bluuebunny/crossref_metadata_2025 huggingface dataset:
Mattheddleite, a new mineral of the apatite group from Leadhills, Strathclyde Region
Authors: Livingstone A. , Ryback G. , Fejer E. E. , Stanley C. J.
Published: January 2010

Synopsis

Mattheddleite, a new lead member of the apatite group with sulphur and silicon totally replacing phosphorus, occurs as tiny crystals (<0.1 mm) forming drusy cavities in specimens from Leadhills. Optically, the mineral is colourless in transmitted light and is uniaxial with ω2.017 and ε1.999. X-ray powder diffraction data are similar to the synthetic compound lead hydroxyapatite and may be indexed on a hexagonal cell with
a
9.963 and
c
7.464 Å (the cell volume is 642 Å
3
). The calculated density is 6.96 g/cm
3
. The strongest lines in the powder pattern are [
d
, (
I
) (
hkl
)]: 2.988 (100) (112, 211), 4.32 (40) (200), 4.13 (40) (111), 2.877 (40) (300), 3.26 (30) (210). Single crystal Weissenberg photographs are close to those of pyromorphite, space group

P6
3
/m.

Chemically, mattheddleite does not contain S and Si in the expected 1:1 ratio, and the ideal formula may be expressed as Pb
20
(SiO
4
)
7
(SO
4
)
4
Cl
4
. The infrared spectrum is very similar to that of hydroxyellestadite. Associated minerals are lanarkite, cerussite, hydrocerussite, caledonite, leadhillite, susannite, and macphersonite.

The mineral is named after Matthew Forster Heddle (1828–1897), a famous Scottish mineralogist.
Palaeomagnetism and age of the quartz-porphyry intrusions, Isle of Arran
Authors: Mussett A. E. , Dagley P. , Hodgson B. , Skelhorn R. R.
Published: January 2010

Synopsis

Most of the quartz-porphyry intrusions of Arran, many of which form the acid member of composite intrusions, have been sampled palaeomagnetically. Though both normal and reversed polarity may be found in a single intrusion it is concluded that the reversed polarities are due to overprinting by later reversely magnetised intrusions and that all the quartz-porphyries were intruded while the magnetic field had normal polarity.

The age of the Drumadoon quartz-porphyry dyke and, by inference, that of all the other quartz porphyry intrusions, is 58.5 ± 0.8 (lσ) Ma.

It is suggested that normal polarity may provide a stratigraphic ‘horizon’ useful for elucidating the poorly-known succession of Arran Tertiary igenous rocks, most of which are reversely magnetised.

This work forms part of a comprehensive study, using palaeomagnetic polarity and radiometric dating, of the timing and duration of activity in the British Tertiary Igneous Province, and the age quoted above lies in the period of peak activity. This is the first time that a correlation of polarity with a distinctive petrographic rock type has been found.
A palaeomagnetic study of the intrusions and Carboniferous sediments at Dunbar, Scotland
Authors: Xu T. C. , Tarling D. H.
Published: January 2010

Synopsis

Gently tilted Lower Carboniferous sediments on the Dunbar foreshore are intruded by a 20 m thick dyke and a subparallel narrow dyke. Heating by the Big Dyke can be traced for 80 m, but the strongly altered Small Dyke only has a 1 m aureole. The Big Dyke remanence differs from that of the unheated sediments, which show similar directions to the Small Dyke. The sequence of superimposed components in the aureole of the Small Dyke suggest that the remanence of the unheated sediments is oldest, followed by the baking effect of the Big Dyke and then by the Small Dyke. This implies a Lower Carboniferous age for the magnetization of the sediments and the Big Dyke, and a Permian age for the Small Dyke. However, the corresponding pole positions suggest Permian ages for the sediments and Small Dyke, and Lower Carboniferous for the Big Dyke. Only the reversed pole (23°S 341°E) for the Big Dyke appears to be substantiated.
The nature and age of the debris accumulation at Gribun, Western Mull, Inner Hebrides
Authors: Dawson A. G. , Lowe J. J. , Walker M. J. C.
Published: January 2010

Synopsis

In the Gribun area of western Mull, Scottish Inner Hebrides, a large debris accumulation is interpreted as a morainic complex. Although the outermost moraine ridge is located well beyond the limits of the Loch Lomond (Younger Dryas) glaciation previously proposed for the island, lithostratigraphic and biostratigraphic evidence from a deep basin enclosed within the moraine suggest that the feature formed during the Loch Lomond Stadial. At that time the regional firn line altitude in western Mull may have been as low as
c.
100 m. The pollen stratigraphy of the basin sediments indicates that the site was ice free before the close of the Loch Lomond Stadial,
sensu stricto,
reflecting the low altitude of the glacier and its relatively small size. Evidence from Gribun supports the view that deglaciation in parts of Highland Britain may have been underway as early as 10,600 B.P.
A Devensian glaciomarine sequence in western Islay, Inner Hebrides
Authors: Benn D. I. , Dawson A. G.
Published: January 2010

Synopsis

A sedimentological description is given of three closely spaced exposures of interbedded glacigenic and water-sorted sediments at Kilchiaran, western Islay, Scottish Inner Hebrides. The sediments are considered to be Devensian in age and to have been deposited in a proximal glaciomarine environment. The descriptions are thought to represent the first detailed account of onshore glaciomarine sediments in Scotland.
Geochemical and petrological characteristics of the Etive granitoid complex, Argyll
Authors: Batchelor Richard A.
Published: January 2010

Synopsis

The Etive granitoid complex in the SW Highlands is a late-Caledonian elliptical pluton emplaced at
c.
400 Ma into Moine and Dalradian metasediments. It comprises an outer ‘Cruachan’ facies of monzodiorite and monzogranite, and an inner ‘Starav’ facies of monzogranite. Sheets of leucocratic ‘Meall Odhar’ granites are intruded into the ‘Cruachan’ facies. Major and trace element data is presented here for a suite of quartz diorite, monzodiorites, monzogranites and syenogranites.

