bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychological validity of certainty factor algebras: an empirical study
Authors: Holsapple Clyde W. , Wu Jen‐Her
Published: May 2007

Abstract: Expert system researchers have paid little attention to studying empirically the psychological validity of alternative methods for combining certainty factors. These combining methods, called certainty factor algebras (CFAs), have been organized into a classification framework and a normative mapping has been prescribed to indicate which operators (e.g. AND, OR, +, −, >) should be mapped into each CFA category. However, with the exception of one study concerned solely with the AND operator, there has been no empirical base for assessing the representativeness of the normative mappings. We report on the results of an experiment that compares certainty‐combining behaviors versus diverse CFA results for logical, arithmetic and relational operators. This includes a consideration of certainty magnitude and operand magnitude effects. The result is a significant improvement in our understanding of the psychological validity of certainty factor algebras. Such an understanding is important both to knowledge engineers and to the creators of expert system development tools.
An exploratory study of two KA methods
Authors: Holsapple Clyde W. , Raj Victor S.
Published: May 2007

Abstract: Empirical research into knowledge acquisition (KA) issues is important in the effort to improve the productivity of expert system developers. From an experimental perspective, the few studies that have been reported suffer from certain control and measurement difficulties. Here we conduct a study to demonstrate the feasibility of a new KA experimental strategy. The results of this study partially confirm and partially question results of earlier KA experiments.
MAPS: a language for multi‐agent system design
Authors: Baujard O. , Pesty S. , Garbay C.
Published: May 2007

Abstract: A language for multi‐agent system design (MAPS) is presented and discussed in this paper. Any agent in MAPS is thought of as an expert system standing on its own. It can communicate through synchronous and asynchronous message sending. Dedicated behaviours are provided which specify how incoming messages are processed. Inter‐agent cooperation is controlled via production rules. Two pre‐defined agent classes are provided, which are given specific problem‐solving roles: Knowledge Server (KS) agents are meant to maintain and transmit knowledge about problem‐solving states, while Knowledge Processor (KP) agents are meant to process these elements in order to progress towards a solution. The duality between agent and resource modelling levels on the one hand and between KS and KP modelling styles on the other is shown to allow the specification of various control strategies. The environment is currently running on HP, SUN and DEC workstations.
Three levels of benefits in expert systems
Authors: Basden Andrew
Published: May 2007

Abstract: This paper is not about knowledge representation, nor knowledge structures, nor knowledge elicitation, nor even expert systems methodology. It is about the use of expert systems in their working context. Little has been written about the usage of expert systems from a theoretical point of view. What has been written from a practitioner's point of view often lacks structure, and thus can make only minor contributions to understanding and predicting the usage of expert systems.

In an attempt to fill this gap, this paper proposes a model of benefits of expert systems. The model has three levels and benefits of various kinds are classified into three types. The paper presents a deductive argument for the model, rather than an inductive one, since full empirical studies have yet to be carried out. However, a case study is outlined that indicates the applicability of the model.
Toward an intelligent architectural design aid
Authors: Hunt John , Miles Roger
Published: May 2007

Abstract: Architectural design is a complex task which requires expert knowledge, a great deal of experience and no small amount of creativity and artistic flair. However, while humans are very good at creativity, intuition, artistry and evaluation, they are notoriously bad at routine mundane tasks. Searching through large databases of past designs can be such a task. This can result in useful design knowledge being ignored. In this paper we present a way to aid architects in their work by providing a software tool aimed at recording, retrieving and evaluating architectural designs.
Process factors in knowledge acquisition
Authors: Holsapple Clyde W. , Wagner William P.
Published: May 2007

Abstract: Knowledge acquisition (KA) is often characterised as a crucial bottleneck in the development of expert system applications. General definitions of KA view it as a collection of subprocesses such as elicitation, analysis and representation, but in actual practice, each KA occurrence may involve one or all of these subprocesses in varying sequences and combinations. No model or framework currently exists for describing the many possible variations in KA processes as they actually occur. This article presents a new way of characterising knowledge acquisition processes that is not tied to one particular technique or approach to KA. Three nested levels are proposed to characterise the many possible variations and combinations of KA dynamics: the process, episode and transaction levels of analysis. Each of these is further delineated in a top‐down manner. Not only does this scheme provide a fairly comprehensive means for viewing KA dynamics as a whole, but it suggests several factors that have heretofore drawn little research attention. The suggested constructs capture more accurately what actually occurs in the practice of KA. In so doing they also provide the foundation for structuring future research into how KA processes may unfold.
SOCIAL JUSTICE
Authors: SCHEDLER GEORGE
Published: May 2007

CONCLUSION

Social justice (which includes retributive and distributive justice) is most clearly satisfied by a system of Divine rewards and punishments: an omnipotent, omniscient, perfectly just Being could determine in each case how much effort was made and effect the appropriate distribution of rewards and punishments. A correct understanding of social justice naturally leads us to suppose that there is an afterlife, a God, a free choice — though it is logically possible at least that social justice could be satisfied in some future (very advanced) human society.

