bluuebunny/crossref_metadata_2025 huggingface dataset:
A concealed Lower Cretaceous outlier at Moss of Cruden, Grampian Region
Authors: Hall A. M. , Jarvis J.
Published: January 2010

Synopsis

Recent excavations at Moss of Cruden, Grampian Region, show that Lower Cretaceous sedimentary rocks pass beneath the margin of the Tertiary Buchan Ridge Gravels and are intensely weathered. These findings indicate that previous interpretations of these rocks as a glacially-transported erratic mass or masses were incorrect and that they are probably
in situ.
The rocks include fine-grained, glauconitic quartz-arenites with pollen of Late Hauterivian-early Barremian age. Overlying flint gravels demonstrate the presence of a former Cretaceous chalk cover and helped the preservation of this small outlier.
New faunal data from the highest Ordovician rocks at Pomeroy, County Tyrone, Northern Ireland
Authors: Harper D. A. T. , Mitchell W. I. , Jia-Yu Rong
Published: January 2010

Synopsis

Two new shelly faunas are reported from the Tirnaskea Formation in the Pomeroy inlier, County Tyrone. The middle part of the formation contains species of the brachiopods
Dedzetina, Sericoidea, Proboscisambon
and
Protozyga
? indicative of a deep-water biofacies and suggesting correlation with the Rawtheyan Stage of the Ashgill Series although an Hirnantian age cannot be excluded. At higher levels within the unit
Dysprosorthis
occurs with
Eostropheodonta
and the trilobite
Mucronaspis,
confirming an Hirnantian age for the upper part of the Tirnaskea Formation. Deep water facies persisted at Pomeroy during the Hirnantian in contrast to the upward shallowing sequence at Girvan, SW Scotland, suggesting a more offshore setting for the Irish deposits.
A revised chronostratigraphy for the lower Durness Group
Authors: Wright David T. , Knight Ian
Published: January 2010

Synopsis

The significant breaks proposed by previous researchers in the Cambro-Ordovician succession of north-western Scotland to explain the absence of Mid- and Late Cambrian faunas cannot be justified by field evidence. Moreover, comparison with the once contiguous succession of western Newfoundland suggests that the Scottish succession contains both Middle and Upper Cambrian strata. Age-diagnostic faunas from the Early Cambrian
Bonnia–Olenellus
Zone in both sequences allow the upper Forteau Formation and the lower Hawke Bay Formation of western Newfoundland to be biostratigraphically correlated with the lithologically similar Fucoid Beds and Salterella Grit, and with the basal dolostones of the Ghrudaidh Formation, in north-western Scotland. Similarly, Early Canadian cephalopods and matching lithostratigraphy allow the correlation of the Scottish Lower Ordovician Sailmhor Formation with the Watts Bight Formation in western Newfoundland. These benchmarks, together with the close similarities of lithostratigraphy, facies, faunal trends and patterns of cyclicity, allow the Eilean Dubh Formation of north-western Scotland to be correlated with the dolostones of the Upper Cambrian Petit Jardin and Berry Head formations of the interior shelf of western Newfoundland. The middle and upper Ghrudaidh Formation can also be correlated with the Middle Cambrian Bridge Cove Member of the upper part of the Hawke Bay Formation and the overlying Upper Middle Cambrian March Point Formation, suggesting that the Cambrian succession in north-western Scotland is largely continuous.
Isotopic evolution of the Lewisian Complex of Tiree, Inner Hebrides and correlation with the mainland
Authors: Whitehouse M. J. , Robertson C. J.
Published: January 2010

Synopsis

We present the first Sr, Pb, and Nd isotopic data from the Lewisian gneisses of Tiree, Inner Hebrides. Depleted mantle Sm–Nd model ages (
t
DM
) from the granulite facies gneisses of SW Tiree range from 2.63 to 2.84 Ga (weighted terrane average of 2.79 Ga) and confirm a late Archaean gneiss protolith age. Pb–Pb data define a
c.
2.7 Ga regression line with a typical mantle μ
1
value of 7.8. The absence of a good isochron relationship for these gneisses is attributed to U/Pb fractionation during metamorphism without complete Pb-isotopic homogenization. Multi-stage Pb-isotopic modelling results are consistent with late Archaean high-grade metamorphism; the alternative of an early Laxfordian (South Harris equivalent) granulite facies event at
c.
1.9–1.7 Ga is rendered unlikely by the high μ
1
values required. Rb–Sr data from the Caoles migmatite complex of east Tiree yield a regression age of 1.68 ± 0.06 Ga with an initial
87
Sr/
86
Sr ratio of 0.711 ± 0.003. The values for ɛ
Nd
(1.7) of
c
. −10, the elevated
87
Sr/
86
Sr(1.7) ratio, and the recently documented presence of probable Scourie dykes (

Muir
et al
. 1993

) suggest that these migmatites formed during Laxfordian reworking of a late Archaean protolith. In addition, the higher
87
Sr/
86
Sr(1.7) values of the migmatitic gneisses, relative to the SW Tiree granulites, suggests either that the late-Archaean high-grade event did not cause pervasive large ion lithophile element (LILE) depletion throughout Tiree, or that the east Tiree amphibolite facies terrane represents a different structural level and/or distinct terrane. Our data allow a correlation of gneiss-forming and reworking events on Tiree with those of the mainland Lewisian and thus answer long-standing questions concerning the nature of the Lewisian in the Inner Hebrides.
The first Middle Jurassic dinosaur from Scotland: a cetiosaurid? (Sauropoda) from the Bathonian of the Isle of Skye
Authors: Clark N. D. L. , Boyd J. D. , Dixon R. J. , Ross D. A.
Published: January 2010

