bluuebunny/crossref_metadata_2025 huggingface dataset:
A Holocene dinoflagellate cyst record from offshore north-east England
Authors: Harland R. , Long D.
Published: December 2009

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

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

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

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.
New developments in the Late Carboniferous geology of the central Pennines, northern England: a review
Authors: Waters C. N. , Maynard J. R. , Wignall P. B.
Published: December 2009

This paper provides an overview of recent work on the Silesian geology of the central Pennines, northern England, and acts as an introduction to the thematic set of papers presented in this issue of the
Proceedings.
The thematic set includes a paper derived from the Yorkshire Geological Society field meeting to Bradford, held on 16 and 17 September 1995 (
Waters
et al.
this volume). The remaining papers stem from talks presented at the general meeting of the Yorkshire Geological Society, held at Huddersfield University on 7 October 1995.
Late Carboniferous stratigraphy and sedimentology of the Bradford area, and its implications for the regional geology of northern England
Authors: Waters C. N. , Aitkenhead N. , Jones N. S. , Chisholm J. I.
Published: December 2009

This paper presents descriptions and sedimentological interpretations of a number of sections in the Millstone Grit and Lower Coal Measures of the Bradford area, West Yorkshire. These are used to discuss the application of sequence stratigraphic models to cyclicity, particularly illustrating the problems of interpreting an erosive surface at the base of the Pule Hill Grit (Marsdenian R
2
). A change in basin bathymetry is confirmed as the cause of an evolution of delta geometry from deep basin, turbidite-fronted deltas in the Kinderscoutian (R
1c
4), to shallow marine, sheet-like deltas from late Kinderscoutian to Yeadonian, and increasingly lacustrine environments during Langsettian times. Evidence is provided for switching of sediment supply in the Langsettian between the Elland, Greenmoor and Grenoside cycles. The importance of intrabasinal sedimentary controls on deposition is discussed in relation to the Elland and Greenmoor cycles. The importance of intrabasinal tectonics is highlighted by slumps in the Stanningley Rock, synsedimentary faults in the Rough Rock Flags and vertical stacking of channel sandstones in the Elland Flags. Displacements on the Denholme Clough and Aire Valley fault systems during early Marsdenian times apparently produced an area of raised sea-bed topography associated with condensed mudstone-successions, diversion of sandy deltaic lobes, lateral transition of the ammonoid-bearing Bilinguites bilinguis Marine Bands into
Lingula
bands and the shallow marine Keighley Bluestone.
Graptolites of the Barnby Hills Shale (Silurian, Ludlow), New South Wales, Australia
Authors: Rickards R. B. , Wright A. J.
Published: December 2009

An upper Ludlow graptoloid fauna of seven taxa from the Barnby Hills Shale, New South Wales, is associated with a diverse dendroid fauna of 20 taxa, in assemblages dominated by graptolites with rare scolecodonts. An association of late forms of
Bohemograptus bohemicus tenuis
(Bouček) with
Egregiograptus egregius byrnesianum
gen. et subsp. nov. suggests a level of approximately the
inexpectatus/kozlowskii
biozones.

The following additional new forms are described:
Dictyonema sherrardae mumbilensis
subsp. nov.,
D. goepperti krafti
subsp. nov.,
D. delicatulum barnbyensis
subsp. nov.,
Stelechocladia talenti
sp. nov.,
S. struszi
sp. nov.,
Acanthograptus aculeatus neureaensis
subsp. nov.,
Thallograptus acanthicus vandenbergi
subsp. nov.,
T. cooperi
sp. nov.,
Coremagraptus kalfusi praekalfusi
subsp. nov.,
Ptilograptus discurrens sherrardae
subsp. nov.,
Linograptus posthumus introvertus
subsp. nov., and
Prolinograptus packhami
gen. et sp. nov. The following are recorded from Australia for the first time:
D. goepperti
Kraft;
Callograptus? pulchellus
Shrock (subspp. 1 and 2)
Desmograptus quebecensis
Ruedemann,
Stelechocladia
Bouček,
Coremagraptus plexus
(Počta),
Coremagraptus kalfusi
Bouček and
E. egregius
Urbanek. In addition are several forms attributable to
Dictyonema, Dendrograptus, Linograptus
and
Pristiograptus.
It is suggested that there are several possible evolutionary origins for
Egregiograptus,
the most likely being from a Ludlow species of
Neolobograptus. Acanthograptus aculeatus neureaensis
subsp. nov. is regarded as an evolutionary derivative of
A. a. aculeatus
(Počta);
Coremagraptus kalfusi praekalfusi
subsp. nov. as an ancestor of
C. k. kalfusi; Thallograptus acanthicus vandenbergi
subsp. nov. to have evolved from
T. a. acanthicus
Bouček; and
Dictyonema sherrardae mumbilensis
subsp. nov. from
D. s. sherrardae
Rickards
et al.
A new elythid spiriferide brachiopod from the Lower Carboniferous (Asbian) reef facies of the British Isles
Authors: Brunton C. H. C. , Mundy D. J. C.
Published: December 2009

