bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-resolution sequence stratigraphy in the early Marsdenian (Namurian, Carboniferous) of the central Pennines and adjacent areas
Authors: Wignall Paul B. , Maynard James R. 
Published: December 2009

SUMMARY

The early Marsdenian (Namurian Series) Readycon Dean Formation of the Pennines and adjacent areas records a complex series of rapid, high-magnitude base-level changes during a short interval of the Pennine Basin’s history. Detailed correlation, using a rapidly evolving ammonoid fauna, enables the details of this complexity to be traced across the basin. Two major base-level rises (flooding events) are seen, one at the base of the Readycon Dean Formation, that led to the establishment of extensive, deep-water, marine shales of the Reticuloceras gracile (R
2a
1) Marine Band and the other that established the R. bilingue (R
2b
2) Marine Band across the region. At the base of this second major transgression is a radioactive, organic-rich dark grey shale (the Denshaw Horizon) that provides a useful marker band. The conditions of intense, basinal anoxia responsible for this horizon have also been observed in a similar basal transgressive shale from the overlying Yeadonian succession. It would appear that stagnation during initial transgression was a recurrent theme in the Pennine Basin’s history. Both marine incursions were followed by the progradation of a single distributary channel sandstone body during highstand conditions: the Readycon Dean Flags and Scotland Flags respectively.

Two major sequence boundaries or unconformities also occur in the study interval. The lower sequence boundary shows the development of a 25 m deep palaeo-valley partially infilled with thin beds of sandstone and siltstone of the new Howels Head Flags Member. The valley may have been the feeder channel of the Alum Crag Grits (a thick, turbidite sandstone lobe) but the incision mechanism is enigmatic. The upper sequence boundary is marked by a period of strong erosion (at least 80 m of incision can be demonstrated locally) throughout the basin and, towards the basin margin, substantial portions of the Readycon Dean Formation have been removed. A marked shallowing of facies is associated with this second sequence boundary and it is everywhere overlain by fluviodeltaic facies of the Pule Hill Grit Formation.
Reworked palynomorphs as provenance indicators in the Yeadonian of the Pennine Basin
Authors: McLean D. , Chisholm J. I. 
Published: December 2009

SUMMARY
The Lower and Upper Haslingden Flags may be differentiated from other Yeadonian strata in the Pennine Basin by their bulk lithology (‘green-facies’) and the reworked palynomorphs that they contain. These characteristics allow correlative finer-grained sedimentary rocks to be recognized where arenaceous lithologies have died out, and put some constraints on the possible provenance of the Haslingden Flags. The source area must have included outcrops of unmetamorphosed (i.e. extra-Caledonide) Lower Palaeozoic rocks and marine Devonian strata, and/or marine Devonian sediments containing reworked Lower Palaeozoic palynomorphs. Previous palaeocurrent studies indicate a western provenance for the Haslingden Flags. The new palynological data suggest that some sediment may have come directly from Avalonian Ordovician terranes: suitable source areas extend from the Wales-Brabant High (St George’s Land) towards Newfoundland. However, the reworked palynomorph material may have been supplied to the Pennine Basin via multiple phases of reworking, involving marine Devonian rocks to the west of St George’s Land.
Some dinoflagellate cysts from the Kimmeridge Clay Formation in North Yorkshire and Dorset, UK
Authors: Bailey David , Milner Paul , Varney Tim 
Published: December 2009

SUMMARY

Four new dinoflagellate cyst species are described;
Circulodinium copei
sp. nov.,
Rhynchodiniopsis martonense
sp. nov. and
Trichodinium piaseckii
sp. nov. are from the Kimmeridge Clay Formation of North Yorkshire (Kimmeridgian,
Pectinatites pectinatus
Zone), and
Senoniasphaera clavelli
sp. nov. is from the Kimmeridge Clay Formation (Kimmeridgian,
Aulacostephanous autissiodorensis
Zone) in Dorset, England. These taxa have potential for use as stratigraphic markers and have also been recorded from equivalent sediments in the North Sea, Mid-Norway and Barents Sea areas.
Marine ostracods in the Lower Carboniferous fluviatile Fell Sandstone Group: evidence for base level change and marine flooding of the central graben, Northumberland Basin
Authors: Turner Brian R. , Dewey Chris , Fordham Charles E. 
Published: December 2009