Synopsis

The limb bone of a dinosaur was discovered from the Valtos Sandstone Formation (Bathonian, Middle Jurassic) near Valtos, Isle of Skye. The bone preserves the eroded proximal and distal ends and is missing the mid-shaft. It represents the first unequivocal Middle Jurassic dinosaur bone from Scotland. The bone is of a sauropod dinosaur and may be the femur of a cetiosaurid.
The first Lower Jurassic dinosaur from Scotland: limb bone of a ceratosaur theropod from Skye
Authors: Benton M. J. , Martill D. M. , Taylor M. A.
Published: January 2010

Synopsis

A partial right tibia of a carnivorous dinosaur is reported from the Lower Jurassic Broadford Beds Formation of southern Strath, Skye. The bone consists of the proximal end and shaft of a tibia, and this shows characteristic features of the ceratosaur theropods, a group of medium-sized predatory dinosaurs that were widespread during the Early Jurassic. This tibia, and a partial sauropod tibia from the Middle Jurassic of Skye, represent the first clear records of dinosaur body fossils from Scotland.
The chloritoid schists of Shetland and their thermal metamorphism
Authors: Flinn Derek , Key R. M. , Khoo T. T.
Published: January 2010

Synopsis

Three narrow bands of chloritoid-bearing pelitic schist cross Shetland and are distinguishable both in field appearance and chemical composition (high Al and/or high Fe
2+
/Mg) from adjacent non-chloritoid-type pelitic schists. Of these three, the easternmost band, the Dunrossness Phyllites (upper Dalradian), is a chloritoid–muscovite phyllite also containing chlorite, quartz, kyanite and paragonite, overlying muscovite–chlorite–quartz pelitic phyllites, the Clift Hills Phyllites. Both types of pelite are cut by the Spiggie Granite. Thermal metamorphism extends 2 km from the granite in the Dunrossness Phyllites, but only 0.5 km in the adjacent Clift Hills Phyllites. In the Dunrossness Phyllites thermal zones based on the incoming of chloritoid, chloritoid–staurolite, staurolite–biotite, and retrograde chloritoid (near the granite contact) are recognizable, as are thermal zones based on the incoming of kyanite, andalusite, and fibrolite (near the contact). In the Clift Hills Phyllites, thermal zones based on the incoming of garnet, staurolite–biotite (in continuity with that in the Dunrossness Phyllites), andalusite and fibrolite occur. In Unst, in the northward continuation of the Dunrossness Phyllites, the Skaw Granite produces similar zones, except that thermal andalusite is absent, indicating metamorphism at greater pressure. The difference in response to metamorphism of the chloritoid and the non-chloritoid-type pelites in terms of reactivity and mineralogy, is further emphasized by the widespread presence of andalusite, chloritoid, white mica and chlorite as retrograde minerals in the Dunrossness Phyllites.
On the origin of a reddened interflow bed within the Palaeocene lava field of north Skye
Authors: Bell B. R. , Williamson I. T. , Head F. E. , Jolley D. W.
Published: January 2010

Synopsis

A reddish brown to reddish orange interflow bed from the Palaeocene lava field of north Skye at Lochan nan Dunan is considered to be of epiclastic origin, with features which distinguish it from
in situ
palaeosols and solely volcaniclastic deposits. It has sharp upper and lower contacts, is clay matrix-supported, and is dominated by clasts of lateritic rock, together with clasts of somewhat altered basaltic rock and siltstone. Also present are: crystals of fresh clinopyroxene (Wo
46.26–47.35
En
45.29–45.91
Fs
6.85–8.18
), plagioclase (An
70–75
) and alkali feldspar (Or
30–50
Ab
50–70
An
<1
); shards of hawaiitic glass; and secondary hydrothermal minerals in a variety of associations.

The clasts of lateritic rock and the fine-grained matrix of the bed were both derived from a previously developed palaeosol and the clasts of volcanic and sedimentary material were also derived from considerably weathered material. The crystals and glass shards are considered to have been derived either from primary ash eruptions or from contemporaneous, unaltered ash deposits. Palynological investigations reveal that the bed is devoid of pollen and spores, and contains only fragments of inertinite, indicating that it was exposed at the Earth’s surface for a relatively short time interval, and confirms that the reddening ‘event’ occurred prior to deposition of the bed.

The bed contains valuable information about pyroclastic material and phenocryst-bearing magmas not preserved elsewhere in the lava field, and the fresh nature of this material indicates that the time intervals between eruption of the ash, deposition of the bed, and the eruption of the overlying lava flow(s) were relatively short.
Palaeoenvironmental significance of marine and terrestrial Tertiary sediments on the NW Scottish shelf in BGS borehole 77/7
Authors: Evans D. , Morton A. C. , Wilson S. , Jolley D. , Barreiro B. A.
Published: January 2010

Synopsis

BGS borehole 77/7, located to the north of Scotland, drilled through Quaternary deposits into Neogene and Palaeogene sediments before terminating in Lewisian basement. The pre-Quaternary rocks have been analysed using a variety of petrological, geochemical and bio-stratigraphical techniques. The basement comprises amphibolite schist, and has a deeply weathered surface which, it is argued, is likely to have developed during the early Eocene. Overlying terrestrial lignitic deposits are palynologically dated as upper Oligocene; they were deposited in a forest swamp environment at a time of hinterland uplift, and are comparable with sediments of similar age and character found in basins along the length of western Britain. Following a rise in sea level, marine conditions prevailed during the Miocene, as recorded by glauconitic siltstones which are of a facies that is extensively developed on the outer shelf and slope NW of Scotland.
New evidence for the origin of the Buchan Ridge Gravel, Aberdeenshire
Authors: Bridgland D. R. , Saville A. , Sinclair J. M.
Published: January 2010