There will still be those who have their doubts about the correctness of any view according to which justice cannot be attained by fallible creatures who have an incomplete knowledge of one another's behaviour. But, surely, these doubts are not sufficient to discredit my view. There is no a priori reason for rejecting such a view. There is nothing about our use of the term ‘justice’ and its cognates which implies that such a view is mistaken. (Otherwise the statement “There is no justice in this world’ would be meaningless.) To the contrary, there are widely held religious views, Christian as well as non‐Christian, which take this view quite seriously. If there is no a priori reason for rejecting this view, then there must be some independent reason for rejecting it. In other words, we need some independent reasons for believing that social justice can be attained by fallible creatures with limited knowledge. The mere fact that we might feel uncomfortable with my theory is not reason enough to reject it.

Finally, those who do experience this discomfort might ask themselves whether such discomfort stems from their moral experience or whether they are simply intent on finding justice in imperfect human institutions.
THE ABSENT AUTHOR: MAURICE BLANCHOT AND INSPIRATION
Authors: PURCELL MICHAEL
Published: May 2007

But when you are handed over, do not worry about how to speak or what to say; what you are to say will be given to you when the time comes, because it is not you who will be speaking; the Spirit of your Father will be speaking in you (Matt 10:19‐20).
Exclusivist or Universalist? Origen the ‘Wise Steward of the Word’ (CommRom. V.1.7) and the Issue of Genre
Authors: GREGGS TOM
Published: May 2007

Abstract:  This article explores the issue of Origen's universalism. It identifies the two seemingly self‐contradictory strands in the Origen corpus which have led to dual pictures of Origen as either an arch‐universalist or an exclusivist. To make sense of this, the hermeneutical key of CommRom. V.1.7 (in which Origen states Paul covers over his universalism to be a ‘wise steward of the word’) is applied to Origen's own texts. Identifying the different genres in Origen's works, it is clear that different stances on universalism are taken dependent upon the genre of his work. The question is posed as to whether such a move in theology is justifiable and biblical.
Folate deprivation increases presenilin expression, gamma‐secretase activity, and Abeta levels in murine brain: potentiation by ApoE deficiency and alleviation by dietary S‐adenosyl methionine
Authors: Chan Amy , Shea Thomas B.
Published: May 2007

Folate deficiency has been associated with age‐related neurodegeneration. One direct consequence of folate deficiency is a decline in the major methyl donor, S‐adenosyl methionine (SAM). We demonstrate herein that dietary deficiency in folate and vitamin E, coupled pro‐oxidant stress induced by dietary iron, increased presenilin‐1 expression, gamma‐secretase activity, and Abeta levels in normal adult mice. These increases were potentiated by apolipoprotein E deficiency as shown by treatment of transgenic mice homozygously lacking murine apolipoprotein E. Dietary supplementation with SAM in the absence of folate attenuated or alleviated these deleterious consequences. These findings link nutritional and genetic risk factors for age‐related neurodegeneration and underscore that dietary supplementation with SAM may be useful to augment therapeutic approaches.
Microsatellite markers for the endangered European mink (Mustela lutreola) and closely related mustelids
Authors: CABRIA M. T. , GONZÁLEZ E. G. , GÓMEZ‐MOLINER B. J. , ZARDOYA R.
Published: May 2007

The European mink (Mustela lutreola L., 1761) is an endangered carnivore species whose populations suffered a severe decline during the last century. The genotyping of eight polymorphic microsatellite loci revealed a relatively low number of alleles per locus (two to eight), as well as low levels of polymorphism (observed and expected heterozygosity values per locus were 0.49 and 0.54, respectively). Cross‐specific polymerase chain reaction amplifications were successful in seven closely related mustelid species suggesting that these loci may be useful not only for assessing genetic variability in European mink populations but also for determining potential hybridization events between M. lutreola and other mustelid species.
Isolation and characterization of 12 microsatellite loci for population studies of Sulawesi tarsiers (Tarsius spp.)
Authors: MERKER S. , DRILLER C. , PERWITASARI‐FARAJALLAH D. , ZAHNER R. , ZISCHLER H.
Published: May 2007

This study reports the development and characterization of the first 12 microsatellite markers for tarsiers. Nine loci were isolated from Dian's tarsier, Tarsius dianae and three from the Philippine tarsier, Tarsius syrichta. The 12 markers were used to screen 40 individuals of Dian's tarsier and 40 individuals of the Lariang tarsier, Tarsius lariang for allelic diversity. This suite of highly polymorphic microsatellites provides the first chance to genetically study parentage patterns in tarsiers.
The Kamuikotan zone in Hokkaido, Japan: tectonic mixing of high‐pressure and low‐pressure metamorphic rocks
Authors: ISHIZUKA HIDEO , IMAIZUMI MASAYUKI , GOUCHI NOBUO , BANNO SHOHEI
Published: May 2007

