bluuebunny/crossref_metadata_2025 huggingface dataset:
GENERALIZED COOPER PAIRING IN SUPERCONDUCTORS
Authors: DE LLANO M. , ANNETT J. F.
Published: September 2007

We review Cooper pairing starting from its simplest, original 1956 version of two electrons interacting above the Fermi sea of an ideal Fermi gas (IFG). The two-electron interaction assumed extensively (if not exclusively), is the attractive two-parameter Cooper, and then BCS, model interactions. Hole Cooper pairs (CPs) and electron-hole CPs are then included along with the initial electron-CPs in terms of the single-fermion Green functions implied by the Bethe-Salpeter (BS) integral equation in the ladder approximation. A purely-imaginary CP energy "instability" is recovered that is well-documented in the literature at least since the late 1950's. A novel interpretation of this instability is that an unperturbed Hamiltonian different from the IFG one first used by Cooper suffices to obtain meaningful CPs. Instead of the IFG sea, a BCS-correlated Fermi "sea" used in the BS equation interpreted as the associated unperturbed Hamiltonian leads to real CP energies (with small imaginary terms implying damping). We survey how this has been achieved in 1D, 2D and 3D, and give a more detailed treatment in 2D. A vital distinction is that the original and generalized CPs are true bosons in contrast with BCS pairs that are not ordinary bosons but rather "hard-core bosons" as they do not obey strict Bose commutation rules. Another important common element of the original or generalized CPs (particularly in 2D where ordinary Bose-Einstein condensation (BEC) does not occur) is their linear dispersion relation in leading order in the total (or, center-of-mass) momentum power-series expansion of the CP energy. This theory encompasses, in principle, all empirically known superconductors including quasi-2D superconductors such as cuprates and the ET organic compounds, as well as quasi-1D ones such as the organometallic Bechgaard salts and nanotubes.
STABILIZATION OF INTERNAL SPACE IN NONCOMMUTATIVE MULTIDIMENSIONAL COSMOLOGY
Authors: KHOSRAVI N. , JALALZADEH S. , SEPANGI H. R.
Published: September 2007

We study the cosmological aspects of a noncommutative, multidimensional universe where the matter source is assumed to be a scalar field which does not commute with the internal scale factor. We show that such noncommutativity results in the internal dimensions being stabilized.
CONSTRAINTS ON THE MASSIVE SUPERNOVA PROGENITORS
Authors: ARBUTINA BOJAN
Published: September 2007

The generally-accepted scheme distinguishes two main classes of supernovae (SNe): Ia resulting from the old stellar population (deflagration of a white dwarf in close binary systems), and SNe of type II and Ib/c whose ancestors are young massive stars (died in a core-collapse explosion). Concerning the latter, there are suggestions that the SNe II are connected to early B stars, and SNe Ib/c to isolated O or Wolf–Rayet (W–R) stars. However, little or no effort was made to further separate SNe Ib from Ic. We have used assumed SN rates for different SN types in spiral galaxies in an attempt to perform this task. If the isolated progenitor hypothesis is correct, our analysis indicates that SNe Ib result from stars of main-sequence mass [Formula: see text], while the progenitors of SNe Ic are more massive stars with [Formula: see text]. Alternatively, if the majority of SNe Ib/c appear in close binary systems (CBs) then they would result from the same progenitor population as most of the SNe II, i.e. early B stars with initial masses of order [Formula: see text]. Future observations of SNe at high-redshift (z) and their rate will provide us with unique information on SN progenitors and the star-formation history of galaxies. At higher-z (deeper in the cosmic past), we expect to see the lack of type Ia events, i.e. the dominance of core-collapse SNe. Better understanding of the stripped-envelope SNe (Ib/c), and their potential use as distance indicators at high-z, would therefore be of great practical importance.
BBN CONSTRAINTS ON NEUTRINO OSCILLATIONS PARAMETERS RELAXED OR STRENGTHENED
Authors: KIRILOVA DANIELA
Published: September 2007

Big Bang Nucleosynthesis (BBN) with nonequilibrium νe ↔ νs oscillations, in the more general case of non-zero population of νs before oscillations δNs ≠ 0, is discussed. 4 He primordial production Yp(δNs) in the presence of νe ↔ νs oscillations for different initial populations of the sterile neutrino state 0 ≤ δ Ns ≤ 1 and the full range of oscillation parameters is calculated. Non-zero δNs has a two-fold effect on 4 He : (i) it enhances the energy density and hence increases the cosmic expansion rate, leading to Ypoverproduction, and (ii) it suppresses the kinetic effects of oscillations on BBN, namely, the effects on pre-BBN nucleon kinetics, caused by the νe energy spectrum distortion and the [Formula: see text] asymmetry generation by oscillations, leading to decreased Yp production. Depending on oscillation parameters one or the other effect may dominate, causing, correspondingly, either a relaxation of the cosmological constraints or their strengthening with the increase of δNs. More general BBN constraints on νe ↔ νs oscillation parameters, corresponding to 3% Yp overproduction, for different initial populations of the sterile state are calculated. Previous BBN constraints were derived assuming empty sterile state before oscillations. It is shown that the cosmological constraints strengthen with the increase of δNs value, the change being more considerable for nonresonant oscillations.
Taiwan as a Clinical Trial Center of Excellence in the Asia Pacific
Authors: Chan Wing-Kai , Chen Ding-Shinn
Published: September 2007

