bluuebunny/crossref_metadata_2025_split huggingface dataset:
Schackoina moliniensis
Reichel from the Lower Cenomanian of north-east England and its stratigraphical significance
Authors: Mitchell S. F. , Veltkamp C. J. 
Published: December 2009

SUMMARY

The planktic foraminiferan
Schackoina moliniensis
Reichel is recorded and described for the first time from the Hunstanton Formation (Red Chalk) of north-east England. Its distribution in two sections is presented: the upper part of the Red Cliff Hole Member of the Hunstanton Formation at Speeton in the Cleveland Basin; and from a
Thalassinoides
burrow beneath the erosion surface near the top of the Hunstanton Formation at South Ferriby on the East Midlands Shelf. This horizon, with
S. moliniensis
, represents an important, easily recognizable, planktic foraminiferal marker horizon in the lower part of the Lower Cenomanian of north-east England, and enables the extent of the non-sequence at the Albian-Cenomanian boundary on the East Midlands Shelf to be assessed.
Isotopic variation in fossils and matrix of the Cretaceous Red Chalk at Speeton and South Ferriby, Yorkshire, England
Authors: Price G. D. 
Published: December 2009

SUMMARY

Macro- and micro-fossils (belemnites, planktonic and benthonic foraminifera) and coccolithic matrix from the middle Cretaceous Red Chalk of Yorkshire, UK, have been examined using petrographic, isotopic, and chemical methods to investigate the conditions within which they were formed or altered. Only the belemnites (
Neohibilites sp.)
attain the petrographic and geochemical criteria for being well preserved. In contrast, the foraminifera and matrix reveal evidence of diagenetic alteration. Mean belemnite δ
18
O values are −0.97‰ (PDB) from South Ferriby and −1.28‰ (PDB) from Speeton. Assuming a sea water SMOW value of −1.0‰, mean palaeotemperatures calculated from the oxygen isotopic compositions are 15.9°C and 16.8°C respectively. The range of isotopic values provided by the belemnites in this study suggests that the isotopic values obtained from early studies of the Chalk, that used only petrographic and/or hand specimen descriptions to screen for diagenetic alteration, could largely represent unaltered values. The palaeotemperatures interpreted from the belemnites are comparable to recent estimates of middle Cretaceous temperature from general circulation model predictions.
Interpretation of structural domains in discontinuity data from Nirex deep boreholes at Sellafield
Authors: Barnes R. P. , Dee S. J. , Sanderson D. J. , Bowden R. A. 
Published: December 2009

SUMMARY
Knowledge of the fracture network is fundamental to the fluid transport and geotechnical modelling necessary to assess the suitability of a rock mass to host a potential underground repository for the disposal of radioactive waste. However, in the early stages of a site investigation programme, site-specific fracture data are frequently available only from boreholes. This was the case at Sellafield, where characterization of borehole fracture data presented a number of inter-related problems including the volume of data, two data sets for each borehole and borehole sampling effects. A solution to the presentation and interpretation of such data was found in simple graphical display which allows rapid appraisal of a range of fracture attributes in relation to depth, lithostratigraphy and structure or in any other context.

The succession sampled by the boreholes in the immediate vicinity of the proposed repository at Sellafield comprises three major units. The Borrowdale Volcanic Group, of Ordovician age, is unconformably overlain by a Permo-Triassic cover sequence comprising up to 100 m of sedimentary breccia (Brockram) succeeded by
c.
450 m of the fluvial St Bees Sandstone to rockhead. Fracture data from these are available from logging of the borehole core and from interpretation of resistivity and acoustic images of the borehole wall, providing accurate frequency and orientation information respectively. These show that the discontinuity character of each of the major units is distinctive, indicating overall lithological control on the fracture network. Fracture frequency in the sedimentary cover rocks is relatively low, especially in the Brockram, and orientation patterns are dominated by bedding. The fracture frequency in the volcanic rocks is generally high and orientation typically very variable in the volumetrically dominant welded ignimbrites. However, interbedded units of non-welded lapilli tuff and breccia have lower fracture frequency and simpler orientation patterns. In all units, variations in fracture frequency and orientation character on a scale of a few metres to 100 m can be correlated with fault intersections indicating a structural overprint.