This petrological and geochemical study has highlighted six major features. The outer Cruachan monzodiorite facies consists of at least three magma pulses. The three monzodiorite pulses display reverse zonation. The monzodiorites have a chemical signature which does not represent a liquid composition. The Starav monzogranite facies is composed of four normally-zoned nested pulses. The Meall Odhar leucogranites consist of independent intrusions of syenogranite and monzogranite. The Cruachan and Starav magmas were derived from two independent parent magmas, each of which followed a chemical evolution consistent with fractionation of clinopyroxene or amphibole and plagioclase feldspar (>An
50
) as the major phases.
Early sinistral transpression in the Lower Old Red Sandstone of Kincardineshire, Scotland
Authors: Robertson S.
Published: January 2010

Synopsis

A zone of disrupted strata within the Lower Old Red Sandstone of Kincardineshire is described. Disruption resulted from transcurrent faulting of partly lithified sediments close to the margin of the developing Lower Old Red Sandstone basin.
The age and origin of the Eastern Grampians Newer Granites
Authors: Harrison T. N. , Hutchinson J.
Published: January 2010

Synopsis

Four new Rb-Sr whole rock ages and initial ratios are reported for the Monadhliath (419 ± 4.7 Ma), Glen Gairn Phase II (403.9 ± 6.1), Kincardine, Water of Feugh (416.2 ± 9.9) and Kincardine, porphyritic Main granite (416.4 ± 4.1). These ages are representative of members of two newly recognised groups of Newer Granite in the Eastern Grampians: one group, emplaced at
c.
415 Ma, is associated with relatively abundant dioritic precursors, whereas the other group was emplaced at
c.
408 Ma and is not associated with any mafic precursors. These two groups cannot be distinguished on the basis of their strontium initial ratios. The two episodes of granitic magmatism are thought to represent the transition between subduction and strike-slip faulting during the very last stages of the Caledonian orogeny. The later group of granites are found at the intersection of pre-Caledonian basement lineaments with post-subduction strike-slip faults, and the introduction of mantle material into the root zones of these faults may have initiated melting in the lower crust and granite generation. The dioritic and the granitic rocks of the early group are considered to be partial melts of relatively mafic lower crustal material. The later group of granites are akin to A-type granites in their proposed source material (depleted granulitic lower crust) and tectonic setting, and an analagous situation to the Eastern Grampians has been recognised from the Western Cordillera of the United States.
Seismic and well evidence for the early development of the Faeroe–Shetland Basin
Authors: Haszeldine R. S. , Ritchie J. D. , Hitchen K.
Published: January 2010

Synopsis

The Faeroe–Shetland Basin occurs between the Faeroe and Shetland Islands north of the United Kingdom mainland. Most geologists currently favour an early Cretaceous rifting event for the origin of this basin. However, data from cores, cuttings, geophysical logs and seismic reflection profiles pertaining to well 206/5–1 show that Lower, Middle and Upper Jurassic marine sediments were deposited within the Faeroe–Shetland Basin. Therefore this basin had formed by the early Jurassic. The early and mid-Jurassic sediments probably record submarine fan sequences; the late Jurassic sediments are interpreted as fault scarp talus marginal to a deep muddy marine basin. As well 206/5–1 did not reach metamorphic basement, older sediments must also be present within the Faeroe-Shetland Basin.

Southeast of the Faeroe-Shetland Basin, the West Shetland Basin accumulated a wedge of Middle and Upper Jurassic nearshore sediments showing that both basins were then subsiding under the same regional tectonic influence. Three wells in the West Shetland Basin terminated at approximately 2.2 km, 2.6 km and 2.7 km within Triassic sediments. Below this, seismic data demonstrate that up to 3.9 km of older sediment remains undrilled above metamorphic basement. We therefore confidently infer a Permian or older origin for the West Shetland Basin. Seismic data shows the Jurassic and pre-Jurassic shapes of the West Shetland Basin to be almost identical. If the same tectonic control also influenced the Faeroe-Shetland Basin, we must infer a Permian or older age for the Faeroe-Shetland Basin. A long-lived deep marine Faeroe-Shetland Basin implies the presence of pre-Mesozoic hydrocarbon source rocks, plus the possibility of deeply buried reservoirs.
Phosgenite from Lossiemouth, Grampian Region: Confirmation of the first Scottish occurrence
Authors: Starkey R. E.
Published: January 2010

Synopsis

The rare lead mineral phosgenite (Pb
2
(CO
3
)Cl
2
) has been collected
in-situ
, from an outcrop on the coast near Lossiemouth, Grampian Region. It is associated with lead-zinc mineralisation in the Cherty Rock (Triassic). Associated minerals include galena, sphalerite, pyrite, quartz, cerussite and pyromorphite. The phosgenite is considered to result from the reaction between galena and seawater. This is the first authenticated record of this species in Scotland.
The stratigraphy and structure of the metasedimentary rocks of the Loch Laggan-Upper Strathspey area, Inverness-shire
Authors: Okonkwo C. T.
Published: January 2010

Synopsis

The metasedimentary rocks of the Loch Laggan-Upper Strathspey area form part of the Grampian Division of the Caledonides in the Grampian Highlands. They comprise two lithostratigraphic successions, the Glenshirra and the Corrieyairack successions, which are separated by a zone of high strain, the Gairbeinn slide. Both successions consist dominantly of non-calcareous clastic metasediments. They may be correlated with similar lithostratigraphic units in the Loch Killen and the Corrieyairack Pass areas.

