bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term progression of Alzheimer's disease in patients under antidementia drugs
Authors: Gillette‐Guyonnet Sophie , Andrieu Sandrine , Nourhashemi Fati , Gardette Virginie , Coley Nicola , Cantet Christelle , Gauthier Serge , Ousset Pierre‐Jean , Vellas Bruno ,   REAL.FR study group
Published: November 2011

Background

Patients with Alzheimer's disease (AD), even in the presence of symptomatic relief from medical intervention, face a persistent worsening of cognitive decline and performance in activities of daily living. Data regarding the long‐term disease progression outside of therapeutic trials are lacking. We examined the effects of standard of care for AD patients on the prognosis of the disease in a real‐life study over a 4‐year period.

Methods

A total of 686 patients with mild‐moderate AD were enrolled in 16 memory clinics (REseau sur la maladie d’ Alzheimer FRançais [REAL.FR] cohort) and followed up twice annually with tools used in therapeutic trials (Mini‐Mental Status Examination, Alzheimer Disease Assessment Scale‐cognitive subscale [ADAS‐cog]: cognitive function, Clinical Dementia Rating: dementia severity, Activity of Daily Living [ADL]: incapacities, NeuroPsychiatric Inventory: neuropsychiatric symptom).

Results

More than 90% of the patients used AD‐specific medication over 4 years. Patients lost on average 2.4 points per year on the Mini‐Mental Status Examination and gained 4.5 points on the ADAS‐cog. ADL and NeuroPsychiatric Inventory scores became significantly worse over time. Incidence of incapacities for ADL and worsening of neuropsychiatric symptoms were 52.5 (95% confidence interval [CI]: 47.7–57.4) and 51.1 (95% CI: 46.2–56.1), respectively. Rates of mortality and institutionalization were 7.4 (95% CI: 6.2–8.5) and 13.4 (95% CI: 11.7–15.1). In all, 17% of patients in mild stage at baseline (Clinical Dementia Rating = 0.5) did not experience a major event (functional disabilities, neuropsychiatric symptoms, or death) over a 4‐year period.

Conclusions

As compared with previous surveys, the current study shows slower rates of decline in AD patients. The present data also underline the high level of variability of disease progression among AD patients. Outcome measures commonly used in clinical trials will need to take into account the recent changes in the prognosis of the disease.
Evidence of crystallization in residual, Cl–F-rich, agpaitic, trachyphonolitic magmas and primitive Mg-rich basalt–trachyphonolite interaction in the lava domes of the Phlegrean Fields (Italy)
Authors: MELLUSO LEONE , DE' GENNARO ROBERTO , FEDELE LORENZO , FRANCIOSI LUIGI , MORRA VINCENZO
Published: November 2011

The lava domes in the northwestern (Cuma), northern (Punta Marmolite) and central (Accademia) parts of the Phlegrean Fields are the subject of this study. The Cuma and Punta Marmolite trachyphonolitic lava domes are among the oldest Phlegrean products cropping out. The Cuma rocks have an agpaitic groundmass, with early alkali feldspar, Fe-rich clinopyroxene, Fe-edenite and sodalite and late rosenbuschite, fluorite, baddeleyite, pyrochlore, britholite, monazite, aegirine (often Zr-rich) and exceptionally Fe–Mn-rich olivine. The bulk-rock compositions at Cuma have some of the highest concentrations of Zn, Mn, Zr, Nb, Th, U and lanthanides among the Phlegrean Fields rocks, and some of the lowest MgO, P2O5, Sr, Eu and Ba. The Punta Marmolite dome is chemically less evolved, and lacks characteristic agpaitic minerals, but features alkali feldspar, sodalite, nepheline and relatively Na-poor, Fe-rich hedenbergite, with rare Ca-rich plagioclase xenocryst cores. The Accademia dome, belonging to the recent activity, is latitic to trachytic in composition, has highly forsteritic olivine (with chromiferous spinel inclusions), calcic plagioclase and Mg-rich diopside (± phlogopite) xenocrysts in an evolved host rock (with phenocrysts and microlites of alkali feldspar, Fe-rich clinopyroxene, Fe-rich amphibole, magnetite, Fe-rich olivine and accessory baddeleyite, zirconolite and fluorite). There is clear evidence of open-system magma crystallization in the form of interaction between a crystallizing, primitive shoshonitic basalt in a reservoir already filled by rather evolved trachytic magma. The magmatic evolution towards the evolved compositions is dominated by crystallization of more and more Na-rich alkali feldspar in a Cl-, F-rich and relatively H2O-poor environment. Input of mafic magma is evident in many trachytic eruptions of the Phlegrean Fields and even in the products of the Campanian Ignimbrite, but eruptions having mineral assemblages rich in xenocryst phases as well as eruptions virtually free of mafic magma input are also frequently observed throughout the history. This suggests a variable pattern of open- and closed-system crystallization, which may or may not be linked to explosive activity, and that can be caused by intermittent supply of basaltic magma from depth.
Absence ofHelicobacter pyloriin healthy laryngeal mucosa
Authors: Pajić-Penavić I , Đanić D , Maslovara S , Gall-Trošelj K
Published: November 2011

Objectives:

To evaluate the presence ofHelicobacter pyloriin healthy laryngeal mucosa.

