bluuebunny/crossref_metadata_2025_split huggingface dataset:
Portable Apparatus for Collecting Small Oriented Cores in the Field
Authors: Brown H. C. , Khan M. A. 
Published: May 2009

AbstractPortable apparatus for obtaining small oriented cores for geophysical or geological purposes is described. It consists of a 34 c.c. two-stroke engine with a 12 ft. long flexible shaft to a drilling head which accommodates the drilling bit and includes a pipe through which coolant from a pressure container may pass. All this weighs under 50 lb. Imperfectly cylindrical specimens may be obtained by hand drilling, or perfect cores with the aid of either of the two rigs described. The first weighs 21 lb. and allows a number of closely spaced specimens from horizontal and inclined outcrops to be obtained. The second weighs 15 lb. and is for obtaining specimens some fixed distance apart from more difficult vertical faces. Magnetic and non-magnetic orienting devices are described. The merits of the method of sampling are briefly discussed.
An Occurrence of Kyanite Pseudomorphing Andalusite from Southern Rhodesia
Authors: Workman D. R. , Cowperthwaite I. A. 
Published: May 2009

AbstractAn occurrence of kyanite pseudomorphing andalusite, from the Urungwe District of Southern Rhodesia, is described. The pseudomorphs, which include some of the largest of their kind so far recorded, occur in profusion in certain Pre-Cambrian pelitic schists. The original andalusite was completely converted to kyanite during regional metamorphism but the shape of the original crystals was perfectly preserved. This, together with the habit of the kyanite within the pseudomorphs, shows that the change took place under conditions of insignificant shearing stress.
Tectonic Structures in the Devonian Rocks near Plymouth, Devon
Authors: Fyson W. K. 
Published: May 2009

AbstractMinor folds in slates and sandstones are upright in the south and northerly overturned towards the north, and plunge approximately E.N.E. and W.S.W. towards three major N.W.–S.E. dextral faults. The folds are monoclinal and angular; regardless of attitude, the short limbs lie on the northerly sides of anticlines. Both slaty and fracture cleavages tend to parallel axial planes and local directions of extension. Similarly, the vertical axial planes may closely parallel those of major folds.Boudins and W.N.W.–E.S.E. dextral oblique faults indicate extension along fold hinges, N.W.–S.E. dextral cross faults a change to N.–S. compression. Folded basic dykes parallel to faults and joints suggest early initiation of the fractures.
An Index of Weathering for Silicate Rocks
Authors: Parker Andrew 
Published: May 2009

SummaryAn index of weathering for silicate rocks is proposed, based on the proportions of the alkali and alkaline earth metals present. These are considered to be the most mobile of the major elements. The bond strengths of the elements with oxygen are used as weighting factors in the index, which measures both the degree to which a rock has already been weathered with respect to the parent material, and also its susceptibility to further weathering.
Geology of the Comores Archipelago, Western Indian Ocean
Authors: Esson J. , Flower M. F. J. , Strong D. F. , Upton B. G. J. , Wadsworth W. J. 
Published: May 2009

SummaryThe Comores Archipelago comprises four principal islands, lying in a WNW–ESE line at the northern end of the Mozambique Channel. The Islands are almost entirely volcanic and show a simple age progression from Grande Comore, with its active shield volcano Kharthala (2650m), east-south-eastwards through Mohéli and Anjouan, which are quite deeply dissected, to Mayotte, which is in an advanced stage of erosion and subsidence, and is encircled by a barrier reef. There is also evidence of minor volcanic rejuvenation in relatively recent times in Mayotte, and perhaps Anjouan and Mohéli. The lavas of Kharthala, and the neighbouring extinct shield volcano (Massif de la Grille) on Grande Comore are all basaltic, ranging from oceanitic and ankaramitic to aphyric types. Numerous tuff cones occur, especially on the flanks of Massif de la Grille. Basaltic lavas, similar to those of Grande Comore, form the bulk of the dissected volcanic shields of Mohéli and Anjouan, but there is also evidence of differentiation towards alkalic under-saturated end products, both as lavas and as intrusive bodies. Lherzolitic and gabbroic nodules are locally abundant on each of the islands, while xenoliths of sandstone and quartzite have been found on the three westernmost islands. Petrochemical data are presented for a considerable variety of Comores rocks, and the volcanic activity is discussed in terms of the major structural features of the Madagascar-Mozambique region.
The occurrence of ottrelite along the thrust zone in the Pakhals of Yellandlapad area, Andhra Pradesh, India
Authors: Rao T. Ramamohana 
Published: May 2009

