bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating the probability of river channel adjustment
Authors: Downs Peter W. 
Published: February 2007

AbstractRiver channels respond not only to natural external controls, and natural controls internal to individual drainage basins, but also to the influence of human activity. Although many site‐specific instances of change have been documented, the complexity of the process interactions means that very little is known about the general nature of different styles of adjustment, or their relative sensitivity to drainage basin controls. Data obtained from the Thames Basin, southeast England, are used in a probabilistic approach to differentiate between four styles of river channel adjustment and a variety of drainage basin characteristics. Adopting a probabilistic approach quantifies the degree of confidence attributable to any prediction of river channel adjustment while acknowledging that certainties are difficult to obtain in studies of the natural environment. This approach could thus allow environmental planning decisions to be made with a quantified degree of uncertainty.Four multivariate logistic regression models are described which use a combination of continuous and categorical variables to associate drainage basin characteristics with four styles of river channel adjustment derived from a reconnaissance evaluation survey. In comparison, it is shown that laterally migrating river channels are the most common ‘natural’ channel type in the Thames Basin, and their probability of occurrence rises to 71 per cent in sand/gravel environments. In channels regulated by low weirs, deposition is the most likely channel activity where gradients are lower than 0·0040, whilst above this threshold the majority of channels are morphologically inactive. In urban channels, many of which are also lined by concrete, the likelihood of obtaining a stable channel is mostly in excess of 80 per cent. In channels straightened during this century, deposition is most likely in gradients below 0·0050, whereas erosional enlargement is most probable above this value. In channels which were initially channelized prior to this century, deposition gives way to stability at a threshold gradient of 0·0080.
The holocenic evolution of a stretch of an eastern italian alpine valley
Authors: Friz Corrado , Villi Vigilio , Turrini Maria Chiara 
Published: February 2007

AbstractThe morphological evolution of a stretch of an alpine valley located in the Eastern Italian Alps is described. This has been conditioned by a great alluvial fan that was formed as a consequence of interconnected events, deriving from large rockfalls which occurred in the late glacial period at the head of the Missiaga–Bordina valley, on the left side of the Agordo basin. The aggradation of the alluvial fan blocked the Cordevole valley south of the Agordo basin and produced a lake that is documented by lacustrine sediments. Age determination by 14C techniques on wood remnants found in these sediments fixes the life of the lake at between approximately 5880 and 5300 years BP. This represents, indirectly, the age of the main phase of the development of the fan. After the building up of the alluvial fan, an erosional phase began, leading to the formation of the present landscape. A series of illustrations depicts the sequence of the fan's development.
Comprehensive linkage and linkage heterogeneity analysis of 4344 sibling pairs affected with hypertension from the Family Blood Pressure Program
Authors: Greenwood Tiffany A. , Libiger Ondrej , Kardia Sharon , Hanis Craig , Morrison Alanna C. , Gu C. Charles , Rice Treva , Miller Michael , Turner Stephen T. , Myers Richard H. , Grove John , Hsiao Chin‐Fu , Weder Alan B. , Schork Nicholas J. 
Published: February 2007

AbstractLinkage analyses of complex, multifactorial traits and diseases, such as essential hypertension, have been difficult to interpret and reconcile. Many published studies provide evidence suggesting that different genes and genomic regions influence hypertension, but knowing which of these studies reflect true positive results is challenging. The reasons for this include the diversity of analytical methods used across these studies, the different samples and sample sizes in each study, and the complicated biological underpinnings of hypertension. We have undertaken a comprehensive linkage analysis of 371 autosomal microsatellite markers genotyped on 4,334 sibling pairs affected with hypertension from five ethnic groups sampled from 13 different field centers associated with the Family Blood Pressure Program (FBPP). We used a single analytical technique known to be robust to interpretive problems associated with a lack of completely informative markers to assess evidence for linkage to hypertension both within and across the ethnic groups and field centers. We find evidence for linkage to a number of genomic regions, with the most compelling evidence from analyses that combine data across field center and ethnic groups (e.g., chromosomes 2 and 9). We also pursued linkage analyses that accommodate locus heterogeneity, which is known to plague the identification of disease susceptibility loci in linkage studies of complex diseases. We find evidence for linkage heterogeneity on chromosomes 2 and 17. Ultimately our results suggest that evidence for linkage heterogeneity can only be detected with large sample sizes, such as the FBPP, which is consistent with theoretical sample size calculations. Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
Presidential address to the liverpool geological society. The glacial geomorphology of the south‐eastern part of the lake district
Authors: Gresswell R. Kay 
Published: February 2007