Borehole sampling effects are illustrated by comparison of data from differently orientated boreholes and the underlying causes reviewed. Orientation bias is a well known problem usually addressed by weighting according to the probability of the borehole intersecting a planar feature in a particular orientation. However, data from borehole wall imagery are subject to additional sampling effects which reduce the effectiveness of such weighting. A different approach is suggested, using the probability density function of the population from non-censored parts of the sample.
Evolution of the Ludlow (Silurian) graptolite genus
Bohemograptus
Přibyl 1936
Authors: Rickards R. B. , Wright A. J. 
Published: December 2009

SUMMARY

The characteristic and long-ranging Ludlow graptoloid

Bohemograptus

Přibyl, 1967 is considered to have originated from

Lobograptus progenitor cudalensis

through

B. urbaneki

or

Monograptus idoneus

Keren’, 1992. The

Bohemograptus

stem lineage gave rise to

B. b. tenuis

as a temporal subspecies near the base of the Ludfordian Stage; there followed immediately a considerable diversification into a number
of

Bohemograptus

species

(B. praecornutus

Urbanek, 1970,

B. cornutus

Urbanek, 1970,
B.
n. spp. A. & B. Rickards & Wright, in press); and several genera
(

Korenea,

Rickards
et al.,
1995;

Polonograptus

Tsegelnuk, 1976;

Egregiograptus

Rickards & Wright, 1997a;

Neolobograptus

Urbanek, 1970; and

Neocucullograptus

Urbanek, 1970. The bizarre gracile species

Monograptus proegregius

Urbanek, 1970 is made the type species of a monotypic new genus,

Urbanekia,

derived in the

parascanicus

Biozone from an unknown lobograptid; and

Lenzia lenzi

gen. et sp. nov. is established for cladia-bearing neolobograptids.

Egregiograptus pribyli

sp. nov. is described.

Bohemograptus

n. spp. A & B are interpreted as examples of heraldic evolution.
New sauropod dinosaur prints from the Saltwick Formation (Middle Jurassic) of the Cleveland Basin, Yorkshire
Authors: Romano M. , Whyte M. A. , Manning P. L. 
Published: December 2009

SUMMARY

Undoubted sauropod prints are recorded for the first time from the Aalenian, Middle Jurassic, of the Cleveland Basin. This is only the third site known from which sauropod prints of this age have been reported. Eight pes and manus prints from the Saltwick Formation, near Whitby, Yorkshire are described and interpreted, and include prints up to nearly 1 m in length. The prints show features in common with those of the ichnospecies of
Brontopodus
and
Breviparopus.
The Saltwick Formation is a coastal plain deposit and indicates the print producers inhabited a humid, subtropical environment.
The karstification of the Permian strata east of Leeds
Authors: Murphy Phillip James 
Published: December 2009

SUMMARY
The outcrop of Permian strata to the east of Leeds exhibits a variety of karstic and palaeokarstic features. The area is crossed by an extensive network of dry valley systems and lacks surface water. Two different karst types are recognized: dolomite and dolomitic limestone karst, and gypsum karst. Dolomite and dolomitic limestone karst is characterized by small isolated dolines whereas gypsum karst is characterized by large-scale dolines, many occurring in groups. An appreciation of the karstic nature of parts of the Permian outcrop is becoming increasingly important because of pressure from development and waste disposal.
Magnetic survey of the Holy Island Dyke on Holy Island, Northumberland
Authors: Goulty N. R. , Peirce C. , Flatman T. D. , Home M. , Richardson J. H. 
Published: December 2009

SUMMARY
The Holy Island Dyke on Holy Island, Northumberland strikes E-W along the south coast of the island. It intrudes Lower Carboniferous rocks and crops out as five discrete segments of dolerite. Flat tops on the two largest segments, benches on the southern flanks of three segments, and flat surfaces with amygdales at several locations on the outcrop have all been cited as evidence that the exposures represent the original top surface of the dyke, where it terminated within the country rocks. The results of a magnetic survey of the dyke show that the principal outcrops are connected to the northern edge of a sill whose top surface lies within 10 m of the present ground surface. The sill is exposed on the foreshore adjacent to St Cuthbert’s Isle in the west, where it forms an outcrop near the low water mark that has not previously been reported. The sill is about 100 m wide in the N-S direction and, at its southern edge, is connected to a subsurface dyke that extends downwards. Thus the dolerite outcrops appear to be part of a step-and-stair transgression of bedding. This interpretation accounts for all the features previously cited as evidence of the upward termination of the Holy Island Dyke within the sedimentary succession.
Rich silver-bearing lead ores in the Northern Pennines?
Authors: Dunham K. C. , Young B. , Johnson G. A. L. , Colman T. C. , Fossett R. 
Published: December 2009

