bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Granite Controversy
Authors: Reynolds Doris L. 
Published: May 2009

This year, the 150th anniversary of Hutton's death, we are particularly reminded of the lively struggle of the eighteenth century between Vulcanists and Neptunists; the more so since that struggle finds its counterpart to-day in the divergence of opinion between two schools of petrology whose respective members might aptly be called Magmatists and Transformists. Much of the disagreement between the modern opponents arises from a belief on the part of the Magmatists that Hutton proved the magmatic origin of granite, and, in addition, the disagreement is probably strengthened by a misunderstanding of the views held by Transformists, and by lack of knowledge or experience of the evidence on which they base their conclusions. Indeed, Transformists might be tempted to preface their writings with the following very apposite quotation from Werner (1781):—“I must here present a request to all who would judge of this theory, or communicate their sentiments on it to the public, viz. to begin by reading through the whole treatise, and then to peruse it a second time, with attention. Such a request will not only appear strange to many persons, but even superfluous ; I find myself, however, under the necessity of making it from the manner followed by some individuals with my book on the external characters of fossils. They have often represented me as saying quite the contrary of what I have expressly written. This may have been done by some, through design, but in by far the greater number of instances, it has happened from that work not having been read through ; and in this manner the public has frequently been led into an error, at least for some time.”
The Geology and Petrology of the Cockburn Law Intrusion, Berwickshire
Authors: Midgley H. G. 
Published: May 2009

X.SummaryThe Cockburn Law intrusion is a small sheeted boss of late Caledonian age, intruded into Silurian rocks of Llandovery age.The following are the chief stages in its formation:—1. The earliest igneous activity was the intrusion of basic rock, now only found as xenoliths. This intrusion was followed at some later stage by—2. The main plutonic magma which assimilated the basic rock and country rock to produce the following hybrids—(a) Hybrid hypersthene diorite, from contamination by the Silurian pelites and greywackes.(b) Hybrid diopside diorite, from contamination by the basic rock.(c) Hybrid pyroxene diorite, from contamination by material from both basic igneous and sedimentary rocks.3. After the consolidation of the marginal hybrids the main body of the magma began to solidify, but had time to differentiate in place to give a composition ranging from adamellite through granite to granophyric microgranite.4. The heat from the intrusion metamorphosed the Silurian sediments to biotite cordierite hornfels which grade insensibly into the hybrid hypersthene diorite.5. Following the consolidation of the plutonic mass there was considerable activity by vapours to form pneumatolytic products, while differentiation of the residual magma produced the aplitic, acidic, and lamprophyric dykes.The intrusion may form a cupola from a bathylith, which may possibly belong to a series of bathyliths lying in a Caledonian direction from Newry to the Firth of Forth.
The Petrography and Correlation of the Igneous Rocks of the Torquay Promontory
Authors: Shannon W. G. 
Published: May 2009

The Middle and Upper Devonian rocks of the Torquay Promontory give evidence of a volcanic phase in Middle Devonian times, recurring in the Upper Devonian, and completed by a hypabyssal phase, which was post-Culm and pre-Permian. The tuffs are basic in nature, of glass and lava fragments, cemented by calcite. The only lava recognized is a spilite, probably Upper Devonian.Complementary rocks: a soda-porphyrite and an augite-lamp-rophyre, have been recognized at Babbacombe.An albite-dolerite is described from Black Head, carrying small amounts of olivine and with the characteristic albite-segregation veins. This mass has been shown to include the Ilsham Manor and the Red Rocks outcrop at Babbacombe. Metasomatic change due to silicification is characteristic of its flanks: this is especially developed at Anstey's Cove, where quartz-hæmatite veins are later than the cleavage of the slates.It has been shown that there is strong evidence for the post Culm date of this intrusion and hence for the tectonic movements of the area. The latter have been in the sequence:—tilting, intrusion, folding, thrusting, cleavage, and faulting, Some strike faults may be anterior to all these, but were repeated after the cleavage movements.
The Petrography of the Sands of the Upper Lias and Lower Inferior Oolite in the West of England
Authors: Boswell P. G. H. 
Published: May 2009