AbstractThe south‐eastern part of the Lake District was glaciated almost entirely by local ice. The valleys show many typical features: cirques, cirque tarns, valley‐heads, U‐shaped troughs with over‐steepened sides, and change of slope above the maximum glacier‐ice level, hanging valleys, valley‐steps, rock barriers, paternoster lakes, rock‐basins, ice spillways, and a large variety of moraines, drumlins and roches moutonnés. The glaciers from Grasmere and Langdale converged on Windermere and there produced the northern rock‐basin. Ice spillways into the Kent and Winster valleys resulted in the shallow central part of the present lake. The addition of ice from the Esthwaite glacier produced the southern rock‐basin. The glacier moved southwards by Cartmel, but the present fluvial drainage follows Backbarrow Gorge to the Greenodd estuary.
Notes on the genera Prolecanites and Epicanites with descriptions of two new species
Authors: Moore E. W. J. 
Published: February 2007

AbstractThe type species of the genus Prolecanites is discussed. The generic name Paraprolecanites Karpinsky 1889 is invalid, being founded on a hypothetical suture line. Forms showing this type of suture line have since been found and the genus Epicanites was erected by Schindewolf 1926 to include such forms. A possible development from Prolecanites to Epicanites is suggested.
The lower carboniferous rocks of ireland
Authors: Turner J. Selwyn 
Published: February 2007

AbstractFollowing introductory notes on the historical aspect of the subject, this review of Irish Carboniferous Limestone and associated beds discusses the distribution of the principal lithological types in Ireland. The zonal stratigraphy is then reviewed throughout the island, opportunity being taken to incorporate certain unpublished results of recent work. Then follows a résumé of the history of the period from the palaeogeographical point of view. Detailed bibliographies (a) by counties, (b) of more general papers, are prefixed to the paper.
Composite minor intrusions, and the slieve gullion complex, ireland
Authors: Bailey E. B. , McCallien W. J. 
Published: February 2007

AbstractThe paper consists of two parts, both furnishing evidence that partially consolidated basalt can chill against penetrating acid veins. This recalls work by R. E. Wilcox on a mixed lava at Gardiner River, 1944. Part I is mainly concerned with certain composite intrusions where basic margins carry quartz xenocrysts and acid interiors carry quartz phenocrysts. It is argued that basalt magma rose from a deep source through quartz‐porphyry rock, melting and incorporating contacts. Presently the quartz‐porphyry melted bodily, and, no longer penetrable, followed its basaltic forerunner into the upper world. Being cooler than the basalt, it often appreciably chilled what it did not drive forward. Part II introduces some new features into the structural interpretation of the North‐West Belt of intrusions at Slieve Gullion, and claims that these intrusions and also the ring‐dyke of earlier date have been accompanied by marked distortion of country‐rock. The granophyre of the North‐West Belt seems to be essentially earlier than the associated dolerites. These latter melt the granophyre at contact and chill against rheomorphic veins. Much of D. L. Reynolds' work from 1937 onwards is accepted, including extensive remaking of Newry Devonian granodiorite under Tertiary conditions; but certain hypotheses of surface volcanitity and deep‐seated metamorphism are criticised.
New record of the gastrioceras listeri marine band in flintshire
Authors: Shanklin J. K. 
Published: February 2007