Design:

Prospective analysis ofHelicobacter pyloricolonisation in healthy laryngeal mucosa, using the13C urea breath test and polymerase chain reaction analysis.

Subjects:

Twenty randomly chosen men (28–78 years) without laryngeal pathology or gastrointestinal disease were investigated. All subjects were scheduled for elective operative procedures, under general, endotracheal anaesthesia. Cytobrush samples were taken forHelicobacter pyloriDNA detection. Nested polymerase chain reaction testing was performed on DNA solutions using two primer pairs from the urease A gene of theHelicobacter pylorigenome. The13C urea breath test was performed on two exhalation samples.

Results:

Eight (40 per cent) of the subjects were positive for urease on urea breath testing; none were positive forHelicobacter pyloriDNA on polymerase chain reaction testing.

Conclusion:

Based on these results, we do not considerHelicobacter pylorito be a normal constituent of healthy laryngeal microflora.
Simultaneous occurrence of a thyroglossal duct cyst and a lingual thyroid in the absence of an orthotopic thyroid gland
Authors: Madana J , Kalaiarasi R , Yolmo D , Gopalakrishnan S
Published: November 2011

Objective:

We report an extremely rare case of the simultaneous occurrence of a thyroglossal duct cyst and a lingual thyroid in the absence of an orthotopic thyroid gland, in a seven-year-old girl from South India.

Method:

Case report and a review of the English language literature on the subject.

Results:

The patient presented with a mass on the tongue that had been present for three years, and an anterior neck swelling that had been present for two years. Examination revealed a midline, pinkish, firm mass present on the posterior one-third of the tongue. The neck showed a midline cystic swelling in the infrahyoid position. Radiological imaging confirmed the clinical findings, revealing the absence of her thyroid gland in the normal location. Sistrunk's procedure was performed leaving behind a lingual thyroid. At 13-month follow up, the patient was euthyroid with no recurrence.

Conclusion:

To our knowledge the association of a lingual thyroid and a thyroglossal cyst has only been reported once in the literature. The presence of a lingual thyroid in the absence of a normally located thyroid gland or functioning thyroid tissue along the thyroglossal tract, confirmed by radionuclide and computed tomography imaging, may indicate the failure of the normal descent of the thyroid gland during embryonic development. This probable absence of the descent of the thyroid raises questions regarding the origin of thyroglossal duct cysts.
Remote sensing analysis reveals habitat, dispersal corridors and expanded distribution for the Critically Endangered Cross River gorillaGorilla gorilla diehli
Authors: Bergl Richard A. , Warren Ymke , Nicholas Aaron , Dunn Andrew , Imong Inaoyom , Sunderland-Groves Jacqueline L. , Oates John F.
Published: November 2011

Habitat loss and fragmentation are among the major threats to wildlife populations in tropical forests. Loss of habitat reduces the carrying capacity of the landscape and fragmentation disrupts biological processes and exposes wildlife populations to the effects of small population size, such as reduction of genetic diversity and increased impact of demographic stochasticity. The Critically Endangered Cross River gorillaGorilla gorilla diehliis threatened in particular by habitat disturbance because its population is small and it lives in an area where high human population density results in intense exploitation of natural resources. We used remotely-sensed data to assess the extent and distribution of gorilla habitat in the Cross River region and delineated potential dispersal corridors. Our analysis revealed > 8,000 km2of tropical forest in the study region, 2,500 km2of which is in or adjacent to areas occupied by gorillas. We surveyed 12 areas of forest identified as potential gorilla habitat, 10 of which yielded new records of gorillas. The new records expand the known range of the Cross River gorilla by > 50%, and support genetic analyses that suggest greater connectivity of the population than previously assumed. These findings demonstrate that considerable connected forest habitat remains and that the area could potentially support a much larger gorilla population if anthropogenic pressures such as hunting could be reduced.
Swimming locomotion modeling for biomimetic underwater vehicle with two undulating long-fins
Authors: Shang Liuji , Wang Shuo , Tan Min , Cheng Long
Published: November 2011

A biomimetic underwater vehicle, which is propelled by two undulating long-fins, is introduced in this paper. The undulating or oscillating movements of symmetrical long-fins cause the complex locomotion of biomimetic underwater vehicle. For convenience, three motion modes are proposed and considered firstly. Then an inertial unit is installed for collection of accelerations and angular velocity. The underwater vehicle's MIMO model is reduced into a SISO model by some simplifications. A sine wave function deduced from the long-fin's time-varying membrane is proposed and used as the input of the biomimetic underwater vehicle ARMA model, and velocity or angular velocity is considered as the model output. The algorithms based on recursive weighted least squares are applied for model parameter identification. Experiments carried out with a long-fin propelled underwater vehicle. The experimental results show that the proposed methods can build valid locomotion models for three motion modes efficiently.
Comments on ‘Evidence for a Caledonian orogeny in Poland’ by J. D. Johnston, J. A. Tait, J. H. Oliver and F. G. Murphy
Authors: Moczydłowska Małgorzata
Published: November 2011