This article shortly illustrates about Taiwan as a clinical trial center of excellence in the Asia Pacific.
General News
Authors: Tan Cheryl
Published: September 2007

Asia's Leading Process Engineering, Controls, Instrumentation and Scientific Equipment Event to Return to Singapore.
Database Center for Life Science in Japan
Authors: Nagai Keiichi , Takagi Toshihisa
Published: September 2007

This article shortly explains about the Database center for life science in Japan.
Does Idiosyncratic Volatility Matter? New Zealand Evidence
Authors: Drew Michael E. , Marsden Alastair , Veeraraghavan Madhu
Published: September 2007

Standard asset pricing models ignore idiosyncratic risk. In this study, we examine if idiosyncratic or unique risk affects returns for New Zealand stocks using the factor portfolio mimicking approach of Fama and French (1993, 1996). We find evidence of a negative relationship between firm size and a stock's idiosyncratic volatility. We also find that high idiosyncratic volatility firms have high betas and generate low earnings on book equity.
The Difference Between Measuring Internal Funds Allocations in Groups and in Diversified Firms
Authors: Jegers Marc , Jung Kooyul , Kim Byungmo
Published: September 2007

Dependent variables used by Kim, Jung and Kim (2005) to assess the effect of the ownership structure of Korean chaebols on internal funds allocations are a priori misspecified in the context of their research, as they were designed to be applied when studying diversified firms and not groups consisting of legally independent entities. The conditions under which this misspecification has no effect on their conclusions are discussed. Re-analyzing their data with a more appropriate internal funds allocation variable leaves their conclusion on the presence of tunnelling effects intact, though it paints a partly different picture of internal allocations as such.
Intra-Industry Effects of Delayed New Product Introductions
Authors: Chen Sheng-Syan , Chung Tsai-Yen , Ho Kim Wai , Lee Cheng-Few
Published: September 2007

We find that for a sample of 324 announcements of delayed new product introductions in 52 industries from 1989 to 1997, the rivals overall experience significantly negative share price response. The results suggest that, for the sample as a whole, the information-signaling effect dominates the competitive effect. We further classify the rivals' share price response by industry and find that about 60% of industries have negative response. We also find that a product delay conveys more negative information about the competitors in those industries that are more likely to have product delays. Finally, we show that rivals' share price response is significantly positively related to the announcement effect on the product delay firm, the degree of industry competition, and the industry growth opportunities, and is significantly negatively related to the degree of relatedness of the announcing firm to the industry, and to the level of the announcing firm's free cash flow relative to that of its competitors.
A Simplified Firm Value-Based Risky Discount Bond Pricing Model
Authors: Wang Alan T. , Yang Sheng-Yung
Published: September 2007

This paper proposes a simplified risky discount bond pricing model based on Longstaff and Schwartz (1995). The advantage of this model is that it yields a closed form solution for probability of default. Also, a practical feature with our model is that computing durations and other risk management tools become computationally less expensive, while the appealing properties in the LS model are preserved. The numerical comparisons show that the differences in credit spreads between this model and Longstaff and Schwartz are within a few basis points for fairly general parameter values. Moreover, the computational time is shown remarkably reduced by the simplified model. Sensitivity analysis of credit spread with respect to different parameter values is presented.
SECONDARY INSTABILITY AND MODE JUMPING OF DEEP THERMOELASTICALLY BUCKLED COMPOSITE LAMINATES
Authors: CHEN HUI , YU WENBIN
Published: September 2007

An analytic method is presented to study the secondary instability (bifurcation) and mode jumping of thermomechanically deep buckled composite laminates. Unlike most ad hoc approaches, the governing partial differential equations (PDEs) and constitutive relations are rigorously derived from an asymptotically correct, geometrically nonlinear theory. A novel and simpler solution approach is developed to solve the two coupled fourth-order PDEs, namely, the compatibility equation and the dynamic governing equation. The generalized Galerkin method is used to solve boundary value problems corresponding to antisymmetric angle-ply and cross-ply composite plates. The variety of possible modal interactions is expressed in an explicit and concise form by transforming the coupled nonlinear governing equations into a system of nonlinear ordinary differential equations (ODEs). The comparison between the present method and the finite element analysis (FEA) shows a pretty good match in their numerical results in the primary postbuckling region. While the FEA may lose its convergence when solution comes close the secondary bifurcation point, the analytic approach has the capability of exploring deeply into the post-secondary buckling realm and capture the mode jumping phenomenon for various combinations of plate configurations and in-plane boundary conditions. Qualitatively different propagations of buckling pattern are observed before and after mode jumping. Free vibration along the stable primary postbuckling and the jumped equilibrium paths are also studied.
HECKE OPERATORS ON HILBERT–SIEGEL MODULAR FORMS
Authors: CAULK SUZANNE , WALLING LYNNE H.
Published: September 2007

