bluuebunny/crossref_metadata_2025_split huggingface dataset:
The rapakivi texture of feldspars in a plutonic mixing environment: A dissolution‐recrystallization process?
Authors: Bussy François 
Published: February 2007

AbstractA new hypothesis is formulated to explain the development of rapakivi texture in and around the mafic enclaves of porphyritic granitoids, i.e. in environments involving magma mixing and mingling. The formation of a plagioclase mantle around alkali feldspar megacrysts is attributed to the localized presence of a melt resulting from the reaction of these megacrysts, with host hybrid magma with which they are in disequilibrium. This feldspathic melt adheres to the resorbed crystals and is virtually immiscible with the surrounding magma. Its composition is modified in terms of the relative proportions of K2O, Na2O, and CaO through selective diffusion of these elements, thus allowing the specific crystallization of andesine. With decreasing temperature, the K‐feldspar, again stable, crystallizes along with the plagioclase, leading to mixed mantle structures.
Layering in felsic granites in the main East pluton, Hinchinbrook Island, North Queensland, Australia
Authors: Stephenson P. J. 
Published: February 2007

AbstractHinchinbrook is an island 36km long and is composed of late Palaeozoic igneous rocks. The main East pluton is 16km long and intrudes volcanics, granodiorites, and granites, and cuts a felsic ring dyke related to it. The rocks forming the pluton are varied, strongly‐fractioned hypersolvus granites, some of which contain late‐crystallized arfved‐sonite.The mountains show quasi‐horizontal jointing and layering at many localities. Some details indicating downwarddirected solidification are evident. These are varied but commonly involve comb‐quartz layers or plumose quartzfeldspar intergrowths. Variations in the textures can be ascribed to varied undercooling whereas comb quartz layers grew from a separate aqueous fluid.Directional layering is sporadically developed over the full section from sea level to the peaks above. It is concluded that the exposures represent a thick roof facies. However, the roof contact is not preserved.
A diverse ichnofauna from silurian flysch of the aberystwyth grits formation, Wales
Authors: Crimes T. P. , Crossley J. D. 
Published: February 2007

AbstractThe most extensive ichnofauna yet recorded from a deep water Lower Palaeozoic sequence occurs within the distal turbidites of the Lower Silurian Aberystwyth Grits Formation of Central Wales.The strata contain an abundant assemblage comprising 25 ichnogenera: Asteriacites, Bergaueria, Chondrites, Cochlichnus, Cosmorhaphe, Glockerichnus, Gordia, Helicolithus, Helminthopsis, Helminthoida, Hormosiroidea, Lorenzinia, Megagrapton, Monomorphichnus, Neonereites, Nereites, Palaeophycus, Paleodictyon, Planolites, Protopaleodictyon, Spirorhaphe, Spirophycus, Squamodictyon, Subphyllochorda, Taphrhelminthopsis; 36 ichnospecies are described, three of which (Asteriacites aberensis, Helminthopsis regularis, Cosmorhaphe elongata) are new.The inorganic sedimentary structures and trace fossils of some 418 sandstone beds were examined in detail; 16 per cent of the beds commence with Divisions A or B and 84 per cent with Division C of the turbidite sequence. This indicates a relatively distal environment, mainly receiving low velocity turbidity currents, and favouring trace fossil preservation. The most common traces were Helminthopsis, Paleodictyon, and Squamodictyon which were found on 46 per cent, 34 per cent, and 19 per cent of the beds examined.Data from this, and other recently described sequences, confirms that there was a gradual increase in trace fossil diversity in the deep oceans throughout the Lower Palaeozoic, in contrast to the situation in shallow water shelf seas where a peak was reached as early as the Lower Cambrian.
The genesis of the west shropshire orefield: Evidence from fluid inclusions, sphalerite chemistry, and sulphur isotopic ratios
Authors: Pattrick R. A. D. , Bowell R. J. 
Published: February 2007