The two successions share a similar deformational history and were both subjected to amphibolite facies metamorphism. A sub-horizontal foliation associated with an early isoclinal folding which is intensely developed in the vicinity of the Gairbeinn slide has been refolded by tight, upright, NE-SW trending folds, which have in turn been refolded by open folds with generally NW-SE trending axial traces.

The absence of the Gairbeinn Pebbly Semi-psammite described from the Corrieyairack Pass area by

Haselock
et al.
(1982)

may be attributed either to tectonic excision during the sliding or to lateral facies variations.
The thrust and normal faults of the Ullapool–Strath Kanaird region and their implications for NW Highland tectonics
Authors: Coward M. P.
Published: January 2010

Synopsis

In the Ullapool to Strath Kanaird region of the NW Highlands the thrusts of the Moine thrust zone generally show a foreland propagating sequence but there are important anomalies. The Moine thrust itself appears to be a late structure, slicing across the earlier thrust stacks. There are several ages of normal fault movement. An early set formed synchronous with thrusting and involved extension in a WNW–ESE direction, parallel to general thrust transport, but also extension NE–SW, perpendicular to thrusting. These variations in movement indicate non-plane strain conditions, with important implications for section restoration. The early normal faults are either cut by or decouple on the Sole thrust to the Moine thrust system. There are late normal faults however, which are well-developed in the Ullapool area, and these are probably Mesozoic in age.
Hydrogeological provinces and groundwater flow systems in Scotland
Authors: Robins N. S.
Published: January 2010

Synopsis

There are two principal hydrogeological provinces in Scotland: the Caithness and Moray Firth province, and the Midland Valley province (Central Lowlands). Regional groundwater flow patterns are developed in these provinces with deep-seated, but slow, transport of groundwater. Shallower local systems are also present. Annual recharge of up to 500 mm occurs to the more permeable aquifers at outcrop but is much reduced to less permeable aquifers and areas covered by till. Baseflow is related to the hydraulic conductivity of the aquifer and is highest in parts of Morayshire and Fife.
Proximal Cu + Zn exhalites in the Argyll Group Dalradian, Creag Bhocan, Perthshire
Authors: Scott R. A. , Polya D. A. , Pattrick R. A. D.
Published: January 2010

Synopsis

Stratabound Cu + Zn mineralization at Creag Bhocan, near Tyndrum, represents the proximal equivalent of previously reported distal exhalites in the Ben Challum Quartzite of the Argyll Group Dalradian. The Creag Bhocan mineralization is characterised by pyrite, chalcopyrite and sphalerite hosted by chloritic schists and albitic quartzites. Mineral inclusions within syngenetic pyrite suggest ore formation at temperatures between 250°C and 350°C from reducing, acidic (pH3–5) hydrothermal fluids, in which H
2
S was the dominant aqueous sulphur species.

Affinities with the volcanic-associated massive sulphide (VMS) group of deposits are suggested for the Creag Bhocan mineralization. High heat flow and minor intrusives associated with crustal extension are thought to have driven the circulation system, and the mineralization within the Ben Challum Quartzite as a whole has many characteristics similar to those of Besshi-type deposits.
A radiocarbon date on plant detritus beneath till from the type area of the Loch Lomond Readvance
Authors: Rose J. , Lowe J. J. , Switsur R.
Published: January 2010

Synopsis

This paper records the first radiocarbon determination on plant detritus from beneath
in-situ
till of Loch Lomond Stadial age in Scotland. The age of 10,560 ± 160 BP provides additional stratigraphic control for the Loch Lomond Readvance in its type area at the southeastern part of the Loch Lomond basin and for the timing of the glacial episode in western Scotland.
A review of radiocarbon dates on peat and wood from Holocene coastal sedimentary sequences in Scotland
Authors: Haggart B. A.
Published: January 2010

Synopsis

158 radiocarbon dates from Holocene coastal sedimentary sequences are assessed in terms of their tendency of relative sea-level movement. Three subdivisions of greater, intermediate and lesser uplift history are made in order to assess the degree of synchroneity or diachroneity present in the data. The most successful demonstration of diachroneity is for the initiation of the mid-Holocene fall in relative sea-level. This may correspond approximately with the formation of the Main Postglacial Shoreline throughout Scotland. However on the national scale this shoreline may be a composite feature. A notable departure from the expected pattern of diachroneity is recorded for south-west Scotland.
An ancient manganese-iron deposit of freshwater origin, Islay, Argyllshire
Authors: Nicholson Keith
Published: January 2010

Synopsis

Veins composed of manganese and iron oxides occur within the Dalradian Jura Quartzite (Argyll Group) on the SW coast of Islay. The manganese oxides, which are composed principally of hollandite with minor pyrolusite and rare groutite, frequently display a colloform texture centred upon silicate grains. In a single section an oolitic texture was displayed by hollandite in a hematite groundmass. Hematite and goethite, in variable amounts, constitute the iron oxides, and usually enclose fragments of the host quartzite. The manganese and iron oxides frequently occur as separate, discrete patches within the vein material. The geochemistry of the oxides shows that, of the target and pathfinder elements, only Ba attains elevated levels (up to 4.9%). The absence of enrichments in the diagnostic hydrothermal assemblage (As–Ba–Cu–Mo–Pb–Sb–Sr–V–Zn) and in the marine assemblage (Na–K–Ca–Mg–Sr; Co–Cu–Ni) imply that this is a freshwater deposit. This conclusion was confirmed by discriminatory scatter plots of Na vs Mg and (Co + Ni) vs (As + Cu + Mo + Pb +V + Zn) which indicate a fresh-water, non-hydrothermal origin for the veins. The oxides were deposited from groundwater which penetrated the Jura Quartzite via a local fault system probably in Permo-Triassic time. The veins have no economic potential as manganese ore and the prospect of related base or precious metal mineralisation is remote.
Interpretation of magnetic anomalies over the Skye Tertiary intrusive complex
Authors: Tantrigoda D. A.
Published: January 2010

Synopsis

A 64 × 64 km
2
region of the aeromagnetic anomaly map over the Skye igneous complex was digitized at 1 km intervals and transformed into pseudogravimetric anomalies. A three-dimensional interpretation of the pseudogravimetric anomaly was performed using the end correction method.

