neighbourhood of Oxford. When, after the lapse of several years, there seemed to be no hope of his return, the present writers, one of whom (J. A. D.) had already shared much of the work, decided to continue the research into other areas, and together have completed the investigation of the formation from Oxford to the South Coast at Weymouth.
That part of the outcrop now described runs through the counties of Oxfordshire, Wiltshire, Gloucestershire, Somerset, and Dorset.
Since the publication in 1894 of H. B. Woodward's Geological Survey Memoir on the Jurassic Rocks of Britain, if we judge from the scanty references to the formation made by later writers, the Cornbrash has been regarded as of comparatively little stratigraphical interest, exhibiting only slight variation in character when traced along its outcrop, and admitting of no detailed subdivision.

Although J. F. Blake, in his unfinished Monograph of the Fauna of the Cornbrash, the first part of which was published in 1905, gives no account of the zonal distribution, it has long been known that two main zones can be recognized: a lower zone characterized by
Clydoniceras,
and an upper by Ammonites of the
Macrocephalites
group.

The critical faunas of these
The Major Intrusions of South-Eastern Iceland
Authors: Cargill Hilda Kathleen , Hawkes Leonard , Ledeboer Julia Augusta 
Published: October 2009

The intrusions of plutonic habit in Iceland have their greatest development in the south-east of the country, and our present knowledge of them is summarized by Thoroddsen, who gives the location of the main occurrences (VII, pp. 264–87). Beyond this little is known of the relationship of the intrusions to the country- rocks or their petrological character; there is one short paper by Helland dating from 1884 (V).
The present study is the result of four summer field excursions by the second-named author, and one excursion by his collaborators, who are responsible for the section on the Slaufrudal stock only. Some intrusions have been mapped on the ‘Generalstabens Topografiske Kort’ (1: 50,000) ; but this map is not yet completed, and more detailed work on certain areas is on that account held up.
The country-rocks are mainly plateau-basalts of Tertiary age, with some rhyolitic lavas, tuffs, and breccias, having a north-westward to west-north-westward dip of 5° to 20°, and cut by numerous dyke-intrusions of a regional north-easterly to north-north-easterly trend. Some of the gabbros are beneath the Vatna Jökull ice-cap, and are represented by pebbles in the southern outwash fans. The outcrops of the rocks here described are indicated on the sketch-map (fig. 1, p. 506).
On some Dolerite-Sills Containing Analcite-Syenite in Central Ayrshire
Authors: Tyrrell George Walter 
Published: October 2009

The petrographical province of analcite-rich rocks in Ayrshire is thoroughly basic in character. The most abundant type is teschenite, which frequently passes into picrite and peridotite. Other thoroughly basic types, such as kylite, essexite, crinanite, and monchiquite, are known ; while the effusive phase of this igneous episode has, in the Mauchline basin, given rise to olivine-basalts, analcite-basanites, nepheline-basalts, monchiquite-lavas, and limburgites, which verge on the ultrabasic. It is all the more interesting, therefore, to find in a few localities subacid rocks rich in analcite, evidently belonging to the same suite. This rock constitutes a new type, analcite-syenite. The rock is so fresh, and the primary character of the analcite so undeniable, that this occurrence must take its place as the principal type of this rock-species.
Alkali-syenites and felspathoidal syenites of any description are rare in the British Isles. The best-known examples are found in the remarkable masses of Cnoc-na-Sroine and Loch Ailsh (Suther-land). Prof. S. J. Shand described one of the rocks from the first-named locality as ‘analcite-syenite ’; but in a later paper he withdrew this term, as the analcite was found to be secondary, and he then regarded the rock as merely a leucocratic unspotted variety of borolanite. An analcite-syenite was also described by Hibsch from Grosspriesen in the Bohemian Mittelgebirge, but later the rock was described as sodalite-syenite with a little secondary analcite. Many nepheline-syenites, as, for example, those of Madagascar, contain analcite, some of which Prof. A. Lacroix now believes to be of primary
A Note on the Pleistocene History of Western Buchivacoa (Venezuela)
Authors: Parkinson John 
Published: October 2009

During 1925 and part of 1926 scattered observations on the occurrence of Pleistocene or late Pliocene beds were taken over a stretch of country in Western Buchivacoa, the area being defined as follows:—--From about 30 miles east of Altagracia, on the eastern shore of Lake Maracaibo and opposite the town of that name, in a straight line about 10 miles eastwards, thence southwards for 30 to 35 miles, the rectangle, when completed, embracing an area of between 300 and 350 square miles.
The observations, although necessarily incomplete, proved very considerable changes of sea-level and also peculiarities of deposition of sufficient interest, it is hoped, to deserve brief description.
The solid geology of the district passed through consists of an alternating series of false-bedded sandstones and sandy clays, the whole essentially arenaceous, and in many localities very sharply folded along east-north-easterly axes.
When sufficiently eroded, the centres of the folds show Burdigalian and Aquitanian fossils. It was in the upper beds, about 3 miles south of the El Mene Oilfield, that the bones of the new genus of Toxodont were found (see map, marked x ). The age of these upper beds is uncertain, owing to an unconformity between them and the underlying beds of Lower Miocene age, and the lack of fossils, as the deposits are estuarine or freshwater. They are in the locality concerned nearly horizontal or very gently undulating; whereas, as exposed a few miles away, the lower series is tightly folded. A Lower to Middle Pliocene age appears most probable.
The Geology of the District around Meifod, Montgomeryshire
Authors: Robinson King William Bernard 
Published: October 2009

