bluuebunny/crossref_metadata_2025_split huggingface dataset:
PALAEOMAGNETIC STUDIES OF SOME DINANTIAN LIMESTONES FROM THE CRAVEN BASIN AND A CONTRIBUTION TO ASBIAN MAGNETOSTRATIGRAPHY
Authors: TURNER P. , METCALFE I , TARLING D. H. 
Published: December 2009

SUMMARY
A palaeomagnetic survey of Dinantian limestones in the Craven basin shows that limestones of Arundian/Holkerian and Asbian age (Skibeden Shales-with-limestones and Draughton Limestone) in the Skipton Anticline area have anomalous directions of magnetization. Although some of the Asbian limestones in this area are proximal turbidites, none of the sampled horizons are conglomeratic or intraclastic limestones and the anomalous directions cannot be accounted for by the derivation of previously lithified (and magnetized) clasts. The anomalous direction also occurs in non-turbiditic Arundian/Holkerian limestones which supports this contention. The directional characteristics of the NRM indicate that the limestones in this area have suffered partial to complete remagnetization. The remagnetization is characterised by the presence of a normal component of magnetization superimposed on an original reversed component. However, some specimens have Lower Carboniferous directions of magnetization which suggests that the remagnetization effect is inhomogeneously distributed throughout the limestones. The remagnetization process stopped prior to the Permo-Carboniferous folding of the area and was probably associated with diagenetic processes such as dolomitization and silicification which took place in the Skipton area prior to the deposition of the Bowland Shales in Brigantian times.
The Pendleside Limestone in the Thornton Anticline area is the lateral correlative of the Draughton Limestone but shows completely different palaeomagnetic results. The results agree closely with known Lower Carboniferous directions and it is concluded that these limestones retain their original magnetization. A detailed study of a 40 m section of alternating limestones with shales shows that all the limestone beds are reversely magnetized, a feature taken to indicate that the late Asbian geomagnetic field was reversed for prolonged periods.
ACRITARCH DATING OF ARENIG VOLCANISM IN THE LAKE DISTRICT
Authors: TURNER R. E. , WADGE A. J. 
Published: December 2009

SUMMARY

A volcanic sequence cropping out in the south-western Lake District has been dated as mid-Arenig by acritarchs of probable upper
D. extensus
Zone age. This is the oldest episode of volcanic activity identified in the Lake District and shows that the local Ordovician island arc system was active during Arenig times.
SEDIMENTARY MODELS FOR THE NON-MARINE SCALBY FORMATION (MIDDLE JURASSIC) AND EVIDENCE FOR LATE BAJOCIAN/BATHONIAN UPLIFT OF THE YORKSHIRE BASIN
Authors: LEEDER M. R. , NAMI M. 
Published: December 2009

SUMMARY
Alternative alluvial and deltaic depositional models for the topmost Scarborough and Scalby Formation are outlined. Biostratigraphical and sedimentological arguments are used to deduce that a lengthy time gap of around 9.0 m.y. existed between deposition of the shallow marine Scarborough Formation (middle Bajocian) and the fluvial Moor Grit Member of the Scalby Formation (? upper Bathonian). This rules out acceptance of the deltaic model for the successions and is taken to indicate that much of the Yorkshire Basin was uplifted or became positive during late Bajocian/Bathonian times. Uplift may have been linked to rift-related processes acting in the North Sea basin, especially on the Pennine/Mid-North Sea High which acted as the hinterland and sediment source area for the Scalby alluvium.
SUBSIDENCE AND UPLIFT IN EAST YORKSHIRE AND LINCOLNSHIRE: A DOUBLE INVERSION
Authors: KENT P. E. 
Published: December 2009

Summary

The land ward part of the Mesozoic southern North Sea Basin in eastern England includes two major structural units, the Cleveland Basin of north-east Yorkshire
*
and the East Midlands Shelf. The Market Weighton Block north of the Humber is the northernmost sector of the Shelf. Each of these units continues offshore, the Cleveland Basin linking with the Sole Pit Trough, a Jurassic and Lower Cretaceous basin which was inverted in the late Cretaceous, and the East Midlands Shelf continuing as far east as the Dowsing Fault belt. The Market Weighton Block terminates eastwards beyond the coast some 80 km east of the Jurassic outcrop.