The model obtained essentially consists of two bodies. One of them can be identified with the basic and ultrabasic rocks of the Cuillin centre. This body, which has a shape resembling that of a truncated cylinder, has a base which deepens towards the SW from 1.5 to 3.0 km. It is reversely magnetized and has a magnetization of 4.9 Am
−1
. The other body is situated below the Red Hills and takes the approximate shape of a truncated cone extending to a depth of 14.0 km. This body is normally magnetized with a magnetization of 1.1 Am
−1
. Basaltic lavas situated west of the Cuillin centre were also incorporated in the interpretation.
Grandidierite from the Comrie aureole
Authors: Helmers H. , Lustenhouwer W. J.
Published: January 2010

Synopsis

Grandidierite (Mg, Fe, Mn)Al
3
O
2
(BO
3
)(SiO
4
) with Fe
2+
/(Fe
2+
+ Mg + Mn) up to 0.47 is described from the inner contact aureole of the Comrie granodiorite. It was formed during an influx of boron-bearing fluid close to the peak of contact metamorphism at around 600–670°.
Palaeomagnetic dating of pseudotachylyte formation in the Lewisian complex
Authors: Piper J. D. A. , Poppleton T. J.
Published: January 2010

Synopsis

Magnetic remanence is employed to date episodes of pseudotachylyte formation within the Lewisian terrane. In the Southern Zone on the mainland directions of magnetisation correlate with late stages of post-Laxfordian uplift and imply that these examples were either contemporaneous with the LM3 metamorphism or with early Torridonian rifting. In the Outer Hebrides the pseudotachylytes yield both mid-Proterozoic and Caledonian directions of magnetisation. The Proterozoic examples were formed late in the post-Laxfordian uplift cycle while the Palaeozoic examples are linked to formation of the Outer Hebrides thrust zone and presumably to the Caledonian thrusting on the mainland. The latter examples imply that differential uplift of the order of several kilometres has taken place between the Outer Hebrides and the Mainland since Caledonian times; their presence here explains why Torridonian and Lower Palaezoic cover rocks are not preserved in the former area.
New problematical pterioid bivalve species in the British Carboniferous
Authors: Graham D. K.
Published: January 2010

Synopsis

Pterioid bivalves apparently belonging to two species are tentatively referred to the genus
Placunopsis
Morris and Lycett, previously unrecorded in the Carboniferous. The name
Placunopsis
?
propediscus
sp. nov. is ascribed to the more common of these forms.
The age of the South Connemara Group, Ireland, and its relationship to the Southern Uplands Zone of Scotland and Ireland
Authors: Williams D. Michael , Armstrong Howard A. , Harper David A. T.
Published: January 2010

Synopsis

The South Connemara Group lies to the south of the Dalradian rocks of Connemara. It consists of approximately 3 km of interbedded pillow lavas, cherts, sandstones and conglomerates with significant amphibolite intrusives. Hitherto its age has been unknown although it has been contact metamorphosed by the Devonian Galway Granite. New palaeontological evidence suggests an early Ordovician age for the sequence. The petrofacies of the clastic units within the group, its structural style, age and tectonic position suggest similarities with parts of the Southern Uplands of Scotland and its equivalents in Ireland. The South Connemara Group bears greatest similarities to Tract 2 of the Southern Uplands. The age of the group supports the apparent SW to NE diachronism of clastic sedimentation in this part of the Caledonides. The proposed correlation imposes a constraint on the position of the Southern Upland Fault in Ireland.
Sedimentology and early diagenesis of the Lower Jurassic, Applecross, Wester Ross
Authors: Searl Alison
Published: January 2010

Synopsis

The Jurassic strata at Applecross comprise 60 m of mixed siliciclastics and carbonates deposited in a variety of shallow marine environments including shallow carbonate shelf with patch reefs, oolitic shoal, restricted lagoon, beach and siliciclastic mudflats. Vadose cement fabrics, blackened carbonate allochems, evaporite pseudomorphs and plant remains indicate several phases of sediment emergence during deposition. Changes in the source of siliciclastic sediment during deposition are also evident. The complex nature of the sequence is related to interplay of a regional marine transgression across the Hebridean area and localised uplift immediately north of Applecross. Differential offshore subsidence continually modified the topography of the depositional basin altering the hydraulic regime in the Applecross area.
Stevensite, a smectite-group mineral from Corstorphine Hill, Edinburgh
Authors: Davidson P. J.
Published: January 2010

Synopsis

Specimens of pectolite, from Corstorphine Hill, Edinburgh, were found to be coated by the smectite-group mineral stevensite. This is the first recorded occurrence of stevensite in Scotland, although the specimen was registered (as pectolite) in 1898. X-ray diffraction and spectrometry, infra-red and electron probe micro-analytical techniques were used to identify the material, which occurs as a brown gel-like phase, and is both intermixed with, and coating, the pectolite.
Mid-Wenlock acritarchs from a Silurian inlier in the Cheviot Hills NE England
Authors: Barron H. F.
Published: January 2010

