bluuebunny/crossref_metadata_2025_split huggingface dataset:
The temnospondyl amphibians from the Viséan of East Kirkton, West Lothian, Scotland
Authors: Milner A. R. , Sequeira S. E. K. 
Published: November 2011

ABSTRACTA new temnospondyl amphibianBalanerpeton woodigen. et sp. nov. is represented by over 30 complete or partial skeletons from the Viséan limestones, shales and tuffs in East Kirkton Quarry, Bathgate, near Edinburgh, Scotland. It is the commonest tetrapod represented in the East Kirkton assemblage and grew to about half a metre in length. Although superficially like the laterDendrerpeton, it is more advanced in possessing small premaxillaries each bearing a pronounced alary process, large external nares, large rounded interpterygoid vacuities, broadly bordered by the vomers anteriorly, a narrow vomer-pterygoid suture and a rod-like stapes. It is characterised by an unusual dental configuration in which each dentary bears a smaller number of larger teeth than the corresponding upper jaw ramus. A second probable temnospondyl is represented by two straight ribs of a much larger form.The relationships of basal temnospondyls and other amphibian groups are discussed and it is proposed that the sister-group of the temnospondyls is the Microsauria and that neither colosteids norCaerorhachiscan be considered to be temnospondyls, as both fall outside the temnospondyl-microsaur clade. A preliminary study of character distribution across a selection of primitive temnospondyls, includingBalanerpeton, suggests that it is more advanced than the long-snouted Edopoidea and the Dendrerpetontidae despite its Viséan age. This implies that by the Viséan, significant diversification of temnospondyls had taken place.
Westlothiana lizziaefrom the Viséan of East Kirkton, West Lothian, Scotland, and the amniote stem
Authors: Smithson T. R. , Carroll R. L. , Panchen A. L. , Andrews S. M. 
Published: November 2011

ABSTRACTWestlothiana lizziaeis known from the Brigantian of East Kirkton, Scotland. The skull resembles that of later amniotes in the large size of the parietal, the apparent loss of the intertemporal, and the absence of a squamosal notch, palatal fangs and labyrinthine infolding of the marginal teeth, but is primitive in the absence of a transverse flange of the pterygoid. The individual trunk vertebrae resemble those of amniotes; large intercentra are retained, but the neural arch is fused to the centrum. A surprising feature is the presence of 36 presacral vertebrae, as is the relative size of the very small but highly ossified limbs. The humerus is much shorter than the femur, but similar in configuration to that of early amniotes. There are three proximal tarsals as in primitive tetrapods, but an amniote phalangeal count. The presence of massive dorsal as well as ventral scales is a more primitive feature than that of most anthracosaurs.Westlothianais ‘reptiliomorph’, and is judged to be a stem-group amniote on features of the skull roof, the absence of an otic notch, the gastrocentrous vertebrae and the pedal phalangeal formula. It has not, however, reached the amniote condition in the structure of the tarsus, and the palate is more primitive than that of both early amniotes and the ‘diadectomorphs’.
The Rhinns Complex: Proterozoic basement on Islay and Colonsay, Inner Hebrides, Scotland, and on Inishtrahull, NW Ireland
Authors: Muir R. J. , Fitches W. R. , Maltman A. J. 
Published: November 2011

ABSTRACTThe Precambrian basement on the islands of Islay, Colonsay and Inishtrahull comprises a deformed igneous association of mainly syenite and gabbro, with minor mafic and felsic intrusions. This association is collectively referred to as the Rhinns Complex. Isotopic data indicate that the complex represents new addition of material to the crust at c. 1·8 Ga. The igneous protolith was juvenile mantle-derived material, not reworked Archaean crust. Overall, the complex has an alkalic composition, with major and trace element patterns similar to igneous rocks generated in a subduction-related setting: high LILE/HFSE and LREE/HREE ratios, together with negative Nb, P and Ti anomalies.The formation of the Rhinns Complex was contemporaneous with the Laxfordian tectonothermal cycle in the Lewisian Complex. These Proterozoic events are most likely associated with an extensive 1·9–1·7 Ga mobile belt around the southern margin of Laurentia-Baltica. As part of this belt, the Rhinns Complex forms a link between the Ketilidian province of South Greenland and the Svecofennian of Scandinavia.Inherited isotopic signatures in the Caledonian granites on the north side of the Highland Boundary Fault may reflect the presence of a large area of Proterozoic basement (?Rhinns Complex) beneath Scotland and NW Ireland. Alternatively, the Proterozoic signature could be derived from the incorporation of Moine or Dalradian sediment into the granitic magmas.
Sedimentation and palaeogeographical significance of the Silurian rocks of the Louisburgh–Clare Island succession, western Ireland
Authors: Maguire C. Kelly , Graham John R. 
Published: November 2011