Differential subsidence of the Cleveland Basin relative to the East Midlands Shelf took place in the Lower and Middle Jurassic. During this time the Market Weighton Block was relatively more buoyant (frequently marked by shoal areas and deposition of thinner sediments) than the more southerly parts of the East Midlands Shelf, and true uplift with erosion of accumulated sediments took place at intervals, specifically in the late Pliensbachian, Aalenian/Lower Bajocian and Callovian. During the earlier Upper Jurassic the regional relationship changed and the Cleveland area functioned as a stable shelf, with attenuated and shallow water deposits, while the East Midlands Shelf (with the Market Weighton Block) continued to subside normally, with Oxford and Ampthill Clays deposited in deeper water than the equivalents in Cleveland.
Major uplift and erosion preceded Albian (Red Chalk) deposition over the northern part of the East Midlands Shelf, with a culmination in the Market Weighton sector. In this and the earlier phases, southward tilting extended some 120 km southwards across the Market Weighton Block into Lincolnshire.
Subsequently the East Midlands Shelf retained in part its Upper Cretaceous cover, while the Cleveland Basin was uplifted, gently folded and extensively eroded, a phase of inversion relative to the Shelf, similar on a smaller scale to that of the Sole Pit Trough.
On land, deep boreholes show a comparable earlier history. The Cleveland area coincides with a Lower Carboniferous basin which was extensively eroded before the Permian, whereas the East Midlands Shelf shows block-type Lower Carboniferous with thin Upper Carboniferous but still retains its Coal Measures cover, an inversion analogous to that of the Mesozoic.
AN ASSOCIATION OF MINOR FINING-UPWARD CYCLES AND ALIGNED GUTTER MARKS IN THE MIDDLE LIAS (LOWER JURASSIC) OF THE YORKSHIRE COAST
Authors: GREENSMITH J. T. , RAWSON P. F. , SHALABY S. E. 
Published: December 2009

Summary
Two thin sandstone and siltstone horizons in the Middle Lias (Lower Jurassic) of the Yorkshire coast, informally called the lower and upper striped beds, are characterised by small-scale fining-upward layers associated with filled scour channels (gutter marks). The gutters are up to 5 m long, 50–500 mm wide and up to 200 mm deep, and have variable cross-sections. Some have a simple, fining-upward laminated structure, others a complex, multiple-stacked structure. They show a remarkably uniform, approximately east-west, orientation at localities 20 km apart. The trend of rare ripple marks is approximately at right angles to the gutter marks.
The striped beds are interpreted as deposits of submarine sheet flows, with contemporary scour and fill, in a prodelta - open shelf slope setting.
PETROGRAPHIC TEXTURE AND VITRINITE REFLECTANCE VARIATION ON THE ALSTON BLOCK, NORTH-EAST ENGLAND
Authors: CREANEY S. 
Published: December 2009