In a recent paper Johnston et al. (1994) have provided an innovative interpretation of the tectonostratigraphic relationships between distinct terranes juxtaposed along the Intra–Sudetic Fault in the Sudetes Mountainsof the Polish Variscides. They identified this fault as a major crustal fracture between Gondwana and Baltica, rramed the Tornquist Suture, resulting from the closure of the Tornquist Sea during the Caledonian orogeny. This interpretation is based on new U/Pb ages on zircon and titanite from igneous and metamorphic rocks (Oliver et al. 1993), field observations and reassessment of pre–existing data. Previously, the Sudetes were generally thought to haveformed during the Hercynian orogeny, although Caledonian age deformation was also inferred (Oberc 1977, 1986; Don 1984, 1986, 1990).
Reply to Comments by M. Moczydłowska
Authors: Johnston J. D. , Tait J. A. , Oliver G. J. H. , Murphy F. G.
Published: November 2011

We are happy to receive constructive comments of our paper by Moczydlowska and thank her for adding new relevant data. We will attempt to reply to each of her points.
Mafic granulites of the Schirmacher region, East Antarctica: fluid inclusion and geothermobarometric studies focusing on the Proterozoic evolution of the crust
Authors: Rao D. Rameshwar , Sharma Rajesh , Gururajan N. S.
Published: November 2011

In the Proterozoic complex of the Schirmacher region of East Antarctica, a retrograde pressure–temperature (P–T) history has been inferred through quantitative geothermobarometry and fluid inclusion studies of the mafic granulites. Microthermometric investigations of the fluid phases trapped in quartz and garnet identified three types of inclusions, namely, earliest pure CO2 inclusions (0·987–1·057 g cm−3), CO2–H2O inclusions and aqueous inclusions.

The temperature and pressure of metamorphism have been estimated through different calibrations of geothermometers and geobarometers. The mineral reactions and compositional zoning in the minerals record P–T conditions from nearly 837 ± 26°C, 7·1±0·2 kbar to 652 ± 33°C, 5·9 ± 0·3 kbar. A good correlation between the fluid and mineral data is observed. The isochores typical of highdensity CO2 fluids fall well within the P–T box estimated by mineral thermobarometry. The abundance of primary CO2 inclusions in early metamorphic minerals (notably quartz and primary garnet) and the general correspondence between fluid and mineral P–T data indicate a ‘fluid-present’ carbonic regime for the high-grade metamorpism; however, from the present data largescale CO2 advection could not be envisaged. The subsequent stages involved a decrease in CO2 density, a progressive influx of hydrous fluids and the generation of retrograde amphibolite facies metamorphism in the area.

The estimated P–T conditions of the region suggest that the rocks were metamorphosed at a depth of 19–24 km, with a geothermal gradient of c. 3°5C km−1. The estimated P–T conditions of the rocks imply a clockwise P–T–t path with a gradual decrease in temperature of around 250°C and a decrease in pressure of around 1700 bar. They have a dP/dT gradient of ≈7 ± l bar °C−1, arguing for an isobaric cooling history of the terrane under normal thickened crust after the underplating of mantle-derived material.
The morphology and phylogenetic significance ofKerygmachela kierkegaardiBudd (Buen Formation, Lower Cambrian, N Greenland)
Authors: Budd Graham E.
Published: November 2011

Specimens ofKerygmachela kierkegaardiBudd are described, from the Lower Cambrian Sirius Passet fauna of N Greenland. The cephalic region is characterised by a pair of stout unsegmented appendages each bearing long spinose processes, and an anterior mouth. The trunk shows alternating rows of tubercles and transverse annulations along the axis, to which are attached 11 pairs of gill-bearing lateral lobes and lobopodous limbs. The caudal region is small, and bears two long tail spines. There is some evidence for circular musculature arranged around the trunk and a dorsal, longitudinal sinus, and several details of the muscular pharynx have been preserved.

The combination of characters found inKerygmachelaallows it to be allied with the lobopods, represented in the extant fauna by the onychophorans, tardigrades, and possibly the pentastomids, and in the Cambrian fossil record by a morphologically diverse set of taxa, some of which are not assignable to the extant groupings. It also shares important characters with the previously problematic Burgess Shale formsOpabinia regalisWalcott andAnomalocarisWhiteaves, and the Sirius Passet form Pambdelurion Budd. These taxa together form a paraphyletic group at the base of the clade of biramous arthropods. The position of the so-called ‘Uniramia’ remains unclear. It can be demonstrated from the reconstruction of the arthropod stem-group that full arthropod segmentation has a different derivation from that of the annelids. In line with other recent analyses, this suggests that the ‘Articulata’ of Cuvier should be dismantled, and the arthropods considered to be a group of protostomes which are phylogenetically distinct from the classic spiralians. Arthropod affinities may rather lie with the other moulting animals, in the so-called ‘Ecdysozoa’.
The postcranial skeleton ofDiscosauriscusKuhn, a seymouriamorph tetrapod from the Lower Permian of the Boskovice Furrow (Czech Republic)
Authors: Klembara Jozef , Bartík Ivan
Published: November 2011