ABSTRACTThere are three distinct Silurian successions exposed in South Mayo and North Galway, western Ireland, of which the Louisburgh-Clare Island succession is the most northerly. It is separated from the adjacent Croagh Patrick succession by the Emlagh Fault. Three of the formations (Strake Banded, Knockmore Sandstone, Bunnamohaun Siltstone) in this 1·5 km Louisburgh–Clare Island succession had previously been interpreted as intertidal to offshore marine deposits. Almost all the facies present display characteristics of fluvial sedimentation and there is evidence for a contemporaneous volcanic centre to the west of the present outcrop. The exceptions are some grey laminated mudrocks with a fragmentary fauna which are interpreted as lacustrine and which show striking similarities to parts of the Silurian inliers in the central Midland Valley of Scotland. Despite these similarities the evidence for direct connection between western Ireland and Scotland is unproven. Within western Ireland correlations are hindered by uncertainties of the age of the Louisburgh-Clare Island succession and the age span of the adjacent Croagh Patrick succession.
Dykes or diapirs?
Authors: Petford Nick 
Published: November 2011

ABSTRACT:Until the last few years, diapirism reigned supreme among granitoid ascent mechanisms. Granitoid masses in a variety of material states, from pure melt through semi-molten crystal mushes to solid rock, were believed to have risen forcefully through the continental crust to their final emplacement levels in a way analogous to salt domes. The structural analogy between granite plutons and salt diapirs, which gained acceptance in the 1930s, has clearly been attractive despite the pessimistic outcomes of thermal models and, at best, ambiguous field evidence.In contrast with traditional diapiric ascent, dyke transport of granitoid magmas has a number of important implications for the emplacement and geochemistry of granites that have yet to be fully explored. Rapid ascent rates of ≍ 10 2m/s predicted for granite melts in dykes (cf. m/a for diapirs) mean that felsic magmas can be transported through the continental crust in months rather than thousands (or even millions) of years, and that large plutons can in principle be filled in <104 a. Granitic melts are likely to rise adiabatically from their source regions, leading to the resorption of any entrained restitic material. Ascending melts in dykes close to their critical minimum widths may have little opportunity to assimilate significant amounts of country rock, and if source extraction is sufficiently rapid, most crustal contamination will be restricted to the site of emplacement. Rates of pluton and batholith inflation will be determined by the amount and rate of melt extraction at source.The construction of large plutons and batholiths piecemeal from a number of magma pulses separated by periods of relative quiescence provides a means of reconciling rapid ascent rates with times for batholith construction based on average rates. Field and seismic evidence that shows batholiths as large, sheet-like structures with flat roofs and floors is consistent with a general model for plutons and batholiths as laccolith-type structures, fed from depth by dykes. The overall geometry of this type of structure helps ameliorate the space problem, which developed as a consequence of the unrealistic volumes of upwelling granite associated with the classical diapir model.
Compositional variation within granite suites of the Lachlan Fold Belt: its causes and implications for the physical state of granite magma
Authors: Chappell B. W. 
Published: November 2011