Synopsis

Archaeological excavations of prehistoric flint-extraction sites at Skelmuir Hill and Den of Boddam, Aberdeenshire, have provided opportunities for detailed study of the Buchan Ridge Gravel, which provided the source of the flint. Remnant bedding structures and rounded ‘ghost clasts’ have been observed, combining with the roundness of the flint cobbles to suggest that the deposit was once a clast-supported marine gravel that has suffered extensive weathering of non-durable clasts. The occurrence of naturally flaked flints, shaped by battering in a high-energy environment, provides important new evidence in support of a beach origin. The degree of weathering is suggestive of a pre-Quaternary age, as is the implication of a high relative sea level, with marine gravels preserved at above 120 m OD.
Ice-rafted sediments of Loch Lomond Stadial age in western Scotland
Authors: Peacock J. D.
Published: January 2010

Synopsis

At two former oil platform sites (Portavadie and Ardyne) in the Clyde estuary, several metres of very poorly sorted gravelly and cobbly silt and sand of the Portavadie Formation were deposited during the Loch Lomond Stadial. The sediments are thought to have been ice-rafted from the shore nearby, and part of the mud fraction removed by tidal currents and wave action, either at the time of deposition or at a later date. It is suggested that the rafting process is an intensification of that present throughout the earlier Windermere Interstadial, and may account for near-shore supposedly glaciomarine gravel-, cobble- and boulder-rich deposits of Lateglacial age elsewhere.
Marine palynomorphs from the Staffin Bay and Staffin Shale formations (Middle-Upper Jurassic) of the Trotternish Peninsula, NW Skye
Authors: Riding James B. , Thomas Joanna E.
Published: January 2010

Synopsis

The Staffin Bay and Staffin Shale formations of Trotternish, Skye represent an important Middle–Upper Jurassic (Callovian–Kimmeridgian) reference section. The succession is 133 m thick, mudstone-dominated, and the Staffin Shale Formation is rich in zonal ammonite faunas. Both formations have yielded abundant palynofloras rich in marine microplankton. The Staffin Bay Formation is lowermost Callovian on both dinoflagellate cyst and regional evidence. Only one ammonite has been recorded from its uppermost division, the Belemnite Sands Member. Miospores dominate the Staffin Bay Formation and the relatively low diversity dinoflagellate cyst floras are consistent with a palaeoenvironmental interpretation of restricted, nearshore marine conditions. Dinoflagellate cysts and other marine microplankton are relatively abundant and diverse throughout the Middle Callovian to Lower Kimmeridgian Staffin Shale Formation, thereby indicating an open marine depositional setting. The stratigraphical distributions and relative proportions of the dinoflagellate cysts are largely consistent with those observed in England and elsewhere in northern Europe. Established dinoflagellate cyst zonal schemes can be applied to both formations. Certain species, however, exhibit minor stratigraphical differences in overall ranges.
Wanaea acollaris
Dodekova 1975, for example, is recorded in the Lower Oxfordian Dunans Clay Member (Staffin Shale Formation); the range top of this species was previously thought to be within the Upper Callovian. Certain species recorded in the Staffin Shale Formation are interpreted as being of Boreal affinity; these include
Ambonosphaera? staffinensis
(
Gitmez 1970
)
Poulsen & Riding 1992
,
Paragonyaulacysta
spp. and
Gonyaulacysta dentata
(
Raynaud 1978
) Lentin & Vozzhenikova 1990.
Subglacial meltwater erosion at Loch Treig
Authors: Glasser Neil F. , Nicholson Frank H.
Published: January 2010

Synopsis

Reports of small scale features of glacial erosion by meltwater are rare in Scotland. During the spring of 1996 unusually low water levels in the Loch Treig reservoir revealed an assemblage of exceptionally well-preserved glacial erosion forms sculpted in bedrock, including a suite of meltwater erosion forms. Within the assemblage of landforms at Loch Treig, there is a predominance of forms created by the flow of subglacial meltwater and limited evidence of glacial abrasion. The Loch Treig features are therefore classed as subglacial meltwater erosion forms (s-forms and not p-forms). As such they are probably unique in Scotland. The meltwater forms described from this site include scallops, chutes, chute pools, potholes, and the less specific ‘undulose smoothing’ of bedrock surfaces. Large groups of 1–1.5 m-diameter scallops are interpreted as phreatic (formed below the water table) in origin. The potholes range from 0.5 m to over 3 m in diameter, with the larger potholes usually occurring in a series with interconnecting chutes. Chutes, chute pools and potholes are interpreted as vadose (formed above the water table) in origin. This interpretation of the suite of features accords well with the established Loch Lomond Stadial events in the area, which suggests that a substantial active glacier was still present in the north end of Glen Treig after the drainage of an ice dammed lake at 260 m in the Spean–Laggan area.
Palaeoclimatic significance of calcretes in the Dinantian of the Cockburnspath Outlier (East Lothian–North Berwickshire)
Authors: Andrews Julian E. , Nabi Ghulam
Published: January 2010

