bluuebunny/crossref_metadata_2025_split huggingface dataset:
The petrology and diagenesis of Permo-Triassic rocks of the Sellafield area, Cumbria
Authors: Strong G. E. , Milodowski A. E. , Pearce J. M. , Kemp S. J. , Prior S. V. , Morton A. C. 
Published: December 2009

SUMMARY
A study of the petrology and diagenesis of the Permo-Triassic rocks of the Sellafield area has been undertaken as part of the Core Characterisation Programme for UK NIREX Ltd. This paper summarizes observations of the petrology and diagenesis from boreholes 1/1A, 2, 3, 7A and 7B of the Brockram, St Bees Evaporites, St Bees Shale and St Bees Sandstone and proposes a series of Diagenetic Episodes (denoted DE1 to DE10) to describe paragenetic relationships inferred from these observations.
As might be expected from closely spaced boreholes, overall paragenetic characteristics are laterally similar for each stratigraphic unit, although the degree of development and preservation of authigenic minerals, cements and porosity characteristics varies between boreholes. However, there are more significant differences in diagenetic characteristics between stratigraphic units. In general, the diagenesis of the Brockram breccias is characterized by precipitation of anhydrite, calcite, ferroan calcite, dolomite, ferroan dolomite, ankerite, hematite, barite, kaolinite and illite; the St Bees Shales and Evaporites by sulphates and dolomite; and the St Bees Sandstone by non-ferroan dolomite, quartz, ferroan and non-ferroan calcite and late illite.

Total porosity in the Brockram, St Bees Evaporites and St Bees Shales is negligible (<1 %), but there is significant porosity (
c.
15–25%) in the St Bees Sandstone, most of which is considered here to be secondary porosity attributed to removal of carbonates by present-day groundwaters, but ultimately due to early preservation of non-compacted fabrics by an inferred early evaporite cement, probably anhydrite, which was subsequently removed during diagenesis.
The post-Triassic structural evolution of north-west England and adjacent parts of the East Irish Sea
Authors: Chadwick R. A. , Kirby G. A. , Baily H. E. 
Published: December 2009

SUMMARY
Available data suggest that, subsequent to Triassic basin development, syn-depositional normal faulting continued in Jurassic and early Cretaceous times with subsidence of the East Irish Sea and Solway basins relative to the Lake District Block. Cessation of extension in the mid-Cretaceous led to regional subsidence with little distinction between blocks and basins. Palaeogene times heralded a period of regional uplift and erosion, associated with development of the Icelandic Plume and emplacement of the Scottish Tertiary igneous province. Superimposed upon this, Alpine crustal compression produced minor oblique-reversal of the basin-margin faults and weak basin inversion. Depth of burial estimates from well-log data agree with uplift values computed from thermal modelling of apatite fission-track palaeotemperatures. They indicate that post-Cretaceous uplift ranged from less than 1750 m over the Lake District Block, to 2000 m at Sellafield and more than 2200 m over the surrounding basins.
Deformation of the Upper Cretaceous Chalk at Selwicks Bay, Flamborough Head, Yorkshire: its significance in the structural evolution of north-east England and the North Sea Basin
Authors: Starmer I. C. 
Published: December 2009

SUMMARY
Four deformation phases (D1–4) can be recognized in the Upper Cretaceous Chalk of Selwicks Bay.
D1 ENE–WSW compression formed gentle NNW–SSE buckles in Selwicks Bay, with localized overturned folds and minor thrusts to the south. Regionally, D1 is correlated with Laramide sinistral slip on the Dowsing Fault, inversion of the Sole Pit Basin, and N–S to NNE–SSW folding in the Cleveland Basin. Subsequent D2 extensional fracturing developed during general post-Laramide tension, with a dominant E–W component at one stage.
D3 N–S compression produced gentle E–W folds, later tightened in the south of Selwicks Bay as sinistral E–W strike-slip faults formed in the north: subsequent southward and northward thrusting resulted from NW–SE transpression across the whole area. North of Selwicks Bay, the Bempton Fault Zone underwent E–W folding and N–S thrusting, and the E–W Cleveland Anticline was enhanced, causing some inversion of the Cleveland Basin. The strike-slip faulting is interpreted as a derivative of Alpine dextral slip on the Dowsing Fault, which subsequently caused the NW–SE transpression.
D4 deformation at Selwicks Bay produced N–S normal faults with later dextral shear, followed by northward spreading of faulting in a N–S extension complex. Regionally, this is correlated with E–W tension, caused by North Sea subsidence, becoming modified and eventually dominated by uplift (enhanced inversion) of the Cleveland Basin: this tilted the region south to Selwicks Bay, where hinging produced a classic N–S extension complex.
Bromine content of English Zechstein Cycle 3 chloride salts on Teesside and in the Staithes area of Co. Cleveland, N.E. England
Authors: Smith D. B. , Raup O. B. , Holmes R. 
Published: December 2009