The genus
Nebenothyris
Minato, 1963 closely resembles the common spiriferoid genus
Phricodothyris,
but differs in having median ridges in both valves. It has seldom been mentioned in British faunas, but has been recognized in brachiopod collections from the Craven Reef Belt, North Yorkshire. We review the occurrence of
Nebenothyris
and recognize a new species,
N. rhachis,
from B2b ‘reefal’ limestones of late Asbian age in northern England and Ireland.
An igneous dyke complex in the Carboniferous Limestone of north Derbyshire and its significance
Authors: Cope F. Wolverson
Published: December 2009

Descriptions are given of exposures, mostly temporary, of tholeiite dykes and kindred intrusions cutting Lower Carboniferous (Asbian) limestones in Great Rocks Dale near Buxton, Derbyshire. The presence of unusually severe marmorization of the limestones in contact with the intrusions and the outstanding thickness of the Lower Miller’s Dale Lava in the same area give indirect evidence that the various flow-units of the Lower Lava were fed by fissure eruption probably beneath the sea.
Yorkshire stone for building the Houses of Parliament (1839–
c
.1852)
Authors: Lott Graham K. , Richardson Christine
Published: December 2009

The use of a Yorkshire stone, from Anston in South Yorkshire, for the building of the ‘New’ Houses of Parliament in London, which began in 1839, was something of an accident. The original stone chosen, after extensive studies by a Select Committee which included several eminent geologists, was Permian Lower Magnesian Limestone (now known as the Cadeby Formation) from quarries at Bolsover Moor (Derbyshire) and subsequently at Mansfield (Nottinghamshire). However, neither of these quarries was able to meet the considerable stone output demanded for the building and within a short space of time Magnesian Limestone from the quarries at Anston, transported via the Chesterfield Canal, was substituted and used for most of the upper fabric.
A sequence stratigraphic model for deposition of the Lower Kinderscout Delta, an Upper Carboniferous turbidite-fronted delta
Authors: Hampson Gary J.
Published: December 2009

Late Kinderscoutian (Upper Carboniferous) strata in the central Pennines, northern England, were deposited in a turbidite-fronted delta, here termed the Lower Kinderscout delta. Existing depositional models of this delta system are based solely on facies analysis and imply that its lithostratigraphic components were coeval and genetically linked. However, detailed sedimentological logging of these strata at outcrop reveals a range of key elements, some of which can be traced regionally and which record distinct breaks in deposition, thereby contradicting these models. Key elements include: (1) high-relief (up to 40 m) erosion surfaces at the bases of coarse-grained fluvial and deltaic sandstone bodies, (2) thin coals, (3) surfaces across which there are a number of abrupt changes, including changes in depositional process from turbidity-current dominated to traction-current dominated, in sand:shale ratio and in ichnofauna, (4) intensely-bioturbated siltstones and (5) condensed shales, including marine bands. Each of these key elements records a change in sediment supply and/or accommodation space, implying that they have the potential for time correlation within a conceptual sequence stratigraphic framework. A new depositional model is proposed which is based on such a conceptual framework. A crucial feature of this model is the recognition of major erosional unconformities (sequence boundaries) which were produced by fluvial incision during discrete periods of falling relative sea level, when sediment was bypassed into the deep basin, and across which there are no genetic links in facies. Facies architecture is repeated, and therefore predictable, between the sequence boundaries. The sequence stratigraphic model therefore represents an important alternative to existing depositional models, particularly with regard to the timing and distribution of sandstone bodies.
Westphalian B marine bands and their subsurface recognition using gamma-ray spectrometry
Authors: O’Mara Peter T. , Turner Brian R.
Published: December 2009

Palaeogeographic reconstructions, marine band deposition and the variations of uranium enrichment in sediments enable marine bands to be divided into four types: (1) Namurian marine bands, which represent marine anoxic black shale events, with thick ammonoid acme phases that concentrate uranium; (2) Vanderbeckei marine bands have thin ammonoid acme zones and abundant benthos, resulting from shallower water depths and poorly developed anoxic events with negligible uranium enrichment; (3) Westphalian B/C marine bands are more marginal and have an abundance of land-derived plant fragments with adsorbed uranium, as well as uranium entrapped within phosphatic tests of
Lingula;
(4) brackish water
Lingula
beds with abundant terrigenous matter and negligible uranium response. This classification scheme provides a means of predicting the uranium response of individual marine bands which is attributed primarily to the type and amount of organic matter, and the salinity of the waters responsible for deposition. This approach allows marine bands to be recognized and identified in the subsurface from their gamma ray and spectral gamma response, and together with palynological analysis allows the marine band to be placed more accurately within the regional stratigraphic framework.
A comparison of the Skiddaw and Manx groups (English Lake District and Isle of Man) using neodymium isotopes
Authors: Strong P. , Evans J. A.
Published: December 2009