Synopsis

Calcretes are present at two horizons in the Dinantian Inverclyde and Strathclyde Groups of the Cockburnspath Outlier. The lower calcrete, probably uppermost Courceyan to Chadian in age (at the top of the Hurker Member, Ballagan Formation), was formerly interpreted as a tectonic breccia. Petrology shows that the bed is a calcrete with associated root casts. Pyrite within this calcrete suggests that it underwent marine hydromorphism, probably caused by rising marine groundwater associated with relative sealevel rise. The upper calcrete, probably Asbian in age (in the Cove Harbour Member, Aberlady Formation), is mature (stage 3) and has undergone
in situ
gratification caused by desiccation and shrinkage

The Hurker Member calcrete (and other palaeoclimatic indicators) suggest that semi-arid climatic conditions prevailed in Scotland throughout the Lower Carboniferous until Chadian times. This is consistent with palaeoclimatic indicators elsewhere in Euramerican rocks. The Cove Harbour Member calcrete probably correlates with calcretes in the Sandy Craig Formation in Fife. However, it occurs in a rock sequence dominated by humid climatic indicators (coals, sideritic mudstone palaeosols and oil-shales), implying a regionally significant semi-arid period, during otherwise humid conditions. This finding is consistent with fluctuating humid to semi-arid palaeoclimatic phases proposed for the Dinantian of England and Wales.
Rare-earth-bearing minerals fergusonite and gadolinite from the Arran granite
Authors: Hyslop E. K. , Gillanders R. J. , Hill P. G. , Fakes R. D.
Published: January 2010

Synopsis

A suite of rare earth element bearing minerals has been identified from miarolitic cavities in the northern Arran granite. This is the first occurrence in the British Isles of
in situ
fergusonite and gadolinite to be confirmed by X-ray analysis. The presence of these minerals reflects the enrichment of rare earth elements in the highly fractionated granites in the southern sector of the British Tertiary Igneous Province.
Metabentonites from the Silurian inliers of the southern Midland Valley of Scotland: distribution and geochemistry
Authors: Batchelor R. A.
Published: January 2010

Synopsis

A survey of eight Silurian inliers in the southern Midland Valley of Scotland has identified four new metabentonite occurrences within the Telychian Stage of the Llandovery, in the Bavelaw Castle, Hagshaw Hills, Lesmahagow and Girvan Main inliers respectively.

The bulk geochemical composition of the metabentonites highlights two broad associations: an intermediate/mafic, slightly alkaline group represented by the Lesmahagow samples, and a rhyodacitic group comprising samples from the other inliers surveyed. A potential correlation is proposed between a metabentonite from the Wether Law Linn Formation of the North Esk inlier and one from the west end of the neighbouring Bavelaw Castle inlier. The unique character of the Lesmahagow metabentonites will assist in further correlation studies of Upper Llandovery successions.
A geochemical investigation of palaeosols developed on Lewisian rocks beneath the Torridonian Applecross Formation, NW Scotland
Authors: Young G. M.
Published: January 2010

Synopsis

Alteration zones are developed on biotite gneiss and amphibolite of the Lewisian Basement Complex beneath Neoproterozoic rocks of the Applecross Formation of the Torridon Group in northwestern Scotland. The age and origin of these altered rock s has been disputed but systematic sampling and chemical analyses reveal patterns in A1
2
O
3
− CaO + Na
2
O − K
2
O space that are identical to weathering trends in palaeosols elsewhere. The Lewisian palaeosols, like other ancient weathering profiles, display significant loss of Ca and Na and exhibit strong K-metasomatism. K/Rb ratios in the profiles exhibit systematic variations that are thought to be related in part to the nature of metasomatizing fluids, rather than reflecting their provenance. Chondrite-normalized REE patterns for the host rocks and palaeosols demonstrate the conservative nature of these elements. There are, however, some differences between REE patterns obtained from the fresh and altered basement rocks and those of mudstones of the Applecross Formation. These differences suggest that the provenance area for the Applecross sediments included rock types other than those of the immediately underlying Lewisian basement.
On the origins of layered calc-silicate rocks from the Buchan Dalradian and their bearing on the diagenetic history of the Southern Highland Group
Authors: Hudson Neil F. C. , Kearns Stuart L.
Published: January 2010

Synopsis

Calc-silicate rocks from the Southern Highland Group of the Dalradian at Banff are metamorphosed carbonate concretions. Many original sedimentary features are preserved even though the calc-silicates now have amphibolite facies mineral assemblages. Those occurring in the andalusite and staurolite zones contain layered mineral assemblages that are characterized by the presence of calcite, clinopyroxene, hornblende, cummingtonite, and biotite from centre to margin. It is unlikely that the layering formed principally by synmetamorphic diffusional processes since diffusion modelling demonstrates that the relative values of phenomenological diffusion coefficients required to reproduce this set of layers are inconsistent with known values. The layer order, with pyroxene adjacent to carbonate and amphibole adjacent to pelite, is also inconsistent with their formation by infiltration of an H
2
O-rich fluid into a pure carbonate body. The layers can be best explained as resulting from metamorphism of compositionally zoned, diagenetic carbonate concretions. If the metamorphism was essentially isochemical, then composition profiles present in the calc-silicates may be compared with those in unmetamorphosed concretions and interpreted in terms of known diagenetic processes. A decrease in CaO from centre to margin results from the progressive elimination of the primary porosity during compaction of the sediment, a conclusion supported by the presence of relict sedimentary structures. Such calc-silicates contain important information about the early burial history of the sedimentary basin where their host rocks were deposited prior to the onset of metamorphism. There is some evidence that the alkali profiles have been modified during metamorphism. However it is not appropriate to use such calc-silicates for studies of synmetamorphic diffusion or other synmetamorphic processes without taking pre-metamorphic composition gradients into account.
Environmental geology: reaching out to a wider audience
Authors: McKirdy Alan
Published: January 2010