ABSTRACT:Granites within suites share compositional properties that reflect features of their source rocks. Variation within suites results dominantly from crystal fractionation, either of restite crystals entrained from the source, or by the fractional crystallisation of precipitated crystals. At least in the Lachlan Fold Belt, the processes of magma mixing, assimilation or hydrothermal alteration were insignificant in producing the major compositional variations within suites. Fractional crystallisation produced the complete variation in only one significant group of rocks of that area, the relatively high temperature Boggy Plain Supersuite. Modelling of Sr, Ba and Rb variations in the I-type Glenbog and Moruya suites and the S-type Bullenbalong Suite shows that variation within those suites cannot be the result of fractional crystallisation, but can be readily accounted for by restite fractionation. Direct evidence for the dominance of restite fractionation includes the close chemical equivalence of some plutonic and volcanic rocks, the presence of plagioclase cores that were not derived from a mingled mafic component, and the occurrence of older cores in many zircon crystals. In the Lachlan Fold Belt, granite suites typically evolved through a protracted phase of restite fractionation, with a brief episode of fractional crystallisation sometimes evident in the most felsic rocks. Evolution of the S-type Koetong Suite passed at about 69% SiO2 from a stage dominated by restite separation to one of fractional crystallisation. Other suites exist where felsic rocks evolved in the same way, but the more mafic rocks are absent. In terranes in which tonalitic rocks formed at high temperatures are more common, fractional crystallisation would be a more important process than was the case for the Lachlan Fold Belt.
Crystallisation of anhydrite-bearing magmas
Authors: Baker Leslie L. , Rutherford Malcolm J. 
Published: November 2011

ABSTRACT:Anhydrite has been identified as a phenocrystic phase in some silicic volcanic magmas, but it is not commonly described in plutonic rocks. Anhydrite-bearing magmas tend to form in arc environments and to contain hydrous, low-temperature, oxidised mineral assemblages. Phenocrystic anhydrite coexists with sulphur-enriched apatite and sometimes with pyrrhotite, in silicate melt that contains from 50 ppm to 1 wt% S, depending on temperature and conditions. Vapour coexisting with anhydrite- and water-saturated magma may contain from a few tenths of a mole per cent to a few mole per cent sulphur gases (SO2 and H2S), with the exact composition and gas speciation depending on temperature and oxygen fugacity. Samples of one anhydrite-bearing magma, the 1991 Pinatubo dacite, have been experimentally crystallised to determine whether the magma retains its characteristic sulphur-rich mineral phases during solidification. Results show that anhydrite and sulphur-rich apatite are retained throughout crystallisation and vapour phase evolution. This suggests that anhydrite-bearing intrusive equivalents of the Pinatubo dacite should be present in arc plutonic complexes.
Kilbuchophyllid corals from the Ordovician (Caradoc) of Pomeroy, Co. Tyrone: implications for coral phylogeny and for movement on the Southern Uplands Fault
Authors: Scrutton Colin T. , Jeram Andrew J. , Armstrong Howard A. 
Published: November 2011

AbstractAn excavation in the mid-Ordovician (Caradoc) Bardahessiagh Formation at Pomeroy, Co. Tyrone, Northern Ireland in 1992 has yielded a rich fauna of invertebrates, including several specimens of the scleractiniamorph coralKilbuchophyllia. The material is assigned to the speciesK. clarksoni, previously described from penecontemporaneous levels in the Kirkcolm Formation of the Northern Belt of the Southern Uplands. The diagnosis ofK. clarksoniis extended to include specimens of significantly greater size than the Southern Uplands material. All the material is mouldic but includes composite moulds, which in comparison with the preservation of other faunal elements, strongly suggests an original aragonitic composition for the kilbuchophyllid skeleton. Furthermore, details of insertion of higher cycles of septa visible on one particularly well preserved specimen confirm the process of septal substitution in these corals. Septal substitution is otherwise unique to post-Palaeozoic scleractinian corals and indicates the presence of paired mesenteries in the kilbuchophyllid polyp. The significance of this for the evolution of these corals and related anemones is discussed. The discovery of kilbuchophyllid corals at Pomeroy supports the view that post-Caradoc sinistral strike-slip movement on the Southern Uplands Fault was unlikely to have exceeded 200 km.
The anatomy and seed plant affinities ofRhacopterisandSpathulopterisfoliage from the Dinantian (Lower Carboniferous) of Scotland
Authors: Galtier Jean , Meyer-Berthaud Brigitte , Brown Rachel 
Published: November 2011