Summary
A detailed study of the petrography and vitrinite reflectance of coals has been used to elucidate patterns of heat flow on the Alston Block. Four petrographic/rank vitrinite groups have been distinguished: I. Non-thermally metamorphosed with a vitrinite reflectance below 1.80% (approximately). II. Thermally metamorphosed and showing a granular mosaic. III. Thermally metamorphosed with no granular mosaic. IV. Non-thermally metamorphosed with reflectances in excess of 1.80%. Transitional vitrinites are also described. Certain features of the Group II vitrinites suggest a coking coal rank prior to Whin Sill intrusion and the Group II – Group III transition has been interpreted as a pre-Whin 1.60% isoreflectance contour. This isoreflectance surface has been traced laterally across the block and is shown to dome across the cupolas of the Weardale Granite, indicating that the pre-Whin Sill basement heat flow was channelled through the basement granite stock. Temperatures, calculated by the method of Karweil (1973), for this coalification interval were probably in excess of 185°C at the Great Limestone horizon around the cupola margins. This indicates that some form of rejuvenation of the Weardale Granite occurred at depth, probably in response to the Hercynian orogeny.
The intrusion of the Whin Sill (295 ± 6 Ma) produced the Group II and Group III vitrinites and caused an exponential increase in vitrinite reflectance towards its contacts. Graphitisation has occurred immediately adjacent to the Whin Sill in certain localities where pre-Whin Sill rank and intrusion temperatures were favourable. The abnormally wide zone of natural coke above the Whin Sill is attributed to the high background temperatures present in the Alston Block during intrusion. A detailed lateral survey of vitrinite reflectance at the horizon between the Great and Little Limestones has revealed both the dependence of this parameter upon the Whin Sill thickness and stratigraphic horizon in the central part of the block, and a spatial relationship between vitrinite reflectance and the Weardale Granite subcrop around the block margins. The post-Whin Sill mineralisation has had no discernable effect on vitrinite reflectance.
STOMATOPORA VOIGTIANA
(KING 1950): A CYCLOSTOME BRYOZOAN FROM THE PERMIAN OF COUNTY DURHAM
Authors: TAYLOR PAUL D. 
Published: December 2009

Summary

Aulopora voigtiana
King 1950 is redescribed from the single known specimen. It is assigned to the cyclostome bryozoan genus
Stomatopora
and as such is probably the only Permian cyclostome known from anywhere in the world. The occurrence of
S. voigtiana
in the Upper Permian provides an important link between the abundant cyclostomes of the Lower Palaeozoic and those of the post-Palaeozoic.
CARBONIFEROUS STRATIGRAPHY AND MINERALISATION AT NINEBANKS, WEST ALLENDALE, NORTHUMBERLAND
Authors: JOHNSON G. A. L. , NUDDS J. R. , ROBINSON D. 
Published: December 2009

SUMMARY

During a programme of mineral exploration at the abandoned Longcleugh Mine (lead) near Ninebanks, West Allendale, Northumberland, a series of three surface and fourteen underground boreholes were put down to prove the Carboniferous stratigraphy, structure and mineralisation. For the first time in this region a continuous succession of the Lower Namurian and Upper Dinantian strata from above the Little Limestone to below the Jew Limestone has been proved. The Great Whin Sill (quartz-dolerite), intruded into the Dinantian sequence near the horizon of the Tyne Bottom Limestone, proved to be 81 m thick. This is the maximum recorded thickness of the Whin Sill. The mineralogy of the dolerite is also unusual as euhedral crystals of hornblende are reported in pegmatite bands for the first time. The structure and lead-witherite mineralisation at Longcleugh and the adjacent Kiersley well Row mines are described. A brief account is also given of
Lithostrotion decipiens
(M’Coy) subsp.nov., a new stratigraphical marker in the Brigantian (Lower Carboniferous) succession of the northern Pennines and Northumberland.
DELTAIC SEDIMENTATION IN THE ROACHES GRIT AND ASSOCIATED SEDIMENTS (NAMURIAN R
2
b) IN THE SOUTH-WEST PENNINES
Authors: JONES C. M. 
Published: December 2009