SUMMARY
Seven species of ostracod have been identified from the coarser, more silty laminae within a thin shaly siltstone interval within the Lower Carboniferous Fell Sandstone Group in the eastern part of the Northumberland Basin, all of which indicate a quiet, nearshore, shallow water marine environment. This is the first documented occurrence of marine ostracods from the Fell Sandstone which has always been regarded as entirely of non-marine origin, with any marine influences confined to the westernmost part of the basin. The shaly siltstone was proved in the Alnwick Borehole drilled through the upper section of the Fell Sandstone in an otherwise sandstone-dominated succession. The presence of marine influenced conditions more than 60 km inland from the coeval shoreline reflects contemporaneous intrabasinal tectonics and the location of the Alnwick Borehole at the northeastern end of the central graben within the Northumberland Basin. Marginal fault activity, contemporaneous with Fell Sandstone deposition, caused gentle tilting of the graben floor, thus allowing marine conditions to penetrate farther inland than previously known.
The ostracod-bearing marine shaly siltstone, which lies above and below braided river sandstones, provides a key sequence stratigraphic surface across this part of the basin. The base of the unit is a transgressive surface with the shale itself equivalent to a maximum flooding to truncated shale prone early high stand. The immediately overlying erosion surface records low stand incision, facies tract dislocation and the development of a possible sequence boundary, with the overlying stacked, cross-bedded, coarse pebbly braided channel sandbodies referred to the lower and middle parts of a transgressive systems tract that spans the boundary between the Fell Sandstone and succeeding, more marine influenced Scremerston Coal Group. The lower, finer-grained, fluvial succession beneath the transgressive surface is tentatively assigned to part of an incompletely exposed transgressive systems tract.
The Moorby Microgranite: a deformed high level intrusion of Ordovician age in the concealed Caledonian basement of Lincolnshire
Authors: Pharaoh T. C. , Allsop J. M. , Holliday D. W. , Merriman R. J. , Kimbell G. S. , Rundle C. C. , Brewer T. S. , Noble S. R. , Evans C. J. 
Published: December 2009

SUMMARY
A granophyric microgranite has been proved in the sub-Carboniferous basement at Moorby, near Horncastle in south Lincolnshire. The microgranite is interpreted as a high level intrusion which has suffered strong alteration and deformation subsequent to emplacement, including the development of a spaced pressure-solution foliation and brecciation. The microgranite has yielded a U-Pb zircon age of 457 ± 20 Ma (late Ordovician) interpreted as the age of emplacement. A Rb-Sr whole-rock isochron age of 400 ± 9 Ma (early Devonian) is strongly discordant with the U-Pb age, and is interpreted to reflect thorough post-emplacement hydrothermal disturbance of the Sr isotope system, either associated with the development of the tectonic foliation during the Acadian phase of the Caledonian Orogeny or subsequent uplift. Geochemical data suggest that the affinities of the Moorby Microgranite lie with the arc-related Ordovician intrusions of the Lake District (e.g. the Ennerdale and Eskdale plutons) rather than with the early Devonian high heat production (HHP) granites such as Shap, Skiddaw and Weardale. While the physical properties of the Moorby Microgranite are comparable to those of the HHP granites, gravity modelling suggests that the microgranite is unlikely to be a major component of the inferred Caledonide Wash - north Norfolk Batholith.
The Palaeozoic corals, II: structure, variation and palaeoecology
Authors: Scrutton Colin T. 
Published: December 2009