SUMMARYThe regional metamorphism of the Pakhals in the Yellandlapad area is synchronous with folding and is superimposed in the east by dislocation metamorphism due to overthrust. The development of ottrelite is contemporaneous with the overthrust. It is suggested that the conditions of growth of ottrelite may be distinctive from those of chloritoid.
A Geochronological Study of the Crystalline Rocks of Charnwood Forest, England
Authors: Meneisy M. Y. , Miller J. A. 
Published: May 2009

AbstractPotassium-argon age measurements made on samples of rock from Charnwood Forest and surrounding districts indicate that the porphyroids and syenites probably date from late pre-Cambrian times. The area was affected by both the Caledonian and Hercynianorogenies. A number of the intrusive rocks of the Forest have been shown to date from Caledonian times. A dolerite from the Leicestershire coalfield gave a Permian age.
The influence of deep fractures on some areas of Ashgillian—Llandoverian sedimentation in Wales
Authors: James David M. D. , James Joan 
Published: May 2009

SUMMARYStudy of arenite—rudite bodies within the traditional Welsh basin reveals two contrasted modes of situation, here termed concordant and discordant It is inferred that the former represent submarine fans developed on relatively level topography and the latter represent submarine channels adjacent to (and incising) major breaks in palaeoslope. The size and disposition of these palaeoslopes makes their control by deep fractures very probable.
Ludlovian Classification—A Reply
Authors: Holland C. H. , Lawson J. D. , Walmsley V. G. 
Published: May 2009

AbstractThe revised classification of the Ludlovian rocks is defended. It is maintained that there is no need for separate rock-stratigraphical and biostratigraphical classifications. The nine new divisions are, therefore, combined units; their number is justified by the detailed mapping and their names are dictated by the requirements of the rocks and not by an arbitrary code of rules. The old classification, using Aymestry Limestone, is considered to be still usable as a crude rock-stratigraphical classification.
Microplankton from the Speeton Clay of Yorkshire
Authors: Neale J. W. , Sarjeant W. A. S. 
Published: May 2009

AbstractNew genera and species of microplankton from a borehole through the Speeton Clay (Lower Cretaceous) of West Heslerton, Yorkshire, are described. One genus, two subgenera and seven species of dinoflagellates, and three species of hystrichospheres, are described, and a new family of dinoflagellates, the Muderongiidae, is set up.
Geological Interpretation of Airborne Magnetometer Observations from Nelson to Waikato River, New Zealand
Authors: Wellman H. W. 
Published: May 2009

AbstractA map is presented showing a series of airborne magnetometer profiles from the north end of the South Island of New Zealand to the mouth of Waikato River. The two southern profiles are related to the exposed Upper Palaeozoic igneous rocks which are considered to extend north across Cook Strait and along the west coast of the North Island to cause the anomalies in the northern profiles. The North Island profiles are considered to reflect the Kawhia Syncline and a major anticline to the east. The eastward displacement of the magnetic low relative to the synclinal axis at the surface is considered due to the eastward dip of the axial plane of the syncline.
The Mt. Barney Central Complex, S.E. Queensland
Authors: Stephenson P. J. 
Published: May 2009

AbstractThe general geology of the Mt. Barney Central Complex is described. This intrusive complex shows close similarity in type to the classic Tertiary ring complexes of Western Scotland and Northern Ireland. In this discussion of the complex, the similarities shown by ring dykes, cone sheets, a forcefully intruded granophyre boss, and a closed ring fault are indicated.
Sequence and Structure in the Silurian Rocks of Kirkcudbrightshire
Authors: Craig G. Y. , Walton E. K. 
Published: May 2009

AbstractThe generally accepted interpretation of the structure of the Southern Uplands has been that of an anticlinorium to the north-west flanked by a synclinorium to the south-east. This structure, however, has always been illustrated as one large anticlinorium since the Hawick rocks in the core of the synclinorium have been considered to be older than the Riccarton (Wenlockian) Beds which lie to the south. In Kirkcudbrightshire, a reverse age relationship is demonstrated with the result that the beds could in fact form the southern limb of the synclinorium. When this is shown to be the case doubts are thrown on the validity of the fold and two alternative interpretations are given.
Lower Devonian Crinoids from Toongabbie, Victoria, Australia
Authors: Philip G. M. 
Published: May 2009

