bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Unusual Gabbroic Intrusion from Northern Rhodesia
Authors: Newton A. R. 
Published: May 2009

AbstractGabbro is intruded near the contact of gneiss and schist groups in the Southern Province of Northern Rhodesia. The petrography of normal and altered rocks is described. The rocks may have originated as an intrusion into an original reversed drag fold which it has emphasized and distorted. Intrusion took place at a late stage of regional metamorphism and folding.
A Note on Greisening in the Bodmin Moor Granite
Authors: Exley C. S. 
Published: May 2009

AbstractSome differential weathering of tors on Bodmin Moor has been found to be due to narrow zones of greisen. These zones are not related to the joint system in the granite and appear to have arisen by the alteration of feldspars in the path of escaping late-magmatic fluids.
Structural Behaviour of Quartzite in a Migmatite Area, Tanganyika
Authors: Brown P. E. 
Published: May 2009

AbstractQuartz-magnetite rocks occur as lenses in an area of migmatitic mica gneiss and have acted as resisters to deformation as well as migmatization. Due to plastic deformation in the enclosing gneisses a quartzite lens now strikes perpendicular to the trend of other resisters which are abruptly truncated.
The Permian and Trias of the Oman Peninsula, Arabia
Authors: Hudson R. G. S. 
Published: May 2009

AbstractThe lower part of the limestone succession of the Hagab Monocline in the Oman Peninsula, Arabia, is divided into the Bih Dolomite (Permian, 650 m.), Hagil Limestone (Permian, 260 m.), Ghail Limestone (Trias, 600 m.) and the Elphinstone Beds (Noric, 431 m.). The latter consists of five formations, two of which are very fossiliferous. The succession also occurs to the south in borings in the forelands of the Oman Mountains and is similar to that of the foreland of the Zagros Range of Iran.
The Late Palaeozoic Glaciation of Gondwanaland in Relation to West Africa and to Northern South America During Carboniferous Time
Authors: Anderson M. M. 
Published: May 2009

AbstractLower Carboniferous strata are shown to be absent from the Amazon basin and Ghana, the Bermejo series of Bolivia is Permo-Triassic, the Sekondi series of Ghana does not include glacial deposits and may prove to be Devonian, early Carboniferous glaciation is unknown in Africa and restricted to Argentina in South America. In the light of these interpretations the extent to which late Carboniferous glaciation affected northern South America and Africa is briefly reviewed and shown to conflict with the reconstructions by L. C. King (1958). The non-glaciation of Africa and South America north of at least latitude 25 degrees South during early Carboniferous times is regarded as proving that these areas did not pass through the south polar region at that time. The known distribution of early and late Carboniferous glacial deposits is considered in relation to continental drift and movement can only have been westwards during the Carboniferous period.
Intrusive Phenomena of the Whin Sill, East of the R. North Tyne
Authors: Randall B. A. O. 
Published: May 2009

AbstractThe Whin Sill of this district has the form of a series of sills at different stratigraphical levels. Minor scarps at right angles to the main trend of the sill are explained by intrusion of offshoots, from its upper surface, along low angled fractures in the superincumbent strata. An intrusion mechanism is suggested to account for the presence of the Oxford Limestone both above and below the Whin Sill.
The Structure of the Grantown Granite Complex, Morayshire
Authors: Mackenzie David H. 
Published: May 2009

AbstractThe field relations and petrography of the Grantown Newer Granite are described. The structure of the country rocks—Moine gneisses—is compared with that of the numerous blocks included in the granite, the results being synoptically presented. The blocks originally bore the same orientation as the country rocks and have been rotated in the granite during its emplacement. From east to west three zones of orientation, showing increasing rotation of blocks from their original position, are recognized in the granite. As the granite lacks an internal penetrative structure the kinematics of the blocks in the granite remains uncertain. All the evidence suggests that the granite did not form in situ, but was emplaced in a plastic state by dilation of the country rocks mainly along their foliation.
Pelagic Foraminifera in the Tertiary of Victoria
Authors: Carter Alan Norval 
Published: May 2009

AbstractA sequence of eleven faunal units characterized by pelagic foraminifera and embodying thirteen significant events has been recognized in the Tertiary of Victoria. They form a continuous sequence from the Upper Eocene to the Middle Miocene. Some of these events have been recognized in the same order in New Zealand, Europe, North America, the Caribbean region, and Saipan.
On the Occurrence of Ankerite in a Band of Non-marine Lamellibranchs from the Lancashire Coal Measures
Authors: Broadhurst F. M. , Howie R. A. 
Published: May 2009