The main conclusions of the paper may be briefly stated thus:—1. The deposits, which are of neritic facies, possess a characteristic and peculiar mechanical and mineralogical composition, differing therein from any other British deposit.2. They exhibit a general constancy in grade from the Dorset coast to the Cotteswolds. Within this limit they conform to two chief types containing respectively 40 to 50 and 60 to 80 per cent, of the very fine sand grade (greater than 0·05 and less than 0·1 mm.). No variation of mechanical composition with hemeral change can be observed.3. The sands are blue and glauconitic in depth. At the surface they are decalcified and are yellow and brown as a result of oxidation. Minerals such as pyrite and pyrrhotite occur only in depth.4. The mineralogical composition indicates an abundance of highly angular brownish-pink to colourless garnets (possibly derived from rocks like those of the Lizard), but few red or purplish-red varieties; also of micas (including a pseudo-uniaxial, pale-green to colourless variety), together with chlorite, chloritoid, kyanite, staurolite, orthoclase, and microcline.5. Tourmaline is only moderately common and is always the grey-brown variety.6. The abundance of titanium-minerals is characteristic of the deposits. Red and yellow varieties of rutile and sagenite-webs are exceedingly abundant, and anatase, brookite, and sphene are locally so. A reciprocal relation may exist between the occurrence of sphene, ilmenite, and the oxides of titanium.7. Epidote and glaucophane are rare.8. Chlorite, chloritoid, glaucophane, kyanite, and staurolite increase in quantity as the deposits are traced southwards.9. A change in lithology and mineralogy sets in as the deposits are followed north-eastwards into the Midlands and Yorkshire.10. The sands differ markedly in petrology from the various Palæozoic rocks of Wales and the West Country, from the Trias, and from the Cretaceous and Eocene of Devon and Dorset.11. The Ordovician, Domerian, Toarcian, and Aalenian of Normandy and Brittany have been examined petrologically for purposes of comparison, but show little resemblance to the sediments under discussion, having been derived locally from the Palæozoic and pre-Cambrian rocks.12. It is concluded that the Lias–Inferior Oolite sands have been derived from the south or south-west, notably from rocks like those of western Brittany.13. The rise of the Mendip axis was not sufficiently complete at this time to cut off the supply of sediment from the south or south-west. The deposits north and south of the ridge have the same general character.
The Geology of the British Virgin Islands
Authors: Earle K. W. 
Published: May 2009

The geological structure of the British Virgin Islands correlates them indisputably with the Greater and not with the Lesser Antilles. The latter are composed essentially of Tertiary volcanic rocks of andesitic or basaltic type, with or without development of sedimentary strata which, when present, only dip at gentle angles and never show the violent effects of such dynamic forces as have been responsible for the folding and “up-ending” of the strata in the Virgin Islands. The tremendous depth of the channel separating the British Virgin Islands from the Lesser Antilles lias been ascribed to faulting, probably initiated in Pliocene times.The work of Cleve (1), Hill (4), Vaughan (5), and others (6) in the American Virgin Islands, Porto Rico, the Dominican Republic, Cuba, Haiti, and Jamaica, indicates that the British Virgin Islands form geologically only the eastern termination of that main group of islands and have been subjected to the same earth movements as them. The evidence for attributing a Cretaceous age to the sedimentary series has already been referred to.With regard to the age of the folding and igneous intrusion, Vaughan considers that the folding took place between upper Eocene and middle Oligoccne times, and that the intrusion of the diorites took place at approximately the same date. (7)Wythe Cooke considers that the igneous basal complex in the Dominican Republic certainly dates from Cretaceous time, but that part is probably older. He also considers that the stresses that folded and sheared these rocks were probably active during Eocene time or earlier, and that the intrusion of the great masses of dioritic rocks probably occurred before the deposition of the Eocene sediments.According to Hill (4), however, “in mid-Tertiary times granitoid intrusions were pushed upward into the sediments of the Greater Antilles, the Caribbean, Costa Eican, and Panamic regions.” Frazer, on the other hand (8), considered the nuclear axis of Cuba and San Domingo, and possibly of all the Caribbean islands, to be Archaean, a view upheld also by Dr. W. Bergt. (9)There is no doubt that the key to these problems lies in the larger islands of the Greater Antilles, for it is only there that unaltered fossiliferous sediments occur and can be studied in relation to the igneous intrusion and metamorphism. There appears, however, to the writer to be nothing either in the geological or faunal evidence necessarily indicating previous land connexion at any time between the Virgin Islands and the Lesser Antilles, ahd on this matter it is hoped to furnish further evidence at a later date.
The Base and Top of the Coral-rock in Barbados
Authors: Trechmann C. T. 
Published: May 2009