SUMMARY
The Roaches Grit and related underlying sediments form a thick deltaic sequence which accumulated in north Staffordshire during the late Marsdenian. The sequence represents the fourth and last major stage of fill in the Namurian north of England basin and the first widespread phase of shallow-water delta top conditions in north Staffordshire. The delta prograded from the south-east, but the sediments were of northerly derivation, having been diverted into the basin to the east of the present area of outcrop.
The sequence is subdivided into three facies associations representing deep-water turbidite fan, delta slope and delta top environments. The deep-water association is restricted in distribution and outlines the limits of the deep-water basin existing prior to the incoming of the delta. Faulting on the upper delta slope allowed down-slope escape of sediment, some eventually reaching the basin floor in turbidity currents, the rest being trapped on the downthrow side of growth faults. River-generated density currents also flowed down the slope depositing rippled sands with bivalve resting traces.
The delta top is dominated by the fills of large, mutually-erosive fluvial channels forming sheet sandstones of wide lateral extent. At the Roaches, systematic offsetting of younger channels towards the north suggests tectonic control of sedimentation. Within the channels a variety of bedforms existed and structures within their deposits suggest a regime with a markedly fluctuating discharge.
THE OCCURRENCE OF BITUMEN IN THE GREAT LIMESTONE AROUND MATFEN, NORTHUMBERLAND – ITS CHARACTERISATION AND POSSIBLE GENESIS
Authors: CREANEY S. , JONES J. M. , HOLLIDAY D. W. , ROBSON P. 
Published: December 2009

SUMMARY
The physical and chemical properties of a bitumen located in veins cutting the Great Limestone at Moot Law Quarry (NZ 010768), Northumberland have been assessed and it has been classified as an albertite or epi-impsonite. Several similar occurrences are also described from adjacent Great Limestone quarries including a multiphase bitumen from Kirkheaton (NZ 018773) and a contact metamorphosed bitumen from a quarry near Capheaton (NZ 016787). This Capheaton occurrence exhibits a characteristic mesophase structure implying contact metamorphism by an adjacent Whin dyke. The bitumen is thus pre-Whin dyke in age which allows two possibilities for its genesis: 1. If the Whin dyke post dates the Whin Sill then the bitumen may be a pyrolysate from closer to the sill contact, which has condensed in cooler overlying strata and been metamorphosed by the later dyke. 2. If the Whin dyke and sill were intruded together then the most likely origin of the bitumen is probably related to an earlier period of heating of the Carboniferous sediments overlying the Alston Block to the south.
ISOTOPIC AGE DETERMINATIONS ON A BASALT INTRUSION AND ULTRABASIC XENOLITHS, SOUTH BUTE, SCOTLAND
Authors: MITCHELL J. G. , INESON P. R. , BUIST D. S. 
Published: December 2009

SUMMARY
K-Ar isotopic age determinations are reported from a basaltic sheet and some xenoliths from South Bute, Scotland. The age of the intrusion, 309 ± 5 Ma (pre-middle Carboniferous), is in agreement with the date inferred from its petrology. The results from the ultrabasic xenoliths do not permit a simple interpretation.
GLACIALLY TRANSPORTED LIASSIC RAFTS AT UPGANG, NEAR WHITBY
Authors: HEMINGWAY J. E. , RIDDLER G. P. 
Published: December 2009

SUMMARY
Two rafts of shales and ironstones of the Middle Lias Cleveland Ironstone Formation are described. Both lie at the same horizon in the Newer Drift of the Yorkshire coast and both were truncated by intraglacial aqueous erosion. A third Liassic raft occurs at a lower horizon.
GEOGRAPHICAL EVOLUTION FROM LAURASIA TO PANGAEA
Authors: JOHNSON G. A. L. 
Published: December 2009