Synopsis

Six samples from the S margin of the Greyhound Law Inlier on the southern slopes of the Cheviot Hills yielded diverse, moderately well preserved middle Silurian palynomorph assemblages. The taxa present suggest a mid- to late Sheinwoodian or earliest Homerian age, which is in agreement with new graptolite collections of
Crytograptus ellesae
to
Cyrtograptus lundgreni
Zone age. Thick-walled
Leiosphaeridia
, suggestive of deposition in a hemipelagic environment, are common in the assemblages and are associated with diverse non-sphaeromorph acritarchs and some miospores that were derived from shelf areas by turbidity currents. Acritarch and spore colours are consistent with low thermal maturation, with palaeotemperatures probably in the region of 60–130°C.
A review of the hiatellid bivalves
Saxicavella jeffreysi
Winckworth [=
S. plicata
(Montagu)],
S. cylindrica
(Wood) [=
S. fragilis
(Wood)
non
(Nyst)] and
S. carinata?
(Brocchi)
Authors: Graham D. K.
Published: January 2010

Synopsis

A presently surviving form of the hiatellid bivalve
Saxicavella
is compared to two others which, in Britain and Belgium at least, appear to occur only as Crag (late Pliocene-early Pleistocene) fossils. Differences in their shell morphologies are shown to be sufficiently pronounced that they should be regarded as three distinct species.

The use of the name
Saxicavella jeffreysi
Winkworth for the first form is claimed to be taxonomically more correct than
S. plicata
(Montagu), by which it is also known. A case is presented for the adoption of the name
S. cylindrica
(Wood) for the more common of the Crag forms in preference to
S. fragilis
the recognised, but taxonomically inadmissable, name.
Manganese minerals in Scotland
Authors: Nicholson Keith
Published: January 2010

Synopsis

Mining for manganese in Scotland first commenced in 1841. Trials were made at several sites, but no venture lasted longer than 5 years. Thirty-one manganese minerals are known to occur at 80 sites in Scotland, with over 70 localities recorded for manganese oxides alone. Birnessite, found at five sites, is the most common manganese mineral in Scotland. Most of the silicates and phosphates occur in Lewisian-Moine metamorphic rocks, while the majority of oxides are supergene in origin, varying in age from Early Ordovician to Pleistocene. Examples of birnessite and rhodochrosite formed by both hydrothermal and super-gene processes are known, and as such these are the only minerals to occur with more than one origin. The following manganese minerals have been recorded in Scotland: oxides: birnessite, braunite, chalcophanite, coronadite, cryptomelane, groutite, hollandite, jacobsite, lithiophorite, manganite, pyrolusite, pyrophanite, quenselite, ramsdellite, romanechite, todorokite, woodruffite; carbonate: rhodochrosite; phosphates: arrojadite, graftonite, jahnsite, rockbridgeite, triplite; silicates: axinite (undifferentiated), bustamite, ferrobustamite, johannsenite, knebelite, pyroxmangite, rhodonite, spessartine. Birnessite was first discovered in Scotland, and 13 of the above 31 minerals have their first British occurrence recorded in Scotland.
Fold and thrust structures in the Kintradwell ‘Boulder Beds’, Moray Firth
Authors: Roberts Alan
Published: January 2010

Synopsis

The Kimmeridgian shales, sands and ‘boulder-beds’ exposed at Kintradwell Point in Sutherland display a complex series of ‘soft-sediment’ deformation features, which can be assigned to four categories, on the basis of both geometry and temporal relationship.

Small, closely-spaced, syn-depositional normal faults, throwing down to the S/SE.

Slump folds with intensely curvilinear hinges, produced by differential movement within a wet-sediment pile slumping to the south, obliquely away from the Helmsdale Fault.

‘Thrust’ faults together with related low-angle slides and extensional faults. These gravity-driven structures moved perpendicular to and away from the Helmsdale Fault. They represent a section through the leading edge of a large, detached gravity-slide.

Isolated, down-to-the-SE, brittle normal faults, tens of metres in length. These offset slump-fold and slide structures.

Structures belonging to category 4 may be the product of tectonic strain related to the opening of the Moray Firth Basin. The remainder are all thought to be local, gravity-driven structures, generated on a late Jurassic palaeoslope dipping away from the Helmsdale Fault.

Many geometric analogues for the Kintradwell structures are found not only in slump sheets documented elsewhere but also in the internal parts of contractional orogenic belts. Familiarity with the analysis of such ordered structures from within orogenic belts such as the Caledonides of the Scottish Highlands, facilitates an understanding of the section at Kintradwell.

Sequences similar to that at Kintradwell have been discovered during offshore hydrocarbon exploration in the North Sea. The observations presented in this paper have implications for the analysis of cores from such sequences.
Geochemistry and sedimentology of Grampian Group metasedimentary rocks, Upper Strathspey
Authors: Okonkwo C. T.
Published: January 2010

Synopsis

The sedimentological attributes of the metasedimentary rocks of Upper Strathspey are inferred from their major and trace element geochemistry. The rocks of the Glenshirra Succession have high oxidation ratios and are of a lithic nature which suggests shallow water, probably alluvial, environments. The Corrieyairack Succession has turbiditic greywackes of a more basinal environment.

Within the Glenshirra Succession, the Allt Luaidhe Semi-psammite has semi-pelites with relatively higher Ba/Rb, CaO/Y and Sr/Y ratios which indicate its higher contents of detrital feldspars and suggest that its sediments were less “mature” than those of the other formations. Sorting of the sedimentary particles produced a compositional fractionation with the semi-pelitic fractions being enriched in TiO
2
, A1
2
O
3
, total Fe, MgO, K
2
O, P
2
O
5
, Cr, Y, Rb, Ba and Ni whereas the psammitic fractions are enriched in SiO
2
and Zr.