Synopsis

Whilst public awareness of environmental issues currently enjoys the highest profile, both nationally and internationally, understanding of the physical component of the natural world remains weak. There is an almost universal appreciation of many issues relating to ecological aspects of the environment, such as the need to conserve endangered species or threatened wildlife habitats, but by contrast, there is little understanding of the physical processes that have shaped our world. So the loss of key geological sites or landforms would be unlikely to occasion much public attention or comment. The challenge for the new millennium is that the geological profession reach out to a wider audience than hitherto, thereby ensuring a greater empathy with the physical component of the environment and its relevance to our everyday lives.
The Gribun Formation: clues to the latest Cretaceous history of western Scotland
Authors: Hancock Jake M.
Published: January 2010

Synopsis

In the Inner Hebrides the Gribun Conglomerate Formation (possibly Maastrichtian in age) lies above the Cretaceous Chalk and below the Palaeocene basalts. It is best developed on the Island of Mull, but is also found further north in Skye. The Gribun Formation and the Chalk record several episodes of widespread silicification during the Late Cretaceous and possibly again very early in the Palaeocene. This silicification is evidence of arid or semi-arid terrestrial conditions. The possible absence of Campanian sediment may have been caused by magmatic underplating.
Intertidal peat deposits and early Holocene relative sea-level changes, Traigh Eileraig, Isle of Coll, Scottish Hebrides
Authors: Dawson A. G. , Dawson S. , Mighall T. M. , Waldmann G. , Brown A. , Mactaggart F.
Published: January 2010

Synopsis

An intertidal organic deposit is described for Traigh Eileraig, Isle of Coll, Scottish Inner Hebrides. The organic sediments are overlain by sands containing marine diatoms. Radiocarbon dating and diatom analysis indicate that a relative marine transgression took place in Coll at
c.
8000
14
C years
bp
, an interpretation consistent with the results of pollen analysis of the organic material. The age and biostratigraphical interpretation of this relative marine transgression is in agreement with the results of sea-level research undertaken in recent years at Arisaig, western Scotland. However, the altitude at which the early-Holocene relative marine transgression is recorded in Coll is significantly lower than Arisaig, this difference reflecting the influence of differential glacio-isostatic uplift across the Inner Hebrides.
Garnet-bearing olivine-websterite within the Eastern Glenelg Lewisian of the Glenelg Inlier, NW Highlands
Authors: Rawson J. R. , Carswell D. A. , Smallwood D.
Published: January 2010

Synopsis

This paper documents the first identified occurrence of a garnet-bearing olivine-web-sterite rock within the Eastern Glenelg Lewisian of the Glenelg inlier. Bulk chemistries of the rock and associated websterites are comparable with komatiite or ultrabasic intrusive rocks. However, comparison with zoned ultrabasic–basic gneisses from the Scourie area suggests that the rock may be genetically linked to associated eclogites and represents a cumulate from a magma of basaltic composition. Geothermobarometry indicates that the rock equilibrated at eclogite facies
P–T
conditions: 20 ± 3 kbar, 730 ± 50°C. It is suggested that the magmatic protolith for this rock was emplaced during the Scourian, and from the textural evidence of the pyroxene grains, experienced granulite facies conditions followed by cooling prior to being subject to eclogite facies metamorphism during Grenville events.
The graptolite fauna from the Superstes Mudstone Formation in the Ordovician of the Girvan Cover Sequence
Authors: Rushton A. W. A.
Published: January 2010

Synopsis

The graptolite fauna from the Superstes Mudstone includes at least 12 taxa that indicate a low level in the
Nemagraptus gracilis
graptolite zone. The graptolite fauna is correlated with those from the Craigmalloch and Currarie formations in SW Scotland and the Athens Shale of Alabama, USA, but is older than any graptolite fauna known from the Glenkiln Shale Formation of the Southern Uplands Terrane. Several species are discussed briefly and Scottish specimens of
Dicellograptus alabamensis
Ruedemann are described.
Melt segregation structures within the Inzie Head gneisses of the northeastern Dalradian
Authors: Johnson T. E. , Hudson N. F. C. , Droop G. T. R.
Published: January 2010

Synopsis

The Inzie Head gneisses of the NE Dalradian are syntectonic metapelitic schollen migmatites containing numerous sill-like bodies of granite and diorite. Leucosomes with clear evidence of melt-present crystallization exhibit a wide variety of segregation structures. Initial
in situ
melting occurred within, or at the margins of, fertile metasedimentary horizons and was strongly controlled by variations in bulk-composition. Intergranular melt-pockets coalesced into thin (<10 mm), discontinuous stromatic horizons which subsequently joined laterally and/or became interconnected in extensional shear-zones. A diktyonitic structure formed, enabling buoyancy aided upward migration of melt into low-strain sites such as boudin-necks and shear-zones. Metre-scale leucosome channels containing abundant schollen and having diffuse, unchilled contacts against the migmatites were supplied from this network and may represent the foci of H
2
O-rich fluid influx. Bodies of nebulitic granite contain abundant ‘ghost’ schollen in the final stages of assimilation. Diorite sills show extensive magma mingling and hybridization with granitic leucosome and were clearly contemporaneous with the crustal melting. A variably developed flattening fabric within the migmatites was in part due to inflation following intrusion of the diorites. Immediately beneath diorite intrusions, melt loss from the migmatites was pronounced indicating that pure-shear dominated deformation is a strong driving force for melt segregation. Garnetiferous aplites at higher crustal levels and contemporaneous with the peak of regional metamorphism represent melt frozen in channelways that potentially contributed to nearby, large-scale Grampian granitic bodies.
Pb-isotope evidence for contrasting crustal contamination of primitive to evolved magmas from Ardnamurchan and Rum: implications for the structure of the underlying crust
Authors: Geldmacher J. , Troll V. R. , Emeleus C. H. , Donaldson C. H.
Published: January 2010