SUMMARY
We present profiles of the vertical distribution of bromine in cores of the late Permian (Zechstein) Boulby Halite Formation (EZ3 Na) from lower Teesside and from the potash field around Boulby Mine, Staithes, North Yorkshire. The profile for the Teesside core shows that the bromine content of the halite there (and therefore the salinity of the originating brine) lies in the lower part of the range regarded as normal for marine-derived brines throughout deposition of the formation and increases only slightly near the top. The bromine content of the Boulby Halite in the potash field core is generally slightly greater than that in the Teesside core, but, as predicted by conventional theory, increases sharply in the Boulby Potash Member near the top of the formation. Comparison of the two bromine concentration profiles suggests a close correlation. This suggested correlation needs to be tested against other bromine profiles but, if correct, implies (a) that closely sampled bromine profiles are a useful tool in the correlation of salt deposits, and (b) the Boulby Potash is entirely, or almost entirely, younger than the Boulby Halite of Teesside, possibly indicating basin-shrinkage.
Calcite concretions in carbonate rocks of the late Permian Raisby Formation, north-east England
Authors: Lee M. R. 
Published: December 2009

SUMMARY
Calcite concretions have been discovered recently in metre-thick limestone beds close to the base of the Raisby Formation. They are composed of coarse, inclusion-rich, radiating calcite crystals and pass laterally into thin, impersistent, coarsely crystalline dolostone beds. The concretions are inferred here to have formed by aggrading neomorphism of partially dolomitized aragonite and high magnesian calcite-dominated carbonate sediments during early burial. Concretion calcite was precipitated from a radially advancing solution film in a relatively open diagenetic environment. After concretion calcite had ceased to precipitate, aragonite and high magnesian calcite in carbonate sediments surrounding the concretions continued to dissolve, leaving a porous residue of less soluble fossils, corroded dolomite crystals and non-carbonate grains. During Mesozoic burial, this residue was partially or completely cemented by coarse ferroan dolomite. Following regional uplift during the late Mesozoic/Tertiary, porosity remaining in the residue was occluded by zoned calcite cements, authigenic clays and iron sulphides. The morphological and petrographical similarities between calcite concretions in the Raisby Formation and those in other late Permian carbonates are probably the result of the independent recurrence of a distinctive style of replacive calcite crystal growth.
The age of Acadian cleavage in northern England, UK: K–Ar and TEM analysis of a Silurian metabentonite
Authors: Merriman R. J. , Rex D. C. , Soper N. J. , Peacor D. R. 
Published: December 2009

SUMMARY

K–Ar and
40
Ar–
39
Ar isotope analysis and transmission electron microscopy were used to study the cleavage developed in a metabentonite during the Acadian tectonometamorphic event in northern England. The Foredale metabentonite, from the Ribblesdale inlier in the Pennines, is one of numerous K-bentonites preserved in the hemipelagic Horton Formation of Lower Ludlow (Gorstian) age. It consists of over 90% phengitic white mica crystallized during deformation and cleavage development under mid-anchizonal metamorphic conditions. Temperatures approaching 250°C combined with strain energy to completely eliminate original smectite interlayers, producing stable crystallites of 1M and 2M mica polytypes. Mica concentrates analysed by the K–Ar method have a weighted mean apparent age of 397 ± 7 Ma;
40
Ar–
39
Ar total fusion analyses have a weighted mean apparent age of 418 ± 3 Ma. The true cleavage-forming event lies within this age range. An inferred geothermal gradient of <25°Ckm
−1
, based on the white mica
b
lattice dimension, suggests that the Foredale metabentonite was buried under at least 10km of overburden, much of it Lower Old Red Sandstone, prior to late Lower Devonian (Emsian) uplift in northern England.
Lithostratigraphy and biostratigraphy of the Hunstanton Formation (Red Chalk, Cretaceous) succession at Speeton, North Yorkshire, England
Authors: Mitchell S. F. 
Published: December 2009