The description of the postcranial skeleton of larval, metamorphic and early juvenile specimens of the genusDiscosauriscusis based on three-dimensional material and includes a description of the ontogeny of the swollen neural arches and the central elements of the vertebrae.Discosauriscushas 24 (or 23) presacral vertebrae. The morphology of the atlas–axis complex is similar to that inSeymouria sanjuanensis. The neural arches start to swell slightly in specimens of late larval stage; they are completely swollen immediately after metamorphosis. There are about 40 caudal vertebrae and one sacral vertebra. The atlantal pleurocentrum is paired in metamorphic individuals. In postmetamorphic individuals, the pleurocentra 2–5 are not completely closed dorsally; the pleurocentra 6–30 form complete discs. The first haemal arch is situated on the sixth caudal vertebra. The atlantal rib is present. There are six caudal ribs.Discosauriscushas an anocleithrum which is the first record of this dermal pectoral element within seymouriamorphs and Lower Permian tetrapods. The scapula and the coracoid are separate elements. The phalangeal formula of the manus is 2, 3, 4, 5, 3. The iliac blade has a massive, almost horizontally oriented posterior process; the anterior process is absent. The phalangeal formula of the pes is 2, 3, 4, 5, 3. Rounded ventral scales are present. The comparison and evaluation of the available postcranial elements ofDiscosauriscus, Utegenia, AriekanerpetonandSeymouriasupport the view thatDiscosauriscusandAriekanerpeton, forming the family Discosauriscidae, are immediately related genera.
The East Kirkton Limestone, Viséan, of West Lothian, Scotland: introduction and stratigraphy
Authors: Rolfe W. D. I. , Durant G. P. , Baird W. J. , Chaplin C. , Paton R. L. , Reekie R. J.
Published: November 2011

A brief history of research into the unusual laminated and spherulitic East Kirkton Limestone (Brigantian, Viséan) is given. It documents the paucity of fossil finds until 1984, when S. P. Wood discovered a previously unsuspected terrestrial biota. Some early finds, such as stromatolites, have since been overlooked, while others were misinterpreted, e.g. a ‘fish-bone’ collected before 1870 proves to be amphibian. A formal lithostratigraphic description is given of the three beds that comprise the c. 15 m sequence in East Kirkton Quarry: the East Kirkton Limestone, overlain by Little Cliff Shale and Geikie Tuff, the latter two being here formally named. Lithological descriptions and a unit-by-unit distribution of major elements of the biota are provided for a measured section comprising 88 units. This is based on bed-by-bed excavations carried out 1985-92, supplemented by nine boreholes. Two 3 m-thick massive limestones lenses are recorded from the quarry and a probable third was proved in a borehole. Brief reports are given on the ‘stromatolites’ (by M. R. Walter), bivalve molluscs (R. M. C. Eagar and R. B. Wilson), ostracods (J. Pollard) and gypsum pseudomorphs.
Palaeoecology of the Viséan of East Kirkton, West Lothian, Scotland
Authors: Clarkson E. N. K. , Milner A. R. , Coates M. I.
Published: November 2011

The Viséan sequence at East Kirkton was deposited in a shallow lake, set within a richly vegetated landscape formed of volcanic cones a few hundred metres high. There was little volcanic activity, however, while the lake existed, and the many tuff horizons within the sequence were washed in during weathering. The lake may have been generally cool, though of unusual water chemistry, as a result of which the spherulitic East Kirkton Limestone precipitated. At times, however, water temperatures may have risen sharply through localised hot-spring activity; both factors deterred ‘normal’ aquatic life.

The bulk of the preserved biota consists of plants (permineralisations and compressions) and dominantly land-living animals, including the oldest terrestrial tetrapods (amphibians and reptiliomorphs), large terrestrial-aquatic eurypterids, the first harvestman and rare millipedes. All these animals lived close to the lake, in a fire-prone forest dominated by gymnosperms and pteridosperms.

At a late stage in the history of the lake, deposition of spherulitic limestones was replaced by black shales, bearing a ‘standard’ Oil-Shale fish fauna, suggesting that the isolated lake had linked with a larger fish-bearing water body. This is coupled with a shift to a lycopod-dominated flora and may indicate a climatic change to wetter conditions. Finally the lake silted up with tuff, ending an existence of only a few tens of thousands of years.
Fertility of metapelites and metagraywackes during leucogranite generation: an example from the Black Hills, U.S.A.
Authors: Nabelek Peter I. , Bartlett Cindy D.
Published: November 2011

In order to elucidate how mineralogy and composition of crustal sources influences production of leucogranite magmas, we modelled the potential fertility of a sequence of metapelites and metagraywackes from the Black Hills, South Dakota, U.S.A., using a least-squares mixing approach. Rocks analogous to the Black Hills schists were the sources of the Harney Peak leucogranite. Both muscovite and biotite fluid-absent melting reactions (MM and BM, respectively) were investigated. Using the Harney Peak Granite composition as the melt analogue and mineral compositions from the schists for mixing calculations, it is shown that MM of metapelites would lead to highly variable residue mineralogy in the investigated samples. The average residue includes 36 wt.% biotite, 32 wt.% quartz, 12 wt.% plagioclase, 8 wt.% K-feldspar, 9 wt.% sillimanite and 2 wt.% garnet. Melt production ranges from 5% to 23% with an average of 14%. It is limited by the amount of H2O that must be in the melt at the conditions of melting, relative to the amount that is in muscovite in the source rocks. Plagioclase-rich metagraywackes contain little to no muscovite, thus MM cannot occur in them.