SUMMARY
The main lead ore mineral within the Northern Pennine carbonate-hosted galena-fluorite orefield is silver-bearing galena. Numerous reliable assay and recovery records, from the heyday of lead mining during the eighteenth and nineteenth centuries, indicate that silver values in the ores then being mined were typically fairly modest, in the range 100–250 ppm Ag. Historical records from the area written during the eleventh and twelfth centuries, although very much less complete and more open to interpretation, indicate levels of silver production which could not have been sustained from such ores. It is suggested that lead ores with much higher silver content may have been available in these earlier times. A few scattered occurrences of galena with enhanced silver content may represent the vestiges of these ores.
Preservation of fossils in clay minerals; a unique example from the Upper Ordovician Soom Shale, South Africa
Authors: Gabbott S. E. , Norry M. J. , Aldridge R. J. , Theron J. N. 
Published: December 2009

SUMMARY

In the Soom Shale, labile soft tissues have been replaced rapidly after death by authigenic clay minerals which now have an illitic composition. There are two possible pathways for this mineralization: (1) initial replacement of soft tissue by kaolinite which was then diagenetically transformed to illite; or (2) direct replacement of soft tissue by illite. Comparison of the compositions of the authigenic illites that replace the soft tissues and of the detrital illites in the host rock show that the former have higher magnesium numbers and enhanced potassium contents. These compositional differences are better explained if illite directly replaced the soft tissues. Kaolinite and/or illite stability are controlled by the pH and the ratio of K+/H+ in the fluid, expressed as: 2(KAl
3
Si
3
O
10
(OH)
2
) + 3H
2
O + 2H
+
↔ 3(Al
2
Si
2
O
5
(OH)
4
) + 2K
+
. Although the porewaters of the Soom Shale were anoxic and, at times, euxinic, and so might well have favoured kaolinite authigenesis, the conditions within the local environment of the carcasses could have been very different. Ammonia, produced by protein decay, and potassium, concentrated within the tissues, would have been elevated relative to the surrounding pore waters, so that the K
+
/H
+
ratio would have favoured illite authigenesis. Authigenic illites have higher magnesium numbers than detrital sedimentary illites owing to extensive and early pyrite precipitation, indicated by small pyrite framboid diameters (average 4.3 μ), which left the porewaters depleted in iron. The magnesium number in authigenic illites could also have been enhanced by the inclusion of magnesium from seawater.
The stratigraphy of the Namurian Great/Main Limestone on the Alston Block, Stainmore Trough and Askrigg Block of northern England
Authors: Fairbairn R. A. 
Published: December 2009

SUMMARY

The internal stratigraphy of the Great/Main Limestone over the Alston Block, Stainmore Trough and the Askrigg Block is described. The occurrence and distribution of
Gigantoproductus, Latiproductus, Dibunophyllum
and other macrofossils are recorded. Locations where chert-rich bands have been recorded, and where evidence of bioturbation occurs, are described. Areas of localized thinning and their relationship to thick developments of sandstone and chert above and below the limestone are also noted. These variations are related to the structural features of the region.
The geochemistry and significance of sills within the Ordovician Borrowdale Volcanic Group around Black Combe, SW English Lake District
Authors: Kanaris-Sotiriou R. , Mathieson N. A. , Johnson E. W. , Millward D. 
Published: December 2009