Abstract. In the Kamuikotan zone, central Hokkaido, Japan, two distinct types of metamorphic rocks are tectonically mixed up, along with a great quantity of ultramafic rocks; one type consists of high‐pressure metamorphic rocks, and the other of low‐pressure ones. The high‐pressure metamorphic rocks are divided into two categories. (1) Prograde greenschist to glaucophaneschist facies rocks derived from mudstone, sandstone, limestone, a variety of basic rocks such as pillow and massive lavas, hyaloclastite and tuff, and radiolarian (Valanginian to Hauterivian) chert, among which the basic rocks and the chert, and occasionally the sandstone, occur as incoherent blocks (or inclusions) enveloped by mudstone. (2) Retrograde amphibolites with minor metachert and glaucophane‐calcite rock, which are tectonic (or exotic) blocks enclosed within prograde mudstone or serpentinite, or separated from these prograde rocks by faults. The K‐Ar ages of the prograde metamorphic rocks (72, 107 and 116 Ma on phengitic muscovites) are younger than those of the retrograde rocks (109, 132, 135 and 145 Ma on muscovites, and 120 Ma on hornblende). The low‐pressure metamorphic rocks consist of the mafic members of an ophiolite sequence with a capping of radiolarian (Tithonian) chert with the metamorphic grade ranging from the zeolite facies, through the greenschist (partly, actinolite‐calcic plagioclase) facies to the amphibolite (partly, hornblende‐granulite) facies. The low‐pressure metamorphism has a number of similarities with that described for‘ocean‐floor’metamorphism. The tectonic evolution of such a mixed‐up zone is discussed in relation to Mesozoic plate motion.
Mineralogy and petrology of a piemontite‐bearing schist, western Otago, New Zealand
Authors: KAWACHI YOSUKE , GRAPES RODNEY H. , COOMBS DOUGLAS S. , DOWSE MARTIN
Published: May 2007

Abstract. Pink piemontite‐spessartine‐bearing and grey‐green spessartine‐bearing manganiferous quartzose schists derived from siliceous pelagites, and green quartzofeldspathic schists, are described from the greenschist facies of the Haast Schist terrane, near Arrow Junction, western Otago. Electron microprobe data are reported for sphene, spessartine‐rich garnet, manganoan epidote, piemontite, tourmaline, phengitic muscovite, chlorite, albite, haematite, rutile, manganoan calcite and chalcopyrite.

Metamorphism occurred at about 6.4kbar, 400°C. Xco2 was above the quartz‐rutile‐calcite‐sphene buffer (Xco2± 0.02) throughout the recorded metamorphic history of the piemontite schists. It dropped from above to below this critical buffering value in a spessartine‐rich schist and it was close to or below the buffering value in the quartzofeldspathic schists. Production of piemontite required high fO2, believed to be inherited from MnOx in the parent pelagite. Substantial loss of O2 (e.g. minimum of 0.19% by weight in one rock) during diagenesis and/or metamorphism is inferred. In the grey‐green schists this inhibited piemontite formation. Slight loss of O2 and Ca2+ accompanied minor late‐stage replacement of piemontite by second generation spessartine. Observed zoning and mineral replacements indicate rise of temperature, drop in pressure, or invasion by solutions of lower fO2 and XCO2 equilibrated with surrounding schists.

The detailed chemistry of the minerals studied correlates with available Mn and with bulk‐rock (Fe3+ x 100)/(Fe2++ Fe3+). The oxidation ratio ranges from 24 in average green quartzofeldspathic schist, through 78 in average grey‐green manganiferous quartzose schist, to almost 100 in some piemontite‐bearing schists. As Fe2+ gives way to Fe3+, Mg/Fe ratios tend to rise in chlorite, phengite, tourmaline, spessartine, and calcite, Mn increases and Ti decreases in haematite, Mn increases in spessartine and calcite, and Fe increases in rutile. Available divalent cations are depleted relative to Al; chlorite is more aluminous, and phengite more paragonitic than in typical Haast schists.
The muscovite‐melt bathograd and low‐P isograd suites in north‐central Wopmay Orogen, Northwest Territories, Canada
Authors: ST‐ONGE MARC R.
Published: May 2007

In north‐central Wopmay Orogen, syntectonic low‐P(Buchan‐type) suites of mineral isograds outline regional metamorphic temperature culminations that are associated, at the higher structural levels, with emplacement of early Proterozoic plutons in the west part of a deformed and eastward transported continental margin prism. The mapped isograds mark the first occurrence of biotite, staurolite, andalusite, sillimanite, sillimanite‐K feldspar and K feldspar‐plagioclase‐quartz ± muscovite (granitic) pods in metapelites, with increasing proximity to the plutons.

Microprobe analyses and field observations have resulted in the formulation of reactions for the ‘ideal’pelitic system K2O‐Na2O‐FeO‐MgO‐Al2O3‐SiO2‐H2O‐Al2O3‐SiO2‐H2O, to account for the various mineral assemblages of each metamorphic zone. A P‐T petrogenetic grid showing erosion surface P‐T curves for the northern Wopmay Orogen pelites, compiled on the basis of the mapped isograds and the inferred reaction(s) for each metamorphic zone, documents a variation in exposed metamorphic pressure ranging between 2 and 4 kbar.

The configuration of a new bathograd, based on the invariant model reaction sillimanite + K feldspar + plagioclase + biotite + quartz + vapor ± muscovite + liquid and interpolated across three metamorphic suites, is consistent with a major regional structure culmination and with independently determined pressures obtained from anorthite‐grossular‐quartz‐Al2SiO5 geobarometry. The positive correlation between the configuration of the bathograd and the structural and pressure culmination points to the pressure‐dependence of anatectic‐granitic‐pod mineral associations.
The generation of quartz‐normative melts and corundum‐bearing restites by crustal anatexis: petrogenetic modelling based on an example from the Lewisian of North‐West Scotland
Authors: CARTWRIGHT I. , BARNICOAT A. C.
Published: May 2007