Although BM is continuous over a wide temperature range, for the purposes of modelling melting at 975°C and 10kbar was chosen. The temperature is near the terminal stability of biotite, thus the calculations give near-maximum melt production. At this temperature, the mineralogy of the model residues from both metapelites and metagraywackes is dominated by garnet. The potential melt production in the metapelites ranges from 0% to 58% with an average of 32%. It is limited by the availability of plagioclase in the source rocks. Potential melt production in the metagraywackes ranges from 9% to 37% with an average of 23%. At the chosen conditions of melting, melt production is limited by the available K in biotite, although at lower temperatures, the available H2O limits melt production. The total potential melt production (MM + BM) in the metapelites is higher because they have on average a low normative An/Ab ratio (0·14) that approaches the ratio in the leucogranites (0·04). The paragonite component in muscovite significantly contributes to the low ratio in the metapelites. The higher ration (0·27) in the metagraywackes is denned by the feldspar composition.

Using the calculated melt fractions and residue mineralogies, we modelled the concentrations of Rb, Sr and Ba in the melts, as these elements are important indicators of melt-generating processes. The results indicate that both Sr and Ba are likely to be heterogeneous in extracted melt batches and will be depleted in partial melts relative to their pelitic sources, irrespective of whether the melting is fluid-absent or fluid-present.
Granite genesis related to geodynamics from Hf—Y in zircon
Authors: Pupin Jean-Pierre
Published: November 2011

Zircon is a very interesting accessory mineral, a kind of ‘crustal diamond’, easily recycled and recording through large morphological variability the main rock-forming events. Since 1985, a systematic study of chemical variability of zircon in magmatic rocks has led to the definition of three main generations in zircon populations: inherited phase 1, magmatic phase 2 and late magmatic phase 3. Hafnium and yttrium appear to be the most useful for source characterisation, especially if using phase 2 data. As a consequence, a new diagram of HfO2versus Y2O3is proposed, divided into domains la to 6b to describe the distribution of the genetic groups and the specific domains for anorogenic and orogenic rocks. Zircon in anorogenic granitoids: tholeiitic plagiogranites (high Y, low Hf), hypersolvus (medium to low Y, low Hf) and subsolvus (medium to high Y and Hf) alkaline granites/rhyolites, has separate mean distributions. Genetic relations existing between rocks with obvious textural differences (granites, microgranites, rhyolites) are also recognised. Zircon in orogenic granitoids is Y-poor and shows a very limited distribution, but the minimal average values in magmatic zircon vary from 11 000 wt ppm HfO2in the calc-alkaline suite, to 12 000 ppm in the peraluminous porphyritic granites and to 13 500 ppm in entirely crustal anatectic granites and migmatites. Mixing-mingling processes are proposed to explain the intermediate characteristics of zircons and rocks in the peraluminous porphyritic and K-subalkaline granites. This is consistent with the time emplacement and space distribution of these two orogenic members, but leads to a new proposal of emplacement of some alkaline subsolvus magmas during orogenic cycles.
Age and significance of the Old Red Sandstone around Clew Bay, NW Ireland
Authors: Graham John R. , Richardson John B. , Clayton Geoffrey
Published: November 2011

The stratigraphy of red bed successions in the Clew Bay area of County Mayo (Ireland) is described, and new palynological evidence for the age of some of the rocks is presented. The Old Red Sandstone in the Clew Bay area comprises several lithostratigraphic units. The Louisburgh succession is interpreted as part of a Silurian marginal marine sequence. Devonian strata are represented by the Islandeady Group which has yielded plant spores which suggest that these rocks should be assigned to the Lower Devonian (Siegenian to Emsian) and the Beltra Group which contains Middle Devonian (Eifelian) spores. These Lower and Middle Devonian strata are probably separated by an unconformity, and are overlain with clear unconformity by the highest unit, the Maam Formation, which is Dinantian (Carboniferous) in age. The Clew Bay Old Red Sandstone succession, therefore, shows important differences from that of the Midland Valley of Scotland, with which it has previously been compared.
Shell-boring algae on the Scottish continental shelf: identification, distribution, bathymetric zonation
Authors: Akpan E. B. , Farrow G. E.
Published: November 2011

3050 dead molluscan shells and fragments of calcareous algae were collected from 104 benthic stations at depths from 2 to 160 m in the Firth of Clyde, the Firth of Lorne and on the Orkney shelf, British Isles. The following micro-algal borings were recognised and are described: (i) Rhodophyta: Conchocelis, (ii) Chlorophyta:Ostreobium quekettii, Eugomontia sacculata, Phaeophilasp. and (iii) Cyanophyta:Plectonema terebrans, Hyellaspp.

These endolithic algae are bathymetrically zoned.Eugomontia, Phaeophilaand the cyanophytes characterize the upper part of the photic zone (2–20 m). Shallow sheltered environments are typified by a high density of algal borings, most of them aligned perpendicular to shell surfaces. The lower photic zone is characterized byOstreobiumand Conchocelis whose borings are parallel to shell surfaces. The photic limit is about 40 m for the open Orkney shelf (59°N), and about 22 m for the partly enclosed firths (56°N).

The Orkney population is dominated by two chlorophyte taxa: rhodophytes and cyanophytes are absent. This may be due to higher tidal energy conditions.
Volcanic and sedimentary processes during formation of the Saefell tuff-ring, Iceland
Authors: Leys Clyde A.
Published: November 2011

The Recent Saefell tuff-ring on Heimaey, Iceland was formed by surtseyan activity in shallow seawater. The tuff-ring has a basal diameter of about 3 km, a maximum rim height of 188 m above sea-level and a crater diameter of 1300 m. Three tuff-units are recognised, separated by unconformities on and inside the crater rim due to syndepositional slumping. The crater contains a nested rim which was constructed above slumped crater tuffs. Directional data indicate strongly directed blasts to the SW at a late stage in the activity.