1. The coral-rock commences nearly everywhere with a basal bed of varying thickness containing a fauna of pre-Pleistocene aspect among which the genus Haliotis (absent from these coasts at the present day), Pleurotomaria, Meiocardia, etc., are noticeable. This faunule may have lived at a depth of 700–1,000 feet.2. The supposition that the southerly anticlines are a later uplift than the main portion of Barbados is supported by the absence of ravines, and the presence of post-coral-rock beds which occur as coastal veneers at low altitudes, and in greater thickness in the south-east corner near Whitehaven.3. The south-east part of the island from Consett Point to Ragged Point has probably extended further seawards in comparatively recent times ; the series of converging faults and dislocations in the cliff sections suggest that the thrusts from the west or south-west may have been resisted by this part of the island.4. The relative claims of fault-scarping or marine erosion in production of the rising terraces is discussed ; and new information regarding the thickness of the coral-rock at sea-level from a boring is detailed.5. The finding of a faunule with Pliocene or possibly Miocene affinities at the base of the coral-rock puts the Oceanic series further back, into the Miocene.
The Fishes of the “Crangopsis Bed” at Ardross, Fifeshire
Authors: White Errol Ivor 
Published: May 2009

One of the first authors to note the Ardross fauna was the Rev. T. Brown (1861, pp. 394–5), who “detected small scales of some species of Palaeoniscus, and a good specimen of an Amblypterus, which seemed to be theA. striatus.There were teeth and scales also of a Holoptychius; and their resemblance to the figure of theH. portlocki… seemed to be complete”.The fauna was summarized by Peach (1902, pp. 357–375), who, in addition to two plants, four arthropods, five brachiopods, and six lamellibranchs, gave the following list of fishes:—
On some Ordovician Fossils from Northern Argentina
Authors: Harrington H. J. 
Published: May 2009

The list of fossils described in this paper and their stratigraphical distribution is shown in the Table on p. 122.TheKainellaandLeiostegiumzones of the Quebrada del Toro are the equivalent of the Late Ozarkian of Western North America.The fauna of the arenaceous-calcareous beds of the marine-glacial deposits of the Saladillo group is not characteristic enough to enable an exact determination of the age. Nevertheless, from the stratigraphical position of these beds, they could be considered as indicating Upper Beekmantown age.The lower part of the Parcha group, with the single determinable fossilBasilicoides taurinusgen. et sp. nov. has been provisionally referred to the Llandeilian.The faunule of theAsaphelluszone of the Quebrada de Chalala shows affinities with part of the Tremadocian of England, the Tomkolian of South Chosen, and the upper zones of the “ Ceratopygeregion ” of Scandinavia.The stratigraphical relationship between theKainellaandLeiostegiumzones of the pre-Puna and theAsaphelluszone of Purmamarca is not known.
Precambrian Para-Gneisses of Southern Eyre Peninsula, South Australia
Authors: Tilley C. E. 
Published: May 2009

SUMMARY1. Garnet gneisses of sedimentary origin are described from the oldest group of sediments recognized in Southern Eyre Peninsula, South Australia. The high-grade metamorphism which these rocks have undergone has resulted in the development of felspar, garnet (almandine), sillimanite, and green spinel. 2. The mineralogical association of these constituents is described, and their genetic relations are discussed. 3. A sedimentary origin of these gneisses is attested by their interbanding with undoubted sediments, their mineralogical composition, and lastly by chemical analysis. 4. In the garnet gneisses developed in the Grenville series of North America, notably those of the Adirondack region, and in the province of Quebec, these para-gneisses find their most striking analogues.
Transfusion Phenomena in Lamprophyre Dykes and their bearing on Petrogenesis
Authors: Reynolds Doris L. 
Published: May 2009