Abstract
Rare layers of an aluminous, muscovite‐rich rock from the Lewisian Complex at Stoer, North‐West Scotland, display evidence which suggests that the rock has undergone local partial melting to form quartz‐bearing veins and a corundum‐bearing restite. The assemblages observed in these rocks match those predicted by modelling in the system KAlO2‐NaAlO2‐Al2O3‐SiO2‐H2O (KNASH) where certain bulk compositions melt peritectically to give corundum‐bearing restites and quartz‐normative melts. Study of the model system shows that the observed parageneses could have formed from a range of bulk compositions with a variety of possible values of aH2O which could have been internally or externally buffered. The KNASH petrogenetic grid, together with another in the system CaO‐Na2O‐FeO‐Al2O3‐SiO2‐H2O (CNFASH), allows the P–T path of the rocks to be delineated and an estimate to be made of the conditions at the peak of metamorphism as > 11 kbar and 900‐925°C. This estimate is in agreement with P–T estimates using thermobarometric methods on adjacent lithologies: The activity of H2O in the system throughout metamorphism is calculated to have been >0.3.
Petrology of marble and peridotite in the Seiad ultramafic complex, northern California, USA
Authors: LIEBERMAN J. E. , RICE J. M.
Published: May 2007

Abstract
Peridotite and infolded marble of the Seiad ultramafic complex were recrystallized in the upper amphibolite facies as part of the regional progressive metamorphism of the Rattlesnake Creek terrane. Field relations, including the occurrence of metarodingites, and metasomatic zones between dissimilar rock types, demonstrate that the metasediments and serpentinized ultramafic rocks were juxtaposed prior to regional, barrovian metamorphism. Temperatures are estimated to have reached 760–800°C at pressures of 7–8 kbar during the peak of metamorphism. Four low‐variance parageneses have been identified within a small (3 km2) area of the complex, which may reasonably be assumed to have formed under the same P and T conditions. Isobaric T‐Xco2 diagrams of appropriate equilibria are presented for three different internally consistent sets of thermodynamic data. Despite the seemingly small numerical differences between the standard state thermodynamic properties of the data sets, only one diagram allows the four observed assemblages to coexist within a reasonable temperature range. All three phase diagrams require differences in fluid composition on the scale of a thin section; strong evidence for effective control of pore fluid composition by local mineral reactions during metamorphism.
Amphibolitization of metagabbros in the Scottish Highlands
Authors: MONGKOLTIP P. , ASHWORTH J. R.
Published: May 2007

Abstract
Compositions of actinolite, hornblende and cummingtonite, together with pyroxene and plagioclase, are studied in basic intrusions in the Dalradian of north‐east Scotland, and the Glen Scaddle complex in the West Moine. Amphibolitization is due to influx of water from the country rocks. Pyroxene compositions are found to have adjusted to the regional metamorphic environment. Owing to the difficulty of diffusion of Al and Si, calcic amphiboles are zoned and commonly contain quartz blebs. Discontinuities in zoning give rise to actinolite‐hornblende pairs. Compared with north‐east Scotland, disequilibrium is less strong in the Glen Scaddle area: in the latter, plagioclase compositions have been greatly changed, Na partition between hornblende and plagioclase is close to equilibrium, the maximum Al content of hornblende is lower and zoning patterns are more consistent. The Fe/Mg ratio in calcic amphiboles varies with Al content, while approaching equilibrium partition with other minerals. Both zoning patterns and Fe/Mg partition with cummingtonite suggest that Fe/Mg of the calcic amphiboles increases more strongly with increasing (Alvi+Fe3+) than can be explained simply by substitution of Al,Fe3+ for Mg on M2. Model reactions for amphibole formation are constructed. Cummingtonite formed at lower chemical potential of CaO than actinolite: Ca was exchanged for Mg,Fe between orthopyroxene‐derived and clinopyroxene‐derived local systems. Both cummingtonite and actinolite were formed because of kinetic constraints, as intermediate reaction products: actinolite‐hornblende pairs represent disequilibrium. This work suggests that many occurrences of actinolite with hornblende, where the minerals are zoned, may also be due to diffusion kinetics.
Stability relations of Mn–Fe–Al piemontite
Authors: KESKINEN MARY , LIOU J.G.
Published: May 2007

Abstract
Comparison of the stability relations of Fe‐piemontite, Pm17Ps17Cz66 (Ca2Al2Mn0.5 Fe0.5Si3O12(OH)), with similar experimentally determined results on Pm33Cz67 suggests that, at moderate fo2, addition of Fe to piemontite raises its thermal stability and slightly decreases its sensitivity to oxygen fugacity. Reversal study of the reaction: Fe‐piemontite + quartz = garnet (Gr33Sp27And40) + anorthite + fluid at Pfluid= 2 kbar in cold‐seal apparatus using solid oxygen buffers was completed. The data indicated breakdown of Pm17Ps17Cz66 at 645°± 10° C along the Cu2O–CuO buffer, 477°± 10° C along the Cu–Cu2O buffer, and 365°± 10° C for the hematite‐magnetite buffer. Mn‐free clinozoisite and epidote have been shown to be stable to much higher temperatures than piemontite at moderate fo2 (< Cu–Cu2O). At very high fo2, however, the presence of Mn+3 in a distorted octahedral site may permit persistence of piemontite to higher temperatures than Mn‐poor epidote minerals.