AbstractRecent brings by the National Coal Board/Opencast Executive in the Mostyn Area have shown the presence of the Grrctrioceras listen' Marine Band some 90 feet above the Garrrioceru subcrenatm Marine Band. Faunal assemblages from these horizons are here lisred and a sketch map (Fig. 1) of the area is presented.The sigdicance of the record is noted and an earlier record of G. lisrm' near Connah's Quay referred to.
Mobilisation of Granophyre in Eire and sinking of Olivine in Greenland
Authors: Bailey E. B. 
Published: February 2007

AbstractI. Two quarries show Tertiary dolerites of the Carlingford Complex traversed by granophyric veins against which the dolerites chill. The veins have almost certainly resulted from remelting.II. A picritic sill in Ubekendt Ejland, West Greenland, can be harmoniously interpreted as owing much of its character to pre‐intrusion sinking of olivine in an underlying supply‐reservoir. It also shows repeated evidence of marginal magmatic erosion during intrusion, and this has affected its post‐intrusion cooling.
The Nantglyn Flags; Mid‐Salopian basin facies in Wales
Authors: Cummins W. A. 
Published: February 2007

AbstractThe Nantglyn Flags consist of very thinly interbedded mudstones and laminated muddy siltstones with less frequent thin beds of calcareous siltstone. The lithology, sedimentary structures and fauna of these three rock types are described and discussed. It is concluded that the calcareous siltstones bed were deposited by turbidity currents.
New work on petrofabrics
Authors: Voll G. 
Published: February 2007

AbstractRecent work on petrofabrics, particularly work written in German, is reviewed in the light of the author's own experience. Topics discussed include quantitative comparison of fabric diagrams, the thermodynamics of crystal growth under stress, interpretation of grain boundaries, comparison of fabrics of metal and silicate crystal aggregates, recrystallisation fabrics, quantitative evaluation of rock deformation using parameters of ooliths, fossils and folds, and structural sequence in orogenic zones.
A Ludlovian facies boundary in south Central Wales
Authors: Bailey R. J. 
Published: February 2007

AbstractOver much of its outcrop in south Central Wales, the earliest facies of the Ludlovian, comprising grey shaly mudstones, is overlain by an important turbidite facies. In the present paper these two facies are described and the boundary between them is fixed at the first appearance in the succession of numerous thick turbidite beds. While its horizon cannot be precisely defined with reference to the faunal sequence, there are grounds for believing that this boundary is not significantly diachronous in the area considered. Finally, some suggestions are made as to the possible significance of the facies boundary.
Natural liquids and the phonolitic minimum
Authors: Carmichael I. S. E. 
Published: February 2007

AbstractThe composition of the feldspar phenocrysts, and the enclosing glassy or finely crystalline ground‐masses, of three phonolites suggests that the addition of calcium or the addition of excess sodium (molecular ratio Na2O + Ka2O > Al2O3) to compositions in the feldspar field of the system NaAlSiO4‐KAlSiO4‐SiO2 will change the composition of the minimum on the nepheline‐feldspar boundary when this is projected into this system.
Late Caledonian dyke‐swarms in Southern Scotland: New field, petrological and geochemical data for the Wigtown Peninsula, Galloway
Authors: Barnes R. P. , Rock N. M. S. , Gaskarth J. W. 
Published: February 2007