Synopsis

Using Pb isotope ratios we compare crustal contamination of primitive to evolved magmas from the Ardnamurchan and nearby Rum Igneous Centres, located on different crustal provinces in the British Tertiary Igneous Province (BTIP). The results confirm that compositional variations of parental cone-sheet magmas in Ardnamurchan can be explained by assimilation of granulite facies Lewisian gneiss at moderate crustal levels and subsequent contamination of evolved magmas with Moine schist metasediments within the uppermost crust during fractional crystallization. In contrast, samples from the Rum Centre have an uncontaminated mantle signature for the basaltic end-member, whereas the evolved rocks show Pb isotope evidence of contamination by Lewisian amphibolite facies rocks. Rum is separated from Ardnamurchan by a major thrust. The absence of a Moine-type isotopic influence in the Rum rocks supports an earlier interpretation, based on field evidence, that these overthrust rocks were eroded from Rum prior to the Palaeocene magmatic activity.
A new spiny species of
Pseudoclimacograptus
from the Ordovician of the Sanquhar area, Southern Uplands
Authors: Rushton A. W. A.
Published: January 2010

Synopsis

Pseudoclimacograptus setosus
sp. nov., from the
Nemagraptus gracilis
Biozone in the Sanquhar area, is unusual in having mesial spines on each of the first three thecae. Possible functions of the spines are briefly considered.
The Lamington Conglomerate: further evidence for an ophiolitic source for the Ordovician Marchburn Formation, Northern Belt, Southern Uplands
Authors: Barron Hugh F. , Phillips Emrys R. , Floyd James D.
Published: January 2010

Formerly regarded as an outlier of Lower Old Red Sandstone conglomerate within the Northern Belt of the Southern Uplands, the newly defined Lamington Conglomerate Member is now proposed to be an integral part of the Marchburn Formation (Tappins Group) of Ordovician (Caradoc) age. Pebbles and cobbles (up to 210 mm in size) are dominated by gabbroic and basaltic lithologies, with subsidiary amounts of tonalite, serpentinite, volcanic breccia and sedimentary lithic clasts. The matrix to the conglomerate is composed of a distinctive pyroxene-bearing sandstone. The member also has unusually high magnetic susceptibility, reminiscent of other units within the Tappins Group further to the SW, and consistently higher than any Old Red Sandstone conglomerate. The clast content supports an ophiolitic provenance for this part of the Marchburn Formation and is consistent with the overall petrography of the Tappins Group.
Palaeomagnetic study of the Canisp Porphyry, NW Scotland: an Early Silurian palaeomagnetic pole from the Laurentian Foreland
Authors: Darabi M. H. , Piper J. D. A.
Published: January 2010

Synopsis

The Canisp Porphyry is a member of the acid alkaline suite in the Northern Highlands of Scotland. It was emplaced between 460 and 430 Ma into Torridonian and Cambrian–Ordovician sediments of the NW foreland to the Caledonian Orogen where it is cut by the Sole Thrust. The interior of the body has a magnetism dominated by multidomain magnetite that partially preserves a primary ‘A’ remanence with NE direction. A distributed range of easterly positive directed (‘B’) components with some reversed equivalents is also widely represented and Early Devonian (‘C’) overprints are more sporadically present. The chilled margin against Torridonian sandstones preserves a clear record of the ‘A’ component accompanied by diminishing partial overprinting of primary Torridonian Components within 6 cm of the contact. The ‘A’ component (mean D/I=23/ −36°, α
95
=4.4°) yields a pole position at 342°E, 11S° comparable to magnetizations observed in Caledonian alkaline plutons within the Northern Highlands. It demonstrates that these are post tectonic magnetizations representative of the Laurentian Foreland in Late Ordovician to Early Silurian times. The collective data define a rotation of this region during Early Silurian times at
c.
440–425 Ma. Poles from the Canisp Porphyry and alkaline igneous bodies within the adjoining orogenic belt correlate with contemporaneous North American poles on the pre-drift configuration and confirm the integrity of the Early Silurian palaeomagnetic record from the North Atlantic continents. The ‘B’ components in the porphyry (mean D/I=58/31°) are similar to minority components in other intrusions and to overprinted magnetizations observed in the Torridon Group sediments. The latter are therefore inferred to be Caledonian acquisitions imparted by fluid flow resulting from loading of the foreland during orogenesis.
Record of fluid flow history through fractured conglomerates, Lower Old Red Sandstone of central Scotland
Authors: Baron Martin , Parnell John
Published: January 2010

Synopsis

Extensively fractured quartzite clasts in Lower Old Red Sandstone conglomerates adjacent to the Highland Boundary Fault Zone in central Scotland contain multiple populations of healed microfractures delimited by fluid inclusion planes. Microthermometric analysis indicates that the healing of microfractures oriented perpendicular to the trend of the Highland Boundary Fault Zone, which probably formed during Acadian overthrusting towards the SE along the fault zone in Middle Devonian times, involved moderate temperature (T
h
102 to 238°C), low to moderate salinity (3 to 17 wt% NaCl eq.) aqueous fluids. The clasts also contain a second set of fluid inclusion planes oriented parallel to the Highland Boundary Fault Zone, which formed during extension associated with the intrusion of late Carboniferous quartz dolerite dykes. The healing of this set of microfractures involved low temperature (T
h
58 to 155°C), low to moderate salinity (1 to 12 wt% NaCl eq.) aqueous fluids.
Use of non-parametric statistics as a tool for the hydraulic and hydrogeochemical characterization of hard rock aquifers
Authors: Banks David , Morland Geir , Frengstad Bjørn
Published: January 2010