AbstractPermineralised material ofRhacopteris lindseaeformis(Bunbury) Kidston andSpathulopteris obovata(Lindley & Hutton) Kidston, showing both external morphology and excellent anatomical preservation, is described from the Lower Carboniferous (?Asbian, Upper Viséan) tuffs and dolomitic ashes outcropping at Weaklaw–Gullane, East Lothian, Scotland. These specimens provide the first anatomical information on these two well-known plant compression genera. The rachises haveLyginorachis-type anatomy with distinctive characters in the two species.Spathulopterisrachises correspond toLyginorachis kingswoodenseMeyer-Berthaud, previously described from the localities of Kingswood and East Kirkton, whereasRhacopterisshows similarities with the petiole attributed toBiligneafrom Oxroad Bay. Both foliage types conform to seed-fern frond organisation. This new evidence contradicts previous interpretations ofRhacopterisas a fern or a progymnosperm. We suggest thatRhacopteris lindseaeformisandSpathulopteris obovatarepresent the foliage of some of the arborescent gymnosperms which are found associated in several contemporaneous localities.
First record of a Hirnantia Fauna from Spain, and its contribution to the Late Ordovician palaeogeography of northern Gondwana
Authors: Villas E. , Lorenzo S. , Gutiérrez-Marco J. C. 
Published: November 2011

AbstractA new occurrence of the Hirnantia brachiopod fauna is documented from the Criadero Quartzite of Almadén, Ciudad Real Province, Spain. This unit is the regional development of a largely unfossiliferous sandy facies that frequently overlies the typical Late Ordovician diamictitic glaciomarine formations in the Iberian Peninsula and the Armorican Massif. The new occurrence establishes palaeontologically the latest Ashgill age of the quartzite, at least for its lowest horizons, and adds new data on a fauna that, although widespread, has been very rarely documented from peri-Gondwanan Europe. The new collection contains only Hirnantia sagittifera and Plectothyrella crassicosta chauveli. The subspecific status of the latter and its inclusion within Plectothyrella crassicosta is discussed herein, based on the continuous variation in rib thickness of several samples of both forms. The extremely low diversity and the occurrence of the key form P. c. chauveli, are both typical of the Bani Province that developed on the subpolar margins of Gondwana. This contrasts with other occurrences of the Hirnantia Fauna in peri-Gondwanan Europe, such as those from Sardinia and the Carnic Alps, which are characteristic of the more temperate Kosov Province.
The Polish Sudetes: Caledonian or Variscan?
Authors: Aleksandrowski P. , Kryza R. , Mazur S. , Pin C. , Zalasiewicz J. A. 
Published: November 2011

AbstractThe Polish Sudetes on the NE margin of the Bohemian Massif comprise a complex mosaic of pre-Permian basement units, traditionally included in the Variscides. A hypothesis of significant Caledonian orogenesis in this area originated in the 1920s, was subsequently rejected, and then was recently revived in models which invoked Early Palaeozoic to Early-Mid Devonian subduction and continental collision along a proposed extension of the Tornquist suture zone. We reassess the evidence invoked in support of the Caledonian orogeny, such as supposed regional pre-Upper Devonian unconformity, Ordovician bimodal magmatism and radiometric, palaeontological, palaeomagnetic and structural data, and suggest these are either inconclusive or misinterpreted. On the other hand, the Sudetes record Mid?-Late Devonian blueschist metamorphism followed by an Early Carboniferous regional high temperature event, widespread Late Devonian/Early Carboniferous flysch/molasse sedimentation and abundant granite intrusion in the Carboniferous to Early Permian. We discuss the usage of the term ‘Caledonian’ in a plate tectonic context and suggest it should not be used simply to denote Early to Mid-Palaeozoic tectonic activity. The tectonic evolution of the Sudetes was temporally different from, and resulted from convergence of different crustal domains than that of the British-Scandinavian-Pomeranian Caledonides. The Sudetic Palaeozoic sequences most probably developed on Armorican Neoproterozoic crust and in adjacent oceanic(?) domains and, therefore, the Sudetes form part of the Variscan orogenic belt.
Pre-Quaternary landscape evolution in the Scottish Highlands
Authors: Hall A. M. 
Published: November 2011