Throughout the volcanic activity, base-surges formed antidunes, U-shaped channels, vesiculated tuffs, small ripples and plastering structures. One antidune reflects a decrease in surge flow power during deposition and subsequent slumping due to base-surge drag and instabilities developed during growth. On the basis of field characteristics, the structures are divided into those deposited by hot, dry, fast-moving surges and those by cooler, wet, slow-moving surges. Base-surges are compared with turbidity currents and deposition of distinct structures by the head, body and tail regions is interpreted.
Sequential development of metamorphic fabric and structural elements in polyphase deformed serpentinites in the Svecokarelides of eastern Finland
Authors: Park Adrian F.
Published: November 2011

Serpentinites are a major component in a distinctive suite of metasedimentary and metamorphosed igneous rocks, the Outokumpu association, in the early–middle Proterozoic Svecokarelides of eastern Finland. Like the adjacent mica schists and associated supracrustal rocks, they show the effects of at least six phases of deformation (D1–D6). The tectonic history began with the emplacement of the Outokumpunappe (pre-D1), but a study of relict assemblages in the serpentinites and theirenvelope rocks reveals evidence for a complex pre-nappe history involving ultramaficmagmatism with extensive high-temperature hornfels development, and low-temperature serpentinisation contributing to sea-floor exhalation of sulphide ores.

The serpentinites subsequently underwent recrystallisation during several phases of regional metamorphism giving rise to mineral fabrics, including a pressure-solution initiated segregation (M1–D1), anthophyllite growth during the thermal climax (D2–M2—600–680°C, 2·5–4 kb), and steatitisation (D2c–M2c). Steatitisation is structurally controlled, occurring where serpentinite bodies impinge upon localised shear zones (wrench faults—D2c). Talc–carbonate–brucite assemblages reflect the influx of CO2 in this environment. Deformation during late metamorphic retrogression (greenschist—D3–D4) has a dichotomous expression with crenulations developed in strongly anisotropic phyllonitised serpentinite and irregular fracturesin massive rock.

The implications of such polyphase reconstitution for geochemical and isotopic studies are assessed and discussed.
Basement–cover relationships during polyphase deformation in the Svecokarelides of the Kaavi district, eastern Finland
Authors: Park Adrian F. , Bowes D. R.
Published: November 2011

For much of its length in eastern Finland, the contact between the late Archaean granitoid terrane and early Proterozoic supracrustal rocks is that of a depositional unconformity tectonically modified during the Svecokarelian orogeny. In the Kaavi district, this modification has been extensive, particularly because of thrusting which resulted in tectonic slices of basement being present as inliers within the cover rocks and cover rocks as outliers within the main basement outcrop. Both basement and cover have undergone repeated deformation and metamorphic recrystallisation reflected by the presence of multiple tectonic fabrics and sequential mineral growths. However, it is only locally in major zones of movement that the basement rocks of the Presvecokarelides show major modification as the result of the deformation which had such a profound effect on the cover rocks during the development of the Svecokarelides. Over large areas, the products of four phases of deformation (DI–IV) remain in the basement gneisses together with the products of basic and acidic intrusion whose positions in the deformational sequence can be established‥

In the cover rocks, early nappe emplacement (Outokumpu nappe) was followed by the development of isoclinal folds associated with prograde metamorphism (D1). Regionally expressed asymmetrical folds, overturned to the E, with attenuation of overturned limbs and thrusting, involving basement, followed (D2). Subsequent deformation related to wrench faulting (D2c) was followed by the development of more open folds associated with declining geotherms (D3, D4); F3–F4 interference structures are expressed as domes, some of which were a locus of granitoid emplacement (Maarianvaara granitoid suite). D5 and D6 are expressed as cleavages and fractures.

Correlation of the structural features in the Kaavi district with those in the Outokumpu and adjacent districts forms the basis both for establishing the regional disposition of basement and cover units and for determining the structural evolution of this part of the Svecokarelides.
New information on the coaptative devices in the Ordovician trilobitesPlacopariaandCrozonaspis, and its significance for their classification and phylogeny
Authors: Henry J.-L.
Published: November 2011

Many Ordovician trilobites possess morphological structures on the cephalon, the pygidium and sometimes also on the thoracic segments, which interlock during enrolment. These coaptative devices, also known in living arthropods, are functional, inherited, and seem to remain stable at the species level. Significant evolutionary changes in coaptative devices occur throughout time within the generaPlacoparia(Pliomeridae) andCrozonaspis(Dalmanitidae). New data are presented which have relevance for the details of the coaptative structures inPlacoparia(Coplacoparia), and for the classification of the dalmanitid speciesmorenensisanddujardini. In some species ofCrozonaspisand inPlacoparia(Coplacoparia), interlocking structures prevent the possibility of shearing between cephalon and post-cephalic exoskeleton.
The Ordovician graptoloid Didymograptus murchisoni in South Wales and its use in three-dimensional absolute strain analysis
Authors: Jenkins C. J.
Published: November 2011

The dimensional statistics and proximal development characters of the Llanvirnian pendent didymograptid D. murchisoni are defined using the type material from near Builth Wells (Powys) and other collections from Abereiddi Bay (Dyfed). Population variability (as expressed by variation coefficients) in the undeformed faunas amounts to about 10% for the sicula lengths and thecal spacings, but is over 20% (up to 200%) for stipe lengths and divergences. Characters with low variability have greater species-diagnostic value. Proximal development in the species involves a dicalycal th 11 and a low origin for that theca from the sicula. The taxa Didymograptus amplus, D. nanus, D. geminus, D. geminus latus and D. acutus are varieties within populations of D. murchisoni and are therefore junior synonyms.