AbstractThe shell-substance of the non-marine lamellibranchs from a band in the Lower similis-pulchra Zone of Lancashire is shown to be ankerite. The same mineral also forms pockets inside certain of the shells, the pockets being developed most frequently in the stratigraphically uppermost part of the spaces between the valves. It is considered that the ankerite in the pockets has occupied spaces left by shrinkage of the original mud-filling of the shells. Chemical analyses, specific gravity, and optical properties of the ankerite are given; its composition closely approximates to (Mg2Fe)Ca3(CO3)6.
The Significance of Septa and Sutures in Jurassic Ammonite Systematics
Authors: Westermann G. E. G. 
Published: May 2009

AbstractA study of Stephanocerataceae and Perisphinctaceae of the Middle Jurassic demonstrates that the structure of the septa comprises a complex vault and pillar system which is functionally adapted to the dimensions of the tube so as to give maximal stability to the shell. Only through a study of the septum can we interpret the different forms of the suture and discriminate between important and unimportant features. Different septa may have analogous sutures, especially in the external parts. These septal patterns are strikingly consistent within subfamilies or families even where other features suggest overlap between the groups. Some parts of the septum are not adapted, but either retained from earlier ontogeny or inherited, and constitute vestigial (genotypic) characters distributed through taxons.These empirical results have been applied to the taxonomy of some groups of hitherto doubtful systematic position (Cadomitinae, Normannitinae, Sphaeroceratinae, Parkinsoniidae, Spiroceratidae).
Pyroxenes from the Dawros Peridotite and some comments on their nature
Authors: Rothstein A. T. V. 
Published: May 2009

AbstractThe paper contains eight analyses of primary and recrystallized pyroxenes from the layered ultramafic peridotite at Dawros. The assemblages in which these pyroxenes occur are compared to those from other peridotites and some comments are made on the pyroxene sequence. Consideration is also given to the problems arising as the result of the metamorphism of the primary igneous accumulate at Dawros.
Pre-Cambrian Rocks in Co. Wexford
Authors: Baker J. Wellstood 
Published: May 2009

AbstractAn area of rocks in S.E. Co. Wexford, the age of which has not been previously established, is now shown to be a metamorphic assemblage, probably of Pre-Cambrian age. It is suggested that this formed the south-western extension of the L. Palaeozoic Irish Sea geanticline postulated by previous workers.
Alkali Metasomatism and the Petrology of Some Keratophyres
Authors: Battey M. H. 
Published: May 2009

AbstractPetrographic and chemical study of New Zealand keratophyres, occurring in a typical spilite-keratophyre association, shows that they were originally partly glassy flow-rocks and breccias comparable with rhyolites of young volcanic areas. They are now composed of a low temperature mineral assemblage inconsistent with textural evidence of high temperature extrusive origin, and alkali metasomatism has enriched some rocks in soda and others in potash, so that their compositions are symmetrically disposed about that of a primary rhyolite magma with roughly equal amounts of the two alkalis.Data from other occurrences suggest that this condition is common amongst described keratophyres.Though the rocks do not originate from any special magma, the term keratophyre should be retained, with appropriate qualifiers, for old rhyolites with low-temperature mineralogy, which, incidentally, will often be found to have been affected by alkali metasomatism.
Metamorphism of the Manx Slates
Authors: Gillott J. E. 
Published: May 2009

AbstractThe chief metamorphic minerals are described and, in addition to those reported by Lamplugh, cordierite (at scattered localities along the structural axis) and staurolite (at Glion Darragh, Archal-lagan) are found to occur. The distribution of metamorphic minerals recorded by Lamplugh is confirmed. The age relation of the new minerals to the movements is deduced from microscopic evidence. This is: early folding and development of biotite; relaxation of stress and development of cordierite; shearing and recrystallization of biotite along planes of fracture-cleavage; high grade metamorphism at Archallagan which outlasted the fracture-cleavage movements.It is concluded that the postulate of a buried granite beneath the axial belt most readily accounts for the distribution of the metamorphism.
The Upper Carboniferous Rocks of the Stainmore Coalfield
Authors: Ford T. D. 
Published: May 2009