High concentrations of the large ion lithophile elements e.g. K, Ba, Rb and Sr, were found suggesting source rocks in middle or upper continental crustal layers, intruded by evolved granite. The
c.
1100 Ma Grenville crust is believed to be a major source of the sedimentary detritus.
A reappraisal of the supposed Ardersier Readvance, inner Moray Firth
Authors: Firth Callum R.
Published: January 2010

Synopsis

Previous authors have proposed that the deglaciation of the Late Devensian ice sheet in the inner Moray Firth area was interrupted by the “Ardersier Readvance”. The morphological and lithological evidence indicates that the Ardersier features were not produced by a major readvance of ice but more probably represent glaciomarine deposits formed while ice occupied the Inverness Firth. Similarly the Late Devensian shoreline sequence of the area does not support the readvance hypothesis; instead it suggests that the sediments were deposited as relative sea level fell and the ice mass retreated westward.
Palynological evidence for the extent of the Loch Lomond Readvance in the Awe valley and adjacent areas, SE Highlands
Authors: Tipping R. M.
Published: January 2010

Synopsis

Palynological evidence for the age of ice-dammed lacustrine deposits at an infilled lake basin at the SW end of Loch Awe shows the lake and the kame deposits forming the dam to be of Loch Lomond Stadial age. The absence of Devensian Lateglacial sediments at six sites within the Awe valley, and the virtual synchroneity in the earliest Flandrian of their basal biostratigraphic records also indicates ice cover in the valley during the Loch Lomond Stadial. This evidence is at variance with recent reconstructions of the extent of this ice advance in this part of Scotland. Similar lines of evidence from other localities in adjacent valleys suggest that the Loch Lomond Readvance in this region was of markedly greater magnitude than currently envisaged.
Late Devensian organic deposits beneath till in the Teith Valley, Perthshire
Authors: Merritt J. W. , Coope G. R. , Taylor B. J. , Walker M. J. C.
Published: January 2010

Synopsis

Organic silts (Torrie Silts), dated by radiocarbon, arthropod fauna and pollen flora to the Lateglacial (Windermere) Interstadial and the early part of the Loch Lomond Stadial, have been discovered beneath till near Callander in the upper Teith Valley. The till overlying the Torrie Silts was deposited by a valley glacier which terminated in the vicinity during the Loch Lomond Stadial. A new radiocarbon date of 12,750 ± 70 BP has been obtained from plant detritus close to the base of the organic sequence. The profile at Torrie, which constitutes one of the longest polleniferous sequences through Lateglacial Interstadial and Loch Lomond Stadial deposits in Scotland, indicates a considerable time lag between the onset of the Stadial and the arrival of the valley glacier.
The deglaciation of Glen Croulin, Knoydart
Authors: Bennett Matthew
Published: January 2010

Synopsis

The remarkable glacial geology of Glen Croulin has resulted from the interaction of regional ice flowing down Loch Hourn with local ice in Glen Croulin. The regional ice in Loch Hourn dammed up the valley mouth, while local ice occupied the upper part of the glen. This interaction probably dates from the Loch Lomond Stadial. The complex assemblage of landforms in Glen Croulin is interpreted here as a suite of ice marginal moraines and terraces, implying that the deglaciation occurred by active retreat as opposed to stagnation. A detailed picture of the pattern of this decay can be established and leads to the conclusion that the local ice in Glen Croulin reached its maximum extent and had begun to retreat prior to the maximum of the regional Loch Hourn ice.
The biostratigraphy and chronostratigraphy of BGS Borehole 78/4, North Minch
Authors: Graham D. K. , Harland R. , Gregory D. M. , Long D. , Morton A. C.
Published: January 2010

Synopsis

The British Geological Survey’s offshore borehole 78/4 has provided one of the most complete late Devensian to Flandrian Quaternary successions observed in Scottish waters. Molluscs from this sequence have provided radiocarbon dates ranging from 12,785 to 8,240 years BP. These dates are discussed in the context of the palaeoenvironmental history of the succession as indicated by its floras and faunas. Concentrations of volcanic glass shards indicate an ash fall, apparently equivalent to the Vedde Ash of western Norway.
Geochemistry, provenance and climate of the Upper Proterozoic Stoer Group in Scotland
Authors: Stewart A. D.
Published: January 2010

Synopsis

Stoer Group red beds, filling the lower part of a Proterozoic rift in NW Scotland, rest unconformably on Archaean gneisses strongly depleted in Th, Rb and K. The lowest sediments, despite their evident derivation from the gneisses, are relatively enriched in these elements (and also in Mg), indicating an additional, undepleted source. An analysis of vitric tuff from a member within the Group also shows high Rb, K and Mg, suggesting that much of the sequence was deposited under an intermittent rain of fine volcanic ash, now present as clay and chlorite in the finer grained fraction of the sediments. This helps to explain the low crustal residence age (τ ≃ 2.2 Ga) deduced from Nd isotope studies of shales in the Group.

Massive red siltstones and sandstones which appear at several levels in the Group owe their structureless nature to the seasonal wetting and drying of smectite. By analogy with vertisols the annual dry season was likely to have been 4–8 months, the rainfall 300–1200 mm and the palaeolatitude 10–30°, matching that deduced from the palaeomagnetism. Low rainfall is also suggested by the insignificant Ca depletion shown by certain tuff-free sandstones relative to the parental gneiss.