AbstractThe Pb + Zn + Ba veins of West Shropshire, England, occupy fractures in Ordovician and Precambrian rocks of the Shelve Inlier. Precipitation of sphaleritic ores was succeeded by galena + baryte mineralization, with chalcopyrite also occurring late in the mineralizing episode. Three generations of sphalerite are recognized, and second being chemically zoned with distinct Fe + Cd‐rich growth zones. Associated with these iron‐rich bands are smaller (∼ 10 μm) zones rich in indium (>1.0 wt%) and copper, electron electron probe microanalyses suggesting coupled substitution of Cu+ + In+3 in the ZnS. Based on the sequence of growth zones and their chemistry a sphalerite stratigraphy can be recognized within the orefield.Fluid inclusions studies reveal the mineralizing fluids to be highly saline (18–30 wt% CaCl2 equivalent) Na + Ca‐richbrines, with mineralizing temperatures in the range 200–120°C. A trend from higher temperature‐low salinity to low temperature‐high salinity fluids with time is recognized. Sulphide sulphur isotopic ratios are consistent and suggest a ΔS34SH2S of the mineralizing fluid of 10%, while 34Sbaryte values are in the range + 14 to + 19%, indicating separate sulphate and sulphide sulphur sources. The mineralogical, fluid inclusion, and isotopic data suggest the saline fluids rose into an open plumbing system where mineral precipitation was mainly controlled by fluid cooling. The baryte however, formed due to mixing with oan overlying sulphate‐bearing reservioir.Theree possible fluid sources are considered, namely: Lower Carboniferous seawater, basinal brines, and metamorphic fluids. However, the information available does not allow the source to be positively identified.
Zoning and layering in diorites of the scottish caledonian appinite suite
Authors: Platten Ian M. 
Published: February 2007

AbstractDioritic plugs (< 1 km across) are common associates of the late Caledonian, post‐tectonic granites of the Scottish Highlands. These contain a very wide range of rock types from ultramafic through mesocratic diorites to anorthositic and granitic. These rocks form steeply dipping, wall‐parallel layers and zones within the plugs. Outer layers are shown to form first, inner layers later. Mafic zones are composed of the minerals seen as phenocrysts in chilled margins and have the chemical characteristics of cumulates. The inner margins of the mafic zones reflect the onset of plagioclase crystallization. Core zones also show inward variations in mineralogy and texture which define vertical, wall‐parallel cylinders. These variations are ascribed to fractional crystallization accompanying accretion of rock onto the pipe walls. Cores in different intrusions may be mafic, mesocratic, or leucocratic, which indicates vertical zonation in the bodies. The mafic cores additionally show that recharge with less evolved magma occurred in some cases. The few larger (> 1 km diameter) intrusions show examples of layering and lamination dipping at low to moderate angles. These indicate the beginning of a change from wall‐dominated to floor‐dominated crystallization as intrusion diameter increases. A comparison is made with the nature and origin of layering in other intrusions.
Lower Carboniferous (Dinantian) stratigraphy and structure of the Walterstown‐Kentstown area, Co. Meath, Ireland
Authors: Pickard Neil A. H. , Jones Gareth Li. , Rees John G. , Somerville Ian D. , Strogen Peter 
Published: February 2007

AbstractStratigraphic units are defined and described for the Lower Carboniferous succession in the Walterstown‐Kentstown area of Co. Meath, Ireland. A complete (unexposed) Courceyan succession from the terrestrial red bed facies of the Baronstown Formation to the Moathill Formation of the Navan Group has been penetrated in several boreholes. Although the lower part of the sequence is comparable with the Courceyan succession at Navan and Slane, the middle part of the sequence differs markedly in the Walterstown‐Kentstown area and two new members, the Proudstown and Walterstown Members, are defined in the upper part of the Meath Formation.Syndepositional faulting was initiated during the Courceyan, probably in latest Pseudopolygnathus multistriatus or early Polygnathus mehli latus time. Movement on the ENE trending St. Patrick's Well Fault influenced the deposition of the Walterstown Member and the overlying Moathill Formation and was probably associated with the development of the East Midlands depocentre to the south of the area. A second episode of tectonism in the latest Courceyan or early Chadian resulted in uplift and erosion and the development of ‘block and basin’ sedimentation.Subsequent transgression of the uplifted block led to the establishment of the Kentstown Platform, bounded to the north, west and south by rocks of basinal facies. The Milverton Group (Chadian‐Asbian), confined to this platform, unconformably overlies Courceyan or Lower Palaeozoic strata and is subdivided into three formations: Crufty Formation (late Chadian), Holmpatrick Formation (late Chadian‐Arundian) and Mullaghfin Formation (late Arundian‐Asbian). The Walterstown Fault controlled the western margin of the Kentstown Platform at this time. Contemporaneous basinal sediments of the Fingal Group (Lucan and Naul Formations) accumulated to the west of the Walterstown Fault and are much thicker than age‐equivalent platform facies.Platform sedimentation ceased in latest Asbian to early Brigantian time with tectonically induced collapse and drowning of the platform; platform carbonates of the Mullaghfin Formation are onlapped northwards by coarse proximal basinal facies of the Loughshinny Formation.A distinct gravity anomaly in the Kentstown area suggests the presence of a granitoid body within the basement. The Kentstown Platform is therefore considered to have formed on a buoyant, granite‐cored, footwall high analogous to the Askrigg and Alston Blocks of northern England.
Petrology and petrogenesis of a tertiary bimodal dolerite‐peralkaline/subalkaline trachyte/rhyolite dyke association from Lundy, Bristol Channel, UK
Authors: Thorpe R. S. , Tindle A. G. 
Published: February 2007