AbstractThe sequence of Upper Carboniferous rocks in the outlier at the western end of Stainmore Pass is described. The Upper Yoredale Series is shown to be separated by an unconformity from the overlying “Millstone Grit” series. The Coal Measures are about 800 feet thick and appear to be unconformable on the “Millstone Grit”. Hitherto unrecorded non-marine faunas and floras indicate horizons near the base and at the top of the Modiolaris zone. The sequence of Upper Carboniferous rocks at Stainmore is briefly compared with those of surrounding coalfields.
Some Devonian Fish Remains from North Central Vestspitsbergen
Authors: Dineley D. L. 
Published: May 2009

AbstractFish remains from the Wijde Bay Series of the Wijdefjorden area include (1) pteraspids, not previously recorded from so high an horizon, which appear to bear sensory canals upon the exterior surface of the ventral disc; (2) an Asterolepis, and (3) rhizodontid scales, resembling those of Holoptychius. A very large antiarch from an unknown horizon is also recorded.
Corundum from Ceylon
Authors: Wells A. J. 
Published: May 2009

AbstractThe origin of precious corundum found in the gem-bearing gravels of Ceylon has long been unknown. An occurrence of sapphire is described from a contact zone where syenite has been intruded into, and desilicated by, crystalline limestone. The process of desilication in such contact zones is considered capable of accounting for much of the gem-quality corundum of the island.
The Occurrence of Chloritoid in the Hecla Hoek Formation of Prince Charles Foreland, Spitsbergen
Authors: Atkinson D. J. 
Published: May 2009

AbstractIn the Hecla Hoek rocks of Prince Charles Foreland, field evidence indicates that chloritoid has developed only where conditions of extreme stress have affected pelitic rocks of a certain type. Microscopic examination confirms that many of the chloritoid-bearing rocks are extremely strained, and demonstrates that growth of the mineral was contemporaneous with movement. The distribution of chloritoid is in complete discordance with the pattern of regional metamorphism.
The Stratigraphy of Cuilcagh, Ireland
Authors: Padget Peter 
Published: May 2009

AbstractOf the three main lithological units on Cuilcagh, namely, Millstone Grit, Yoredale Sandstone, and Yoredale Shale, particular attention is paid to the latter which attains a thickness of 700 feet. Numerous goniatites were collected from the lowermost 450 feet of it and these establish the existence of the P1b, P1c, P2, E1a zones and possibly the E1c zone also. Higher beds are very poorly fossiliferous and their age is uncertain. Brief comparisons are also made with Yoredale Beds in England and in other parts of Ireland.
New Evidence of Intra-Formational Piping at Two Separate Horizons in the Carboniferous Limestone (Dibunophyllum Zone) at South Cornelly, Glamorgan
Authors: Thomas Trevor M. 
Published: May 2009

AbstractLarge-scale extractions from a limestone quarry immediately east of the village of South Cornelly have provided sections of the Dibunophyllum Zone (probably the top of D1 Subzone) showing deep piping at two separate horizons. On the lower sides and floors of some of the larger pipes, the limestones and pseudo-breccias have been metasomatically replaced by a thin layer or by irregular pockets of haematite up to a foot in thickness. All the evidence points to two periods of emergence and sub-aerial erosion followed by lagoonal conditions with a Keuper-like environment when the irregularities of the underlying rock surface were filled with marl.
Progressive Replacement of Limestone Inclusions in Granite at Ballynacarrick, Co. Donegal
Authors: Gindy Amin R. 
Published: May 2009

AbstractLimestone inclusions in granite show a skarn armour made up of definite mineral zones. From the limestone side these are in order: grossular zone (with or without idocrase), clinozoisite zone, plagio-clase-pyroxene zone, and finally a hornblendic or dioritic zone that passes into the biotite-granite or granodiorite of the district. These different zones were not static but moved into the limestone, each zone replacing the one preceding it and being replaced by the zone following it. A mechanism by which limestone inclusions disappear in granite is clearly exemplified.
Daviesiella destinezi (Vaughan), a Lower Carboniferous Index Fossil in North-West Ireland
Authors: Simpson I. M. 
Published: May 2009