AbstractSeveral hundred, dominantly NE‐trending dykes invade Silurian flysch sediments of the Wigtown Peninsula. The most basic dykes are K‐rich biotite‐lamprophyres, hornblende‐lamprophyres and appinites ('diorites' of previous maps). More acidic (qz and cm normative) dykes include restricted andesitic compositions ('porphyritcs', c. 57 per cent SiO2) and a continuum from dacitic to rhyolitic compositions ('acid porphyrites' and 'porphyries', c. 63–71 per cent SiO2). The relative abundance of basic to intermediate + acidic dykes, based on examination of 180 thin sections and 70 new whole‐rock analyses, is approximately 7:1. The biotite‐ and hornblende‐lamprophyres are distinct in chemistry and distribution, biotite‐lamprophyres being confined to the south of the Peninsula. Neither type has any compositional equivalent among the plutonic rocks of the area. Porphyrite and porphyry dykes do not represent simple lamprophyre fractionates, but may be derived from at least two (intermediate and acidic) parent magmas, which may represent crustally‐contaminated lamprophyre or entirely separate crustal melts. Emplacement of all dyke compositions was apparently episodic through Wenlock to early Devonian times (c. 425‐395 Ma). Early dykes post‐date the main deformation (D1) but predate minor (D2) folding, both D1 and D2 being related to thrusting. On the current accretionary model for the Southern Uplands, this implies that dyke emplacement commenced before the end of accretion in a compressional tectonic regime—scarcely consistent with the moderate (up to 6 per cent) crustal extension represented by the dykes. The geochemistry of the lamprophyres requires a deep mantle origin several hundred kilometres behind any subduction zone. This suggests that the 'lapetus suture', at the time of dyke emplacement, was much farther south than its currently inferred position and places the Southern Uplands in a back‐arc situation.
Dinantian sedimentation and the basement structure of the Derbyshire Dome
Authors: Gutteridge Peter 
Published: February 2007

AbstractThe depositional history of the Dinantian on the Derbyshire Dome can be divided into three phases: (1) pre‐Holkerian: onlap of an irregular basement surface by evaporite and carbonate sediments, (2) Holkerian to Asbian: sedimentation on a carbonate shelf formed by the merging of early Dinantian depocentres following burial of the basement topography, and (3) Brigantian: formation of intrashelf basins and the development of a carbonate ramp on part of the pre‐existing shelf.A model of the basement structure underlying the Derbyshire Dome is presented to explain the location of the Brigantian intrashelf basins and carbonate ramp. The basement consists of two main tilted fault blocks separated by a smaller tilt block. Movement on faults bounding the tilt blocks caused the development of intrashelf basins. The basin margins were controlled by structures which developed in the cover sediments. The carbonate ramp present during the late Brigantian developed in response to an eastward tilting of the basement.
The stratigraphy and structure of the Galley Head culmination zone: An area of enhanced shortening related to basin geometry within the Irish Variscides
Authors: Ford Mary 
Published: February 2007

AbstractIn southwest Ireland an Upper Devonian to Lower Carboniferous clastic succession was deposited in an ENE–WSW trending half‐graben, known as the South Munster Basin. Across the Galley Head peninsula on the south coast, this stratigraphical succession is attenuated due to the presence of a palaeogeographical feature called the Glandore High. Evidence suggests that the Glandore High was an east–west feature, faulted to the north and east, which was part of the southern flank (hangingwall rollover) of the South Munster Basin.During post‐Carboniferous Variscan deformation the relatively thin stratigraphy of Galley Head underwent prolonged folding, causing a local periclinal fold pair to develop within the hinge zone of a regional syncline. The main cleavage then developed parallel to bedding on the overturned south limb of the anticline of this fold pair. The local enhanced shortening caused the development of a structural culmination, and south facing, tight to isoclinal folds. The culmination was enhanced and tightened by a fault system of contractional, strike‐parallel faults linked by cross faults. Secondary folds occur across the hinges of regional anticlines and also on major fold limbs as isolated fold pairs and in monoclinal fold zones, some of which may have nucleated on irregular sandstone bodies. Local crenulation cleavages are related to late fault movements. Syn‐cleavage, conjugate, wrench faults record 10 per cent to 15 per cent strike‐parallel extension in the culmination.The deformation chronology of the Galley Head area is somewhat anomalous for the Irish Variscides in that the folds were well established before the onset of the main cleavage development. The enhanced shortening across the area was compartmentalized by major cross faults and a minor component of north–south sinistral shear was also active across the area causing a swing in strike and a late set of minor cross faults.Structural facing directions in southwest Ireland appear to be directly linked with the geometry of the deformed basins. Hence the southward facing along the south coast is due to the proximity of the southern margin of the South Munster Basin. Structural facing directions fan northwards across the basin and major folds are overturned to the north at the northern margin of the basin.
Cleaved microgranite dykes of the Shap swarm in the Silurian of NW England
Authors: Soper N. J. , Kneller B. C. 
Published: February 2007