SUMMARY
Three major continents, Angaraland, Laurasia and Gondwanaland, and a number of microcontinents straddled almost all the climatic zones of the world during the Upper Palaeozoic. The positions of these continents is broadly known from palaeomagnetic, stratigraphical, palaeoclimate, faunal and floral evidence. Using this evidence it is possible to establish the chronological sequence of continental collisions against Laurasia leading up to the assembly of the Pangaea supercontinent in the Permian. Laurasia was the dominant equatorial landmass made up of the existing continents of Europe with Greenland and North America. Continental collisions involving Nova Scotia, Spain, The Mauritanides and south Europe can be recognised during the Devonian and Carboniferous. Collisions between the major continents of Angaraland, Laurasia and Gondwanaland took place in the Permian and forms the final phase of Pangaea accretion. The Pangaea linked assembly of continents is the culmination of Palaeozoic accretion and the essential starting point of the more precisely known Mesozoic continental movements. Throughout the period of Upper Palaeozoic continental convergence the history of migration of the tetrapods, first amphibians and the later reptiles, provides a record of continental connections. The early amphibians in particular were restricted to the vicinity of continental wetlands, but they were able to migrate to new territory during successive continental collisions with Laurasia. During the Permian, at the time of the Pangaea fit, land routes were established between all the continents and the tetrapods quickly dispersed through the vast single landmass. Land connection between
THE STRATIGRAPHY OF THE MAWDDACH GROUP IN THE CAMBRIAN SUCCESSION OF NORTH WALES
Authors: ALLEN P. M. , JACKSON AUDREY A. , RUSHTON A. W. A. 
Published: December 2009

SUMMARY

The Mawddach Group is a new name for the rocks of late St. David’s to Tremadoc age in the Harlech Dome, previously called Menevian Beds,
Lingula
Flags and Tremadoc Slates. It follows conformably the Harlech Grits Group and is unconformably overlain on the eastern side of the dome by the late Tremadoc Rhobell Volcanic Group and elsewhere by sedimentary and volcanic rocks of Arenig age. The Mawddach Group comprises four formations, from bottom upwards called the Clogau, Maentwrog, Ffestiniog Flags and Cwmhesgen (new name). They are formally defined here for the first time and the stratigraphical nomenclature used in this area is revised. The group consists of about two kilometres of predominantly grey argillaceous rocks interbedded at intervals with quartzose sandstone and siltstone. Sedimentary structures show that the group represents a complete cycle of basin formation and infilling. The topmost formation, which consists of the Dolgellau and Dol-cyn-afon (new name) members contains new evidence of volcanism in the late Cambrian. The biostratigraphy of the group is considered in detail. Many of the zones of the Scandinavian succession are recognisable in the present area, but the
brachymetopa
Zone appears to be absent and some other zones remain unproved; the
Acerocare
Zone, however, is here demonstrated for the first time in Great Britain.
THE DISTRIBUTION OF THE ROT HALITE MEMBER IN NORTH YORKSHIRE, CLEVELAND AND NORTH HUMBERSIDE
Authors: RIDDLER G. P. 
Published: December 2009

SUMMARY
In this paper the geophysical borehole log response to the Rot Halite Member and its adjacent beds is identified, the lithology briefly described, and an isopach map of the unit based on available borehole data is presented.
A HYDROGEOCHEMICAL AND STREAM SEDIMENT SURVEY OF THE ASKRIGG BLOCK IN THE NORTHERN PENNINE OREFIELD
Authors: INESON P. R. , AL-BADRI A. S. 
Published: December 2009

SUMMARY

A regional hydrogeochemical reconnaissance survey of the southern part of the northern Pennine orefield (Askrigg Block) was undertaken at a sampling density of 1 per 2km
2
. For comparison a stream sediment survey using a sample density of 1 per 7km
2
was also conducted. The water samples were analysed for Na, K, Ca, Mg, Fe, Mn, Sr, Zn, Cu, Ag, Pb, Cd, Co, and Ni by atomic absorption spectrophotometry. Colourimetric methods were used to determine NO
2
, B, and Si, and Fe, NO
2
and pH were analysed by a specific ion analyser. Li was determined by flame photometry and standard wet chemical methods were employed in the determination of SO
4
, Cl, CO
2
, Fe
2+
and Fe
3+
. The stream sediments were analysed by X-ray fluorescence spectrometry. The analytical results (>10,000) were interpreted using multivariate statistical techniques.

