bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Valentian succession around Llanidloes, Montgomeryshire
Authors: Valory Jones William David 
Published: October 2009

Summary
Llanidloes is situated in the Severn Valley, in the western part of Montgomeryshire, and is surrounded by areas which have been described by other authors. The area of Tarannon (Wood 1906) lies to the north, Ponterwyd (O. T. Jones 1909) to the west, Rhayader (H. Lapworth 1906) to the south, and Abbey Cwmhir (R. O. Roberts 1929) to the south-east. Most of the ground between these areas has now been mapped on the scale of 6 inches to the mile.
Very little detailed work has previously been done in this area. Sedgwick amde journeys across it and Murchison makes occasional references to it; Professor O. T. Jones (1922), however, has discussed in detail its ore occurences.
The greater part of the country is dissected by the Severn drainage system, and the main sequence is exposed in these streams. The Wye system is confined to the south-west and reveals a few good sections in rock-groups near the top of the Valentian. The average height of the higher land is between 1000 and 1500 feet, but the ground rises to nearly 2000 feet in the extreme east. All the higher ground is pasture, while the lower country of the valleys is usually cultivated.
The strata range from Upper Bala to Salopian in age, but only the Valentian rocks are described in detail. Mudstone is the dominant lithological type; intercalations of thin shales occasionally yield graptolites. These organisms are the sole fossils found in the area and are preserved either in full or in half relief; they afford an interesting comparison with the forms preserved in the flattened condition.
The fundamental structure of the district'is a dome which has been named the Clywedog Dome, from the river of that name which joins the Severn at Llanidloes. The Central Wales Syncline passes through the area near its western margin and exhibits a culmination of pitch near tne northern margin. The Towy anticlinal axis does not enter the area but runs some three miles to the south-east, near Abbey Cwmhir (R. O. Roberts 1929).
Faulting" is an important feature; several of the major faults have been identified as belonging to the group of faults and lodes occurring in the Ystwyth Valley, 4 miles to the west. Strike-faulting is not common, but locally the major faults may behave as strike-faults.
The Carboniferous Rocks of the Edale Anticline, Derbyshire
Authors: Hudson Robert George Spencer , Cotton Geoffrey 
Published: October 2009

Summary

The Edale Shales, which both outcrop in Edale and were passed through in the upper 325 feet of a boring in that valley, consist of 150 feet of beds of
Reticuloceras reticulatum
(R
1
) age, 100 feet of
Homoceras
(H) age, 220 feet of
Eumorphoceras Bisulcatum
(E
2
) age, and 406 feet of
E. pseucdobilingue
(E
1
) age. The faunas of the zones and subzones are described and comparison is made with those of Alport Dale to the north and Mam Tor and the Hope boring to the south near Castleton. It is shown that the upper beds (upper E
2
, H, R
1
) in general retain their thickness southwards from Alport to Castleton, where they rest on the Carboniferous Limestone, thus overlapping the lower beds (E
1
and lower E
2
). It is suggested that the greater part of this overlap takes place immediately north of the limestone massif.

In a boring in the Edale Anticline the beds from 325 to 757 feet, the final depth of the boring, were of Upper Viséan age. Goniatites of the genera
Neoglyphioceras
and
Goniatites
occurred in the upper beds, and the zonal scheme based on goniatites was therefore used for the division of the upper part of the succession. Since most of the other fossils were brachiopods, corals being extremely rare, the allocation of the beds to the
Dibunophyllum
zones, D
1
, D
2
and D
3
, was made in part by comparison of the lithologicaI succession with those of other areas with more definite zonal faunas. The lithological succession and the zonal division adopted were aa follows :—
Notes on the Geology of the Southern Rumanian Oil District with Special Reference to the Occurence of a Sedimentary Laccolith
Authors: De Raaf Johan Ferdinand Maurits 
Published: October 2009