The compositional range of natural Fe–Mn–Al piemontites supports these results. Cation partitioning from piemontite‐bearing parageneses also indicates crystallization at high fo2, but application of the cited results should be made with caution. Synthetic phases were too fine‐grained for optical or microprobe analysis, and reaction was often incomplete. The assumption that all Fe + Mn was contained in piemontite and garnet, respectively, in the low‐ and high‐temperature assemblages is supported by the cell dimensions for these synthetic minerals, which are close to predicted values. The reaction is pseudo‐univariant, as solid solution in garnet and piemontite would be fo2‐dependent in a more complex chemical system. Although bulk rock and fluid compositions may also have a marked effect on the stability of natural epidote–piemontite, fo2 is the major control on Fe : Mn : Al in epidote minerals.
Multi‐textured garnets from a single growth event: an example from northern Norway
Authors: RICE A.H.N. , ROBERTS D.
Published: May 2007

Abstract
Textural relationships between porphyroblasts of biotite and garnet in metasediments in the Nordkinn Peninsula area of the Finnmarkian Caledonides of North Norway are apparently complex. There is evidence for two textural zones in both mineral phases and superficially the development of these appears to have overlapped, at least in part, in time and space. This apparently complex porphyroblast growth history can be considerably simplified if only one period of garnet growth occurred and if different inclusion fabrics developed where garnet replaced biotite porphyroblasts and where it overgrew the matrix foliation. The possibility that porphyroblasts with textural evidence for multiphase growth histories actually grew during a single crystallization event is of importance in the interpretation and elucidation of tectonometamorphic relationships.
Temporal and compositional differences between subsolidus and anatectic migmatite leucosomes from the Quetico metasedimentary belt, Canada
Authors: SAWYER E.W. , BARNES S.‐J.
Published: May 2007

Abstract
Migmatites in the Quetico Metasedimentary Belt contain two types of leucosome: (1) Layer‐parallel leucosomes that grew during deformation and prograde metamorphism. These are enriched in SiO2, Sr, and Eu, but depleted in TiO2, Fe2O3, MgO, Cs, Rb, REE, Sc, Th, Zr, and Hf relative to the Quetico metasediments. (2) Discordant leucosomes that formed after the regional folding events when metamorphic temperatures were at their peak. These are enriched in Rb, Ba, Sr and Eu, but display a wide range of LREE, Th, Zr, and Hf contents relative to the Quetico metasediments.

Layer‐parallel leucosomes formed by a subsolidus process termed tectonic segregation. This stress‐induced mass transfer process began when the Quetico sediments were deformed during burial, and continued whilst the rocks were both stressed and heterogeneous. Subsolidus leucosome compositions are consistent with the mobilization of quartz and feldspar from the host rocks by pressure solution. The discordant leucosomes formed by partial melting of the Quetico metasediments, possibly during uplift of the belt. The range of composition displayed by the anatectic leucosomes arises from crystal fractionation during leucosome emplacement. Some anatectic leucosomes preserve primary melt compositions and have smooth REE patterns, but those with negative Eu anomalies represent fractionated melts, and others with positive Eu anomalies represent accumulations of feldspar plus trapped melt.
Porphyroblast inclusion trails: the key to orogenesis
Authors: BELL T. H. , JOHNSON S. E.
Published: May 2007

Detailed microstructural analysis of inclusion trails in hundreds of garnet porphyroblasts from rocks where spiral‐shaped inclusion trails are common indicates that spiral‐shaped trails did not form by rotation of the growing porphyroblasts relative to geographic coordinates. They formed instead by progressive growth by porphyroblasts over several sets of near‐orthogonal foliations that successively overprint one another. The orientations of these near‐orthogonal foliations are alternately near‐vertical and near‐horizontal in all porphyroblasts examined. This provides very strong evidence for lack of porphyroblast rotation.

The deformation path recorded by these porphyroblasts indicates that the process of orogenesis involves a multiply repeated two‐stage cycle of: (1) crustal shortening and thickening, with the development of a near‐vertical foliation with a steep stretching lineation; followed by (2) gravitational instability and collapse of this uplifted pile with the development of a near‐horizontal foliation, gravitational spreading, near‐coaxial vertical shortening and consequent thrusting on the orogen margins. Correlation of inclusion trail overprinting relationships and asymmetry in porphyroblasts with foliation overprinting relationships observed in the field allows determination of where the rocks studied lie and have moved within an orogen. This information, combined with information about chemical zoning in porphyroblasts, provides details about the structural/metamorphic (P‐T‐t) paths the rocks have followed.

The ductile deformation environment in which a porphyroblast can rotate relative to geographic coordinates during orogenesis is spatially restricted in continental crust to vertical, ductile tear/transcurrent faults across which there is no component of bulk shortening or transpression.
Mass transfer and preferred orientation development during extensional microcracking in slate‐belt folds, Elura Mine, Australia
Authors: ROO J. A. DE
Published: May 2007

Microstructures in slate belt rocks at the Elura Mine, near Cobar, south‐eastern Australia, indicate that volume loss by syntectonic dissolution is coupled with mass accretion by reprecipitation of the dissolved material in dilational sites. The mass accretion is sustained primarily by repetitive tensile microfracturing at high pore‐fluid pressures. Oriented growth in the inter‐ and intragranular microcracks is locally host‐controlled, creating lattice‐ and shape‐preferred orientations. The grain‐scale crack‐seal features throughout the rock reflect rhythmic fluid pressure fluctuations; a balance is achieved between the fracture‐induced permeability (and consequent flushing rates), and the rate of fluid build‐up in a relatively sealed environment.