AbstractThree camerate crinoids,Thylacocrinus(?) ignotussp. nov.,Eucalyptocrinites inchoatussp. nov. andHexacrinites(?)sp. are described from the lower Devonian of Toongabbie, Gippsland, Victoria, Australia.
The Mid-Zambezi-Luangwa Rift and Related Carbonatite Activity
Authors: Bailey D. K. 
Published: May 2009

AbstractThe known carbonatite eruptive centres in Northern Rhodesia fall within a linear belt trending N.E.-S.W. the most conspicuous elements of which are the colinear troughs of the mid-Zambezi valley and the Luangwa rift. This lineament is an important and longstanding zone of crustal weakness. Its extensions outside Northern Rhodesia are briefly indicated and its ramifications inside the Territory are examined, particularly in reference to the localization of carbonatite activity around rift intersections.
A Llandovery Shoreline from the Southern Malverns
Authors: Reading H. G. , Poole A. B. 
Published: May 2009

AbstractThe paper describes an unconformable junction of Upper Llandovery upon Malvernian in the Gullet Quarry of the South Malvern Range and discusses the evidence for and the significance of other comparable junctions in the Malverns. It is considered that Taconic movements are a factor in Malvern tectonics and that the importance of a “ western boundary fault ” to the Malvernian has been overstressed in the past.
A Note on the Origin of Ophitic Texture in the Chilled Olivine Gabbro of the Skaergaard Intrusion
Authors: Wager L. R. 
Published: May 2009

AbstractThe textures of the chilled marginal gabbro of the Skaergaard intrusion and of the coarser marginal gabbros 25 yards further in are described and related to counts of the number of separate crystals of the chief mineral species per cubic centimetre of the rock. An explanation of the textures and number of crystal individuals is attempted in terms of various degrees of supersaturation in the magma. In the chilled rock abundant nucleation of plagioclase and olivine, presumably at the middle labile stage of supersaturation, is inferred. This is followed by ophitic or poikilitic crystallization of pyroxene and ilmenite about scarce nuclei, produced at lower temperatures, presumably during the early labile stage of supersaturation for these two minerals. The coarser gabbro, further in from the margin, has about half the number of plagioclase crystals per cm.3 compared with the chilled rock and only one twenty-fifth the number of olivine crystals, and these have a tendency to be ophitic in texture. Under these slower cooling conditions, supersaturation apparently still reached into the middle labile region for plagioclase, giving many nuclei, while olivine, like pyroxene, separated under early labile supersaturation conditions and only relatively few nuclei formed. The contrasting textures of the plateau magma-type basalts of Mull and the tholeiitic basalts of Northern Ireland are explained along similar lines.
Early Transverse Dykes in the Main Donegal Granite
Authors: Pitcher W. S. , Read H. H. 
Published: May 2009

AbstractCertain microtonalite dykes cut across the flow banding of the Main Donegal Granite in the direction of an important cross-joint, yet they and their granite host are shown to have crystallized together and in the same manner as both the darker flow bands in the granite and the pelitic xenoliths within it. It appears that an embryonic joint system existed in the Donegal Granite before consolidation and crystallization were complete. It is suggested that the early dykes represent metasomatized pelitic enclave material and are not differentation products of granitic magma. Comparison is made with the basic analogue provided by the beerbachite enclaves and dykes of the hypersthene-gabbro of Ardnamurchan.
The Efficacy of Natural Selection as an Evolutionary Agent, with Particular Reference to the Fossil Record
Authors: Rhodes F. H. T. 
Published: May 2009

AbstractThe recent suggestion that natural selection of random mutations is inadequate to account for the major features of evolution is rejected. The pattern of evolutionary development in most major groups, the phenomena of extinction and replacement, the rates of appearance of new major taxa, the continuing vitality of the evolutionary process, the overall randomness of evolutionary history, containing directional change within individual lineages, the nature of natural selection, and the geologic evidence for environmental instability are examined. All suggest that natural selection and random variation are adequate to account for the major features of evolutionary history.
Spilitic Rocks in South-east Devonshire
Authors: Middleton Gerard V. 
Published: May 2009