SUMMARY

The Hunstanton Formation (Red Chalk), as interpreted here, is 24 m thick at Speeton and is divided into five members (Queen Rocks, Speeton Beck, Dulcey Dock, Weather Castle and Red Cliff Hole), each of which is characterized by a distinctive lithology. Above the Red Chalk, in the Ferriby Chalk Formation, a further member is established (Crowe’s Shoot Member) which extends the succession up to the regionally important marker, the First
Inoceramus
Bed. The lithological boundaries between the lowest three members of the Red Chalk are close to important changes in the belemnite assemblages and consequently belemnites, which are abundant, provide the most suitable fossils for placing small sections of Red Chalk within the lithostratigraphical scheme. The distribution of the most important macrofossils is described and used to suggest a correlation of the Red Chalk succession at Speeton with the standard ammonite zones and subzones established in southern England. This demonstrates that Red Chalk deposition began in early Mid-Albian times at Speeton, similar to other sections in north-east England (e.g. South Ferriby and Hunstanton), and the transition to ‘white chalk’ deposition occurred during the earliest Cenomanian. The Albian-Cenomanian boundary is recognized using the carbon isotope signature and compared with various biostratigraphical markers previously used for the Albian-Cenomanian boundary. A comparison of the Red Chalk succession between Speeton, South Ferriby and Hunstanton shows a number of regionally important erosional/flooding surfaces, and these have also been recognized in southern England. Three new species of brachiopod
(Concinnithyris microsubundata
sp. nov.,
Nerthebrochus nosetrapensis
sp. nov. and
Atactosia jeansi
sp. nov.) are described.
Three new early Namurian (E
1c
-E
2a
) marine bands in central and northern England, UK, and their bearing on correlations with the Askrigg Block
Authors: Brandon A. , Riley N. J. , Wilson A. A. , Ellison R. A. 
Published: December 2009

SUMMARY
Three new marine bands are recognized in the exceptionally thick Lower Namurian succession of the northern part of the Central Pennine Basin, namely the Blacko (late Pendleian), Cravenoceras gressinghamense (early Arnsbergian) and Saleswheel (early Arnsbergian) marine bands.

The stratotype of the Blacko Marine Band (E
1c
2) is within delta-slope siltstone and sandstone of the Surgill Shale Member at the top of the turbiditic Pendle Grit Formation of the Blacko Borehole (near Colne). It comprises marginal marine siltstone and contains the bivalve
Sanguinolites.
The band is correlated with a bivalve-spat phase in the Widmerpool Gulf, and a
Lingula
band lying within the delta-top Grassington Grit Formation on the south-eastern part of the Askrigg Block.

The Cravenoceras gressinghamense Marine Band (E
2a
2α) succeeds the Eumorphoceras ferrimontanum Marine Band (E
2a
2) in the Roeburndale and Sabden Shale formations. At its type locality, along Gressingham Beck, Hornby, near Lancaster, it has yielded the new name-bearing ammonoid. It also contains the lowest appearance of
Selenimyalina variabilis
(Hind) and is characterized by the presence of
Posidonia lamellosa
(de Koninck). In the Widmerpool Gulf, the band is represented by the
Posidonia
phase at two stratigraphical levels.

The Saleswheel Marine Band (E
2a
2β) lies between the C. gressinghamense and Eumorphoceras yatesae (E2
a
3) marine bands. Its type locality is in the lower part of the Sabden Shale Formation at Ribchester, near Blackburn, where it contains
Anthracoceras.
The marine band thickens dramatically towards the Lancaster district into siltstone beds of the Close Hill Siltstone Member containing a
Sanguinolites
-dominated faunal phase. In the Widmerpool Gulf it is represented by a
Lingula
band.

The dramatic thickness and facies changes of early Namurian marine bands across the Central Pennine Basin and on to the Askrigg Block appear to be controlled primarily by proximity to sediment supply, availability of accommodation space, and the duration, rate and amplitude of glacio-eustatic marine flooding events. A regional non-sequence is developed at the base of the Ward’s Stone Sandstone (and equivalents), associated with marked tectonic discordance. This boundary, together with the newly resolved marine band stratigraphy, necessitates lithostratigraphical revision and re-correlation of early Namurian sandstones in the northern part of the Central Pennine Basin and the Askrigg Block.