Examples of geochemical patterns and anomalies related to geology, pollution and mineralisation are identified. Silica analyses have delineated the Namurian outcrop. Certain Pb, Zn, Cu, V, Na and Cl anomalies are attributed to pollution from agricultural fertilisation and old smelting and/or dressing sites. Zn, F, Pb, Cu, Ni, Co and Ba anomalies are coincident with known mineralisation as well as, as yet, unproven ore deposits.
CALCRETE DEVELOPMENT AT THE JUNCTION BETWEEN THE MARTIN LIMESTONE AND THE RED HILL OOLITE (LOWER CARBONIFEROUS), SOUTH CUMBRIA
Authors: ADAMS A. E. , COSSEY P. J. 
Published: December 2009

SUMMARY
The strata exposed at the junction between the Martin Limestone and Red Hill Oolite (Lower Carboniferous) from around the Leven Estuary, south Cumbria are described in detail. There is evidence that these rocks underwent a complex depositional and early diagenetic history. The sequence begins with a slight angular unconformity, previously undescribed. There follows up to 2 m of varied limestone including features diagnostic of calcretes and indicative of subaerial weathering. Evidence is presented to suggest that there was continued accumulation of sediments in the terrestrial environment while the calcretes were forming. The overlying limestone breccia, previously interpreted as marine, also contains evidence of subaerial weathering and is re-interpreted as a terrestrial deposit, perhaps as a result of mudflow. The sequence at the Martin Limestone/Red Hill Oolite boundary around the Leven Estuary is compared with sections elsewhere in south Cumbria and the conclusion is reached that local tectonic movements were responsible for the period of emergence described.
SOLUTION OF THE GYPSUM CLIFF (PERMIAN, MIDDLE MARL) BY THE RIVER URE AT RIPON PARKS, NORTH YORKSHIRE
Authors: JAMES A. N. , COOPER A. H. , HOLLIDAY D. W. 
Published: December 2009

SUMMARY
Gypsum in the cliff on the west bank of the River Ure at Ripon Parks is being dissolved by the river. The solution rate has been determined from the solution of a large fallen block in the river and is close to laboratory experimental values. In the centre of the river and around the gypsum block flow rates of 1 m/s have been measured. Laboratory based experiments suggest that such rates would produce undercutting of massive gypsum at about 1.7 m/year. However, flow rates adjacent to the cliff are substantially reduced and much slower rates of undercutting, around 0.10 to 0.18 m/year, are predicted. Observed minimum rates of undercutting are close to these values. The massive gypsum at the southern end of the cliff appears to have been undercut up to 5 m in 50 to 60 years, i.e. between 0.10 and 0.08 m/year, and the northern part of the cliff has been undercut a similar distance in around 100 years.
THOMAS SOPWITH’S LARGE GEOLOGICAL MODELS
Authors: TURNER S. , DEARMAN W. R. 
Published: December 2009

SUMMARY
The Sopwith hand-models, representations of simple geological structures in laminated woods, were first issued in 1841 and until quite recently were used for demonstration purposes in University geology departments and other establishments. Less well known are the large models particularly of coal and iron-ore mining areas that were made from about 1838 onwards to illustrate the three-dimensional structures, with the distribution of workings, in economically important mining areas.
For practical purposes, Sopwith designed a model of the Ebbw Vale and Sirhowy area of South Wales where sedimentary iron ores in the Coal Measures were extensively worked in the early part of the nineteenth century. Models were also made to illustrate the structure and distribution of coal seams in the Forest of Dean.
Four models are known to survive, and these are masterpieces of the cabinet-maker’s art, with carved topography masking successive removable trays, each revealing an individual seam and the extent of the workings in it. A model of Ebbw Vale, two models of the Forest of Dean, and an indication of what the model of Nentsberry near Alston must have been, are described and illustrated.