ABSTRACTThe development of the relief of the Scottish Highlands is traced over the last 400 Ma. Evidence from Late Palaeozoic and Mesozoic sediments and near-surface volcanic and igneous rocks shows that post-Devonian erosion of basement has been < 1–2 km and that the main morphotectonic units of the Highlands were already established by the end of the Palaeozoic. During the Mesozoic, the Highlands experienced several major erosional cycles, beginning with uplift, reactivation of relief and stripping of cover rocks, followed by progressive reduction of relief through etchplanation and culminating in extensive marine transgressions in the Late Triassic, Late Jurassic and Late Cretaceous. In the Early Tertiary major uplift affected the Highlands, with downwarping and block movements along basin margins, but levels of uplift and denudation around the Tertiary igneous centres cannot be extrapolated to other areas. Buchan and Caithness remained relatively stable and Mesozoic relief elements were maintained during gradual surface lowering. Earth movements of lesser magnitude continued episodically until at least the end of the Tertiary. After 50 Ma the Highland terrain evolved by dynamic etching, with deep weathering of varied geology under warm to temperate humid environments leading to a progressive differentiation of relief, with formation of basins, valleys, scarps and inselbergs often closely adjusted to lithostructural controls.
The Granton ‘shrimp-bed’, Edinburgh—a Lower Carboniferous Konservat-Lagerstätte
Authors: Briggs D. E. G. , Clark N. D. L. , Clarkson E. N. K. 
Published: November 2011

ABSTRACTNewly discovered crustaceans from the Granton ‘shrimp-bed’ (Dinantian, Lower Oil Shale Group) are described:Bairdops elegans, Minicarissp.,Palaemysis, Tealliocariscf.woodwardi, Pseudogalathea ornatissima, Anthracocaris scotica, Paraparchitescf.okeni, Beyrichiopsis plicata, andEocypridinacf.aciculata, and new observations onWaterstonella grantonensisare reported.Tealliocaris woodwardialone is recorded from bed o, a levelca1 m below the ‘shrimp-bed’. The Granton ‘shrimp-bed’ biota is reviewed—the geological and lithological context of the deposit, the distribution and taphonomy of the biota, its life environment, palaeoecology, the likely causes of mortality, and comparisons are made with contemporaneous shrimp biotas. The nature of this unusual Konservat-Lagerstätte reflects conditions in the sheltered, periodically emergent lagoon which it represents.
An Early Devonian lake and its associated biota in the Midland Valley of Scotland
Authors: Trewin N. H. , Davidson R. G. 
Published: November 2011

ABSTRACTThe Tillywhandland fish bed of the Lower Old Red Sandstone in the Strathmore area of the Scottish Midland Valley accumulated in a lake, here called Lake Forfar, which was created suddenly following a period of fluvial deposition. Lake creation may have been due to basin faulting or the disruption of drainage patterns by contemporaneous volcanic activity. The fish bed laminites accumulated in a hydrologically open lake under a seasonal climatic regime. When fully developed, laminites comprise repeated quadruplets of clastic silt/carbonate/organic/green clay–shale laminae averaging 0·5 mm in thickness. Following 2000 years of laminite deposition an increasingly silty succession with thin current-rippled sandstones provided the lake-fill.The fish fauna is dominated by Mesacanthus and Ischnacanthus with rare Euthacanthus, Parexus, Climatius, Vernicomacanthus and Cephalaspis. Most fish carcasses were partially decayed before deposition in the laminites on the poorly oxygenated lake floor. Abundant coprolites are the result of predation on Mesacanthus and small Ischnacanthus, probably by larger Ischnacanthus. Arthropods present include eurypterids (Pterygotus), washed in as near complete exuviae and fragments, and millipeds which were washed in from surrounding terrestrial environments along with plants, of which Parka and Zosterophyllum are common. Bioturbation indicates that conditions were not permanently anoxic during deposition of the laminites.Comparison of our collections with the Mitchell Collection accumulated in the 19th century indicates that Tillywhandland Quarry was the main source of specimens in laminite lithologies labelled ‘Turin Hill’.