We define Hilbert–Siegel modular forms and Hecke "operators" acting on them. As with Hilbert modular forms (i.e. with Siegel degree 1), these linear transformations are not linear operators until we consider a direct product of spaces of modular forms (with varying groups), modulo natural identifications we can make between certain spaces. With Hilbert–Siegel forms (i.e. with arbitrary Siegel degree) we identify several families of natural identifications between certain spaces of modular forms. We associate the Fourier coefficients of a form in our product space to even integral lattices, independent of basis and choice of coefficient rings. We then determine the action of the Hecke operators on these Fourier coefficients, paralleling the result of Hafner and Walling for Siegel modular forms (where the number field is the field of rationals).
Tectonics of the Variscides in North-Western Germany based on seismic reflection measurements
Authors: Meissner R. , Springer M. , Flüh E.
Published: September 2007

In the area of the Variscides in Germany five seismic reflection surveys were carried out between 1968 and 1978. Near Aachen, at the very northern part of the Variscan deformation front, a thin-skinned overthrust fault was found, while farther south, at the Hunsrück border fault, a steep listric fault zone was mapped which seems to have been initiated as an overthrust, but developed into a deep reaching extensional fault during the post-Variscan formation of the Saar-Nahe trough. The reflection signature of the different experiments, the low seismic velocity in the middle and lower crust, and the generally small crustal thickness together with many geological and petrological observations are compatible with the assumption that during the Variscan orogenies an interstacking of predominantly sialic platelets took place in a generally high-temperature environment. The shifting of the collisional belts from SE to NW is opposite to that of the Appalachian orogenies, although time periods and tectonic framework were similar. A simplified concept of approaching thin sialic platelets toward the rugged remnants of the Caledonian orogeny is presented.
A structural cross-section through SW Devon
Authors: Chapman T. J. , Fry R. L. , Heavey P. T.
Published: September 2007

A new interpretation for the Variscan structure of SW Devon is presented in the form of a structural cross-section. It is argued that the lowest outcropping part of the Lower Devonian, the Dartmouth Beds, has been transported northwards (NW to NNW) over the upper part of the Lower Devonian and the Middle Devonian. It is also suggested that the Middle Devonian (including the Plymouth Limestone) is thrust northwards over the Upper Devonian. Both these thrusts have previously been recognized in SE Devon.
Chemical and isotopic studies of a core of Marl Slate from NE England: influence of freshwater influx into the Zechstein Sea
Authors: Turner P. , Magaritz M.
Published: September 2007

Detailed mineralogical, chemical and stable isotope analyses have been made of single core through the Marl Slate in order to investigate the Zechstein transgression and its associated mineralization. The core (VT8), drilled by the National Coal Board off the coast of NE England, contains three subfacies: (1) dark grey, organic-rich, sapropelic siltstones; (2) organic-dolomite laminites; (3) massive finely crystalline dolostones. Two cycles of deposition which include the sequence sapropel→laminite→dolostone are present although the lower one (112 cm) is much thicker than the upper (32 cm).

There are some close correlations between the lithological and geochemical variables, including the stable isotope values. The sapropelic units are characterized by high Fe content (as iron sulphide) and strongly negative
δ
18
O values in associated carbonate minerals. Quartz silt and organic carbon are also higher in these units but diminish upwards in each depositional cycle. Each cycle of deposition appears to have been initiated by an influx of freshwater into the Zechstein basin which promoted surface productivity, water stratification and regional anoxic conditions. The relative change in
δ
13
C to more positive values higher in the Marl Slate is independent of lithological variation and indicates progressive enrichment of
13
C in the Zechstein Sea in response to the precipitation of large amounts of organic matter.

The distribution of base metals in the Marl Slate in this core strongly suggests that they were introduced by freshwater influx. Although Pb shows no clear relationship to the depositional cycles, Cu and Zn contents are relatively low in the lower sapropelic parts of the cycles and become higher in the upper parts. We take this to indicate that Cu and Zn sulphides were precipitated interstitially when more ‘normal’ marine conditions were re-established in the later part of each cycle.
The conodont
Merrillina divergens
(Bender & Stoppel) from the Upper Permian of England
Authors: Swift A.
Published: September 2007

Conodont elements have been recovered from English Zechstein Cycle 1 carbonate rocks (EZ1 Ca) from three localities in NE England. Most of the elements belong to the apparatus of a single species,
Merrillina divergens
(Bender & Stoppel). The systematic concept of this species is revised.
Diagenesis of nearshore carbonate rocks in the Sprotbrough Member of the Cadeby (Magnesian Limestone) Formation (Upper Permian) of eastern England
Authors: Kaldi J.
Published: September 2007

The petrographic textures in the upper member of the Cadeby (Magnesian Limestone) Formation demonstrate the combined effects of original depositional setting and later diagenetic alteration of a carbonate rock.

Dolomitization was the most ubiquitous diagenetic process to affect these rocks. Dolomites formed (1) penecontemporaneously, (2) perhaps as primary precipitates, (3) as cements during early diagenesis, and (4) as locally controlled late diagenetic replacement and cement. These dolomite textures were subsequently altered by the advent of new diagenetic environments. A drop in Zechstein sea-level exposed much of the upper (Sprotbrough) member to the influence of meteoric waters. The mixing of fresh and marine waters produced solutions capable of dissolving unstable carbonate matter, dolomitizing more resistant grains and replacing earlier dolomite textures with new ones. Generally, later dolomitization events produced coarser crystal textures than the earlier.