Nd-isotope analyses of greywackes from the Skiddaw Group give an εNd range of −9.3 to −4.1, broadly compatible with suggestions of a provenance within an inactive and dissected, continental-margin volcanic arc. There is no clear temporal trend but the youngest greywackes have the lowest εNd values, perhaps suggesting an increase in the proportion of an older continental component through time as the arc was eroded. Two stratigraphical units were also sampled from the Manx Group, the likely lateral equivalent of the Skiddaw Group on the Isle of Man. Of these, the Lonan Flags gave εNd values of −6.0 and −5.1, within the upper part of the Skiddaw Group range. However, a sample from the slightly younger Maughold Banded Group has εNd = +2.1, indicative of a large influx of juvenile volcaniclastic detritus. This influx appears to have occurred earlier (mid-Arenig) in the Manx Group than in the Skiddaw Group where the first volcaniclastic interbeds are seen in the (Llanvirn) Tarn Moor Formation.
Structural evolution of the Lake District Boundary Fault Zone in west Cumbria, UK
Authors: Akhurst M. C. , Barnes R. P. , Chadwick R. A. , Millward D. , Norton M. G. , Maddock R. H. , Kimbell G. S. , Milodowski A. E.
Published: December 2009

The Lake District Boundary Fault Zone (LDBFZ) lies at the boundary between the Permo-Triassic East Irish Sea Basin and the Lower Palaeozoic Lake District Block. It divides northwards, within west Cumbria, into a network of fault strands that lie within the cover sequence of Upper Palaeozoic and younger rocks and Lower Palaeozoic basement rocks, and terminates at the St Bees Fault Zone. The earliest evidence of movement across the LDBFZ during the Ordovician is drawn from the component Thistleton Fault which has a volcanotectonic origin and bounds blocks of distinctive stratigraphy and structure. Reactivation of the LDBFZ in response to regional tectonic events occurred during the Late Palaeozoic, Mesozoic and Cainozoic. Oblique reverse displacement during the late Carboniferous was associated with Variscan basin inversion. East–west extension and syndepositional normal displacement accompanied the formation of the East Irish Sea Basin during Permian and early Triassic times. Analysis of fracture mineralization phases from the fault zone strands demonstrates repeated fault activity from mid-Triassic to early Cretaceous times. Slickenside data from the Sellafield area indicate these phases of Mesozoic faulting accommodated dip-slip displacement and south-west-directed extension. Regional uplift during the Cainozoic was accompanied by basin inversion; oblique-reverse displacement across the LDBFZ at this time was accompanied by Cainozoic folding of the hanging-wall block. The structural evolution and displacement history noted for the LDBFZ is likely to have been similar to that of other major faults of north-north-west trend in northern England, notably the Pennine Fault.
The petrology and paragenesis of fracture mineralization in the Sellafield area, west Cumbria
Authors: Milodowski A. E. , Gillespie M. R. , Naden J. , Fortey N. J. , Shepherd T. J. , Pearce J. M. , Metcalfe R.
Published: December 2009

The petrology and paragenesis of fracture mineralization hosted in the Ordovician, Dinantian (Carboniferous Limestone) and Permo-Triassic rocks of the Sellafield area were studied as part of the United Kingdom Nirex Limited programme of site investigations around Sellafield in west Cumbria for a deep repository for radioactive waste. This paper summarizes the petrological and mineralogical observations from 23 of the deep (up to 2 km) boreholes drilled by Nirex.

A paragenetic sequence of nine Mineralization Episodes (ME1 to ME9) was recognized, and has been interpreted in the context of the geological and hydrogeological history of the Lake District massif and East Irish Sea Basin margin areas. ME1 to ME3 produced silicate and sulphide-dominated Palaeozoic epithermal to mesothermal mineralization associated with pre-Acadian hydrothermal circulation and late-Caledonian (mid-Devonian) intrusions. ME4 to ME7 represent carbonate-sulphate-fluorite-hematite-dominated mineralization associated with warm, complex, Na-Cl-Ca-SO
4
brines expelled from the East Irish Sea Basin area during progressive burial of the thick Carboniferous and Permo-Triassic sedimentary sequence. Sulphate-carrying brines expelled to the basin margin in the Sellafield area mixed locally with cooler, more dilute, sulphate-poor groundwaters carrying barium, resulting in the precipitation of barite. ME8 and ME9, by contrast, are closely related to the development of the present-day groundwater system. ME8 involved telodiagenetic, supergene alteration and weathering by near surface oxidizing groundwaters. Isotopic evidence indicates that ME8 was probably initiated following Late Tertiary uplift and may still be ongoing in some areas. ME9 may be coeval with ME8, but represents mineralization in the deeper, more-reducing groundwater environment. This mineralization episode is dominated by calcite (sometimes associated with pyrite, marcasite, barite, anhydrite or gypsum) precipitated from groundwaters of similar composition to those found in the Sellafield area at the present day. Observations suggest that ME9 mineralization occurred during the Quaternary and is ongoing in the present groundwaters.
The metamorphic history of the Borrowdale Volcanic Group: a petrographic study
Authors: Meller Nicola
Published: December 2009