The resulting rationalised taxonomy allows advances to be made in the use of the species in stratigraphy and tectonics. For example, an occurrence of undeformed (pyritised) D. murchisoni in full relief at Abereiddi in the same beds as flattened and deformed faunas, allows a calculation of the absolute three-dimensional strains to be made for the slates there. The strains are strongly flattening (K < 0 · 3) and involve volume changes of about −56%. The high dilatation values imply that stylolite and grain-boundary pressure solution operated during the deformations to take the changes in volume beyond what is possible with simple compaction (i.e. porosity reduction).
The Balquhidder catchments, Scotland: the first four years
Authors: Blackie J. R.
Published: November 2011

Results emerging from the long-term forestry versus upland grassland paired catchment study conducted by the Institute of Hydrology at Plynlimon, mid-Wales, and from studies of the processes controlling the hydrological responses of areas under forest and grassland, have been accepted by the water and forestry industries as a means of determining the probable effects of afforestation in other areas of Britain. When considering proposals in the late 1970s for a further major expansion of forestry, mainly in Highland Scotland, it became apparent that insufficient information was available to predict with confidence the effects in areas where forestry would replace medium height vegetation (heather sp., bracken) or in areas where a significant proportion of the precipitation falls as snow. Against this background a consortium of interested parties (see Hall 1987), agreed in 1981 to fund parallel systems and process studies of the effects in appropriate areas of Scotland. In this paper the initial stages of the systems study, on two catchments in the Balquhidder area of Central Region, are described. Some preliminary results from phase I, in which the catchment water balances under a mature forest and a mixed heather, bracken, grass cover were obtained, are presented. These water balances suggest that water use by the partly forested catchment is lower than that by the control and also lower than Penman ET. These findings are discussed in relation to the Plynlimon results and to information gained in the current process studies. Plans for phase II of the study, in which the mature forest will be clear-felled and part of the heather, bracken, grass control will be planted, are outlined.
The Loch Dee Project: runoff and surface water quality in an area subject to acid precipitation and afforestation in SW Scotland
Authors: Welsh W. T. , Burns J. C.
Published: November 2011

A description is given of the hydrological regime and associated surface water quality recorded at a multi-disciplinary long-term investigation into the effects of acid precipitation and afforestation. The study catchment at Loch Dee is situated on the margins of the Loch Doon granite complex in SW Scotland. Annual rainfall is in excess of 2200 mm. The three main tributary burns exhibit a rapid response to rainfall with a high percentage of direct runoff. The loch with an average volume of 3650 M1 and a contributing catchment area of 15·6 km2 has an average turn-over of approximately forty days but this has varied from 15 to 100 days. Local physical variations are shown to influence both hydrological response and surface water quality. Generally stream water during spate conditions reflects rainfall chemistry. Occasionally, however, moderately acid rainfall containing large concentrations of sea salts has produced highly acidic runoff through a process of ion-exchange within the surface horizons of the soils. The quality of base flows shows a spatial variation which reflects various lithologies to the extent that pH values ranging from 4·9 to 6·9 have been observed.
Location of trace elements in soil profiles: total and extractable contents of individual horizons
Authors: Berrow M. L. , Mitchell R. L.
Published: November 2011

Total contents of 29 trace and major elements and extractable contents of 20 elements were determined in the horizons of 4 profiles, 2 freely drained and 2 very poorly drained, of Scottish soils on drifts of basic igneous or granitic origin. The probable behaviour of other elements is suggested in the light of the results obtained. It is shown that in the course of pedological weathering, many elements are mobilised and become extractable by relatively weak reagents such as ammonium acetate (when readily exchangeable), dilute acetic acid (when less readily exchangeable or acid-soluble) or EDTA (when chelated or exchangeable). The forms in which different elements occur in the different horizons are assessed. In the surface horizons rich in organic matter many elements, such as Co, Ni, Fe, V, Cu, Cd, Sn and Pb, appear to occur mainly in chelated form; fewer, particularly Mn, are only in exchangeable form with plant uptake being largely responsible. Lower in the profiles the most common forms are acetic acid-soluble or, in gleyed horizons, exchangeable. In these horizons the degree of mobilisation is greater than in the corresponding freely drained horizons, the effect being most apparent for elements in readily weathered minerals.
Graphite in Eastern Ghats Precambrian migmatites, Orissa, India
Authors: Acharya B. C. , Dash B.
Published: November 2011

Graphite bodies of economic importance occur in the Eastern Ghats migmatite complex of Orissa, India, which consists of sillimanite-rich gneiss (khondalite), calc-silicate granulite, basic (pyroxene) granulite and acidic gneiss palaeosomes and a variety of quartzofeldspathic neosomes and pegmatite veins. There is more graphite in migmatised khondalite and calc-silicate granulite than in their unmigmatised counterparts and it is common at pegmatite-country rock margins. Lodes of graphite are structurally controlled by fold hinge zones, necks of boudins and along the dominant foliation in rocks that show the effects of polyphase deformation. Faults, fractures and joints also act as structural controls. The richest lodes are located where there is the coincidence of several lithological and structural features.