AbstractDaviesiella destinezi (Vaughan), a large concavo-convex brachiopod, is very common in some of the Lower Carboniferous limestones of North-West Ireland. It appears to be confined to the C2S1 subzone. Easily recognizable in the field, it is thus a useful index fossil of the subzone. As the previous descriptions of the species are far from complete, a detailed description of some unusually well-preserved specimens from Co. Fermanagh is given and an attempt is made to relate certain features of the morphology of the specimens to their environment.
On the Affinities of the Cretaceous Lamellibranch Genera Trigonioides and Hoffetrigonia
Authors: Cox L. R. 
Published: May 2009

AbstractThe East Asian Cretaceous lamellibranch genera Trigonioides and Hoffetrigonia are discussed after examining new material of the former, and the conclusion is reached that both belong to the Unionidae and not to the Trigoniidae. A proposal to include them in a new family is withdrawn.
Echinotiara arabica sp. nov., A Regular Echinoid from the Toarcian of Central Arabia
Authors: Melville R. V. 
Published: May 2009

AbstractThe new species Echinotiara arabica is described and referred to the family Stomopneustidae Meissner, 1903. It is compared with other Liassic species of “Stomechinus” which are considered to be congeneric with it, and its relationships with the genera Stomechinus, Psephechinus and Jeannetia are discussed.
Supposedly Colpate Pollen Grains from the Jurassic
Authors: Couper R. A. 
Published: May 2009

AbstractSome Mesozoic spores and pollen grains claimed in a recent publication to exhibit angiosperm-like features are discussed. It is suggested that Poroplanites Pflug, is actually a trilete fern spore. The “ germinal apparatus ” of the Poroplanites type is simply an optical section of the characteristic folding of a lobe of a trilete spore, flattened along the polar axis and seen in equatorial view. It is shown that Pflug's Poroplanites type can be reproduced almost exactly in the trilete spores of a living tree fern. Classopollis Pflug, Circumpollis Pflug, and Canalopollis Pflug are pollen grains with distinct annular thickening, similar to the pollen grains of the Jurassic araucarian, Pagiophyllum connivens Kendall.
Petrofabric Analyses of the Loch Tay Limestone from Strachur, Argyll
Authors: Gilmour Paul , Carman Max F. 
Published: May 2009

AbstractThe paper records the results of petrofabric analyses of four specimens of marble from the South-West Highlands of Scotland. The marble fabric has a high degree of homogeneity. Calcite grains are flattened in the foliation plane and are elongate in a direction normal to the fold axis. The c crystal axes lie in a distinct girdle about b, with a maximum near the pole of the foliation; the a crystal axes tend to occupy three maxima, one of which is close to b. Late twinning has occurred on {011¯12} apparently in response to a simple stress system, operating in the ac plane. The symmetry of the general calcite fabric, the twinning and the megascopic structures coincide.
The Carboniferous Rocks of Foynes Island, County Limerick
Authors: Hodson Frank 
Published: May 2009

AbstractThe lithological and faunal successions of some 1,150 feet of Carboniferous beds exposed on Foynes Island, County Limerick, are described and shown to be of Namurian Age. The stratigraphical position of Reticuloceras subreticulatum (Foord) and Homoceratoides divaricatus (Hind) has been ascertained by collecting from the type localities on the island. The palaeogeographical implications of the succession are discussed.
Lamellibranchia and Plants from the Lower Karroo Beds of Northern Rhodesia
Authors: Bond Geoffrey 
Published: May 2009

AbstractA small collection of non-marine lamellibranchs and plants from the Madumabisa Shales of the Gwembi district of Northern Rhodesia is described. It includes a new species of the genus Kidodia, Palaeomutela rhomboidalis, and P. neglecta, associated with Glossopteris indica. The Madumabisa Shales may be correlated with similar beds in Southern Rhodesia assigned to the Tapinocephalus zone of the South African Lower Beaufort Series, and are of Upper Permian age.
The Silurian Succession at Gorsley (Herefordshire)
Authors: Lawson J. D. 
Published: May 2009

AbstractThe oldest formation exposed in the Gorsley area is a hard limestone considered by previous authors to be equivalent to the Aymestry Limestone. All the available evidence, however, supports a correlation with the Wenlock Limestone. The succeeding strata comprise 4½ feet of Dayia Beds and 7 feet of Upper Ludlow Beds, so that the total thickness of Ludlovian strata is only 11½ feet. AH the Lower Ludlow Shales and the Aymestry Limestone are cut out by the unconformity below the Dayia Beds. This remarkably thin development is attributed to movement at various times during the Ludlovian epoch along an axis passing through the Gorsley region. The main movements probably took place in middle Ludlow times.
An Occurrence of Chrysotile Asbestos, Usushwana Valley, Mbabane District, Swaziland
Authors: Hunter D. R. 
Published: May 2009