The geochemistry of alluvial sandstones higher in the Stoer Group (Bay of Stoer and Meall Dearg Formations) indicates a mixed source of 75% amphibolite facies gneisses and 25% siliceous sediments. The alluvial sandstones show even less depletion in soluble components than the basal sediments, suggesting high relief on the rift flanks whence they came.
Magnetostratigraphy of the Tertiary igneous rocks of Arran
Authors: Hodgson B. D. , Dagley P. , Mussett A. E.
Published: January 2010

Synopsis

The Tertiary igneous succession of Arran is poorly known, partly because of a paucity of informative field relationships, so palaeomagnetic polarities and Ar–Ar dates have been measured to provide additional constraints.

New palaeomagnetic results for over 200 sites have been combined with published data. The Northern Granite has normal polarity (N), while the later Central Ring Complex has reversed polarity (R). All sampled quartz-porphyries are N and all felsites (apart from some intermediate direction (I) sites) are R, the only known correlations between polarity and petrography in the British Tertiary Igneous Province. The remaining petrographic types may be found with either polarity. All dykes sampled on the NW coast are N, as are 70% of those on the NE coast, but elsewhere R polarity predominates.

Radiometric dates show that the activity occurred approximately 61 to 58 Ma ago. It spanned at least the magnetic polarity sequence R–N–R, and although additional polarity intervals cannot be ruled out, a tentative succession consistent with R–N–R and with as few as possible recurrences of petrographic types has been constructed. The mean direction of magnetisation of the sites is not consistent with that of an axial, centred dipole for the present latitude: several explanations are offered.
On the type material of the Llandovery (Silurian) graptoloid
Monograptus pseudobecki
Bouček and Přibyl, 1942 and the species’ biostratigraphical importance
Authors: Loydell D. K.
Published: January 2010

Synopsis

The type material, from Meigle Quarry, Galashiels, of
Monograptus pseudobecki
Bouček & Přibyl 1942
, a species with distinctive double curvature and thecae of probable streptograptid form, is redescribed. A number of authors have misidentified the species, in particular confusing it with
Streptograptus pseudoruncinatus
(
Bjerreskov, 1975
). These misidentifications have largely masked the biostratigraphical value of this species. It has so far only been correctly identified from rocks of the upper
Monograptus turriculatus
-lower
M. crispus
Biozones of the Telychian (Upper Llandovery). It may thus prove very useful in subdividing, for example, the very thick sequences, composed largely of turbidites, of Telychian age in Central Wales and southern Scotland.
Westlothiana
gen. nov.: naming the earliest known reptile
Authors: Smithson T. R. , Ian Rolfe W. D.
Published: January 2010

Synopsis

Formal diagnosis of
Westlothiana lizziae,
a new genus and species is given, to differentiate this taxon and to comply with the International Code of Zoological Nomenclature. This is the most primitive known reptile and establishes the presence in the Lower Carboniferous of a reptile fauna sufficiently ancient to have been ancestral to all later amniotes.
Anthraconaia irvinensis
sp. nov., a new Westphalian B bivalve with limited geographical and stratigraphical range
Authors: Brand P. J.
Published: January 2010

Synopsis

A new Westphalian B bivalve,
Anthraconaia irvinensis
sp. nov., is described and the distribution of the specie s recorded. The form has an unusually limited geographical and stratigraphica l range which is regarded as related to the organic content of the host sediment.
Late Oligocene terrestrial sediments from a small basin in the Little Minch
Authors: Evans D. , Hallsworth C. , Jolley D. W. , Morton A. C.
Published: January 2010

Synopsis

Borehole 80/14 in the Little Minch recovered grey, carbonaceous clays with sandy horizons and abundant plant remains from a small basin adjacent to the Minch Fault. Pollen from the sediment is characterised by a
verus-vestibulum
association that demonstrates a Late Oligocene (Chattian) age and indicates a terrestrial floodplain environment with arborescent swamps and fens. Both the age and lithology of the deposit are therefore similar to other terrestrial Oligocene basins found in the western British Isles. Petrological studies confirm the environment of deposition, and suggest that the sediment was predominantly derived from metamorphic basement, although there was also reworking of Jurassic sediments. The source was probably the Lewisian to the west of the Minch Fault; the progression in clay and heavy mineral assemblages suggests, unroofing of less deeply weathered material with time.
Disruption of Dalradian stratigraphy along the Portsoy Lineament from new geological and magnetic surveys
Authors: Fettes D. J. , Leslie A. G. , Stephenson D. , Kimbell S. F.
Published: January 2010

Synopsis

Intrusions, metavolcanic rocks and metasediments which crop out along a zone defining the Portsoy Lineament in the Cabrach area have a well-defined magnetic signature. Multidisciplinary surveys have revealed the regional scale of dislocations within the zone evidenced by the juxtaposition of contrasting Appin and Argyll Group successions. To the west of the lineament a metasedimentary sequence extending from the Blair Atholl to the Easdale Subgroup is correlated with established Dalradian successions to the south. Within and to the east of the lineament, distinctive metasedimentary and metavolcanic sequences have Argyll Group characteristics but cannot be correlated with the western succession. Further east these rocks pass into Southern Highland Group lithologies without the intervening calcareous beds which characterise this part of the Dalradian elsewhere. Major mafic and ultramafic intrusions are confined to the area within and to the east of the lineament and are commonly bounded by shear zones. The major dislocations in this area support the concept of a decoupled NE Grampian regional block and the fundamental role of the Portsoy Lineament in controlling basin development and subsequent tectonic, metamorphic and igneous events.
A local deep-water sediment failure on the NW slope of the UK
Authors: Strachan P. , Evans D.
Published: January 2010