The present investigation establishes the following facts:—(1) Xenoliths of vein quartz in a vogesite dyke near Kircubbin, Ards Peninsula, Co. Down, exhibit felspathic replacement-rims.(2) The replacement-rims have developed as a result of the introduction of alk-aluminous emanations, and to a smaller extent of cafemic constituents, into the quartz xenoliths.(3) Rheomorphic leucocratic veins extend from the felspathized rims through the lamprophyre, the veins being essentially similar in type to felspathic dykes which are associated with British Caledonian lamprophyres.(4) Phenomena similar to those of (1), (2), and (3) are developed in the Newmains dyke, Dumfriesshire.(5) Quartz lenticles in potash-enriched hornfels in the vicinity of the Newmains dyke exhibit similar replacement-rims, and thus bear witness to the high degree of mobility of the emanations which brought about the felspathization.(6) Felspathization of xenoliths is shown, by reference to various recorded examples, to be a phenomenon which characterizes British Caledonian lamprophyres.(7) The Caledonian dyke suite: lamprophyre—porphyrite—porphyry is shown to parallel the rock suites developed by processes of metasomatism and rheomorphism in individual heterogeneous intrusions.(8) Ultrabasic types, such as hornblende-peridotite, biotite-peridotite, hornblendite, biotite-pyroxenite, and scyelite, are shown to be the most basic members of the lamprophyre suite.(9) Chemically, the various components (a) of single heterogeneous lamprophyre dykes and (b) of the Caledonian dyke suite as a whole are shown to be expressible in terms of sialic material, alk-aluminous emanations, and cafemic emanations, the latter being directly related to the ultrabasic types listed in (8).
Gotlandian Vulcanicity in Western Europe
Authors: Turner J. Selwyn 
Published: May 2009

Summary and ConclusionsThe distribution of Gotlandian volcanic rocks covers a narrow belt running about N. 82° W.–S. 82° E., from South-west Ireland to Bohemia. The rocks comprise rhyolites, andesites, “keratophyres,” diabases, and basalts. Their age varies from early Valentian (Brabant) to Upper Salopian (Bohemia).The Gotlandian vulcanicity, as a whole, was independent of the preceding Taconic orogeny, neither is its distribution parallel to the main Caledonian folding. The Irish-Belgian section of the belt corresponds closely to the northern boundary of the Westphalian Zone of the Variscan folding, a structural line of fundamental character. The Anglo-Irish occurrences are related to the intersection of this line with Caledonian and Malvernian structures ; those of Belgium and Bohemia are more truly geosynclinal in character.
A Review of Dinantian and Namurian Vulcanicity in North-Western and Central Europe
Authors: Turner J. Selwyn 
Published: May 2009

IntroductionIn collaboration with Dr. R. G. S. Hudson, the author recently discussed the correlation of the Namurian and Dinantian strata of Western Europe (17) and reviewed the Variscan orogenic movements which attended their deposition (18). Only incidental reference, however, was made to the igneous activity of the periods under consideration and it is the purpose of the present communication to rectify this omission.
Origin of the “Beef” in the Lias Shales of the Dorset Coast.
Authors: Tarr W. A. 
Published: May 2009

SummaryIt is believed that the “ beef ” in the shales-with-“ beef ” resulted from the leaching of the CaCO3 of a fine porous marl by a groundwater solution, and its subsequent redeposition. The initial redeposition was about the grains of calcite along bedding planes or similar divisional openings, and, as more material was added by the solutions moving to these planes, each original grain developed into a fibre in the layer of “ beef ”. Growth was from both sides, but took place faster on the upper side because the dominant movement of the water was downward. Growth stopped due to the exhaustion of the supply of CaCO3 in the marl or CO2 in the solution. The thin paper-shales between the layers of “ beef ” may represent the concentration of the original clay of the marl. This explanation of the origin of the “ beef ” would probably apply to other fibrous deposits of calcite, also.
The Petrography of the Blea Wyke Series
Authors: Rastall R. H. , Hemingway J. E. 
Published: May 2009

SummaryThe general results which have accrued from this investigation may be summarized as follows: the shaly type of Liassic sedimentation with much pyrite, indicating a quiet sea with abundant sulphur compounds, gradually gave place to a regular and at first fairly steady shallowing of the water with, somewhat later, occasional incursions of strong currents bringing pebbles and broken fossils from an area undergoing active erosion. At the same time the amount of iron introduced, both in solution and in the form of derived ooliths, increased steadily, culminating in the siliceous oolite of the Dogger, which is essentially similar to the rocks composing this formation to the west and north-west.
Some Minor Intrusions of Glen Shee, Perthshire
Authors: Williamson W. O. 
Published: May 2009