AbstractThe island of Lundy forms the southernmost igneous complex of the British Tertiary Volcanic Province (BTVP) and consists of granite (≈ 90%) emplaced into deformed Devonian sedimentary rocks (Pilton Shale) and associated with a swarm of dykes of dolerite/basalt, minor trachyte and rhyolite composition. The dolerites are of varied olivine basalt composition and are associated with peralkaline trachyte and subalkaline/peralkaline rhyolite with alkali feldspar and quartz ± alkali amphibole ± pyroxene mineralogy. The dyke swarm is therefore an anorogenic bimodal dolerite/basalt–trachyte/rhyolite BTVP association. Although the dyke association is bimodal in major element terms between dolerite/basalt and minor trachyte/rhyolite, the mineralogy and trace element geochemistry indicate that the dykes may be regarded as a cogenetic dolerite—peralkaline trachyte/rhyolite association with minor subalkaline rhyolites. Sr and Nd isotope data indicate derivation of these magmas from a similar BTVP mantle source (with or without minor contamination by Pilton Shale, or possibly Lundy granite).The petrogenesis of the Lundy dyke association is therefore interpreted in terms of extensive fractional crystallization of basaltic magma in a magma chamber of complex geometry below the (exposed) Lundy granite. Fractional crystallization of a representative dolerite magma (olivine ± clinopyroxene ± plagioclase) yields trachyte magma from which the crystallization of alkali feldspar (anorthoclase) ± plagioclase (oligoclase) + Fe–Ti oxide + apatite results in peralkaline rhyolite. Rarer subalkaline rhyolites result from fractionation from a similar dolerite source which did not achieve a peralkaline composition so allowing the crystallization and fractionation of zircon. The basalt–(minor trachyte)/rhyolite bimodality reflects rapid crystallization of basalt magma to trachyte (and rhyolite) over a relatively small temperature interval (mass fraction of melt, F = ≈ 0.15). The rapid high level emplacement of basalt, trachyte and rhyolite dyke magmas is likely to have been associated with the development of a substantial composite bimodal basalt–(minor trachytel)/rhyolite volcano above the BTVP Lundy granite in the Bristol Channel.
40Ar/39 Ar geochronological constraints on timing of deformation and metamorphism of the Central Norrbotten Caledonides, Sweden
Authors: Page Laurence M. 
Published: February 2007

Abstract40Ar/39Ar geothermochronology is especially useful within the Scandinavian Caledonides, which experienced deformation and metamorphism as a result of two major tectonothermal pulses during the Early and Middle Palaeozoic. This detailed 40Ar/39Ar geochronological study of the Central Norrbotten Caledonides allows examination of the timing of tectonothermal activity within the Lower Köli Nappe, the Seve–Köli shear zone, the Seve Nappe and the shear zone rocks of the Middle Allochthon. The results obtained from a suite of 19 samples from the study area can be incorporated with structural and metamorphic constraints to establish the geological history of the region. Results from this study include: (1) the high grade metamorphism and associated deformation of the Seve units was a Late Cambrian to Early Ordovician event (Finnmarkian) in which the rocks cooled below the respective closure temperatures for hornblende at ≈ 490 Ma and muscovite at ≈ 454 Ma; (2) assuming a simple linear cooling model a cooling rate of 3–6°C/Ma was obtained for the older tectonothermal event; (3) there is evidence for late stage Finnmarkian (450 Ma), relatively high grade shear zones separating different tectonostratigraphic elements within the Seve; (4) the Scandian phase of deformation and metamorphism partially reset some of the Seve hornblendes and most of the muscovites, which indicates that the rocks affected by the Finnmarkian event felt a second tectonothermal pulse of more than 350°C beginning at ≈ 430 Ma; and (5) during the Scandian event all of the far travelled allochthonous tectonic units were juxtaposed and the Middle Allochthon mylonites were formed as these nappes were emplaced above the Baltic Shield. The tectonic units of the Singis‐Nikkaluokta transect were assembled before regional cooling through the closure temperature of muscovite.
Arundian (Dinantian) carbonate mudbanks in north‐west Ireland
Authors: Kelly John G. , Somerville Ian D. 
Published: February 2007