One new species,
Cravenoceras gressinghamense
sp. nov., is described.
Ecophenotypic variation in the early Silurian rugose coral
Palaeocyclus porpita
Authors: Scrutton Colin T. 
Published: December 2009

Summary

Palaeocyclus porpita
(Linnaeus) is a highly distinctive and biostratigraphically important early Silurian rugose coral, widespread in north-west Europe and with scattered records in North America. In eastern North America,
Palaeocyclus rotuloides
(Hall) occupies a similar biostratigraphical position, but differs from
P. porpita
in possessing a thin or imperfectly developed epitheca with septal ridges or exposed septal plates and a distinct profile to the undersurface. The calicular surfaces of
P. rotuloides
and
P. porpita
are essentially indistinguishable. The relationship between
P. porpita
and
P. rotuloides
is resolved by material from the Coralliferous Group of Dyfed, south-west Wales. Collections from siliciclastic horizons have
P. porpita
type epitheca, whereas material from thin bioclastic limestone beds has
P. rotuloides
type epitheca.
P. rotuloides
from eastern North America also appears to be associated with thin bioclastic limestones. It is suggested that these two forms were ecomorphs of the same species,
P. porpita
, in which epithecal development was influenced by the character of the substrate. The stratigraphical and palaeoecological distribution of the species is briefly reviewed.
A new specimen of the Carboniferous trigonotarbid arachnid
Maiocercus celticus
(Pocock 1902) from Lancashire, UK
Authors: Dunlop Jason A. , Horrocks Carl A. 
Published: December 2009

SUMMARY

A new specimen of the fossil arachnid
Maiocercus celticus
(Pocock, 1902) (Arachnida: Trigonotarbida), from the Upper Carboniferous (Westphalian A) Coal Measures of Westhoughton, Lancashire, UK is described. The taxonomy of
Maiocercus celticus
is revised and a new reconstruction is presented.
The
Amoeboceras
faunas of the Upper Calcareous Grit Formation (Jurassic, Upper Oxfordian) of North Yorkshire
Authors: Wright J. K. 
Published: December 2009

SUMMARY

The Yorkshire Upper Calcareous Grit Formation consists of a sequence of sandstones, impure limestones and argillaceous siltstones ranging from 9 m to 20 m in thickness. Though generally poorly fossiliferous, individual horizons at certain localities can be remarkably fossiliferous, and have yielded some 370 cardioceratid and perisphinctid ammonites. Two localities, Newbridge Quarry near Pickering and Laysthorpe Quarry near Nunnington, are the most prolific source of the cardioceratid ammonite
Amoeboceras
in the Glosense Zone in Britain. Six species are described and figured, of which one,
Amoeboceras newtonense,
is new.
Stratigraphy, microfossils and depositional environments of the lowermost part of the Welton Chalk Formation (late Cenomanian to early Turonian, Cretaceous) in eastern England
Authors: Dodsworth Paul 
Published: December 2009

SUMMARY

The lowermost part of the Welton Chalk Formation in eastern England conforms to a succession of eight beds, lettered here A to H in ascending order. Beds A and B are equated with the Plenus Marls (
Metoicoceras geslinianum
Zone) of southern England. The Black Band (beds C to E) has yielded palynological assemblages containing the dinoflagellate cysts
Adnatosphaeridium tutulosum
and
Carpodinium obliquicostatum.
Their presence, along with the absence of
Litosphaeridium siphonophorum,
indicates a late Cenomanian age (
Neocardioceras juddii
Zone) for the Black Band. Bed H contains the planktonic foraminiferan
Praeglobotruncana praehelvetica,
an early morphotype of a Turonian marker fossil. The dark, organic-rich marls of beds C to G are probably contiguous with those of the lowermost part of the Herring Formation in the North Sea Basin and together comprise the regional sedimentary record of a much more widespread ‘black shale’ depositional episode. Alternative hypotheses concerning the origin and timing of this episode are reviewed with reference to new microfossil evidence from eastern England. The late Cenomanian to early Turonian dinoflagellate cyst stratigraphy discussed here appears to be compatible with stratigraphies based on planktonic foraminifera, ammonites and geochemistry (δ
13
C) in north-west Europe and the western interior of the USA, possibly indicating connected basin water masses over much of the area during the Cenomanian–Turonian transition.
A Holocene dinoflagellate cyst record from offshore north-east England
Authors: Harland R. , Long D. 
Published: December 2009