SUMMARYSome additional data are given regarding the “newer” intrusions of an area of which the main petrological features have been described elsewhere. The intrusions are:—
(1) Aplites, pegmatites, quartz-veins, granodiorite porphyries, and biotite-granodiorites in or around the Newer Diorite. (2) A “porphyry” contaminated by cordieritic hornfels and having “clouded ” plagioclase “phenocrysts ”. Evidence is given that the “phenocrysts” have xenocrystic cores. (3) Quartz-felsites with cordierite, andalusite, and garnet, and granodiorite-porphyries, lying between the Newer Diorite and its roof of Ben Lawers Schist. The granodiorite-porphyries post-date the Diorite but the age of the quartz-felsites is uncertain. Contamination, and mechanical and chemical alteration, of the quartz-felsites are recorded. (4) Newer quartz-felspar-porphyries and lamprophyres, not obviously associated with the Newer Diorite.
Notes on Lateritization in Sierra Leone
Authors: Dixey F. 
Published: May 2009

Summary1. Lateritization has been found to affect a variety of rocks in Sierra Leone, including norite, granitic rocks, and detrital deposits.2. The norite of Sierra Leone is not deeply lateritized except in highly jointed areas or in certain bands readily susceptible to the alteration. It yields a gibbsitic laterite. A core of unaltered norite is enclosed in a light-coloured halo (“zone of leaching” of Professor Lacroix), which passes gradually into a red-brown laterite (“zone of concretion”). The transition from core to laterite is a rapid one. The minerals of the norite are attacked in the following order: felspar, diallage, hypersthene, magnetite (titanomagnetite).3. Norite containing only a small quantity of disseminated magnetite is less readily lateritized than norite containing a moderate amount. Where, however, the norite includes an unusually high proportion, as in the streaks of magnetite, lateritization proceeds very slowly.4. The granitic rocks of the Protectorate are frequently lateritized to a depth of 15 feet, and sometimes even to 30 feet. Nevertheless laterite is only slightly developed in the inselberg mountain districts of the northern part of the country. Lateritization of granitic rocks proceeds as follows: the rocks decompose into a white kaolinitic product, which passes into.brown lateritic clay (“zone of leaching”); this lateritic clay then develops into laterite (“zone of concretion”). There is a progressive change from the unaltered rock to the laterite crust, the granitic rocks in this respect presenting a marked contrast to the basic rocks.5. Lateritization affects detrital deposits also, particularly the Pleistocene sands and clays of the coastal plain. The phenomenon is most pronounced in the felspathic sands and diminishes in the more argillaceous beds until it is practically non-existent in pure clay. The typical lateritite is a red-brown scoriaceous rock, moderately hard, and in the hand specimen coarsely porous. It forms a crust about 10 feet thick at the top of the Pleistocene beds. This lateritite is indistinguishable from the laterite derived from other rocks.6. The scoriaceous laterite (lateritite) was produced by the growth and ultimate coalescence of numerous small ferruginous concretions, followed by the removal of the soft material between the concretions.7. The laterite formed from detrital deposits passes locally into lateritic iron-ore by increase in the percentage of iron oxide. Such iron-ores are well developed along the inner margin of the coastal plain encircling the colony, and occur principally in the neighbourhood of Devil Hole, near Waterloo. They were derived originally from the titanomagnetite which enters largely into the composition of the norite, and they are consequently very rich in titanium.8. Lateritization is frequently an important factor in the production of caves and subterranean channels, owing to the ease with which the unconsolidated material is removed from beneath the thick hard crust of laterite.
The Foraminifera of the Hartwell Clay and Subjacent Beds
Authors: Neaverson E. 
Published: May 2009

SUMMARY1. Thirty-six species of Foraminifera are recorded from various localities in the Hartwell Clay and associated beds.
2. The assemblage of species is characterized by:—
(a) the abundance of rotulate Cristellarians of Lower Cretaceous type, and of Cristellaria fragraria.
(b) the common occurrence of Vaginulina harpa, a Jurassic type.
(c) the rarity of arenaceous, and the absence of porcellanous forms.
3. The Foraminifera from the Hartwell Clay are compared with those from other deposits in the Aylesbury district, and with those from foreign deposits of similar age.
4. The relative abundance of glauconite is a point of similarity between the Hartwell Clay and beds hitherto regarded as Kimmeridge Clay.