Petrographic studies of the secondary mineralogy of the Borrowdale Volcanic Group of north-west England suggest that these rocks were affected by at least four metamorphic events during the Palaeozoic. The first event was hydrothermal metamorphism which probably occurred during volcanism and resulted in deposition of chalcedony in veins and vesicles. Celadonite may be a result of this hydrothermal event or later burial metamorphism. The chalcedony was subsequently overprinted by contact and burial metamorphism. Contact metamorphism is defined by the presence of biotite and/or hornblende with or without hornfelsing and extends up a few km from the batholith/volcanic interface. Burial metamorphism is defined by two assemblages: calc-silicate hosted and calcite hosted, where their distribution is interpreted as being controlled by a change in the
X

CO
2

. content of the (predominantly hydrous) fluid associated with burial metamorphism. A fluid with lower
X

CO
2

was responsible for formation of the calc-silicate assemblage, whereas the fluid associated with the calcite hosted assemblage had a relatively higher
X

CO
2

. Burial metamorphic minerals replaced and infilled both hydrothermal chalcedony and primary igneous features (crystals, matrix and vesicles) and reached a maximum grade of prehnite-actinolite to actinolite-pumpellyite facies in the Devonian prior to the Acadian Orogeny. The last metamorphic event is regional metamorphism which is associated with the Acadian Orogeny and resulted in the formation of tectonically aligned white mica. Pervasive carbonate associated with the cleavage may be a result of regional metamorphism or a later post-metamorphic event. Post-metamorphic carbonate veins in the Lake District were probably coeval with post-Brockram carbonate veins in Nirex borehole volcanic sequences.
Microborings in mid-Cretaceous fish teeth
Authors: Underwood C. J. , Mitchell S. F. , Veltkamp C. J.
Published: December 2009

Fish teeth and other remains from the British Cretaceous contain abundant evidence for post-mortem colonization by endolithic organisms. The borings are here recognized as occurring in three morphotypes, including a flask-shaped form not previously recorded. There is strong evidence to suggest that each of these boring types shows a strong preference for a particular substrate histology. The damage and destruction of vertebrate remains by microborings is here considered to exert a major taphonomic conrol on microvertebrate assemblages. The relationships between the intensity of colonization of vertebrate material by endolithic organisms and palaeoenvironment have implications for using these bone microborings as palaeoenvironmental indicators.
The architecture of concealed Dinantian carbonate sequences over the Central Lancashire and Holme highs, northern England
Authors: Evans D. J. , Kirby G. A.
Published: December 2009

Many of the concepts of early Carboniferous carbonate deposition in ‘block’ and ‘basinal’ areas were developed in northern England, although the subsurface extent and nature of these successions were difficult to define due to limited Dinantian outcrop and borehole data. Detailed interpretation of seismic reflection data from this region, calibrated by borehole and outcrop data, has resulted in the identification of two distinct seismic facies in the subsurface, corresponding to shallow-water carbonates and deeper-water basinal lithologies. The subsurface extent and architecture of these facies have been mapped. Shallow-water carbonates are interpreted from seismically ‘transparent’ units which are broadly lens-like and which are restricted to the Central Lancashire and Holme highs. Surrounding and basinwards of these shallow-water carbonates is a ‘stripy’ seismic facies with a wedge-like form representing basinal-facies rocks. The two seismic facies are interdigitated and attest to a complex history of progressive drowning of the intra-basinal highs. Relative sea-level appears to have risen at varying rates during Dinantian times, with periods of rapid rise resulting in the retreat of shallow-water carbonates and periods of less rapid rise, stillstand or perhaps sea-level fall leading to their outbuilding. No evidence is found of significant footwall erosion of strata associated with fault movements in Chadian to Arundian times as suggested by some published tectonostratigraphic models.
Evidence of Late Devensian and early Flandrian processes and environments in the Idle Valley at Tiln, North Nottinghamshire
Authors: Howard Andy J. , Bateman Mark D. , Garton Daryl , Green Frances M. L. , Wagner Pat , Priest Vicki
Published: December 2009