AbstractFelsite‐microgranite dykes, chemically comparable with the Shap swarm and associated with the Shap intrusion, are present in Silurian sediments of the southern Lake District. They were emplaced after the country rocks had undergone Acadian (late Caledonian) folding and cleavage‐formation but are themselves weakly cleaved. This confirms a ‘flattened buckle’ model for the Acadian deformation in NW England, which in turn establishes the link between sinistral transpression in this region and the clockwise transection of the folds by cleavage. The evidence also shows that the Acadian cleavage developed episodically, and that the Shap‐Skiddaw magmatism occurred during one or more stress‐relief episodes. The emplacement age of these intrusions thus constrains the age of the Acadian orogeny in NW England which was late in the Lower Devonian (according to currently available isotopic evidence), significantly later than the Silurian deformation of the Southern Uplands.
Per migma ad magma downunder
Authors: White Allan J. R. , Chappell Bruce W. 
Published: February 2007

AbstractAccording to some early definitions, ‘magma’ had to be completely molten so that granitic rocks containing residual material from their source (restite) were not considered to be magmatic. Granites and volcanics with abundant recognizable restite were called migmatites or migmatitic rocks, and this terminology appears to be still in use by some. However, many felsic granites and volcanics commonly contain at least some restite, and for this reason we suggest that magma be defined either as melt or as rock material with enough melt for it to become mobile and intrusive or extrusive. The rocks crystallizing from these magmas are igneous. They are not migmatites. On the other hand, we suggest that migmatites be defined as rocks that did not have sufficient melt to become mobile; they retain a structural coherency even though the structures may be complex. Differences between the two rock types result from the amount of melt phase. When a critical melt fraction is reached during partial melting, there is a rapid change from migma to magma (migmatite to granite).The geochemistry and mineralogy of migmatites tell us little about reactions that produce more melt and hence about granite formation because of back reactions and other processes that occur during the cooling of migmatite. Back reactions mostly involve H2O that is not lost from the migmatitic system. Because H2O is lost by processes of second boiling and pressure quenching during the crystallization of granite magmas at or near the surface, it is these rocks and their inclusions, not migmatites, that provide the most information about sources and processes of granite formation.
Use and misuse of geophysical data to determine the shape at depth of granitic intrusions
Authors: Vigneresse Jean Louis 
Published: February 2007

AbstractGeological data are seldom reliable enough to quantify the shape of granitic bodies at depth. Remote sensing measurements and geophysical methods may allow hidden features inside plutons to be recognized. Seismic methods can be employed to display the interface between the granite and its sedimentary cover. Unfortunately, impedance contrasts are very low inside the intrusive body resulting in a transparency to seismic waves. In addition, the high cost of seismic lines with sufficient resolution excludes full 3D shaping. The use of magnetic methods is limited by the low content of magnetic minerals in acidic rocks and the observed magnetic field is often flat over plutons. Some high amplitude magnetic anomalies are restricted to the contact metamorphic aureoles surrounding granites. Acidic rocks generally have a lower density than the surrounding country rocks. A negative gravity signature is therefore associated with the intrusion. To assist with geological interpretation, a detailed gravity survey should be made over the pluton with a coverage density of about 1 measurement per km2. This is necessary to register the effects of facies variations. Interpretation should be restricted to 3D methods rather than 2D modelling on profiles because granitic bodies are not uniform along any one direction. However, 3D inversion of data must take into account the regional gravity field and variations of density in and outside the pluton. With these assumptions, models are presented which can be correlated with the structures acquired during the magmatic stage of pluton emplacement. The zones where magmatic foliations are vertical correlate with deep zones identified from gravity data. They are interpreted as magma feeding zones. The information provided by these methods represents a valuable contribution to determining the mode of emplacement of granitic intrusions.