Instability in the balancing factors can lead to localization and intensification of tensile failure (and hence, tension vein formation) in the grain aggregate. Growth of veins by crack‐seal also reflects a steady state, but with more localized fluctuations of fluid flow on the aggregate scale. Still larger imbalances between flushing and fluid accumulation (i.e. pressure variations) induce breccia veining. The larger pressure gradients over greater distances, associated with dilation localization (from pervasive microfracturing to spaced breccia domains), allow fluid channelling with an increased potential for chemical fluid/rock disequilibrium. Therefore, large breccia vein systems tend to be sites of extensive fluid/rock interaction and replacement, as spectacularly illustrated by the syntectonic sulphide orebodies at Elura. The huge amounts of silicate, carbonate and sulphide accumulated during folding at Elura illustrate the large scale of source and sink couples possible in solute mass transfer.
Metastable growth of corundum adjacent to quartz in a spinel‐bearing quartzite from the Archaean Napier Complex, Antarctica
Authors: MOTOYOSHI Y. , HENSEN B. J. , MATSUEDA H.
Published: May 2007

In a granulite‐facies spinel‐bearing quartzite, corundum, orthopyroxene and sapphirine (and rarely cordierite and sillimanite) form partial rims separating spinel from quartz. Textures indicate the reactions:

spinel + quartz = orthopyroxene + corundum, and

spinel + quartz = orthopyroxene + sapphirine.

Thus, corundum and sapphirine are produced by reactions involving quartz. The low Al‐content of the orthopyroxene (0.5–2.8 wt %) and low values for Mg–Fe distribution coefficient for spinel–sapphirine and spinel–orthopyroxene reflect low‐temperature conditions during formation of the reaction products. Absence of zoning in spinel and a constant Mg–Fe distribution coefficient for spinel–sapphirine and spinel–orthopyroxene, over a compositional range, indicate Mg–Fe equilibration. It is suggested that stable reactions such as spinel + quartz = cordierite or spinel + quartz = garnet + sillimanite were over‐stepped and that metastable reactions give rise to the anomalous juxtaposition of corundum + quartz.
40Ar/39 mineral ages from the Scituate Granite, Rhode Island: implications for Late Palaeozoic tectonothermal activity in New England
Authors: DALLMEYER R. D. , HERMES O. D. , GIL‐IBARGUCHI J. I.
Published: May 2007

The alkalic Scituate Granite was emplaced into crystalline sequences within the New England Esmond–Dedham terrane in the Late Devonian (c. 370 Ma). Variably recrystallized amphibole (iron‐rich, hastingsite–hastingsitic hornblende) from four variably deformed samples of the pluton record south‐westerly younging 40Ar/39Ar plateau ages ranging between 276 and 263 Ma. These are interpreted to date diachronous cooling through temperatures appropriate for intracrystalline retention of argon following late Palaeozoic orogenic activity. Iron‐rich biotite concentrates from the samples record only slightly younger ages, and therefore suggest relatively rapid post‐metamorphic cooling. The 40Ar/39Ar ages indicate that the late Palaeozoic tectonothermal overprint was much more regionally pervasive than was previously considered. The apparent timing of this activity is similar to previous estimates for the chronology of high‐grade metamorphism throughout the adjacent Hope Valley terrane and for phases of ductile movement on the intervening Lake Char–Honey Hill fault system.
Geothermobarometry in metasediments of the southern Grossvenediger area (Tauern Window, Austria)
Authors: DACHS E.
Published: May 2007

Metasediments in the southern Grossvenediger area (Tauern Window, Austria) were studied along a cross‐section through rocks of increasing metamorphic grade from the margin of the Tauern Window in the south to the base of the Upper Schieferhülle, including the Eclogite Zone, in the north.

In the southern part of the cross‐section there is no evidence for a pre‐late Alpine metamorphic history in the form of high‐pressure relics or pseudomorphs. Mineral assemblages are characterized by the stability of tremolite + calcite, biotite + calcite and biotite + chlorite + calcite. In the northern part a more complete Alpine metamorphic evolution is preserved. Primary high‐pressure assemblages are dolomite + quartz, tremolite + zoisite, zoisite + dolomite + quartz + phengite I and probably tremolite + dolomite + phengite I. Secondary, post‐kinematic assemblages [tremolite + calcite, talc + calcite, phengite II + chlorite + calcite (+ quartz), biotite + chlorite + calcite, biotite + zoisite + calcite] formed as a result of the dominant late Alpine metamorphic overprint. The occurrence of biotite + zoisite + calcite is confined to the northernmost area and defines a biotite–zoisite–calcite isograd.

P–T estimates based on standard thermobarometric techniques and on stability relationships of tremolite + calcite + dolomite + quartz and zoisite give consistent results. P–T conditions of the main Tertiary metamorphic overprint were 525° C, P= 7.5 ± 1 kbar in the northern part of the cross‐section. The southern part was metamorphosed at lower temperatures of 430–470° C. The Si‐content of phengites from this area is almost as high as that of phengites from the Eclogite Zone (Simax= 3.4 pfu). Pressures > 10 kbar at 420° C are suggested by phengite barometry according to Massone & Schreyer (1987). In the absence of high‐pressure relics or pseudomorphs, these phengites, which lack late Alpine re‐equilibration, are the only record that rocks of the southern part probably also experienced an early non‐eclogitic high‐pressure metamorphism.
Aluminous reaction textures in orthoamphibole‐bearing rocks: the pressure–temperature evolution of the high‐grade Proterozoic of the Bamble sector, south Norway
Authors: VISSER D. , SENIOR A.
Published: May 2007