SUMMARY
Palaeozoic coral faunas were dominated by two orders of Zoantharian corals, the Rugosa and the Tabulata. Almost all rugose and tabulate corals developed an epitheca or holotheca around the corallum and possessed small to minute attachment scars. A limited number had an encrusting life style and many others could facultatively encrust to some extent when settling by chance on a hard substrate. However, most were effectively free living on a soft substrate as mature coralla. A high percentage of rugose corals were solitary and of the colonial genera, few exhibited physical integration of modules within the colony. In contrast, most of the exclusively modular tabulate corals possessed some degree of integration. Colony formation in tabulate corals was, with doubtful exceptions, solely by non-parricidal increase, whereas both non-parricidal and parricidal increase, the latter in a minor role, occur in the Rugosa. The sources of variation in solitary and colonial Palaeozoic corals are reviewed and data on growth rates, measured on the basis of cyclomorphic variation expressed as density band couplets, are assessed. Growth-form variation in solitary corals and its relationship to stability on the substrate are explored. Growth strategies in colonial corals are described and their adaptive success under different environmental conditions is discussed. Colonial growth-forms were a function of the interaction between growth strategy and prevailing conditions during astogeny, although some species had genetically constrained, relatively invariate growth-forms. Factors controlling the distribution of Palaeozoic corals in the environment–substrate and turbidity, water energy, depth, light, temperature and variations in salinity and oxygenation - are reviewed. Palaeozoic coral diversity was much lower than that of Recent hermatypic scleractinian corals in comparable environments. Most Palaeozoic corals were adapted to soft substrates in warm, shelf seas, and made a limited contribution to reef frameworks. It is concluded that none of them developed a symbiosis with algae in contrast to zooxanthellate scleractinian corals.
Palaeomagnetic dating of the west Cumbrian hematite deposits and implications for their mode of formation
Authors: Rowe John , Turner Peter , Burley Stuart 
Published: December 2009

SUMMARY

Palaeomagnetic analysis of six orientated hematite samples from the Florence Mine, Egremont, west Cumbria is described. A total of 21 specimens were subjected to incremental thermal demagnetization and the components of magnetization isolated by principal components analysis. All the specimens displayed a single component of magnetization with no evidence of either multicomponent magnetizations or significant low-temperature secondary magnetic components. The mean direction of the characteristic remanence based on the isolated components has a declination of 203°, and an inclination of −13° (α
95
= 10°,
k
= 12) with the corresponding pole position at 38.6°S, 333.5°E (
D
p
= 5.2,
D
m
= 10.3).

A single primary component is responsible for the characteristic remanent magnetism (ChRM) directions. The initial susceptibilities and magnetic intensities are compatible with petrographic observations that the samples comprise virtually pure hematite. The ChRM originated as chemical remanent magnetism when the hematite precipitated at temperatures over 100°C. Comparison of the calculated pole position for the west Cumbrian hematite deposits with the apparent polar wander path for Britain south of the Iapetus Suture reveals that the ore deposits formed during the Late Carboniferous and Early Permian.
The west Cumbrian hematite deposits therefore are not precipitates of a brine expelled from the Triassic sediments of the East Irish Sea Basin. The hematite may have precipitated from a brine expelled from older sediments (Devonian?), a fluid associated with igneous activity resulting from Permian rifting in the Irish Sea area, or they may be associated with ingress of surface-derived fluids during the Permian.
The identification of syn-depositionally-active structures in the coal-bearing Upper Carboniferous of Great Britain
Authors: Rippon J. H. 
Published: December 2009

SUMMARY
The Upper Carboniferous coalfields of Great Britain occupy various tectonic settings. Excellent data sets allow detailed analysis of any relationship between structure and the depositional patterns. Syn-depositional movement can be identified on a basin scale, and also at the scale of individual faults. However, with the exception of the Scottish Midland Valley, definitive evidence for syn-depositional movement on specific structures is relatively rare, and especially so in the English Pennine Basin. In particular, there is a general scarcity of detailed structural control on coal-depositional patterns. The environments in which coals formed would have been much more sensitive to subtle ground movements than the higher energy environments of the major channel belts. The precursor peats were widespread and commonly diachronous, and probably spanned around half the available time and space during Westphalian deposition across the Pennine Basin. The rarity of localized structural controls on coal patterns is therefore firm evidence of rarity of specific syn-depositional faulting throughout the sedimentary volume. Using mining data mainly from the Pennine Basin and the Midland Valley, this account discusses examples of likely, and less likely syn-depositional features, and proposes structural and sedimentological critieria for systematic assessment.
Distinction between detrital and volcanogenic clay-rich beds in Turonian–Coniacian chalks of eastern England
Authors: Wray David S. , Wood Christopher J. 
Published: December 2009