SUMMARY
Dinoflagellate cyst analysis of a British Geological Survey vibrocore from offshore north-eastern England has revealed a detailed record of Holocene marine conditions for the western North Sea area. Constrained by radiocarbon dating, the almost complete record reveals an initial warming trend followed by changing environmental conditions that can be best explained in terms of the various influences of Scottish or English Coastal Waters as previously defined. The increasing influence of North Atlantic water is present, as is some lowering of seawater salinity at the site during the interpreted Subatlantic with the possible increased run-off from the rivers Tyne, Wear and Tees. This study shows that dinoflagellate cyst analysis is proving to be a useful tool in the high resolution environmental elucidation of offshore marine Holocene sequences.
Conodont biostratigraphy of the attenuated Dent Group (upper Ordovician) at Hartley Ground, Broughton in Furness, Cumbria, UK
Authors: Armstrong H. A. , Johnson E. W. , Scott R. W. 
Published: December 2009

SUMMARY

At Hartley Ground, Broughton in Furness, Cumbria, the Dent Group, a mixed clastic-carbonate succession at the base of the Windermere Supergroup, is attenuated (only 20 m thick) and rests unconformably on the Borrowdale Volcanic Group. This succession includes a debris-flow deposit (Lumholm Member), the age of which was thought previously to be either Ashgill or Llandovery. Five samples from the Hartley Ground succession have yielded an
Amorphognathus ordovicicus
Biozone conodont fauna, considered to be of mid- to late Rawtheyan (Ashgill) age. The conodont fauna occurs in strata below and within the matrix of the Lumholm Member, although reworking within the latter cannot be completely discounted. Conodont colour alteration index (CAI) values of 5 for all the samples suggest these strata have been heated to temperatures of 300–400°C. At normal continental geothermal gradients this would indicate a minimum depth of burial of approximately 10km.

New multi-element reconstructions are proposed for
Amorphognathus ordovicicus
Branson & Mehl and
Birksfeldia circumplicata
Orchard;
Hamarodus europaeus
(Serpagli) is considered to be a member of the family Periodontidae.
Kinderscoutian and Marsdenian successions in the Bradup and Hag Farm boreholes, near Ilkley, west Yorkshire
Authors: Aitkenhead N. , Riley N. J. 
Published: December 2009

SUMMARY

The Bradup and Hag Farm boreholes were drilled by the British Geological Survey (BGS) into strata of the Upper Carboniferous Millstone Grit Group near Ilkley. They prove (beneath glacial till) a rock succession of Namurian (late Kinderscoutian to earliest Marsdenian) age including five faunal marker bands, two of which are the widespread Reticuloceras coreticulatum (R
1c
4) and Bilinguites gracilis (R
2a
1) marine bands. The other three yielded mainly benthonic assemblages and lacked diagnostic ammonoid taxa, but are tentatively assigned to the R
1c
2, R
1c
3, and Butterly marine bands. Four late Kinderscoutian cycles are identified, and a basal fifth cycle is incomplete. Each comprises a coarsening-upwards sequence from marine mudstones to prodelta-slope siltstones and sandstones, then to fluvial sandstones and other delta top deposits. Three of the fluvial sandstones have conglomeratic bases and overlie erosion surfaces which, in the third and fifth cycles, are immediately underlain by laminites comprising alternating grey sandstone and dark grey clay-rich sandstone laminae, the former varying rhythmically in lamina thickness, and the latter invariably having a thickness of 1–2 mm. Preliminary measurements suggest a possible tidal influence on the deposition of the laminites, an influence previously unrecorded in the Namurian of this part of the Central Pennine Basin.
Provenance of Lower Coal Measures around Bradford, West Yorkshire
Authors: Chisholm J. I. , Waters C. N. , Hallsworth C. R. , Turner N. , Strong G. E. , Jones N. S. 
Published: December 2009

SUMMARY
Strata from the base of the Coal Measures up to the top of the Elland Flags were apparently all derived from a distant northern source, probably the same as that which supplied the underlying Millstone Grit. They show strongly micaceous lithologies, clean sandstones, resistate heavy minerals with monazite but no chrome spinel, and palynomorph assemblages exclusively of indigenous Langsettian miospores. A sudden change in sediment type is apparent at the base of the overlying Greenmoor Rock with the appearance of weakly micaceous lithologies of a greenish-grey colour, clayey sandstones with remnants of mudstone lithoclasts, chrome spinel among the heavy minerals (but no monazite) and reworked Devonian palynomorphs in addition to the Langsettian types. Regional palaeocurrent flow during deposition of the Greenmoor Rock was from the west but the ultimate source of this sediment is still in doubt. The northern type of sediment then reappeared in the Grenoside Sandstone, mixed locally with western-derived material. At higher stratigraphical levels, different relationships between lithology and mineral composition appear. Strongly micaceous lithologies become rare, and the presence of chrome spinel is not necessarily associated with greenish grey lithologies.