Aluminous reaction textures in orthoamphibole‐bearing rocks from the Froland area, Bamble, south Norway, record the prograde pressure–temperature path of the high‐grade Kongsbergian Orogeny (c. 1600–1500 Ma) and the low–mid amphibolite facies overprint during the Sveconorwegian Orogeny (c. 1100–1000 Ma). The rocks contain anthophyllite/gedrite, garnet, cordierite, biotite, quartz, andalusite, kyanite, Cr‐rich staurolite, tourmaline, ilmenite, rutile and corundum in a variety of parageneses. The P–T path is deduced from petrographic observations, mineral chemistry and zoning, geothermometry and (N)FMASH equilibria. The results indicate the sequence of metamorphic stages outlined below. (a) An M1 phase characterized by the presence of strongly deformed andalusite, gedrite and tourmaline.

(b) An M2 phase with the development of kyanite after andalusite and the growth of staurolite associated with strong Na–Al–Mg zoning in orthoamphibole, indicating an increase in pressure (4 8 kbar) and temperature (500° 650°C).

(c) Pressure decrease at high P (6–7 kbar) and high T (600–700 °C) during M3a with the production of cordierite ° Corundum between kyanite, staurolite and orthoamphibole and cordierite growth between corundum and orthoamphibole.

(d) Temperature increase to 740 ± 60 °C and 7 kbar; static growth of garnet (M3b) at the metamorphic climax (peak T). The heat supply necessary to explain the temperature increase between the M3a and M3b phases is correlated with synkinematic enderbitic–charnockitic and basic intrusions in the Arendal granulite facies terrain.

(e) M3b metamorphic conditions were followed by an initial isobaric cooling path (early M4) and late‐stage pressure decrease (late M4). Early M4 conditions of 6–7 kbar and 550–600 °C, assuming PH2O < Ptotal are indicated by a retrograde talc–kyanite–quartz assemblage in late quartz–cordierite veins. Late M4 conditions of 3–4 kbar and 420–530 °C are inferred from a kyanite–andalusite–chlorite–quartz assemblage in vein‐cordierite. The M1–M3 stages are interpreted as being the result of the same metamorphic P–T path, which was caused by both tectonic and magmatic thickening. A prolonged crustal residence time is proposed for the Bamble sector before uplift during the later stages of M4 occurred.
METPET: Metamorphic petrology microcomputer programs
Authors: BALL D. G. A. , ROBIN P.‐Y. F.
Published: May 2007

METPET is a package of three interactive microcomputer (IBM PC or compatible) programs. FILEMAN is a utility program to create, edit and print ‘composition files’, i.e. files containing the records of chemical compositions of minerals or rocks, expressed in terms of primary chemical components. PROJECT recalculates selected compositions in terms of new (secondary) components. It then projects these compositions onto a subspace defined by two, three or more of the secondary components, first giving a plot on the screen and then, if requested by the user, on a selected graphic device. REACT calculates a possible set of independent reactions between a set of phases, whether pure compounds or solutions. Any linear combination of the independent reactions can be calculated on request.
The higher grade metamorphic zonation of the Sambagawa metamorphic belt in central Shikoku, Japan
Authors: HIGASHINO T.
Published: May 2007

The higher grade metamorphic zonation of the Sambagawa (= Sanbagawa) belt is established for the first time for the whole area of central Shikoku. As discontinuous reactions to define the isograd are absent, the metamorphic grade is primarily determined by the Mg‐Fe partitioning between garnet and chlorite along representative traverses. However, for regional mapping, mineralogical features of the pelitic schists, such as using mineral assemblages of more than divariant equilibrium, the modal garnet to chlorite ratio, and the optical properties of chlorite, are employed as auxiliary criteria.

The presence of the highest grade mineral zone in the middle of the structural level is confirmed, but its spatial distribution is far more complex than hitherto accepted. Thermal axes are now confirmed at three different structural levels. A model is presented in which the stacking of thrust sheets of different grade took place while metamorphic reactions were in progress. Thermal readjustment brought a continuous metamorphic temperature gradient across and within the thrust sheets. Tectonic blocks of metagabbro and ultramafic rock were emplaced synchronously with thinning and subsequently also re‐equilibrated. Local anomalies of metamorphic grade, represented by mixing of schists of different metamorphic grade, exist, but they are due to a later stage event.
Development of inverted metamorphic isograds in the western metamorphic belt, Juneau, Alaska
Authors: HIMMELBERG G. R. , BREW D. A. , FORD A. B.
Published: May 2007