Synopsis

An example is described, from seismic evidence, of a local deep-water sediment failure on the slope to the west of the Isle of Lewis, an area which otherwise appears to be generally stable. The feature is about 4 km long in the downslope direction and lies above an escarpment at an approximate water depth of 1100 m. The loss of layering on the reflection profile, and the existence of infilled depressions, suggests that excess pore water pressures have been generated and subsequently dissipated. It is conjectured that the failure has been triggered by an earthquake, or possibly by internal wave action. The sediment body is thought to have failed by liquefaction acting retrogressively upslope.
The Darwin Complex, a Tertiary igneous centre in the Northern Rockall Trough
Authors: Abraham D. A. , Ritchie J. D.
Published: January 2010

Synopsis

Seismic reflection data and well information in the North Rockall Trough reveal a large dome of Palaeocene—Eocene basalts and Upper Cretaceous dacites known as the Darwin Igneous Complex. The extrusives dip radially away from the centre of the dome where a volcanic vent with a diameter of
c.
1625 m and a depth of 100 m or more is present. The complex comprises five major volcanic sequences which can be mapped as a series of arcuate scarps. Modelling of the large positive free-air gravity anomaly over the complex suggests the presence of a large mafic pluton with a two-cylinder configuration. The upper cylinder has its top at 3.5–4.0 km beneath mean sea-level and its base at 8.0 km with a 17.0 km diameter while the lower cylinder has its top and base at 8.0 km and 15.0 km respectively with a diameter of 20–30 km. The model suggests that 4–4.5 km of pre-Palaeocene sediments exist between the base of the volcanic pile and the top of the lower pluton. It is possible that some of these sediments are pre-Cretaceous in age.
The Síofra Gabbro, West Connacht, Ireland
Authors: Mohr Paul
Published: January 2010

Synopsis

The Síofra Gabbro, considered to be of Paleocene age, is exposed on the now uplifted late-Tertiary erosion surface of the West Connacht plateau. It is a vertical cylindrical body emplaced into near-vertical Ordovician slates that carry a mild thermal aurcole. The intrusion is composed of labradorite-augite-olivine-leucogabbro containing cognate mafic xenocrysts. Although ‘Mg’ values close to 60 indicate a similar degree of magmatic evolution to that of the coeval alkaline dolerite dyke systems of West Connacht, the gabbro is distinctively subalkaline. It is also relatively enriched in alumina and depleted in both compatible and incompatible trace elements. The Síofra magma appears to have rested and fractionated at the top of a zoned belljar chamber in the upper crust.
The Pannanich Hill Complex and the origin of Crinan Subgroup migmatites in the North-eastern and Central Highlands
Authors: Goodman S.
Published: January 2010

Synopsis

Semipelitic rocks of the Crinan Subgroup Dalradian are, under certain conditions, susceptible to
in situ
reconstitution to form coarse-grained rock, originally mapped as ‘older granite’. The conditions necessary involve extensive shearing allowing fluids to percolate the rock, and increased heat flow from associated basic magmas. A belt of complexes formed in this way can be traced across the N E and Central Highlands of Scotland, and includes the Pannanich Hill Complex. Though the reconstitution of the complexes was probably diachronous along the belt, they all formed during the later part of the Caledonian Orogeny. During the reconstitution, some silicate melt may have formed and migrated along the shear zones, possibly to give the truly intrusive ‘older granites’.
Stratigraphy and sedimentology of the Devonian Rhynie chert locality
Authors: Trewin N. H. , Rice C. M.
Published: January 2010

Synopsis

Recent drilling in the vicinity of the Rhynie chert locality in the Rhynie outlier of Lower Old Red Sandstone allows a local stratigraphic succession to be established. A basal lithic sandstone and pebbly sandstone unit of local derivation rests unconformably on basement, and was deposited in an alluvial fan environment. An andesitic lava flow, now highly altered, overlies the pre-lava sandstone, but is of limited lateral extent. The lava is succeeded by tuffaceous sandstones and shales which grade upwards into a shale-dominated sequence, with greatly diminished volcanic input. The volcanic debris is of local origin, probably derived from eroding tuff cones, but the general depositional environment was an alluvial plain with ephemeral lakes. The Rhynie cherts are siliceous sinters, comprising more than 10 plant-bearing beds and 2 non-plant-bearing cherts and are equivalent to part of the post-lava tuffaceous sandstone and shale sequence. A second plant-bearing chert, together with evidence of a hot-spring vent, has been discovered 700 m from the original locality.

The borehole evidence casts some doubt on the validity of the previously accepted stratigraphy of the Rhynie outlier, particularly with regard to the stratigraphic position of the Dryden Flags and Shales.
Lower Cambrian echinoderm ossicles from the Fucoid Beds, northwest Scotland
Authors: McKie Thomas , Donovan Stephen K.
Published: January 2010

Synopsis

The Lower Cambrian Fucoid Beds of northwest Scotland contain a fauna that includes locally abundant, disarticulated, echinodern ossicles. These plates probably derive from an eocrinoid or some other, unknown primitive pelmatozoan. Available stratigraphic evidence indicates that the Fucoid Beds are Elankian or possibly upper Atdabanian, making this echinoderm one of the oldest known.
Polyphase deformation in Grampian Group rocks of the Monadhliath defined by a ground magnetic survey
Authors: Haselock Paula J. , Leslie A. Graham
Published: January 2010

Synopsis

The stratigraphic and structural interpretation of Grampian Group Dalradian rocks of the Monadhliath is greatly enhanced by integrating conventional mapping techniques with the results of a ground survey of total field magnetic intensity. Grampian age D
1
folds are delineated for the first time in this area.