Evaporite minerals were formed as early nodules within supratidal sediments or as late diagenetic pore-filling cements in the sub-surface. Their dissolution led to the development of considerable vuggy porosity and the addition of Ca
2+
to ground waters. Ca
2+
-enriched fluids calcitized surrounding dolomites to produce dedolomite.

Porosity was controlled by the changes from one diagenetic environment to another. Primary pores were modified by cementation, recrystallization and pressure-solution. Secondary porosity was created by the dissolution of minerals that were unstable in pore fluids of the later diagenetic episodes.
Environmental analysis of basin and schwellen facies in the lower Zechstein of Germany
Authors: Paul J.
Published: September 2007

The Zechstein basin had a schwellen and basin topography, inherited from the late Variscan regime. The basinal facies of the lower Zechstein, mostly thin euxinic shales and limestones, are uniform throughout the basin. Different facies occur at the basin rim and on the schwellen. The schwellen facies of the Kupferschiefer varies from black and red shales to very fossiliferous dolomites. Reefs and other biogenic sediments dominate the shallow-water basin rim environments of the first- and second-cycle carbonates (Ca1 and Ca2). A regression during deposition of the upper part of the first-cycle carbonate led to emergence of the schwellen. This event can be recorded throughout the Zechstein basin. The deposition of great amounts of anhydrite upon the schwellen increased the relief between palaeohigh and basin. Subsequent sedimentation of thick halite blanketed the topography and filled the basin.
Comments on the genesis and structure of the copper-polymetallic ore deposit of the Foresudetic Monocline, SW Poland
Authors: Tomaszewski J. B.
Published: September 2007

The copper-polymetallic ore deposit is situated within the Foresudetic Monocline near its boundary with the Foresudetic Block. The copper-mineralized zone extends through a series of dolomites, dolomite/clay shales and white sandstones of the lowermost Zechstein and, possibly, the uppermost part of the Rotliegendes. Mineral compositions, the manner of their occurrence and the diverse internal structure of this stratified deposit all indicate a multistage origin. Synsedimentary mineralization took place in a reducing environment present both during deposition of the shales and dolomites and during sedimentation of the white sandstones. Black concretions containing large amounts of organic carbon, FeS
2
and FeO occur in the upper part of these sandstones. Mineralization also took place throughout diagenesis, mainly in the sandstones but also in the shales and, to a lesser degree, the dolomites.

Sedimentation was on an unstable shelf within the neritic zone. It is considered that natural marine aqueous solutions were enriched in metal ions (mainly Cu, Pb, Zn) by hot brines flowing out into the sedimentary basin through deep fissures, such as those in the Middle Odra fault zone, situated near the deposit.
The Leine Anhydrite of the Polish Zechstein: a significant lithostratigraphical marker-unit
Authors: Klapcinski J.
Published: September 2007

Three lithostratigraphical members have been distinguished within the Leine Anhydrite of western Poland: (i) pseudospherulitic anhydrite, (ii) spherulitic anhydrite, and (iii) cryptospherulitic anhydrite. Because of its characteristic spherulitic texture and considerable lateral extent, the Leine anhydrite is considered to be a useful marker unit throughout a considerable part of the Central European Zechstein Basin.
The main types of carbonate rocks of the Kungurian evaporite basin of the Urals
Authors: Chuvashov B. I.
Published: September 2007

The Kungurian basin of the Urals is a unique area for the study of evaporite sedimentation. All phases of evolution can be distinguished there, from a basin with a rich and diverse biota to a restricted one with high salt contents and scant biological communities. A similarity between English and German Zechstein sediments and the Kungurian strata of the Urals has long been noted. Some physical conditions of evaporite deposition may be inferred through a study of the associated carbonates.

Kungurian carbonates can be divided into three major groups: biogenic (organic), terrigenous and chemical. The organic carbonates are composed mostly of sediments trapped by blue-green algae and form small build-ups and algal mats, in both brackish-water (in the east) and high salinity (in the west) conditions. Coquinas are locally abundant. Clastic carbonates were transported as blocks, boulders, sands, muds, and in fine suspension. Great masses of micritic limestones accumulated by deposition from the latter. Numerous concretions, oolitic beds and packets of fine-grained dolomites without organic remains were laid down as chemical deposits and are related to the evaporites.
Basement and cover rock history in western Tethys: HT-LP metamorphism associated with extensional rifting of Gondwana
Authors: Hall Robert
Published: September 2007

High-temperature-low-pressure metamorphism of the deep crust is probable during continental lithospheric extension. The 75-65 Ma cooling ages of metamorphic and magmatic rocks preserved in overthrust crystalline slices in the southern Aegean are most plausibly explained by late Cretaceous extension of the Apulian continental margin, rather than by subduction-related magmatism. Metamorphism and magmatism at depth can be correlated with those stratigraphic features of the cover sequences that indicate extension. In particular, the puzzling ‘premier flysch’ of the region is interpreted as one consequence of peripheral uplift associated with stretching.
Holocene serial folding in the Zagros
Authors: Mann C. D. , Vita-Finzi C.
Published: September 2007