SUMMARY

The Borrowdale Volcanic Group (BVG) in the SW of the English Lake District (SWLD) consists predominantly of subaerial pyroclastic rocks that host syn-volcanic intrusions ranging in composition from basalt to dacite. The petrology and geochemistry of the sills verify a broad compatibility with the BVG in the central Lake District. The geochemistry indicates a marginal continental arc setting, a petrogenesis involving
c.
15% partial melting of a lherzolite mantle source and subsequent fractionation of olivine, ortho- and clinopyroxene, plagioclase and Fe–Ti oxide. Three groups of basaltic sills are recognized in the SWLD, one of which bears a close resemblance, geochemically, to the lower BVG (Birker Fell Formation) basaltic lavas and appears to have been emplaced early in the SWLD succession. The other two groups, which may be cogenetic, appear to be some what geochemically distinct from the first, with trace element and rare-earth characteristics suggesting a source slightly more enriched in incompatible elements. It is suggested that the fault-dominated tectonic setting in the Millom Park area of the SWLD may account for the least-evolved magmas being allowed to migrate directly to a high structural level, accounting for a higher proportion of basic lithologies in the upper BVG succession of the SWLD than is found in other parts of the Lake District.
The Mercia Mudstone Group (Triassic) of Manchester Airport, Second Runway
Authors: Wilson A. A. 
Published: December 2009

SUMMARY
The construction of the Second Runway at Manchester Airport generated an extensive drilling programme and created many temporary exposures in the Mercia Mudstone Group. One large natural exposure, the RIGS cliff, was buried under the runway. During infill and benching, good access was gained to this cliff and details are presented. The succession of the upper half of the Bollin Mudstone Formation was recorded in great detail from colour photographs of borehole core from the Terminal Two and Second Runway projects, enabling correlation across the site. Beds formerly placed in the zone of Quaternary halite dissolution were unusually well exposed, revealing breccias, folding and low-angle faulting. Within this subsidence zone, a sequence was established in gently collapsed Byley Mudstone Formation overlying partly brecciated remnants of mudstones formerly placed within the Northwich Halite. The Mobberley Fault was newly exposed in the diversion of Sugar Brook at the western end of the Second Runway. Four other faults, all with easterly downthrow, were detected farther east.
Type belemnites of Simpson’s
Fossils of the Yorkshire Lias
Authors: Doyle P. 
Published: December 2009

SUMMARY
Martin Simpson was curator of the Whitby Museum in the mid-to late-19th century and was influential in systematically collecting and describing the fossils of the North Yorkshire Lower Jurassic (Lias), exposed in mostly excellent coastal sections still accessible today. His species were published in a range of publications between 1843–1884, but, although well described and located, they were not illustrated. The ammonites have subsequently been illustrated, but no comprehensive work illustrating the belemnites has been published. This is a serious omission and the type specimens of 74 of Simpson’s nominal species, from the Lower, Middle and Upper Lias (Sinemurian-Toarcian) are illustrated and discussed here from the originals held in the Whitby Museum.
Jurassic dinosaur tracks and trackways of the Cleveland Basin, Yorkshire: preservation, diversity and distribution
Authors: Romano M. , Whyte M. A. 
Published: December 2009

SUMMARY
Dinosaur tracks are abundant in the Middle Jurassic rocks of Yorkshire and indeed characterize the non-marine sequences developed within the Cleveland Basin. These tracks and associated trackways provide valuable evidence of the possible diversity of the dinosaur communities, their potential makers and behaviour and useful insights into the habitats and palaeoenvironment during the time of deposition. The uneven historical development of research into Yorkshire dinosaur tracks is reviewed and the Middle Jurassic lithostratigraphy, biostratigraphy and chronostratigraphy of the region is outlined. Next, the probable palaeoenvironment of the Middle Jurassic Cleveland Basin, generally regarded as a coastal plain and fluvial complex, is briefly summarized. The terminology used to describe the dominant preservational types of dinosaur tracks, such as surface, transmitted and underprints, is clearly defined, with examples from the Yorkshire sequences. The Yorkshire tracks show considerable morphological diversity and at present 29 different morphotypes have been recognized, which possibly represent at least 15 ichnotaxa. These morphotypes include both quadrupedal and bipedal forms, as well as a distinctive suite of raking prints resulting from swimming activity. The distribution and abundance of the known dinosaur tracks within the Middle Jurassic rocks of Yorkshire is described. For the first time, a range chart of dinosaur tracks is presented that illustrates the persistence of some morphotypes throughout the Ravenscar Group (Middle Jurassic) of the Cleveland Basin. Track distribution and diversity data allow reconstruction of the Yorkshire dinosaur communities that were made up of between 7–10 common types, belonging to sauropods, stegosaurids, ornithopods and theropods. The area is a ‘megatracksite’ of global importance.
A Lateglacial pollen record from Hallsenna Moor, near Seascale, Cumbria, NW England, with evidence for arid conditions during the Loch Lomond (Younger Dryas) Stadial and early Holocene
Authors: Walker M. J. C. 
Published: December 2009