Summary
The Tertiary stratigraphy and tectonics of the Carpathian foothills, north of Bucharest, are briefly described. Apart from slow movements during sedimentation there are two major folding phases, in pre-Burdigalian and post-Levantine times respectively. Normal salt plugs, similar to the “salt domes” of other countries, occur usually in the core of anticlines. Elsewhere along faults intrusions of salt-breccia have been observed. In the vicinity of Campina an intrusion of clayey salt-breccia, along bedding-planes in the Sarmatoid sequence is described in detail. This body of salt-breccia does not represent an ancient mud-flow contemporaneous with the Sarmatoid beds, but an intrusion at a later date of foreign sedimentary material. Rock-salt, although present near the surface in its immediate vicinity, has not been observed in the above-mentioned intrusion, for which tlie author uses the term “sedimentary laccolith”.
The Barrow Hill Intrusion, South Staffordshire
Authors: Marshall Charles Edward 
Published: October 2009

Summary
Geological, magnetic and resistivity surveys indicate that the igneous rock is very largely confined to he higher parts of Barrow Hill, with near-vertical contacts on the northern, eastern and south-eastern flanks. Towards the west and north-west the base of the main intrusion rises transgressively at an angle of approximately 30°; in this direction the country rock (Middle Coal Measures-Etruria Marl) is greatly disturbed and subject to highly irregular, small-scale injection. Pre-intrusion, penecontemporaneous and post-intrusion faulting is in evidence.
The igneous rock is dominantly an extremely fine-grained analcite-bearing olivine-basalt, most frequently microtaxitic in character. Local country-rock zenoliths occur in large numbers, exhibiting a wide range in degree of alteration. The distribution and character of the changes produced, together with the nature and relations of the later-stage mineralization, indicate the importance of the volatile phases in the consolidation history of the igneous rock.
Field and laboratory studies suggest that the Barrow Hill intrusion most probably represents a late Carboniferous feeder.
The Genus
Phialaspis
and the “
Psammosteus
Limestones”
Authors: White Errol Ivor 
Published: October 2009

Summary

1. At least two species of the genus
Phialaspis
are represented among the ostracoderm remains from the Downtonian commonly identsed as “
Psommostrus anglicus
”,
P. symondsi
and a small new form,
P. pococki
, of which a distinct variety and a sub-species are also known.

2. Seventeen records of the genus have been established, which, apart from one , in Scotland, are all in the Anglo-Welsh area. The localities are recorded and the associated faunas listed.

3. It is pointed out that the two species have never been found together, although the localities are interspersed : at all those yielding
P. symondsi
, ten in number, the beds are in Wickham King's stage 1.8 (“
Psammosteus Limestones
”) ; whereas five of the seven occurrences of
P. pococki
are in earlier strata, the age of the fifth being disputed and of the sixth unknonn. The possible use of these species for zoning is noted.

4. It is considered that for the most part the Downtonian and Dittonian vertebrate faunas were not autochthonous, but were of freshwater origin.

5. The new specimens of
Phialaspis
are described in detail. Almost the whole of the carapace is now known, chiefly from specimens from two new localities, Gardener's Bank, Salop, and Sharpness, Gloucestershire, and this shows a number of pteraspid and, to a lesser extent, cyathaspid features ; but it also shows specialized characters that are peculiar to the genus, which is accordingly made the type of an independent group of heterostracans.

6. What is believed to be the earliest instance of vertebrate palaeopathology is recorded.
The Geological Results of the Search for Oilfield in Great Britain
Authors: Lees George Martin , Taitt Alfred Harold 
Published: October 2009

Summary
The search for oil in Great Britain has been carried out in five separate geological provinces—in the Mesozoic of southern England, the Carboniferous of the eastern Midlands, the Triassic and Carboniferous of Lancashire, the Permian of North Yorkshire and the Calcirferous Sandstones Series of the Midland Midland Valley of Scotland. Four oilfields have been discovered in Nottinghamshire and a small field in Lacashire. In addition, a large amount of new stratigraphical information has beeb provided by the exploration borings and extensive geophysical surveys have added cosiderably to existing knowledge of the structure of the Carboniferous in the eastern Midlands. The boring records have given much new information on the development of coal seams in the areas east and sout-east of the present Nottinghamshire Coalfield. A boring in North Yorkshire proved the presence of potash salts in the Permian indicating conditions comparable with those of North-West Germany.
Ophthalmidium:
A study of Nomenclature, Variation, and Evolution in the Foraminifera
Authors: Wood Alan , Barnard Tom 
Published: October 2009