SUMMARY

The acid insoluble <2 μm fraction of 36 clay-rich marls, each from a stratigraphically distinct bed, in the Turonian and Coniacian chalks of Lincolnshire and East Yorkshire has been analysed. All beds are dominated by smectite, with traces of illite and sporadic trace amounts of kaolinite. Major, trace and rare-earth element whole rock data show that the clay-rich beds fall into two groups. The majority have a relatively constant K
2
O/A1
2
O
3
ratio (mean 0.12), low Zr/Al
2
O
3
ratio (mean 0.002) and variable TiO
2
/Al
2
O
3
ratio (mean 0.07); shale normalized rare-earth element (REE) data displays a negative Ce anomaly and a variable, gradual depletion in heavy REE. By analogy with clays in the German Chalk, these beds are considered to be detrital. Six beds (Barton 1, Melton Ross, Deepdale Lower, North Ormsby, Ulceby and Little Weighton 2) are characterized by a variable K
2
O/A1
2
O
3
ratio (mean 0.05), relatively high Zr/Al
2
O
3
ratio (mean 0.007) and low TiO
2
/Al
2
O
3
ratios (mean 0.03). Shale normalized REE data typically displays a slight negative Ce anomaly and a variable, but commonly marked, negative Eu anomaly. By analogy with German examples, these beds are interpreted as bentonites derived from the
in situ
alteration of volcanic tephra. Geochemical data indicate that tephra had a rhyolitic to pantelleritic composition. The occurrence of mid Turonian to mid Coniacian bentonites in the Chalk of eastern England provides the first evidence that clay-rich beds in the English Chalk have more than one origin.
An overview and update of the site characterization studies at Sellafield
Authors: Bowden R. A. , Bumpus C. , Littleboy A. K. 
Published: December 2009

SUMMARY
Nirex is responsible for providing and managing facilities for the safe disposal of intermediate-level and certain low-level radioactive waste. In 1991 Nirex chose an area near Sellafield, west Cumbria as the focus for further investigations, following preliminary geological investigations undertaken there and at Dounreay in Scotland from 1989. The Nirex Science Programme aimed to assess the suitability, or otherwise, of the Sellafield site as the host for a repository. Such an assessment included the requirement to develop an understanding of the geological and hydrogeological characteristics of the area. The background to the selection of the Sellafield area for site characterization for a potential radioactive waste repository and the early results from Nirex’s site investigations at Sellafield were reported to the Yorkshire Geological Society in October 1994. We present an update of the site characterization activities undertaken at Sellafield since then together with an overview of the advances in geological and hydrogeological understanding of the site resulting from those investigations.
Fluid flow in faults: a study of fault hydrogeology in Triassic sandstone and Ordovician volcaniclastic rocks at Sellafield, north-west England
Authors: Gutmanis J. C. , Lanyon G. W. , Wynn T. J. , Watson C. R. 
Published: December 2009

SUMMARY
The structure and hydrogeological properties of subsurface faults in the Triassic Sherwood Sandstone Group and Ordovician Borrowdale Volcanic Group at Sellafield in west Cumbria were investigated in order to develop conceptual and numerical models for input to groundwater flow modelling at the possible site of an underground radioactive waste repository. Eighteen borehole intersections of faults were studied using core, borehole imagery and hydraulic test data (single and multi-well testing). The results were integrated with data and interpretations from seismic surveys and field studies in order to prepare conceptualizations of fault architecture and hydrogeology, suitable for taking forward into numerical modelling. Hydraulic test data indicate that fault zones in the Sherwood Sandstone Group are slightly more permeable than the host rock, and geological observations suggest that flow may be focused in the fault damage zones rather than in the faultrocks, which tend to act as flow baffles. Where present in sufficient numbers, granulation seams appear to be flow inhibitors. In the volcanic rock, hydraulic test data indicate that fault zones have little permeability contrast with the host rock. However, geological observations suggest that minor reactivation may have locally disrupted the baffling effect of faultrocks, thereby creating ‘leak points’. Overall, the study suggests that ground-water flow in faults at Sellafield is highly heterogeneous at the borehole scale, but at larger scales the hydraulic behaviour of faults is more homogeneous.
Geotechnical characteristics of the Borrowdale Volcanic Group
Authors: Davies N. , Chaplow R. 
Published: December 2009