In the south-east Zagros Mountains of Iran, deformation during the Quaternary has occurred by serial folding, with the mountain front advancing westwards at 17 mm/yr. Coastal uplift during the Holocene indicates a horizontal slip of about 30 mm/yr. The geometry of the locked and nascent folds indicates compression by a horizontal force equivalent to between 0.134 and 0.790 kbar according to which model is adopted.
Gondwanaland and the evolution of the Indian Ocean
Authors: Tarling D. H.
Published: September 2007

In regions, such as the Indian Ocean, where geophysical data are largely lacking, reconstructions must be a compromise, allowing for the evolution of ‘passive’ margins and the inclusion of remanent continental blocks that are now isolated within the oceanic basins. Sea-floor spreading anomalies are re-examined in the context of the foregoing considerations, and emphasis is placed on the need to match anomalies that formed within the same transform segments. Despite subsequent attempts, it is considered that Norton and Sclater’s (1979) configuration of Gondwanaland and its Mesozoic-Tertiary breakup only need small, but significant modifications. These allow for the inclusion of small, but critically located continental units between the major continental blocks. Only age differences are proposed for most of their anomaly 16 reconstruction, now largely corresponding to anomaly 20 times. No changes are proposed to Norton and Sclater’s reconstruction for anomaly 34 times. Alterations to older reconstructions are mainly to allow for the inclusion of the Kerguelen, Gaussberg and Broken Ridges between India and Antarctica, and for the Agulhas-Falkland (Malvinas) Plateaux between Africa and Antarctica. The revised Gondwanaland reconstruction for early-middle Jurassic times appears to be more consistent with the geological and geophysical evidence, particularly reducing the need for differential motions of Sri Lanka and of the West Antarctic Peninsula. A review of the palaeomagnetic data indicates caution in the ability of extant data to distinguish between most reconstructions proposed during the last decade; considerable re-sampling and re-evaluation are required to adequately test between such Gondwanan models.
Lower Palaeozoic metamorphism in the Moine-Dalradian belt of the British Isles
Authors: Harte Ben
Published: September 2007

Greenschist- to amphibolite-facies mineral assemblages occur which are of Proterozoic as well as lower Palaeozoic age in the Moine rocks but are only Lower Palaeozoic in the Dalradian rocks. The widespread age of high-grade metamorphism in the Dalradian is 520–490 Ma (Grampian), whilst in the Moines N of the Great Glen high-grade Lower Palaeozoic metamorphism is dated at 460–440 Ma. In Moine rocks, Grampian deformation and metamorphism may be absent N of the Great Glen but present S of the Great Glen, and this may indicate substantial movement on the Great Glen Fault between about 500 and 450 Ma. In addition to Moine metamorphism and deformation, the 460–440 Ma period appears to encompass diverse and extensive tectonic activity near the southern margin of the belt: thrusting in Connemara, Highland Border Downbend formation in Scotland and ophiolite emplacement in the Shetland Isles. A set of probably basement-controlled tectono-metamorphic domains in the Scottish Dalradian is suggested.
Evolution of the Iapetus Ocean and its borders in pre-Arenig times: a synthesis
Authors: Skehan James W.
Published: September 2007

On the margins of the Laurentian continent the interval
c.
800-492 Ma was dominated by (1) rifting involving continental crust and (2) rift sedimentation with or without related volcanicity and plutonism, culminating in (3) the formation of the Iapetus Ocean and succeeded by (4) initial phases of compressional tectonics. The latter involved the approach of volcanic island-arc systems and the partial or complete obduction of ophiolites of the oceanic crust cutting through the slope-rise prism and, at least in some parts of the orogen, being thrust onto the continental-shelf deposits in the Cambrian and Tremadocian. These processes led to the closing of the ocean in the mid-Ordovician Taconian and the Silurian Caledonian orogenies. The earliest and most complete pre-Arenig orogenic movements are recorded in the Finnmarkian orogeny, including obduction of ophiolites in Scandinavia (520–480 Ma). Related sedimentation gaps, preceded by deformation and ophiolite obduction and/or uplift, were accompanied by tectonic melange development and/or volcanicity. These features are recorded widely from northern Britain and Ireland (Grampian orogeny), and from the Appalachians of Newfoundland (Burlington orogenic episode), Maine, USA, and Quebec, Canada (Penobscot orogeny). Movements interpreted as relating to the Penobscotian are now recognized as widespread in the US Appalachians. The Sardic orogenic phase in southern Europe (
c.
510 Ma) is associated with plutonism and metamorphism and may be related to late Cadomian III orogenic movements.