An inverted metamorphic gradient is preserved in the western metamorphic belt near Juneau, Alaska. The western metamorphic belt is part of the Coast plutonic–metamorphic complex of western Canada and southeastern Alaska that developed as a result of tectonic overlap and/or compressional thickening of crustal rocks during collision of the Alexander and Stikine terranes. Detailed mapping of pelitic single‐mineral isograds, systematic changes in mineral assemblages, and silicate geothermometry indicate that thermal peak metamorphic conditions increase structurally upward over a distance of about 8 km. Peak temperatures of metamorphism increase progressively from about 530 °C for the garnet zone to about 705 °C for the upper kyanite–biotite zone. Silicate geobarometry suggests that the thermal peak metamorphism occurred under pressures of 9–11 kbar. The metamorphic isograds are in general parallel to the tonalite sill that is regionally continuous along the east side of the western metamorphic belt, although truncation of the isograds north of Juneau indicates that the sill intrusion continued after the isograds were established. Our preferred interpretation of the cause of the inverted gradient is that it formed during compression of a thickened wedge of relatively wet and cool rocks in response to heat flow associated with the formation and emplacement of the tonalite sill magma. Garnet rim compositions and widespread growth of chlorite suggest partial re‐equilibration of the schists under pressures of 5–6 kbar during uplift in response to final emplacement and crystallization of the tonalite sill. The combined results of this study with previous studies elsewhere in the western metamorphic belt indicate that high‐T/high‐P metamorphism associated with the collision of the Alexander and Stikine terranes was a long‐lived event, extending from about 98 Ma to about 67 Ma.
Buffering in the assemblage staurolite‐aluminium silicate‐biotite‐garnet‐chlorite
Authors: GIARAMITA M. J. , DAY H. W.
Published: May 2007

Abstract
The assemblage muscovite‐quartz‐staurolite‐aluminium silicate‐biotite‐garnet‐chlorite with H2O (SABGC assemblage) is invariant in the K2O‐FeO‐MgO‐Al2O3‐SiO2‐H2O (KFMASH) system. Such five‐phase AFM assemblages should be absent in nature, but reported occurrences from at least ten localities suggest that either the assemblage internally controls μH2O or non‐KFMASH components stabilize one or more of the phases.

Least‐squares regression analysis of minerals from South Royalton and Gassetts, Vermont, USA, demonstrates that subsets of the minerals in single SABGC assemblages from both localities are related by balanced reactions involving water. These results are consistent with the interpretation that the subassemblages fixed μH2O at an arbitrary, specified pressure and temperature. Balanced dehydration reactions also may be written between minerals in the SABGC assemblages and four‐phase assemblages from the same outcrops interpreted to have equilibrated at the same pressures and temperatures as the five‐phase assemblages. These results suggest that different specimens from the same outcrops equilibrated at different values of μH2O, supporting the conclusion that μH2O was not controlled externally. We could not demonstrate internal control of fo2 using measured mineral compositions because oxygen balance occurred in all reactions derived by regression.

Regression analysis of published mineral compositions from New Mexico failed to identify balanced reactions involving water or oxygen either among the phases in a single SABGC assemblage or between SABGC and nearby four‐phase assemblages. These results demonstrate that neither μH2O nor fo2 were fixed by the SABGC assemblages at these localities, and permit the interpretations that the assemblages were stabilized by the non‐KFMASH components Na or Ca and that μH2O and fo2 were controlled externally.
Petrology of spinel granulites from Araku, Eastern Ghats, India, and a petrogenetic grid for sapphirine‐free rocks in the system FMAS
Authors: SENGUPTA P. , KARMAKAR S. , DASGUPTA S. , FUKUOKA M.
Published: May 2007

Abstract
Spinel‐quartz‐cordierite and spinel‐quartz are found as relic prograde assemblages in Fe‐rich granulites from the Araku area, Eastern Ghats belt, India. Subsequent reactions produced orthopyroxene + sillimanite in the former association and garnet + sillimanite in the latter. The first reaction is univariant in the FMAS system, but is trivariant in the present case because of the presence of Zn and Fe3+ in spinel. The second reaction also has high variance because of Zn and Fe3+, but also because of the presence of Ca in garnet. Thermobarometry shows that the metamorphic conditions were approximately 950° C and 8.5 kbar and the fo2 was near the NNO buffer. In Fe‐rich bulk compositions and low‐P‐high‐T conditions of metamorphism, two of the univariant reactions around the invariant point [Sa], namely (Sa, Hy) and (Sa, Cd), change topology due to reverse partitioning of Fe‐Mg between coexisting garnet and spinel. An alternative partial petrogenetic grid in the system FMAS is constructed for such conditions and is applied satisfactorily to several sapphirine‐free spinel granulites. It is shown that bulk composition (XFe and Zn) exerts greater control on the stability of spinel + quartz than fo2. The effect of the presence of Zn and Fe3+ in spinel on the proposed grid is evaluated. Reaction textures in the Araku spinel granulites can be explained from the petrogenetic grid as due to near‐isobaric cooling.
Deep‐crustal granulites with migmatitic and mylonitic fabrics from the Zambezi Belt, northeastern Zimbabwe
Authors: CARNEY J. N. , TRELOAR P. J. , BARTON C. M. , CROW M. J. , EVANS J. A. , SIMANGO S.
Published: May 2007

Abstract
High‐P granulites contained in two allochthonous tectonic units were thrust southwards onto the northern margin of the Zimbabwe craton during the Pan‐African Zambezi orogeny. In the lower sheet, the Masoso Metamorphic Suite contains mafic garnet granulite assemblages formed during a high‐P‐T metamorphic event, although the suite as a whole is predominantly granitic. The garnet granulites occur as relicts within narrow mafic layers characterized by migmatitic and mylonitic fabrics. The annealed mylonites represent surfaces of deep‐crustal tectonic imbrication that formed immediately before the Pan‐African orogeny. Gabbros which intruded the granulites after the main phase of migmatization have formed corona textures that document a low‐P‐T metamorphic event at mid‐crustal levels. The style of deformation then changed and the Masoso Suite with its mylonitic layers was folded and thrusted southwards onto the Archaean Zimbabwe craton.