This paper elucidates the late Pleistocene and early Flandrian environmental history of the Lower Idle Valley through sedimentological, palaeobiological and radiometric dating studies of fluvial and aeolian deposits. The lower part of the sequence comprises braided river sands and gravels with silty peats infilling a scour hollow in their upper surface. Coleopteran and palynological analyses of the organic sediments indicate deposition in a slow moving or static water body with fringing reeds, sedges and substantial beds of wet moss. Away from the water, the vegetation was open and probably of grassland with few trees. Radiocarbon dating indicates accumulation of organic material started towards the end of the Dimlington Stadial,
c.
13,500 cal bp. A cryoturbated, podsolized sandy clay with plant matter was developed on the sands and gravels and is akin to an ‘Arctic Structure Soil’. The sandy clay parent material on which the soil was developed is suggested to have originated in a lacustrine environment, tentatively linked to the Lake Humber complex. The palaeosol is buried, in turn, beneath coversands, the uppermost part of which is reworked. Thermoluminescence (TL) age determinations show that the coversands started to accumulate around 13,700 bp, probably in response to climatic deterioration prior to the Loch Lomond Stadial. Reworking began around 8,500 years ago.
A palynological investigation of the Lower and lowermost Middle Jurassic strata (Sinemurian to Aalenian) from North Yorkshire, UK
Authors: Palliani Raffaella Bucefalo , Riding James B.
Published: December 2009

A palynological investigation of the Lower and lowermost Middle Jurassic (Sinemurian to Aalenian) strata of North Yorkshire has been undertaken which incorporates material from the BGS Brown Moor Borehole, near Acklam and the coastal outcrops between Staithes and Robin Hood’s Bay. The resulting dataset is an additional contribution to the Jurassic dinoflagellate cyst biostratigraphy of northern England. Two distinctive variants of
Liasidium variabile
appear to have biostratigraphical significance in the Upper Sinemurian of North Yorkshire. Specimens of
L. variabile
from the
Caenisites turneri
Ammonite Zone, the
Eparietites denotatus
Ammonite Subzone and the
Oxynoticeras simpsoni
Ammonite Subzone have short apical and antapical horns. Forms from the overlying uppermost
Oxynoticeras oxynotum
Ammonite Zone, however, are characterized by elongate apical horns and rounded hypocysts. The regional dinoflagellate cyst diversity increase in the late Pliensbachian and the disappearance of many dinoflagellate cysts in the Lower Toarcian are both interpreted as being related to eustatic fluctuations. The paucity of dinoflagellate cysts close to the
Dactylioceras tenuicostatum-Harpoceras falciferum
Ammonite zonal transition in the Lower Toarcian was caused by the spread of widespread marine anoxia during the Lower Toarcian maximum flooding event. A new species of dinoflagellate cyst,
Nannoceratopsis symmetrica
, is described.
The Welton Formation (Chalk Group) at Speeton, NE England: implications for the late Cretaceous evolution of the Market Weighton Structure
Authors: Mitchell Simon F.
Published: December 2009

The stratigraphy of the Welton Formation (Chalk Group, Upper Cretaceous) at Speeton, NE England, is described for the first time. The marker horizons of the standard succession on the East Midlands Shelf are clearly recognizable at Speeton and demonstrate that the succession is of comparative thickness to that developed on the East Midlands Shelf. The succession is divided into three: the Flixton, Buckton and Bempton members, which can be traced throughout NE England. Considerations of changes in the rates of sedimentation between the East Midlands Shelf, Market Weighton Structure and Cleveland Basin suggest that the Market Weighton Structure, which had dominated sedimentation styles throughout the Jurassic and Lower Cretaceous, had ceased to be an influence on sedimentation rates during the late Cretaceous.
Early Holocene environments of the River Ure near Ripon, North Yorkshire, UK
Authors: Howard A. J. , Keen D. H. , Mighall T. M. , Field M. H. , Coope G. R. , Griffiths H. I. , Macklin M. G.
Published: December 2009

A sequence of peat and calcareous organic mud from the floodplain of the River Ure near Ripon has yielded pollen, plant macrofossils, Mollusca, Coleoptera, and Ostracoda which allow the first recorded reconstruction of earliest Holocene valley-floor environments for this area. A conventional radiocarbon date on a bulk sample of peat yielded an age of 9710 ± 60bp. The palaeontological evidence suggests that the sediments accumulated in a shallow, slow moving or stagnant water body, surrounded by marshy, damp, grassland, away from contemporary channel processes, probably of a single thread river system. The climate during deposition of the sediments was no warmer than the present, and possibly slightly colder.
Stratigraphic evolution of provenance characteristics in Westphalian sandstones of the Yorkshire Coalfield
Authors: Hallsworth C. R. , Chisholm J. I.
Published: December 2009