In the southeastern landmasses of Gondwanaland (Avalonian-Cadomian-Pan-African) essentially the same time interval (
c.
800–492 Ma) was also dominated initially by rifting of continental crust overlain by late Proterozoic shelf deposits and the obduction and folding of ophiolites (Cadomian I orogeny) and underlying rocks, followed by intrusion of late- to post-tectonic plutons (Bleida). Cadomian II resulted in the deposition of coarse clastics, volcanics and glacigenic sediments (Tiddiline), and folding, erosion and deposition of a thick wedge of late Proterozoic carbonate and clastic rocks with alkaline volcanics (Adoudounian) overlain conformably by lower and middle Cambrian that are overlain disconformably by Tremadocian clastic sediments. During the rifting phase continental fragments drifted away and/or became volcanic arcs with subduction zones and back-arc basins constituting the weakly orogenic Avalonian terrane to the W and the strongly orogenic but discontinuous belt forming a terrane characterized by Cadomian fragments between the Avalonian terrane of the British Isles and the W African craton. Stratigraphic columns and schematic time-slice stratigraphic profiles with interpreted tectonic environments from various parts of the orogen provide comparisons and contrasts in stratigraphic, faunal, structural, volcanic, plutonic and metamorphic evolution.
Polyphase tectonothermal evolution of the Scandinavian Caledonides
Authors: Dallmeyer R. D.
Published: September 2007

A polyphase tectonothermal evolution characterizes many of the allochthonous sequences which constitute the Scandinavian Caledonides. Initial Late Cambrian consumption of Iapetus oceanic crust occurred outboard of the Baltoscandian margin with development of an island-arc above a west-dipping subduction complex. Imbrication, polydeformation and variably high-grade metamorphism of Baltoscandian miogeoclinal rocks and underlying Precambrian crystalline basement occurred within an accretionary prism which developed in the subduction complex. This resulted in eastward younging, diachronous metamorphism throughout the Early and Middle Ordovician. Cooling during subsequent uplift was regionally variable, and is reflected by the wide range of radiometric dates reported for the Baltoscandian allochthons (455–535 Ma). This early Caledonian activity has been termed the Finnmarkian orogeny; however, it is best viewed as a complex, diachronous series of tectonothermal events which variably affected the Baltoscandian margin from the Late Cambrian through the Middle Ordovician.

Almost complete closure of the Iapetus Ocean appears to have been accomplished by the Late Ordovician when eugeoclinal terranes which had developed along the Laurentian margin were tectonically juxtaposed with eroded remnants of the Late Cambrian-Middle Ordovician arc. Initial imbrication of the Laurentian eugeoclinal sequences with the arc occurred during the Early Silurian (Late Llandovery). These were subsequently imbricated and infolded with predeformed Baltoscandian allochthons. The resultant composite allochthon was subsequently thrust eastward onto Silurian sedimentary successions deposited over previously metamorphosed Caledonian basement. This sequence of Early Silurian to Early Devonian tectonic events has been collectively termed the Scandian orogeny; however, they are regionally diachronous and should be bracketed with the local controls available. Scandian dates of 425–430 Ma are locally recorded in allochthons along eastern portions of the orogen and they probably date initial nappe translation to higher crustal levels along the Baltoscandian margin. In lower structural units Scandian dates range from 410 Ma in central to 385 Ma in western portions of the orogen. These are interpreted to date rapid cooling during the uplift associated with a crustal rebound which followed eastward translation of overriding allochthons.
Granitoid plutonism in the Caledonian orogen of Europe
Authors: Stephens W. E.
Published: September 2007

Granitoid plutonism is a feature of all major segments of the Caledonian orogen in NW Europe and Greenland. Available data on geological setting, age and composition are presented for each segment and are collated for use as the basis for a regional and temporal interpretation of magmatism during the Caledonian. Magmatism close to the northwestern foreland was dominantly alkaline whereas both alkaline and peraluminous compositions are represented on the southern foreland. Within the orogen early magmatism N of the Iapetus suture line was dominantly S-type resulting from crustal anatexis of dominantly metasedimentary rocks, while there is a later shift to predominantly I-type granitoid plutonism. S of the Iapetus suture line plutonism within the orogen in Scandinavia is essentially I-type, whereas in Britain and Ireland it has more S-type characteristics supporting recent propositions of two separate southerly plates. The overall pattern of plutonism contrasts markedly with that of younger subduction-related batholiths.
The current status of thermobarometry in metamorphic rocks
Authors: Essene E. J.
Published: September 2007

Information on pressure (P) and temperature (T) is a fundamental aspect of research on metamorphic terrains. Unfortunately, many workers employ thermobarometers that are not experimentally calibrated, are insensitive or too sensitive toP-Tchanges, depend on a priori assumptions of water pressure (such as most petrogenetic grids), or are rapidly reset on cooling. Many systems are based on inaccurate thermodynamic data, involve solids with inadequately characterized structural states, neglect effects of thermal expansion and compressibility, or require long extrapolations inP-T-Xspace. For instance, application of the widely used garnet-clinopyroxeneKDthermometer may require extrapolation to temperatures where current thermodynamic models of pyroxenes and garnets remain uncertain. Current versions of the Mg/Fe exchange thermometer for biotite-garnet involve substantial compositional extrapolations for many applications and the biotite is easily reset while cooling from higherT. The most widely employed barometer is based on dilution of the reaction grossular + kyanite + quartz = anorthite, but failure to correct molar volumes forP-T-Xmay yield systematic errors of 1–2 kbar for barometry of crustal metamorphites. Application of this barometer to rocks equilibrated atT< 600–650°C is presently unwarranted in view of unknowna-Xrelations of garnets and plagioclases at theseT. However, by careful selections, thermobarometry may be accurate to ±50°C and ±1 kbar in many metamorphic terrains if a variety of different equilibria can be applied. Well-calibrated barometers that are useful forTτ 600–650°C rely on continuous reactions based on equilibria such as almandine + rutile = ilmenite + sillimanite + quartz, garnet + quartz = ferrosilite + plagioclase, garnet + rutile = ilmenite + anorthite + quartz, and almandine + sillimanite = hercynite + quartz. An extensive survey of the recent literature on thermobarometry of individual metamorphic facies reveals the range ofP-Tencountered in each facies. Temperature estimates are in good agreement with the inferences of Turner (1968). Barometry reveals that the blueschist, amphibolite and granulite facies give way to the eclogite facies over the pressure range of 12–16 kbar.
Geothermobarometry of high-grade metapelites: simultaneously operating reactions
Authors: Aranovich L. Ya. , Podlesskii K. K.
Published: September 2007