SUMMARY

Pollen data from a Lateglacial and Holocene sequence at Hallsenna Moor, Cumbria, NW England are described. The Lateglacial Interstadial pollen spectra indicate plant succession from open-habitat conditions through the development of
Juniperus
and
Salix
and willow scrub to the establishment of open
Betula
woodland. Based on radiocarbon dating evidence, the climatic amelioration marking the onset of the Interstadial occurred at 13 220 ± 180
14
C yrs BP, whereas the phase of maximum birch woodland development is dated to 11 215 ± 65
14
C yrs BP. A return to arctic conditions during the Loch Lomond Stadial led to the re-establishment of a tundra landscape in which steppe and halophytic taxa associated with bare moving soils were the dominant components of the vegetation. Only a partial Holocene record is preserved at the site (post
c.
8200
14
C yrs BP) and indicates mixed
Quercus
woodland with
Alnus, Betula, Ulmus
and
Corylus avellana.
A distinctive feature of the stratigraphical record at Hallsenna Moor is the marked break in sedimentation between the later Loch Lomond Stadial and the middle Holocene, a period spanning more than 2000 years. This appears to reflect a phase of drier climatic conditions, which corresponds with evidence from elsewhere in Britain and NW Europe.
Correlation between the basal part of the Lower Cretaceous Speeton Clay Formation, Yorkshire, and the Purbeck Limestone Group, Dorset: a bentonite tie line
Authors: Jeans C. V. , Wray D. S. , Mitchell J. G. , Ditchfield P. 
Published: December 2009

SUMMARY

Four beds in the middle and upper parts of the Upper Jurassic–Lower Cretaceous Purbeck Limestone Group at Durlston Bay, Dorset, contain acid insoluble residues that suggest a penecontemporaneous volcanogenic origin, probably as sub-aerial ashfalls. Their particle size distribution patterns, mineralogy, geochemistry and K–Ar signatures indicate post-depositional alteration of fine-grained volcanic glass by pore waters. Major and trace element chemistry indicates that: (1) two beds in the Cherty Freshwater Beds (Lulworth Formation) were derived from ashes of trachyandesite-andesite-rhyodacite/dacite composition that were argillized in saline pore waters enriched in Mg
2+
; (2) a bed in the Unio Beds (Durlston Formation) developed from an ash of trachytic composition; and (3) a bed in the Viviparus Shales and Clays (Durlston Formation) originated from an ash of trachyandesite-andesite-rhyodacite/dacite composition within the suboxic zone of brackish pore waters. Comparison of the four Purbeck volcanogenic beds with bentonite beds in the lower part of the Speeton Clay on the Yorkshire coast and offshore in the North Sea suggests that those from the Unio Beds and Viviparus Shales and Clays are equivalent respectively to Beds D7D and D6J at Speeton.
The occurrence of halite in the Permian A Bed Evaporite, Kirkby Thore, Cumbria
Authors: Worley N. E. 
Published: December 2009

SUMMARY
Borehole investigations carried out in the 1980s east of Kirkby Thore, Cumbria, to locate additional gypsum resources, discovered a 7 m thick halite facies within the upper part of the A Bed. This is the first record of Permian halite in onshore Cumbria. The A Bed comprises a mudstone-dominated sabkha sulphate deposit formed within a continental playa lake setting. The halite is considered to have been deposited sub-aerially within a saltpan centrally located in the A Bed playa.
The cardioceratid ammonite fauna of the Upware Limestone and Dimmock’s Cote Marl (Upper Jurassic) in Cambridgeshire, England
Authors: Wright J. K. , Page K. N. 
Published: December 2009

SUMMARY

The West Walton Formation (Dimmock’s Cote Marl and Upware Limestone members) of Upware, Cambridgeshire, has yielded an abundant cardioceratid fauna. Three assemblages of
Cardioceras,
comprising eight nominal species, are described and figured. Faunas such as these from Maltonense–Tenuiserratum Subzone boundary beds are rare in the UK, and the Upware ammonites add significantly to our understanding of the manner in which
Miticardioceras,
a subgenus of
Cardioceras
important for correlation of Middle Oxfordian strata across northern Europe, appears in the UK.