Summary
Some variable foraminifera from the base of the Upper Lias at Byfield, Northamptonshire, have been used as evidence supporting completely opposed "evolutionary series" based on the "law" of recapitulation and its converse, proterogenesis. The authors obtained closely spaced samples of this foraminiferal clay and studied them in order to establish the actual succession of forms.
The first major portion of the paper (section III), a complicated discussion of nomenclature, is necessary in order to give a name to the forms studied. Here a number of genera and species are established or redefined.
The following section (IV) attempts to establish the bounds of the species by means of a detailed variation study. It is found possible to define closely the species studied; though they are highly variable, no transition from one species to another is seen.
Finally, in section V it is shown that the actual succession of forms does not support the theory of proterogenesis, but rather that of recapitulation. A marked shift of the mode of variation is observed within a time interval represented by the deposition of 2 feet of clay. The contribution which the variation study can make to systematics is also discussed.
Metamorphism of the jasper bars of Western Australia
Authors: Miles Keith Rodney 
Published: October 2009

Summary
Until comparatively recently the true jasper bars of Western Australia have been regarded by local geologists as silicified and replaced shear-zones in greenstone. The evidence in the paper suggests that these jasper bars, like the banded ironstones in the Pre-Cambrian of many other countries, were originally sedimentary formations which have experienced varying degrees of metamorphism leading to the development of certain characteristic mineral associations. No account has been taken of the many superficial so-called jaspers, silicified limonitized surface gossans either of fault gouge or of schists originally impregnated with iron sulphides, which have often in the past been mistakenly identified with the true banded iron formations or jasper bars.
Beds of banded iron formations and related rocks are found associated with rocks of several distinct series of the Pre-Cambrian in Western Australia, namely : the younger Pre-Cambrian (Proterozoic) rocks of the Nutlagine Formation, and the Mosquito Creek, Whitestone, and Older Greenstone Series which form portions of the older Pre-Cambrian rocks. The ironstones of Nullagine age have been subjected only to mild metamorphism and have remained relatively unchanged, except where, under special conditions, fibrous riebeckite (crocidolite) seams have been formed by growth in situ from beds of unique composition.
The banded ironstones and jasper bars of the older Pre-Cambrian series have been metamorphosed both regionally and locally in varying degrees. With increasing grades of metamorphism they have been recrystallized, and the original iron in the more ferruginous types has reacted with silica to form minerals such as grunerite, hedenbergite, iron-rich hypersthene, and fayalite. The grade and type of metamorphic conditions which these rocks have experienced are to some extent indicated by the quantity and the species of the ferrous silicate minerals developed.
It is believed that the failure of early observers to recognize the true nature of these ferrous silicate minerals in jasper bars from highly metamorphosed areas (particularly in the Yilgarn Goldfield) was primarily responsible for the growth of the "shear-zone" theory. Early geologists, mistaking these minerals for amphi-boles similar to the actinolites and hornblendes in the adjacent amphibolitic schists and greenstones, concluded that the jasper bars represented amphibolitic schist partially replaced along parallel shear-planes by later silica and iron ore. This would account for the statement that jasper bars may be seen grading along strike and dip into the adjoining greenstone.
The Compaction of Muddy Sediments
Authors: Jones O. T. 
Published: October 2009