A combined study of heavy minerals and palaeocurrents shows that three main fluvial systems transported sediment to the Pennine Basin during Namurian and Westphalian times. The first, which brought a garnet-rich monazitic heavy mineral suite from the north, peaked in the Namurian and diminished through the Langsettian. The second flowed from the west, bringing heavy mineral suites with low garnet, low monazite and variable amounts of chrome spinel. It started in the late Namurian, replaced the first system in the Langsettian, and dominated thereafter until it was itself replaced in the late Duckmantian by the third system. This brought a garnetiferous heavy mineral suite with both monazite and chrome spinel from the E or SE and continued to the top of the preserved sequence, in the late Bolsovian. The first sourceland lay to the north, perhaps between Laurentia and Baltica, and included high grade metasediments or charnockites and granites. The second sourceland lay to the west and included mature, pre-existing clastic sediments of Devonian and possibly Lower Palaeozoic age. Ultramafic rocks such as ophiolites, possibly associated with Lower Palaeozoic ocean closure, were periodically exposed there. The third sourceland lay to the south, probably within the uplifting Variscan orogenic belt. It included low to moderate grade metasediments, high-grade gneisses, granites and ultramafic rocks.
The Eycott Volcanic Group, an Ordovician continental margin andesite suite in the English Lake District
Authors: Millward D. , Marriner G. F. , Beddoe-Stephens B.
Published: December 2009

The Eycott Volcanic Group, at the northern margin of the Lower Palaeozoic inlier in the Lake District, is the smaller of two substantial middle Ordovician (Caradoc) subduction-related volcanic successions that stratigraphically separate marine sedimentary successions of the Skiddaw Group and Windermere Supergroup. Tabular lavas and subordinate sills, in a sequence up to 2400 m thick, mainly comprise porphyritic basalt, basaltic andesite, andesite and dacite, and are locally interbedded with thin units of volcaniclastic sandstone and pyroclastic rocks; these are overlain by 800 m of acid andesitic pyroclastic rocks. The distribution and form of the lava/sill fades association are consistent with emplacement as a lava plateau sequence, remarkably similar to the Birker Fell Formation, the lower part of the Borrowdale Volcanic Group in the central Lake District. The Eycott Volcanic Group rocks are geochemically coherent with characteristics transitional between medium-K, continental-margin tholeiitic, and calc-alkaline andesite suites. Rocks within the suite can be linked by fractionation of an assemblage of plagioclase, pyroxene, Fe–Ti oxide and apatite. A prominent compositional gap between about 58 and 65% SiO
2
is attributed to the rapid precipitation and segregation of Fe–Ti oxide. Incompatible element concentrations in the mafic members suggest that magmas were derived possibly from a subcontinental lithosphere source, similar to that of the Borrowdale Volcanic Group. The geochemical differences between these two suites arose through the incorporation of different amounts of the subduction component and different fractionation histories.
Felsites and breccias in the Northern Marginal Zone of the Rum Central Complex: changing views,
c.
1900–2000
Authors: DONALDSON C. H. , TROLL V. R. , EMELEUS C. H.
Published: December 2009

As in several other parts of the British Tertiary Igneous Province, breccias and felsite sheets are closely associated on the Isle of Rum. This association has been described and interpreted by several workers over the last 125 years. Opinion has divided into an intrusive origin for both rock types, as explosion breccias and felsite intrusions, versus a sedimentary origin for the breccias and an extrusive origin for the felsite. Evidence is reviewed for both opinions and it is concluded that the latter is substantially correct, as indicated by the presence of sedimentary structures and interbedded tuffs in the breccias and eutaxitic textures in the felsites. The breccias formed by inwards slumping of rocks from the oversteepened walls of a caldera, whereas the felsites formed by eruption of pyroclastic flows which were thick and hot enough to weld. It is inferred that the caldera formed initially and subsided progressively without any accompanying eruptions, and this is attributed to growth of the underlying magma chamber. The breccias accumulated during this stage. There followed a resurgent stage in which caldera collapse occurred in response to repeated ignimbrite eruptions partially emptying the magma chamber. The chamber is inferred to have been chemically and mineralogically zoned.
Constraints on the genesis of the mineralization of the Alston Block, Northern Pennine Orefield, northern England
Authors: Cann J. R. , Banks D. A.
Published: December 2009