AbstractArundian mudbank complexes at Pollower and Carrickbaun in north‐west Ireland are described in detail. The two bank complexes developed on different fault blocks controlled and separated by the Curlew Mountain Fault system which was active during the Dinantian. The two mudbank complexes are composed predominantly of lime mudstone and wackestone textures with abundant peloids and intraclasts. Stromatactoid cavity systems in the banks are extensive and have multiple generations of geopetal internal sediment and radiaxial and bladed cryptofibrous calcite cements. These mudbanks are comparable with earlier Courceyan‐Chadian deep water Waulsortian mudbanks which accumulated on carbonate ramps. Components in the Pollower bank most closely resemble those in subphotic Phase C Waulsortian banks, whereas the Carrickbaun mudbank, which possesses dasycladacean algae, intraclasts and micritized fragmented bioclasts, indicates a much shallower environment of in situ carbonate mud accumulation, comparable to the photic Phase D assemblages of Waulsortian banks. The difference in depositional setting is also reflected by their respective enclosing lithologies. The Pollower bank is surrounded by deep water black argillaceous wackestones and shales, whereas at Carrickbaun shallower water crinoidal packstones and grainstones are developed on the flanks and bank top. The Arundian mudbank complexes have many similarities with the Asbian mudbanks of north‐west Ireland and as such appear to represent an important ‘stratigraphic’ link in the continuum of deep water mudbanks between the two main periods of development in the early Dinantian (Waulsortian) and late Dinantian (Asbian/Brigantian).
Discussion of ‘A late Ordovician/early Silurian non‐depositional slope and perched basin along the Tywi Anticline, Mid Wales’ by D. M. D. James
Authors: Waters R. A. , Davies J. R. , Fletcher C. J. N. , Wilson D. 
Published: February 2007

AbstractIn Volume 26, 7‐26 of the Journal, Dr D. M. D. James described the stratigraphy, sedimentology and structure of the late Ordovician to earliest Silurian succession in the core of the Tywi Anticline between the Sugar Loaf and the Wye Valley. He has used these new data to consolidate his previous model of a non‐depositional slope, established by Ashgill progradation of the shelf margin, separating basinal from shelf facies during the latest Ashgill and early Silurian (James 1983).Over the past four years, we have mapped the northern region of the Tywi Anticline, north‐east of the Chwefru Valley, as part of the survey of the 1:50000 Sheet 179 (Rhayader) (British Geological Survey (a) in press). Our results (Barron et al. 1989; Davies et al. 1991; Smith et al. 1991; Waters et al. in press; Wilson et al. in press) lead us to question aspects of James's Ashgill stratigraphy and the viability of his non‐depositional slope model.
Garn Prŷs: A mid‐Silurian canyon, feeder to the Denbigh Grits of North Wales
Authors: Cave R. , Evans J. A. , Campbell S. D. G. 
Published: February 2007

AbstractA fining‐upward, siliciclastic sequence of Wenlock strata, coarsely rudaceous at the base, infilled a canyon, about 4.5 km wide and 1700 m deep, in older strata. The rudaceous deposits, at the flat base of the canyon, are composed mainly of rounded cobbles and boulders of acid volcanic rocks. These are interpreted as cohesionless debris‐flow deposits that were succeeded by northward‐directed high concentration turbidity currents. The infill is deduced to have been derived from a terrain of acid volcanic rocks to the south, similar in Nd isotope composition to the Llewelyn Volcanic Group of Snowdonia. It implies mid‐Silurian uplift and erosion of the Harlech Dome.
Evidence for neural accommodation to a writing system following learning
Authors: Liu Ying , Dunlap Susan , Fiez Julie , Perfetti Charles 
Published: February 2007