Synopsis

The new EU Water Framework Directive (Directive 2000/60/EC) implies that hard rock units will need to be considered as aquifers, and to be hydrogeologically and hydrogeochemically characterized. This is not a straightforward task, given that such aquifers are heterogeneous, discontinuous and strongly three-dimensional in the distributions of both hydraulic and hydrochemical properties. The Geological Survey of Norway has recently carried out characterizations of Norway’s hard rock aquifers using simple non-parametric statistical techniques, focusing on median and percentile values for aquifer properties and concentrations of chemical parameters. Such characterizations reveal far larger parameter ranges within given aquifer lithological units than between different units. Indeed, for most lithologies, median well yields and concentrations of major chemical parameters (e.g. pH, major ions) are remarkably similar. For certain elements, however, systematic differences can be detected. For example, elements such as uranium, radon and fluoride are significantly enriched in Precambrian granites and gneisses, and depleted in anorthosites.
A history of the Shetland Ophiolite Complex
Authors: Flinn Derek , Oglethorpe Richard J. D.
Published: January 2010

Synopsis

The Shetland ophiolite was derived from an intra-continental, ocean-floored basin that opened shortly after 600 Ma on the eastern edge of Laurentia, during the tensional opening of the Iapetus Ocean. The precursor sedimentary and volcanic extensional basin is exposed in the south of Shetland and can be followed northeastwards by offshore geophysical anomalies. Eastward subduction of the floor of the basin led to hydration of the descending slab and the overlying mantle wedge. At about 500 Ma pressure from the east caused westward obduction of part of the subducting slab. The obduction thrust originated in the overlying mantle wedge and cut through the descending slab from above into underlying mantle. The result is a nappe cutting steeply through the sub-ocean-floor layers. The obducted nappe over-rode highly metamorphosed Shetland–Dalradian schists and gneisses and now forms the Lower Nappe of the Shetland Ophiolite Complex. The exposed pseudo-stratigraphic succession extends from several kilometres deep in the mantle, as exposed in the west, through the lower crust to the base of the sheeted dykes in the east, before passing beneath the sea; a surface distance of some 6 km. The ophiolitic pseudo-stratigraphy occurs as steeply dipping layers within the nappe, which gravity modelling shows to be about 3 km thick. The section through the ophiolite is lying on its side. After its obduction, erosion of the nappe and nearby metamorphic basement led to deposition of fine-grained, laminated siliceous sediments, locally graphitic and conglomeratic. Resumed pressure from the east during the Scandian orogeny telescoped the Lower Nappe, thereby emplacing an Upper Nappe over the Lower Nappe. The two nappes are separated by an imbricate zone incorporating siliceous sediments, ophiolitic hornblende schist and slices of the ophiolite nappes. The Skaw granite was intruded at about 425.6 Ma during this phase.
Lamprophyric magmatism in the Sleat Group (Torridonian), Kyle of Lochalsh: Torridonian sill or ash-flow tuff, or Permo-Carboniferous intrusion?
Authors: Batchelor R. A.
Published: January 2010

Synopsis

A prominent bed which is concordant with its host Sleat Group (Torridonian) rocks near Kyle of Lochalsh, Highland Region, NW Scotland, has been categorized as an alkaline lamprophyre (sannaite). It consists mostly of a yellowish-grey crumbly material with marginal layers of competent rock which exhibit flow textures reminiscent of ash-flow tuffs. A central facies displays trachytic texture. The presence of sanidine, flow textures and pseudomorphed skeletal olivine phenocrysts supports a volcanic origin. The rock’s NE-SW trend is incompatible with local Tertiary NW–SE dyke swarms. While the evidence for this rock being a contemporary late-Mesoproterozoic ash-flow tuff or sill, or a Permo-Carboniferous sill may appear equivocal, the weight of evidence favours a Torridonian intrusive origin, contemporary with the Gardar Igneous Province of Greenland.
Lithostratigraphical subdivision of the Sherwood Sandstone Group (Triassic) of the northeastern part of the Carlisle Basin, Cumbria and Dumfries and Galloway, UK
Authors: Holliday D. W. , Jones N. S. , McMillan A. A.
Published: January 2010

Synopsis

Two formations, the St Bees Sandstone and Kirklinton Sandstone, have been mapped in the past within the Triassic Sherwood Sandstone Group of the eastern part of the Carlisle Basin, Cumbria, and adjacent parts of Dumfries and Galloway, UK. However, previous workers have found considerable difficulty in consistently identifying, defining and mapping the Kirklinton Sandstone Formation. The principal lithological change within the Sherwood Sandstone Group is between mainly fine-grained sandstones that are commonly micaceous and contain numerous mudstone interbeds in the lower and middle parts of the group, and fine- to coarse-grained sandstones with rare or no mica and few mudstone partings at the top of the group. This change occurs within the Kirklinton Sandstone Formation as previously mapped. This paper considers ways of subdividing the group lithostratigraphically and the nomenclature to be adopted. All options have some associated problems, but, in view of the recently determined similarities with the contiguous sandstones offshore, the adoption of the same terminology as that in the adjacent East Irish Sea and Solway Firth basins is suggested, i.e. the St Bees Sandstone Formation below (subdivided where possible into Rottington Sandstone and Calder Sandstone members) and the Ormskirk Sandstone Formation above.
Upper Llandovery–Wenlock (Silurian) palynology of the Pentland Hills inliers, Midland Valley of Scotland
Authors: Molyneux S. G. , Barron H. F. , Smith R. A.
Published: January 2010