New evidence from fluid inclusion compositions and simple physical modelling provide important constraints on the genesis of the ores of the Alston Block in northern England. Evidence from fluid inclusions shows that probably at least four, hydrothermal fluids were involved, two of which are formed by evaporation of seawater, in some cases well beyond halite saturation. Some of the high-temperature fluid dissolved evaporites during its evolution. Physical modelling shows that neither compactional dewatering of the adjacent Carboniferous sedimentary basins nor compressional tilting and throughflow within the Northumberland Trough could have contributed significantly to the hydrothermal fluids of the orefield. Most of the high temperature hydrothermal flow must have been generated by penetrative circulation of surface brines to 8 to 10 km depth in the basement, with the upflow focused and accelerated by the high heat production of the Weardale Granite that unconformably underlies the Carboniferous rocks of the Alston Block. The orefield is considered to have formed during the Upper Permian by the following sequence of events. Initially, fluid movement in the basement was prevented by sealing of pre-existing cracks, and temperatures rose at depth. An episode of extension allowed saline water, probably from the Upper Permian Zechstein Sea, to penetrate deep into the basement, reacting with the rocks there, and becoming heated to as much as 200°C. Penetration to 10 km took a few tens of thousands of years. The granite, at 300°C at that depth, up to 100°C hotter than the surrounding basement, acted to focus the flow, and to generate concentric zones of increasing temperature fluid towards the centre. Once the basement had become cooled, the flow slowed, cracks became sealed, and the episode of hydrothermal circulation and ore formation was complete.
Advances in the study of ‘black shales’: source rocks for bricks and hydrocarbons
Authors: Hudson J. D.
Published: December 2009

Recent advances in methods and concepts in the study of organic-rich mudrocks are reviewed. Organic biomarkers, especially derivatives of isorenieratene, unambiguously identify anoxia within the photic zone of the water column in several well-known black shales. This demands a re-interpretation of much palaeoecological data in terms of intermittent anoxia, rather than only dysoxia, an endeavour aided by increased understanding of the life strategies of benthic invertebrates. The role of sulphur compounds in diagenesis, both organic-bound and as pyrite, is increasingly recognized. Pyrite studies afford anoxicity indices based on pyrite framboids and sulphur geochemistry. The role of organic sulphur is in stabilizing organic matter during kerogen formation, and in ‘fixing’ biomarker molecules. Recycling of nutrients is probably more important than previously thought in forming epicontinental black shales. Reworking of primary organic matter by heterotrophic organisms, especially bacteria, is indicated by isotopic studies on individual organic molecules. All these factors must be integrated with constraints from stratigraphical relationships and basin evolution. Some of these points are illustrated by reference to work by members of the Oxford Clay Working Group in understanding the palaeo-environment of the organic-rich Peterborough Member of that Jurassic formation, a famous source material for bricks and an analogue for hydrocarbon source-rock studies.
Dentalium giganteum
Phillips: a serpulid worm tube
Authors: Palmer C. P.
Published: December 2009

The holotype of
Dentalium giganteum
Phillips 1829, and specimens in the Natural History Museum, London, have been examined and shown to be not scaphopods, but
Ditrupa-like,
serpulid tubes.
The Snelston Ridge: evidence for a concealed ridge of mineralized Dinantian rocks to the south of the Derbyshire Dome
Authors: Cornwell J. D. , Busby J. P. , Colman T. B. , Norton G. E. , Smith N. J. P.
Published: December 2009

Little is known of the southern continuation of the Lower Carboniferous (Dinantian) rocks of the Derbyshire Dome where they lie concealed beneath Triassic rocks at the margin of the Needwood Basin. Evidence from regional Bouguer gravity anomaly surveys pointed to the existence of a ridge of shallow Dinantian rocks, here called the Snelston Ridge, largely concealed by Triassic strata apart from two small inliers. The NNW–SSE trending ridge was proved by a borehole which intersected (Dinantian) Widmerpool Formation rocks at a depth of 61 m. Evidence from a seismic reflection profile indicates that the ridge, at least at Birchwoodpark (Snelston), is probably an asymmetrical, fault-controlled anticline. There is, however, no evidence for any significant changes in the thickness of Dinantian rocks hereabouts. The base metal potential of the Snelston Ridge was investigated using detailed geophysical and geochemical surveys and drilling. A borehole on the top of the mineralized mudmound that forms the Limestone Hill Inlier proved minor replacement galena–sphalerite–baryte mineralization with up to 10% Pb over an intersection of about 11 m. Two boreholes on the flanks of the feature revealed little sign of mineralization, indicating that it is restricted to the exposed dolomitized summit of the mudmound.
Biostratigraphy of Jurassic–Cretaceous boundary strata in the Terschelling Basin, The Netherlands
Authors: Abbink O. A. , Colloman J. H. , Riding J. B. , Williams P. D. B. , Wolfard A.
Published: December 2009