AbstractVolcanism began in South-east Devonshire with the extrusion of keratophyric tuffs in the Lower Devonian. The majority of extra ves in the Middle and Upper Devonian are basic spilites but there are intermediate varieties. Volcanism in the Middle Devonian was local and in the Ashprington area appears to have been continuous throughout the epoch. At the beginning of the Upper Devonian keratophyric crystal and vitric tuffs were extruded in the Dartington area. Later in the Upper Devonian the Chipley pillow lavas were extruded: it is shown that these lavas were widespread and may probably be correlated with similar lavas at Pentire Head in North Cornwall. The final phase of volcanism is represented by the intrusion of swarms of sill-like bodies of spilitic dolerites in Upper Carboniferous times. Intrusive and extrusive rocks are distinguished, mapped, and classified petrographically
Ludlovian Biotite-Bearing Bands
Authors: Tucker E. V. 
Published: May 2009

AbstractAllogenic biotite flakes, together with fish and conodont remains, are concentrated into bands at particular horizons within Upper Ludlovian rocks of Woolhope and other Welsh Borderland areas; and are present but more scattered within the Aymestry Limestone and Dayia Beds. Metamorphic rocks of Malvernian type appear to have provided the source of the biotite.
Seismic Refraction Investigations of the Preglacial Valley of the River Teifi near Cardigan
Authors: Allen Adrian 
Published: May 2009

AbstractTwo short seismic refraction profiles have been shot across the former valley of the River Teifi, above and below Cardigan, with the object of determining the depth to the rock floor. This was found to lie 75 feet below O.D. at Castle Malgwyn, near Llechryd and 107 feet below O.D. at the present estuary. These figures are consistent with the glacial history of the valley indicated by the geological evidence.
A Note on Current-Bedded Moines Near Garve, Wester Ross
Authors: Soper N. J. 
Published: May 2009

AbstractA locality in the Moine series at which well preserved currentbedding may be viewed in three dimensions is described. An analysis of the foreset dip directions shows that the sediment was deposited by current flowing in a direction slightly east of north. The form of the current-bedding is described and the significance of the observations briefly discussed.
The Distribution of Alpha Radioactivity in a Specimen of Shap Granite
Authors: Spears D. A. 
Published: May 2009

AbstractThe distribution of alpha radioactivity in thin sections of Shap granite is discussed and more than 95 per cent of the activity is shown to be concentrated in the accessory minerals. The results of this study are compared with those obtained for the Adamello granodiorite by other workers using similar techniques.
New Irish Tournaisian Fenestellids
Authors: Miller T. G. 
Published: May 2009

AbstractA new genus, Levifenestella, is erected, with L. maeve n.sp. from the Tournaisian of Co. Sligo, Ireland, as type species. A new species of Fenestella, F. polynodosa, from the same horizon and locality, is described. A Russian species, F. rossica Shulga-Nesterenko, is recorded from the Tournaisian of Hook Head, Co. Wexford.
On the Form and Mode Of Emplacement of the Ben Buie Intrusion, Island of Mull, Argyllshire
Authors: Lobjoit W. M 
Published: May 2009

AbstractField evidence and theoretical arguments are used to elucidate the form of the intrusion. In the absence of a more accurate term this is described as chonolithic. Passive injection of the magma into a potential vacuum has enabled control to be exercised on the intrusion-form by the country rocks and their structures. The effects of this control are discussed.
Pleistocene Deposits on the West Side of the Malvern Hills
Authors: Hey R. W. 
Published: May 2009

AbstractA north-south valley west of the Malverns contains a variety of Pleistocene deposits, largely hidden by late Pleistocene solifluxion. Around Eastnor is a stony clay attributed to an ice-tongue that crossed the Malvern Hills from the Severn valley. Various sediments north of Eastnor are thought to have been laid down in a lake held up by this ice-tongue and fed by a stream diverted across the hills north of the Malverns by the main Severn valley glacier. The Upleadon Gravels south of Eastnor are attributed to water released from the lake when the ice-tongue melted. Both lake and glacier are correlated with the Woolridge Gravels and hence with the Penultimate Glaciation.
The Development of the Mid-Zambezi Valley in Northern Rhodesia since Early Karroo Times
Authors: Tavener-Smith R. 
Published: May 2009