In his attempt to correlate pressure with the void-ratio of shales encountered in oil wells Professor Jones made two assumptions, one regarding the relation between pressure and void-ration and one regarding hydrostatic uplift.
Since the relation between pressure and void-ratio under high pressure is a matter of general interest, the writer induced Professor R. B. Peck of the University of Illinois to make consolidation tests on clay under pressures up to 2000 kilograms per square centimetre. These pressures correspond to a depth of overburden of at least 30,000 feet. It was found that the line representing the relation between the void-ratio and the logarithm of the pressure is, for a range of pressure between about 20 nd 2000 kilograms per square centimetre, almost perfectly straight, without any tendency to flatten out. However, it is doubtful whether the compaction of sediments under high overburden pressures follows exactly the same law, because the increase of the overburden pressure is associated with a considerable increase of temperature. Exposure to relatively high temperature over a long period of time is likely to involve mineralogical changes. Such changes may represent and additional source of compaction, not present in laboratory tests. The occurrence of mineralogical changes is indicated by the fact that a shale cannot be reconverted into a clay slurry, whereas the clay which was subjected in the laboratory to a pressure of almost 2000 kilograms per square centimetre still was a clay. It is also indicated by the observation that the transition of a
The Carboniferous Rocks of the Edale Anticline, Derbyshire
Authors: Hudson R. G. S. , Cotton G. 
Published: October 2009

Abstract

From
Mr. R. C. S. Walters :—

The authors are much to be congratulated on giving the full analyses of water from the Barber Booth Well. Such data should prove valuable in any research into the origin of the composition of underground water. Presumably the rest level remained stationary at 200 feet below the surface, but it would be interesting to have the probable levels of lowering in the water when the several quantities of water were abstracted. What is the equivalent of a barrel in gallons?
The volumes of the waters struck were tested by bailing. The maximum amount that could be bailed was about 37 barrels (of 40 imperial gallons) per hour; with any substantially smaller inflow than this the hole was bailed dry and the reported inflows were with the hole approximately in this condition.
At 563 feet the level could be reduced only about 50 feet when bailing 37 barrels per hour, the first 6 barrels removed lowering the level about 30 feet and the next 18 barrels only lowering it 10 to 20 feet farther. At 652 feet the water level could be lowered only 40 feet by removing about 55 barrels in 1| hours, and at 662 feet hours bailing failed to lower the level at all.
In the Alport boring, some 4 miles to the north, no water at all was encountered down to 2555 feet.
Geological factors in gravity interpretation illustrated by evidence from India and Burma
Authors: Evans Percy , Crompton Wilfred 
Published: October 2009

Summary
The interpretation of gravity data has suffered from lack of collaboration between geodesists and geologists, and few general discussions of the subject have made adequate allowance for the effects of relatively light sedimentary rocks in diminishing the observed values of gravity. In an extensive gravity survey of Burma and north-eastern India gravity anomalies (that is, the difference between the observed and computed values) were determined at over 6000 stations, and an endeavour was made to resolve the anomalies into the portions due to known geological causes and the residual (regional) portions due to deep-seated variations in density.

Although the need for applying to gravity data a correction for known geology was emphasized by David White in 1924 and has been discussed by several subsequent writers, so far no attempt seems to have been made to carry out the necessary computations for an area in which sediments are thick. The calculations are laborious, but a graphical method supplied by Colonel (now Brigadier) E. A. Glennie, of the Geodetic Branch of the Survey of India, proved very useful. Difficulties were encountered in determining appropriate densities applicable to sediments buried at great depths, a branch of geology which has received little attention. Sections through representative gravity stations were drawn from geological maps, and by the graphical method it was possible to estimate the gravity effect attributable to known or inferred geological structures. This was subtracted from the anomaly to obtain a
geologically corrected
or
residual
anomaly

Some of the geological corrections are of the same order as many of the anomalies, but in general their application does not lessen the anomalies, and the results confirm the view of de Graaff Hunter and Glennie that it is incorrect " to quote India as a region supporting the hypothesis of Hay ford isostasy ". The residual anomalies show a close relation to the main tectonic lines. A pronounced gravity minimum follows the lines,of maximum uplift in the hills separating Assam and Bengal from Burma and a gravity maximum almost coincides with the nearly parallel volcanic line of Burma. Both these lines can be correlated with the even larger anomalies described by Vening Meinesz in the Netherlands East Indies. A gravity minimum follows the general trend of the eastern Himalayas. The Bengal and Irrawaddy deltas (like the neighbouring deltas of the Indus, Mekong, and Red River or Tongking) are areas of excess gravity. All these major regional anomalies are attributable to variations in the depths to the basic and ultra-basic crustal zones. The broad regularity of the gravity features is interrupted by several local anomalies, of which the most important coincides with a belt of thrusting and may be due to hitherto unsuspected igneous intrusions.
Erosion and tectonics in the East African Rift System
Authors: Dixey Frank 
Published: October 2009