The Jurassic–Cretaceous boundary beds in the Scruff Greensand Formation from Dutch sector North Sea wells L06-2 (between 2245.36 m and 2262.76 m) and L06-3 (between 2028.90 m and 2037.80 m) have yielded both ammonite faunas and abundant marine and terrestrial palynomorphs. Ammonite endemism in Europe was intense at the Jurassic–Cretaceous boundary. This means that pan-European correlations of Jurassic–Cretaceous boundary beds based on macrofossils are problematical. The ammonite faunas of wells L06-2 and L06-3 provide the most extensive and complete marine macrofossil record so far across the Volgian–Ryazanian (Jurassic–Cretaceous) boundary in the Spilsby Province and the North Sea Basin. The Primitivus, Preplicomphalus, Lamplughi, Runctoni and Kochi Zones have been identified. In both wells, the occurrences of the dinoflagellate cyst
Gochteodinia virgula
mean that the successions are no older than latest mid-Volgian. The dinoflagellate cyst associations of L06-2 are indicative of the late Volgian/early Ryazanian. The range tops of
Gochteodinia virgula
and
Amphorula expirata
are revised as a result of correlations with the ammonite zonation. Dinoflagellate cyst floras in L06-3 are indicative of the latest Volgian–? earliest Ryazanian. In particular, the co-occurrence of
Batioladinium? gochtii
and
Gochteodinia virgula
at 2030.60 m in well L06-3, together with ammonite data, indicates that this horizon is of latest Volgian (Lamplughi Zone) age. Both wells contain reworked palynomorphs, including recycled older Late Jurassic dinoflagellate cysts. In addition, the palynological assemblages yield relatively diverse sporomorph associations. The sporomorph succession of both wells is used to establish an ammonite-calibrated sporomorph chronostratigraphy. Comparison with other studies suggests that the Jurassic/Cretaceous boundary occurs within the Cherty ‘Freshwater’ Beds of the Purbeck Limestone Group in Dorset, southern England, and within the Serpulite Member of Germany.
The Pennine Anticline, northern England – a continuing enigma?
Authors: Evans D. J. , Walker A. S. D. , Chadwick R. A.
Published: December 2009

The westward-verging Pennine Anticline extends along the length of the central Pennines. It is an important Variscan fold of flexuous N–S trend developed on the Variscan Foreland. It defines the eastern margins of the Blackburn–Burnley and South Lancashire coalfields, and is commonly viewed as having been formed by the inversion of an underlying down-east Dinantian syn-depositional fault. Seismic reflection and potential field data provide some evidence on the deep structure of the anticline along much of its length. Modelling of gravity data does not provide unique solutions to basement and deep crustal structure beneath the Pennine Anticline. However, the models are consistent with both a basement/upper crustal density boundary and with variations in the Moho topography. In the southern part of the study area, these gravity data appear to define an important NNW–SSE trending, down-east fault that, when traced north, dies out and diverges from the Pennine Anticline. Where imaged by seismic reflection data, particularly over the Central Lancashire High, the fold is underlain by a high-angle reverse fault at basement level. Unusually in this part of northern England, this fault shows little evidence of a Dinantian extensional precursor, perhaps because its trend lay sub-parallel to the Dinantian extension direction. Although the structure remains enigmatic, it is suggested that the two en echelon anticlines mark folding in the Carboniferous cover rocks, developed above a through-going N–S zone of weakness in the basement comprising structures of varying trends. Under NW–SE directed Variscan compression, these structures
The Millstone Grit of northern England: a response to tectonic evolution of a northern sourceland
Authors: Morton A. C. , Whitham A. G.
Published: December 2009

The Carboniferous succession of East Greenland is dominated by sandstones, deposited by a major northward-flowing fluvial system. The succession is divided into two parts by a major unconformity that spans late Visean to early Westphalian A times. This time interval corresponds to the development of the Millstone Grit of the Pennine Basin, which was deposited by a southward-flowing fluvial system. Heavy mineral analysis indicates that there are common elements to the provenance of Late Westphalian A sandstones in East Greenland and the Namurian Millstone Grit. It appears, therefore, that the southward extension of clastic facies into the Pennine Basin during the Namurian occurred when uplift in the Norwegian–Greenland Sea region diverted the northward-flowing fluvial system southwards. Supply of sediment from the northern sourceland diminished when rifting during the Westphalian allowed the northward fluvial system in East Greenland to be re-established.
The Memorial Lychgate at St Mary’s Church, Whitkirk, Leeds
Authors: Mitchell M.
Published: December 2009

The Memorial Lychgate of St Mary’s Church at Whitkirk in east Leeds was dedicated in 1949. It is an unusual, perhaps unique, War Memorial that commemorates symbolic features from the Second World War. Two stonework panels on the outside of the walls contain blocks from six important war damaged buildings. The stones can be identified as follows: Permian Magnesian Limestone (Cadeby Formation, Anston Stone) from the Houses of Parliament, London; Upper Jurassic Portland Stone from St Paul’s Cathedral, London; Triassic New Red Sandstone (Sherwood Sandstone Group, Hollington Formation) from Coventry Cathedral; Middle Jurassic Ketton Stone from St Martin-le-Grand in York (used for 1920–1930s restoration work); Carboniferous Millstone Grit (Lower Follifoot Grit) from Leeds Town Hall; and Carboniferous Coal Measures (Elland Flags, Harehills Stone) from the Leeds Philosophical Hall and Museum. All these stones played an important part in the history of British building stones, and it is remarkable to find examples of them all at one locality. Their source is discussed.