AbstractNative English speakers with no knowledge of Chinese were trained on 60 Chinese characters according to one of three mapping conditions: orthography to pronunciation and meaning (P + M), orthography to pronunciation (P), and orthography to meaning (M). Following the training, fMRI scans taken during passive viewing of Chinese characters showed activation in brain regions that partially overlap the regions found in studies of skilled Chinese readers, but typically not found in alphabetic readers. Areas include bilateral middle frontal (BA 9), right occipital (BA 18/19), and fusiform (BA 37) regions. The activation pattern of Chinese characters was similar across the three groups. However, peak location was different in the left middle frontal region between groups. Direct contrasts between the groups also revealed stronger activation of left middle frontal in the P + M group. The results suggest that learners acquired skill in reading Chinese characters using a brain network similar to that used by Chinese native speakers. The results are consistent with the system accommodation hypothesis: The brain's reading network accommodates to features of an acquired writing system. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Change in spontaneous analogical transfer in young children: a microgenetic study
Authors: Tunteler Erika , Resing Wilma C. M. 
Published: February 2007

AbstractThis study assessed the development of spontaneous analogical transfer from story problems to physical tasks by examining the effects of practice alone, without intervention or explicit prompting. Participants were 216 children aged 5–8 years. The microgenetic technique was incorporated with each age group by following them for six consecutive sessions of three trails each. The role of practice and age was investigated, not only on children's task behaviour, but also on their explanations of their actions. The results indicated that the ability to use analogy spontaneously improves over time with practice regardless of age, and that it develops over a protracted age range, with some children showing competence early, while others show poor performance at the age of 8 years. Furthermore, the study found development of analogical transfer to involve within‐participant variability, as children showed competence on some trials but not on others. Although not a focus of the study, the results revealed intra‐individual utilization deficiency in the domain of analogical transfer. It is concluded that there is strong evidence for gradual rather than step‐like change in the development of analogical transfer. Copyright © 2007 John Wiley & Sons, Ltd.
Multiple roles of the candidate oncogene ZNF217 in ovarian epithelial neoplastic progression
Authors: Li Peixiang , Maines‐Bandiera Sarah , Kuo Wen‐Lin , Guan Yinghui , Sun Yu , Hills Mark , Huang Guiqing , Collins Collin C. , Leung Peter C.K. , Gray Joe W. , Auersperg Nelly 
Published: February 2007

AbstractThe transcription factor ZNF217 is often amplified in ovarian cancer, but its role in neoplastic progression is unknown. We introduced ZNF217‐HA by adenoviral and retroviral infection into normal human ovarian surface epithelial cells (OSE), i.e., the source of ovarian cancer, and into SV40 Tag/tag expressing, p53/pRB‐deficient OSE with extended but finite life spans (IOSE). In OSE, ZNF217‐HA reduced cell–substratum adhesion and accelerated loss of senescent cells, but caused no obvious proneoplastic changes. In contrast, ZNF217‐HA transduction into IOSE yielded two permanent lines, I‐80RZ and I‐144RZ, which exhibited telomerase activity, stable telomere lengths, anchorage independence and reduced serum dependence, but were not tumorigenic in SCID mice. This immortalization required short‐term EGF treatment near the time of crisis. The permanent lines were EGF‐independent, but ZNF217‐dependent since siRNA to ZNF217 inhibited anchorage independence and arrested growth. Array CGH revealed genomic changes resembling those of ovarian carcinomas, such as amplicons at 3q and 20q, and deletions at 4q and 18, associated with underexpressed annexin A10, N‐cadherin, desmocollin 3 and PAI‐2, which have been reported as tumor suppressors. The lines overexpressed EEF1A2, SMARA3 and STAT1 and underexpressed other oncogenes, tumor suppressors and extracellular matrix/adhesion genes. The results implicate ZNF217 as an ovarian oncogene, which is detrimental to senescing normal OSE cells but contributes to neoplastic progression in OSE with inactivated p53/RB. The resemblance of the genomic changes in the ZNF217‐overexpressing lines to ovarian carcinomas provides a unique model to investigate interrelationships between these changes and ovarian neoplastic phenotypes. © 2007 Wiley‐Liss, Inc.