Experimental data on equilibria involving rock-forming minerals in high-grade metapelites (garnet, orthopyroxene, cordierite and plagioclase) have been used to derive an internally consistent system of mineralogical thermometers and barometers based on component reactions and excess mixing properties of solid solutions. Application of these data to a granulite-facies metapelite sample reveals that compositional inhomogeneity of minerals on a thin-section scale is likely to be a result of several reactions opening simultaneously at the retrograde stage of metamorphic evolution. The widely accepted practice of estimating pressure and temperature from separate reactions may thus lead to errors and misinterpretation of
P-T
paths.
A laser-microprobe study of argon isotopes in deformed pegmatites from the Northern Highlands of Scotland
Authors: Irwin James J. , Kirschbaum Charles , Lim Tek. H. , Powell Derek , Glassley William E.
Published: September 2007

In the Highlands of Scotland, the Moine schists are cut by pegmatites that were deformed and metamorphosed after emplacement. The
40
Ar/
39
Ar
κ
ages of laser ‘pits’, in muscovite, feldspar, and some garnet and quartz crystals in two of these pegmatites are consistent with regionally well-established ages of metamorphism of the Moine. The ages of cores, rims and of different sizes of muscovite crystals are the same within errors. Individual crystals of garnet and quartz in the Ardnish pegmatite are heterogeneous in their argon isotopic composition, indicating that the last episode of metamorphism did not equilibrate the noble gas isotopes. Some quartz and garnet crystals from a pegmatite at Ardnish contain radiogenic
40
Ar generated in the last c. 420 Ma and a trapped component having a
40
Ar/
36
Ar ratio close to modern atmosphere. A few garnets from this same pegmatite also appear to contain t least one trapped component of
40
Ar with an
40
Ar/
36
Ar ratio > 10000.
The role of crustal anatexis and magma migration in the thermal evolution of regions of thickened continental crust
Authors: De Yoreo J. J. , Lux D. R. , Guidotti C. V.
Published: September 2007

The results of numerical thermal models are presented that directly take into account crustal melting and the upward transfer of melts in the thermal evolution of regions of thickened continental crust. The results of these models indicate that in regions of moderate to high mantle heat flow (Q
m
> 30 mW m
−2
), extensive melting of the lower crust is likely, but will only moderately affect the rise in temperature of the lower crust. They also show that the ascent of those melts will drastically modify the pressure- temperature-time (
P-T-t
) paths followed by horizons in the upper plate, prolonging loading and producing widespread high-grade amphibolite-facies metamorphism. In these models, both the style and timing of metamorphism above zones of melting is controlled by those melts and, as a consequence of melting, as much as 30–50% of the orogenic root is eliminated by removal of the lower plate through the upward transport of melts and their erosion at the surface.
Pressure, temperature and structural evolution of the Sulitjelma fold-nappe, central Scandinavian Caledonides
Authors: Burton Kevin W. , Boyle Alan P. , Kirk Wendy L. , Mason Roger
Published: September 2007

Pressure(
P
)-temperature(
T
) paths of regional metamorphism have been constructed for pelitic units of the Sulitjelma fold-nappe (SFN), part of the Köli Division of the Upper Allochthon of the Central Scandes. The SFN comprises the Skaiti Supergroup, a sequence of late Proterozoic supracrustal rocks, intruded by the lower members of the Sulitjelma Ophiolite, which is overlain by an Ordovician to Silurian sedimentary carapace, the Furulund and Sjönstå groups.

The
P-T
paths calculated from garnet zoning modelling are temporally related to texturally distinct periods of garnet growth, which can be correlated with regional deformation episodes. In the Furulund Group: (i) static overgrowth of a planar fabric in garnet cores corresponds to heating and compression to 470°C, 6 kbar; (ii) synkinematic growth corresponds to further heating but with decompression to 500°C, 5 kbar; (iii) static growth of inclusion-free rims occurred during near-isothermal compression to 6 kbar. In the Skaiti Supergroup pelites: (i) static growth of poikiloblastic garnet cores occurred during heating and compression to 500–520°C and 9–10 kbar; and (ii) static growth of inclusion-free rims corresponds to minor heating and significant decompression to 540°C and 7 kbar.