AbstractAn occurrence of chrysotile asbestos in the Usushwana river valley some 10 miles west of Mbabane, has been sporadically prospected since its discovery in 1946. No fibre of economic grade has, however, been discovered but certain features concerning the genesis of this deposit are described and may prove of value in the further search for this valuable mineral.Cross-fibre asbestos is confined to narrow mylonitized apple green serpentinite (totally serpentinized) occurring as sharply demarcated bands in dark blue-green serpentinite (partially serpentinized). As these mylonitized bands decrease in width they pass out into fractures less than an inch thick filled by verde antique, sometimes with traces of slip fibre. The widest mylonitized band located was 18 inches wide in which were up to a dozen seams of fibre of maximum width ½ in.The features of the occurrence suggest that fault or shear action has been primarily responsible for the localization of this deposit.
Flow Structure and Laminar Flow in Bostonite Dykes at Armidale, New South Wales
Authors: Spry Alan 
Published: May 2009

AbstractWest of Armidale occur a number of dykes which intrude Woolomin Group greywackes and which are genetically associated with Permian granite. The rocks are similar to bostonites and quartz-bostonites and show remarkably developed flow structures which indicate the condition of the magma at the time of intrusion. It is shown that intrusion probably took place by laminar flow despite the occurrence of a pseudo-turbulent structure in one dyke and it is suggested that evidence of turbulent flow is unlikely to be preserved in intrusions even if such flow did occur.
A Basalt Flow and Feeding Dyke, N.E. Uganda
Authors: Davies K. A. 
Published: May 2009

AbstractTholeiitic rocks, which are well represented in the igneous history of the African Continent, occur as a dyke and related flow found by the writer in the north-east corner of Uganda. They outcrop in an area which is notable mainly for alkaline intrusions and lavas, so a brief attempt is made to explain the relationships and origins of the rocks in this limited area of the continent.
The Development of Monograptus dubius and Monograptus chimaera
Authors: Walker Margaret 
Published: May 2009

AbstractThe growth of the rhabdosome from the initial prosicula is described for two species of Monograptus. Sections of the metasicula have shown the nature of the “Stillstandsgürtel” first described by Kraft, and in both species evidence about the structure of the interthecal septum is given. It appears that there are two forms of Monograptus dubius which have the same external appearance but differ in the details of early development.
Drainage and Fracture Patterns in North-West Scotland
Authors: Auden J. B. 
Published: May 2009

AbstractThe drainage pattern of North-West Scotland is considered in relation to already known and newly inferred fracture zones, and it is concluded that a system of Tertiary fractures, connected with the plutonic centres of the Western Isles, has been superimposed on the rhombic pattern of late-Caledonian faulting.
The Distribution of Radioactivity with Depth in the Continents
Authors: Hills G. F. S. 
Published: May 2009

AbstractThe heat generated by the radioactive elements in the surface of the earth has been calculated by Evans and Goodman (1941) and by H. Jeffreys (1952). The amount of radioactivity in the depths of the continents obviously cannot be directly calculated. In the following paper two physical reasons are given for believing that the amount of radioactivity in the depths exceeds that found in the surface.
Hantkenina alabamensis Cushman and Some Related Forms
Authors: Barnard Tom 
Published: May 2009

AbstractSome variations in the apertures of Cribrohantkenina are arranged in morphological series. The development of the “cribrate” aperture and its relation to other biocharacters, such as the shape of the chambers, development of spines, and globosity of the chambers, is discussed, as also the status of the subgenera of the genus Hantkenina.
Ice-Borne Boulders in the Macduff Group of the Dalradian of Banffshire
Authors: Sutton John , Watson Janet 
Published: May 2009

AbstractThe paper describes a horizon of greywackes outcropping on the coast near Macduff, Banffshire, and containing large boulders of igneous and metamorphic rocks. This horizon belongs to the Macduff Group of the Upper or Banff Division of the Dalradian. It is suggested that the boulders may have been dropped into the greywackes from floating ice.