The graphite occurs in graphite-rich schists and gneisses, as veins and as disseminated flakes along grain boundaries and in microfractures and cleavages. It is present in all rock types except pegmatites emplaced after the D4 deformational phase, and is localised in structures developed during the D1, D2, D3 and D4 phases. Most of the bodies of graphite are lenticular and show pinch and swell characters. Fourteen textural and microstructural habits have been recognised and are described with many of the features of fabric, such as intergrowths, inclusions and kinks being particularly well shown under reflected light.

Methanation of carbonate minerals is considered the most likely initial stage in the formation of the carbon with subsequent pyrolysis of the methane being the process of graphitisation. While the possibility of the carbon being either of sedimentary derivation orfrom igneous-derived CO2 cannot be ruled out, there is no convincing evidence for such sources. Remobilisation of graphite following its formation by pyrolysis of methane in structurally controlled low pressure zones is the dominant mechanism of concentration. Thefabric features point to the graphite having moved as a solid phase along open spaces inthe gangue minerals while still maintaining its crystallinity, and having been deformed in the process. The effects of remobilisation apparently have obliterated evidence relating to other methods of concentration.
Structure and petrogenesis of a mixed-magma ring dyke in the Peruvian Coastal Batholith: eruptions from a zoned magma chamber
Authors: Bussell M. Andrew
Published: November 2011

Ring complex granites of the Peruvian Batholith are tabular bodies with flat roofs emplaced by cauldron subsidence. Marginal precursory ring dykes extend upwards above roof level and a typical intrusion is “H”-shaped in cross-section. Advance of magma by repeated subsidence would give a ladder-shaped profile for such intrusions above the brittle-ductile transition. Close relationships exist between intrusion geometry, emplacement process and petrogenetic evolution. Initially a granodioritic magma chamber lay beneath the present erosion level, trapping a rising mass of dioritic magma. Expansion of granodioritic liquid resulted in the injection of microgranite and tuffisite cone sheets accompanied by roof uplift within a ring fault. Next, during subsidence within the ring fault, liquids from deeper levels in the underlying chamber rose by stoping along the outer margin of the fault to form a ring dyke. Prior to intrusion, this liquid was vertically zoned from rhyodacite downwards to diorite and these liquids became partially mixed during emplacement. Finally, granodioritic magma rose to the present level by subsidence of a roof slab bounded by the ring fault. The precursory ring structures preserve evidence of significant but transient events in the underlying chamber. Liquid differentiation may be significant in the evolution of many large plutons.
Local processes involved in the generation of migmatites within mafic granulites
Authors: Tait Rhoda E. , Harley Simon L.
Published: November 2011

Processes involved in the formation and evolution of melts within the lower crustal mafic granulites are considered with reference to mafic migmatites from late Proterozoic (1200-1000 Ma) granulites of the Rauer Group, East Antarctica. Metaluminous dioritic and noritic leucocratic veins on scales of 1 cm to 1 m show agmatitic, stromatic and schlieren structures. These possible melts are compositionally distinct from charnockitic and enderbitic orthogneisses, which show intrusive contacts with the migmatites in areas of low strain.

Important field relationships include the following:

(a) Leucocratic veins contain plagioclase and rare quartz, coarse subhedral to euhedral orthopyroxene, ilmenite and apatite. Finer (2 cm) veins and layers are richer in mafic phases than larger (2-10 cm) veins.

(b) Selvedges or melanosomes are developed between the larger melt areas and enclosing mafic gneisses. These melanosomes consist of garnet, orthopyroxene, plagioclase and biotite and are apatite-rich.

(c) Pyroxene granulite palaeosomes typically display bleached zones (1-2 cm) adjacent to selvedges and veins, in which the modal proportion of clinopyroxene diminishes in favour of orthopyroxene.

Geochemical and petrological studies demonstrate that localised or near-localised partial melting of the mafic granulites occurred during decompression from 8-9 kb to 7 kbar at a minimum temperature of 800-850°C. Geochemical mass balance calculations using measured vein, selvedge and palaeosome compositions indicate that near-closed system melting behaviour is likely for a large number of major and trace elements, but LILE behaviour is affected by the introduction of biotite probably associated with late stage fluids. Minor- and rare-earth element modelling predicts similar percentages of melting to those observed in the field, but yields reasonable results only when garnet is included as a minor residual phase. HREE concentrations in melanosomes do not show expected enrichments, probably as a result of later subsolidus changes including the breakdown of garnet during decompression.

This study demonstrates that migmatites may form through the near-localised partial melting of basic lithologies within the granulite facies. The exact role of fluids in this case cannot be determined but melting is interpreted to be vapour-undersaturated. This process may be important in the production of volumetrically significant amounts of dioritic to tonalitic calc-alkaline magmas.