Previous work in the area.—The Meifod district was visited by Sedgwick on various occasions in 1832, and again in 1842 and 1843, in the last-mentioned year in company with J. W. Salter. It was from this district that several of the types described by McCoy were collected, and also many of the fossils recorded in Salter's catalogue were obtained during these visits.
It seems strange, since this district was in many ways a connecting link between Sedgwick's Bala succession and Murchison's Shropshire succession, that no further work has been published since Salter's catalogue in 1873.
The general succession was established by Sedgwick, but the exact horizons of some of the beds and the relationship between them needs revision in places: thus Sedgwick attributed the absence of the May Hill Sandstone to the unconformable overlap of the Wenlock Series, whereas, as will be shown in the sequel, the succession is complete at this horizon. It is also unfortunate that the beds in the Mathrafal section were placed by Salter in the Upper Bala (Llandovery rocks = Lower Llandovery of the Geological Survey), since it would now appear that they belong to the base of the Upper or top of the Middle Llandovery of the type area.
The Caradocian deposits on the whole occur in the northern part of the area under discussion, where they form the folded southern flank of the Berwyn dome and the cores of the series of anticlines which run off south-westwards from the main dome. The strata
A Re-excavated Cretaceous Valley on the Mongolian Border
Authors: Brown Barbour George 
Published: October 2009

The ancient caravan route across the Mongolian border of China divides for a short distance immediately north of the frontier-town of Kalgan. The Hanoor trail pierces the Great Wall, and enters a ragged gorge, which, for part of its way, follows the line of an old disinterred Cretaceous river-valley. This, after being filled and buried for half the Tertiary Era, was reopened by erosion and used again by rivers in three distinct geological periods, the channel thus becoming a watercourse successively in Mesozoic, Tertiary, Quaternary, and Recent times, and being filled up again, partly or wholly, during each of the intervening epochs. Moreover, the peculiar conditions of preservation of the valley-deposits have made possible the mapping, with considerable certainty, of the early Cretaceous land-surface and the comparison of its configuration with that of the present day.
Examples of buried erosion-surfaces are known in many regions from the basal contacts of continental deposits, as far back as the Torridonian of Scotland. Striking cases have been cited by Watts from Charnwood Forest, by Johnson from the Cerrillos Hills of New Mexico, and by Haughton & Fronmurze from the pre-Dwyka terrane of the Warmbad District of South Africa. In the Kalgan area, however, the clear evidence of the repetition of erosion and deposition at geologically distinct epochs, with the combination of factors which permit the reconstruction of minor details in the original topography, must be almost without parallel, and appears sufficiently unusual to warrant an account of the main features of the occurrence.
The Geological Structure of the Central Mendips
Authors: Welch Francis Brian Awburn 
Published: October 2009

I. I
ntroduction
.

The area here termed the Central Mendips comprises that part of the Mendip Hills which lies between Cheddar and Shepton Mallet. This paper deals only with the Palæozoic rocks, which occupy the greater part of the area, and appear in inliers among the Mesozoic rocks on the south.
The eastern, western, and northern boundaries of the area are artificial, the lines cutting across the geological structures.
I wish to express my indebtedness to Dr. Stanley Smith for his unfailing help in the field and laboratory and in the compilation of this paper; to Prof. S. H. Reynolds and Dr. T. F. Sibly for much advice and helpful criticism; to the Department of Scientific and Industrial Research for a maintenance grant; to the Colston Research Society for defraying certain expenses; and, finally, to all others who have in any way helped me.
The area was first surveyed by Sir Henry T. De la Beche, over eighty years ago, and his results were embodied in the 1-inch Geological Survey Map, Sheet XIX, O.S. (1845), as also in the Survey Memoir of 1846 [3]. His account of the structure and stratigraphy is remarkably accurate, and forms the basis of all subsequent work. Except for the publication of William Sanders's geological map in 1862, which was the first large-scale map of the area, no works of importance appeared for more than twenty years after De la Beche's Memoir, until Bristow & Woodward [2] wrote an article dealing with prospects of coal south
The Horizons of Bryozoa (Polyzoa) in the Upper Eocene Beds of Hampshire
Authors: Burton Ernest St. John 
Published: October 2009

I. I
ntroduction
.

This communication is for the purpose of describing the horizons on which Bryozoa (Polyzoa) occur in the Upper Eocene Beds (marine clays and sands) of Hampshire. No claim is made to establish special zones with particular species confined to them, but those beds are indicated that contain a relative abundance or deficiency of bryozoan remains, within the three broad divisions of the Upper Eocene (Lower, Middle, and Upper Barton Beds).
The geology of this portion of the Hampshire Basin may first be briefly reviewed. The Barton Clay and Barton Sands form part of the well-known Hampshire Syncline, and are exposed at Christchurch Bay, and also at Alum Bay and Whitecliff Bay, in the Isle of Wight. The type-section at Barton Cliffs on the mainland consists of sandy clays in the lower part (50 feet), dark sandy clays and stiff drab clays in the middle part (56 feet), and clayey sands and light-coloured sands in the upper part (96 feet). (Total = 202 feet.)
Corresponding Upper Eocene Beds in the Isle of Wight attain a greater thickness. At Alum Bay, the western end of the island, they reach a total of 338 feet. At Whitecliff Bay, at the eastern end of the island, they reach a total of 368 feet (9, p. 108).
Even these thicknesses may fall short of the maximum totals in the Isle of Wight, owing to the high angle of dip, and to the compression to which so many of the strata have clearly been