Synopsis

The results of a palynological study on late Llandovery–Wenlock (mid-Silurian) successions in the North Esk, Bavelaw Castle and Loganlee inliers of the Pentland Hills, Midland Valley of Scotland, are documented. Palynological assemblages from the Reservoir Formation are dominated by acritarchs, but chitinozoa, cryptospores and scolecodonts are also present. Assemblages from the lower part of the Reservoir Formation are of low diversity and abundance, but marked increases in both abundance and diversity, particularly of the acritarchs, occur in the upper 200 m or so of the formation. The reasons for the marked increases are unclear, but could reflect changing environmental conditions during deposition of the upper Reservoir Formation, with the marine palynomorphs tracking changes in the location of certain physical and chemical properties of water-masses, for example nutrient availability, salinity or temperature. There is a general decline in the abundance and diversity of acritarchs and chitinozoans above the Reservoir Formation, although both groups, together with rare cryptospores, are present in samples from the Deerhope and Wether Law Linn formations. The Henshaw Formation yielded few marine microfossils, but more abundant and diverse spores and cyptospores than the underlying formations, consistent with an upward transition from marine to prograding terrestrial facies. The microfloras from the Reservoir, Deerhope and Wether Law Linn formations are consistent with the late Llandovery age indicated by graptolite evidence.

A feature of assemblages from the Reservoir Formation, particularly the more productive samples from the upper part of the formation, is the common occurrence of sphaeromorph acritarchs,
Moyeria cabottii
and
Tylotopalla
species. The common occurrence of these forms gives the palynological assemblages a distinctive character. Similar sphaeromorph–
Moyeria
-
Tylotopalla
dominated acritarch microfloras occur at about the same level
(spiralis
Graptolite Biozone) in the Silurian succession of the Girvan Inlier, in the Drumyork Flags Formation. They might therefore be useful for correlating upper Llandovery rocks across the Midland Valley.
Late Devensian palaeoenvironmental changes in the sea area adjacent to Islay, SW Scotland: implications for the deglacial history of the island
Authors: Peacock J. D.
Published: January 2010

Synopsis

From a study of offshore borehole samples collected by the British Geological Survey in 1975, it is suggested that arctic marine or glaciomarine sediments of Dimlington Stadial (DS) age (>13 ka
14
C ka BP) in Loch Indaal, Islay, were laid down following the retreat of a glacier from the head of the loch, possibly only a few hundred radiocarbon years before the opening of the Windermere Interstadial (WI, 13–11
14
C ka
bp
). A reworked molluscan fauna in the DS sediments, which is identical to that living in the area today, is believed to be of last interglacial age or earlier. Sediments of WI age and Holocene age (<10
4
C ka
bp
) have also been intersected in the boreholes. Deposits of Loch Lomond Stadial age (11–10
14
C ka
bp
) are absent from two boreholes investigated from Loch Indaal, but may be present in a borehole east of Islay. The proposal that ice of the Last Glacial Maximum reached only as far west as central Islay is unsupported by both this assessment and the published geomorphological evidence.
Nonalcoholic Fatty Liver Disease: Pathology and Pathogenesis
Authors: Tiniakos Dina G. , Vos Miriam B. , Brunt Elizabeth M.
Published: January 2010

Nonalcoholic fatty liver disease (NAFLD) is recognized as the leading cause of chronic liver disease in adults and children. NAFLD encompasses a spectrum of liver injuries ranging from steatosis to steatohepatitis with or without fibrosis. Fibrosis may progress to cirrhosis and complications including hepatocellular carcinoma. Histologic findings represent the complexity of pathophysiology. NAFLD is closely associated with obesity and is most closely linked with insulin resistance; the current Western diet, high in saturated fats and fructose, plays a significant role. There are several mechanisms by which excess triglycerides are acquired and accumulate in hepatocytes. Formation of steatotic droplets may be disordered in NAFLD. Visceral adipose tissue dysfunction in obesity and insulin resistance results in aberrant cytokine expression; many cytokines have a role in liver injury in NAFLD. Cellular stress and immune reactions, as well as the endocannabinoid system, have been implicated in animal models and in some human studies.
Pathogenesis of Preeclampsia
Authors: Young Brett C. , Levine Richard J. , Karumanchi S. Ananth
Published: January 2010

Preeclampsia is a systemic syndrome that occurs in 3 to 5% of pregnant women and classically manifests as new-onset hypertension and proteinuria after 20 weeks of gestation. Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality. The only known cure is delivery of the placenta. Recent discoveries, however, have led to important advances in understanding the pathogenesis of the condition. Placental antiangiogenic factors are upregulated and disrupt the maternal endothelium. This change in the normal angiogenic balance toward an antiangiogenic state can result in hypertension, proteinuria, glomerular endotheliosis, HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, and cerebral edema—the clinical signs of preeclampsia and eclampsia. The regulation of these antiangiogenic factors in the placenta is unknown. The recent discoveries of upregulated antiangiogenic factors provide promise for future testing to predict and diagnose preeclampsia as well as therapeutic targets for amelioration of the clinical disease.