Summary
From consideration of the Karroo and Jurassic structures within the Rift Zone it is suggested that major folding that took place in later Jurassic time raised locally to great height the resistant pre-Karroo complex, out of which, in successive cycles, the high-level residual plateaux have been carved. In general, throughout the Rift Zone the surviving larger tracts of Karroo and Jurassic sediments still occupy low-lying areas representing the original major synclines, but in some cases trough-faulting that succeeded the folding carried down into the elevated areas strips of sediments which were subsequently eroded to form ancestral " rifts "; within these " rifts " much of the Pleistocene rifting took place and thus formed narrow lake basins within an ancient topography.
The pattern of the ancient residuals on the main watersheds of the Rift Zone indicates that these watersheds were original features on the Miocene peneplain, inherited from the great framework of the Jurassic folds.
Until the rifting of about the Middle Pleistocene carried down the floor of the Nyasa and Tanganyika troughs to form the existing lakes, the history and form of these troughs differed in no essential respect from that of the Karroo troughs of the Luangwa Valley and the middle and lower Zambezi. These troughs had been developed in their present form by a prolonged sequence of planation, continental uplift, and erosion that intervened between the fracturing of the post-Karroo period and that of the Pleistocene. The Pleistocene rifting accordingly took place along existing troughs of ancient origin of which the form was accentuated by the erosion of the Miocene and Pliocene cycles. Similarly, many of the Pleistocene rift fractures of Tanganyika Territory followed ancient fault-line scarps and troughs. The major rifts of the northern part of the Rift System, including the Abyssinia Rift, also show a pronounced pre-Pleistocene phase of ancient origin preceding the Pleistocene rifting, and in two localities there is evidence, too, of movements of Lower Miocene age
The supposed Cambrian foraminifera from the Malverns
Authors: Wood Alan 
Published: October 2009

Summary

The only foraminifera of Cambrian age with wall-structure preserved were described by Chapman in 1900. Originally considered to be derived from a calcareous band in the White Leaved Oak Shales (Upper Cambrian), these specimens are here shown to be derived from a loose fragment of Rhaetic of Lower Liassic limestone. As " the earliest-known well preserved foraminifera ", these have had a great influence on the classification of the group, and the views of certain authors as to the evolutionary sequence of foraminiferal types will have to be completely revised. The genera
Lagena, Nodosaria, Dentalina, Cristellaria, Spirillina
and
Marginulina,
previously considered to range unchanged from Cambrian to Recent, probably range from Mesozoic only. The isolation of Palaeozoic foraminifera becomes now much more marked and the incoming of Mesozoic types must have relatively rapid.
The petrology of two granite-slate contacts at Cape Town, South Africa
Authors: Walker Frederick , Mathias Morna 
Published: October 2009

Summary
The porphyritic biotite-granite of the Cape Peninsula is intrusive into the tightly folded pre-Devonian Malmesbury Series which consists of psammitic hornfelses with subordinate politic intercalations. At two localities within the Cape Town municipal boundary, namely Sea Point and Kloof Quarry, the contact aureole is well exposed and includes a zone of spectacular migmatites. With the aid of 14 new chemical analyses it is shown that the contact phenomena probably arose in four main stages:—
(i) Intrusion and differentiation of a contaminated biotite-granite magma,
(ii) Permeation and softening of the Malmesbury hornfelses by alkaline emanations from the granite,
(iii) Penetration of the hornfelses by granitic material with the formation of migmatites.
(iv) Felspathization of the granite and migmatite zone by late potassic solutions which gave rise to potash pegmatites and large crystals of perthitic micro-cline.
The evidence for the formation of an Mg-Fe front outside the migmatite zone is inconclusive.