SUMMARY

As part of its investigations in the Longlands Farm area near Sellafield, west Cumbria, Nirex has generated a database of geotechnical information on the Borrowdale Volcanic Group rocks. Information has been obtained to depths of over 1000 m. The database was originally created to provide input to post-closure performance assessment studies for a potential radioactive waste repository. However, the information gathered is of generic value in understanding both the geotechnical characteristics of these deep rock units and the techniques available for their characterization. Information on the lithological characteristics of the rock units, the spatial properties of discontinuities, rock material properties,
in situ
stresses and rock mass properties has been collected from investigations including surface mapping, borehole core logging, borehole testing and geophysical surveys. The information has been compiled into a series of data sheets summarizing the characteristics of the identified rock units as a basis for subsequent modelling. Variations in rock mass properties, expressed as rock mass ratings, have been mapped in three dimensions using information obtained from boreholes and from regional geophysical surveys. The paper describes the studies undertaken and presents a summary of the results obtained.
Hydrogeological and geotechnical rock property characterization from geophysics
Authors: Brerton N. R. , Evans C. J. , Kingdon A. 
Published: December 2009

SUMMARY

Boreholes drilled at Sellafield penetrated a variety of rock units. Core samples and wireline logs indicate that rock mass properties and
in situ
fluid properties vary from one unit to another, but that properties are relatively uniform for each unit within a particular borehole. Variability is superimposed upon the bulk rock mass properties, however, where faults or zones of fractured rock intersect a borehole. Furthermore, lateral variability within a particular unit may be expected between boreholes and throughout the rock volume.

The primary objectives of the work were: to establish a means of determining the spatial heterogeneity and distribution of rock mass and fluid properties using measurements made on core samples and derived from wireline logs; to determine the spatial heterogeneity and distribution of rock mass properties away from boreholes and in three-dimensions, by extrapolating the detailed understanding gained from boreholes into the seismic survey volume; and to develop a visualization model of rock mass properties in three-dimensions.
It has been demonstrated that acoustic impedance is the principal property in common between surface seismic and borehole measurements, and that it provides a link between the various scales of measurement. Dynamic rock quality and hydrogeological indices have been developed which allow qualitative comparisons to be made between the boreholes. Empirical relationships have also been established between acoustic impedance and rock quality, and between acoustic impedance and hydrogeological properties. These relationships enable continuous profile quantitative estimations of Rock Mass Rating and hydraulic conductivity to be made from wireline logs, and have allowed these properties to be extrapolated into the seismic acoustic impedance volume, thereby providing three-dimensional visualizations of the spatial heterogeneity of rock mass properties.
The ‘Balladoole Coral’ from the Lower Carboniferous of the British Isles, reinterpreted as the unusual cystoporate bryozoan
Meekoporella
Moore & Dudley, 1944
Authors: Wyse Jackson Patrick N. , Taylor Paul D. , Tilsley John W. 
Published: December 2009

SUMMARY

Michelinia balladoolensis,
originally described by John Smith, in 1911, from the Lower Carboniferous of the Isle of Man, is an unusual fossil with a distinctive morphology. Smith regarded it as a tabulate coral, but subsequent workers have tentatively assigned it to the conulariids or to the Bryozoa. Restudy of the type specimens, together with material from the Asbian of Armagh, and newly collected specimens from the Bee Low Limestones (Asbian) of Derbyshire, demonstrates that
Michelinia balladoolensis
is a cystoporate bryozoan referable to
Meekoporella.
Specimens of
Meekoporella balladoolensis
comprise small inverted pyramids, open-ended and typically five-sided; compound colonies are constructed of clusters of contiguous pyramids. Colonies were apparently arboreal, living attached to crinoid stems or other cylindrical substrata which supported them some distance above the sediment surface in reefal settings. A lectotype and paralectotype are designated for
M. balladoolensis. Meekoporella bancrofti
sp. nov. is described from the Hotwells Limestone (early Brigantian) of the Mendips, and differs from
M. balladoolensis
in having smaller autozooecial apertures and reflexed autozooecial chambers.