Comparison of mesoscale structural features with mineral growth indicates that (i) in both units is related to burial resulting from the closure of the marginal ocean basin floored by the Sulitjelma Ophiolite, while (ii) relates to the emplacement of the SFN onto Baltica, accompanied by overturning of the Ophiolite and its sedimentary cover. In the Furulund Group this occurred during eastward-directed simple shear deformation, giving rise to sheath folds and overturned isograds. In the Skaiti Supergroup there was little deformation during this period suggesting that most of the strain was being taken up by the Furulund Group. The final compressional phase (iii) seen only in the Furulund Group, relates either to the emplacement of the Skaiti Supergroup above the Furulund Group, or to out-of-sequence overthrusting of higher nappes.
Geology and metamorphic evolution of the Sanbagawa metamorphic belt, Japan
Authors: Banno Shohei , Sakai Chihiro
Published: September 2007

The Cretaceous (pre-Japan Sea) Sanbagawa metamorphism affected the Japanese Jurassic complex south of the Median Tectonic Line in the regions now recognized as the Sanbagawa, Mikabu and Chichibu belts. The metamorphic peak (116 Ma) was reached and passed during the tectonic ‘D
1
’ deformation, corresponding to sinistral shear N30°E along the eastern margin of the Asian continent. This was followed by ‘D
2
’ (c. 85 Ma) fold and thrust deformation, the vergence of which is normal to the ‘D
1
’ trend. These deformational events established the present thermal structure. The final regional deformation formed upright ‘D
3
’ folds. The four metamorphic zones based on pelitic assemblages can be enhanced by using basic schists to subdivide the pelitic chlorite zone. Apparent Fe-Mg partition coefficients between chlorite and garnet show an essential regional continuity of metamorphism and that thrust-offsets do not juxtapose elements from different mineral zones. Peak conditions of metamorphism ranging from 250°C and 6 kbars to 600°C and 10 kbars are consistent with simple
P-T-t
loops which progress at higher pressures and return at lower pressures to the surface.
A discussion of alluvial sandstone body characteristics related to variations in marine influence, Middle Jurassic of the Cleveland Basin, UK, and the implications for analogous Brent Group strata in the North Sea Basin
Authors: Alexander Jan
Published: September 2007

The pattern of deposition in the Middle Jurassic Cleveland and North Sea basins was complicated by spatial and temporal variations in the amount of marine influence. These variations ranged from major changes in shore-line position resulting in the alternating deposition of marine and non-marine formations to minor shore-line movements, incursions, tidal back-up, saline wedge intrusion and storm/tide/rain-induced flood events. The fluctuating extent of marine influence resulted from the interplay of factors including sedimentation rate, compaction, local tectonic activity and eustatic variations. The extent of marine influence on the alluvial environment affected the nature and architecture of sandstone bodies and the nature of early diagenesis.

It is probable that within the North Sea area local and regional relative sea-level fluctuations during Ness Formation deposition would have resulted in a range of alluvial sandstone body types similar to those of the Middle Jurassic of Yorkshire seen in outcrop. Major changes in sea-level relative to surface subsidence resulted in changing sandstone body architectural styles, while minor changes in marine influence resulted in significant changes in internal sandstone body characteristics.
Palynological review of the Brent Group, UK sector, north sea
Authors: Whitaker M. F. , Giles M. R. , Cannon S. J. C.
Published: September 2007

A biostratigraphical zonation of the Brent Group, applicable within local oil field areas, has been established. It comprises 11 palynozones and subzones, eight of which are confined to the Ness Formation. Palynomorph associations and palynofacies types are shown to broadly correspond to specific palaeoenvironments. A regional ‘event’ scheme is outlined which establishes chronostratigraphical correlations and suggests temporal relationships between deltaic and delta front sediments. Integrated palynofacies data have allowed the development of deltaic sub-palaeoenvironments and lithofacies to be examined with respect to time and, in this way, to chart the possible progress of the delta as it prograded. Similarly, this approach enables possible areas of concentrated fluvial channel activity to be identified and the likely migration of these fluvial fairways with time. The implications of this depositional model for reservoir development and performance is discussed, showing the varying orientation of the delta front and barrier sands as it changed from a predominantly N-S trend during its early stages to WNW-ESE in its final stages.
Palynology as a palaeoenvironmental indicator in the Brent Group, northern North Sea
Authors: Williams Gwydion
Published: September 2007

The Brent Group of the northern North Sea can be subdivided into a series of 12 assemblage units on the basis of palynomorph and kerogen abundances. These assemblages, which can be identified on a regional basis, have been recognized extensively throughout wells of the Brent Group depositional area. They represent changes in the environment, kerogen source and depositional setting and can be linked to lithostratigraphical units. Changes in assemblages through the Brent Group reflect an initial restricted marine environment followed by progradation in a regressive regime. Progradation ceased and the maximum point of regression occurred within the ‘Mid’ Ness Formation, after which deposition occurred within an abandonment and transgressive regime. These features are defined by palynological data, thus providing input into the regional understanding of Brent Group deposition. The palynological assemblages of the Brent Group are illustrated with reference to two wells: 211/18a-A31 from the Thistle Field and 3/3-5A from the Ninian Field.

Palynomorph assemblages within the Brent Group are largely facies controlled and have an intimate relationship with lithofacies. The identification of these assemblages, therefore, allows for the positive identification of individual lithostratigraphical and reservoir units, particularly in problematic sections where stratigraphical interpretations based on other disciplines are hampered by faulting and truncation or lack of conventional core material and wireline log data, particularly where sidewall core samples are available.