AbstractKarroo sedimentation in the mid-Zambezi area presents an instance of deposition in an intra-cratonic basin during a complete climatic semi-cycle. Mention is made of the tectonic factors which controlled the course of Karroo sedimentation in the area, and the nature of the pre-Karroo surface is commented upon. An account is given of the depositional history of the mid-Zambezi basin during the Karroo period. The structural development of the region since Karroo times is outlined, and it is suggested that the present valley is essentially a downwarped and eroded part of the peneplain which still forms the adjacent plateau to the north-west.
The Pre-Tertiary Geology of the Western Approaches to the English Channel
Authors: Day A. A. 
Published: May 2009

AbstractGeological information obtained by core sampling of the solid rock underlying the loose deposits on the floor of the Western Approaches is set forth. Discoveries of interest include those of Chalk in the area north-west of Cornwall and of nepheline phono-lite from Epson Shoal, 6 miles east of the Wolf Rock. Other samples obtained very probably represent the Devonian, New Red Sandstone and Chalk, and on the basis of the identifications a geological map has been prepared showing the approximate distribution of these formations in the area.
The Compositions of Coexisting Pyroxenes in Metamorphic Assemblages
Authors: Muir I. D. , Tilley C. E. , Scoon J. H. 
Published: May 2009

AbstractChemical and optical data are provided on pyroxene pairs in a range of metamorphic assemblages. Tie line trends in the system CaSiO3–MgSiO3–FeSiO3 for these assemblages are compared with those recorded for plutonic igneous associations.
Palaeontological Evidence for the Age of the Carboniferous and Permian Rocks of Central Vestspitsbergen
Authors: Forbes C. L. , Harland W. B. , Hughes N. F. 
Published: May 2009

AbstractCarboniferous and Permian fossils collected from Central Vestspitsbergen between 1938 and 1957 are listed according to formations and the age of each is assessed from these determinations. Resting unconformably on folded Devonian or metamorphosed Hecla Hoek the succession begins with plant-bearing continental facies and passes upwards into a marine succession with fusuline, coral and brachiopod faunas in limestones and dolomites associated with evaporites and cherts. Correlation with rocks elsewhere in Svalbard, which has been effected largely by lithological facies, is reassessed on palaeontological evidence; this consists of a sequence of plants from approximately Tournaisian to Namurian; of fusulines from theFusulinaZone to thePseudoschwagerinaZone, with the Carboniferous-Permian boundary falling in the middle of the Wordiekammen Limestones; and of brachiopods above this. The youngest fossils may be Upper Permian. The succession has few breaks and with further study will contribute to the correlation of Russian, West European, Greenland, and American rocks.
The Tectonic Pattern of the Lewisian around Clashnessie Bay near Stoer, Sutherland
Authors: King Basil C. 
Published: May 2009

AbstractIn the Clashnessie district the original or Scourian complex is represented chiefly by hornblendic gneisses and shows simultaneous close folding on 55°–235° (A 1) and 155° (A 2) axes. The general disposition of the formations is largely related to open folding on the A 1 axis.The effects of later movements, post-dating the basic dykes, are comparatively slight, but are shown by the sporadic development of a schistosity and a lineation, which plunges to the south-east, together with occasional sharp folds at about 207° (A 3) and 114° (A 4).
Cameral Deposits in Orthoconic Nautiloids
Authors: Flower Rousseau H. 
Published: May 2009

AbstractPrevious investigations of the cameral deposits of nautiloids are reviewed, with a discussion of their morphology, their distribution in shells, and growth relationships with other shell parts. Cameral deposits are developed commonly in the orders Actinoceratida, Michelinoceratida, Discosorida, and Oncoceratida. While the patterns and growth relationships of cameral and siphonal deposits are specific, and therefore of great potential taxqnomic value, the presence of such structures alone is not a valid basis for the recognition of species or genera.
Flow Phenomena in a Limestone on Changalumi Hill, Southern Nyasaland
Authors: Garson M. S. 
Published: May 2009

AbstractA Basement Complex graphite-limestone on Changalumi Hill, along the eastern escarpment of the Southern Nyasaland rift-valley, exhibits various phenomena including contorted exotic boulders, migration of graphite, and injection of discordant veins into adjacent gneiss. These features indicate that the limestone has burst through its anticlinal roof during strong isoclinal folding at a relatively low temperature, engulfing and distorting a minor synclinal infold. The age of the break-through is proved to be pre-Chilwa Series and pre-Rifting.