bluuebunny/crossref_metadata_2025 huggingface dataset:
A REVISED STRATIGRAPHY FOR THE WESTERN SCOTTISH LOWER LIAS
Authors: OATES MICHAEL JOHN
Published: December 2009

Formations within the Lower Lias of western Scotland are stratigraphically re-defined as a result of many new ammonite discoveries.

Three formations are recognized: the Blue Lias, the Broadford Beds and the Pabay Beds. The Broadford Beds and the Blue Lias are approximately contemporary, the former (a nearshore limestone and coarse clastic facies) being restricted to the northern part of the area and the latter forming a northward extension of this formation in England and Wales, occupying the southern Inner Hebrides. The base of the succeeding Pabay Beds is recognized by its disconformable or unconformable relationship over the Blue Lias and the Broadford Beds, and it is dated at or about the
turneri-obtusum
Zone.

The Pabay Beds continue up to the base of the massive Scalpay Sandstone, a horizon within the
ibex
Zone in the northern and the
margaritatus
Zone in the southern Inner Hebrides.

New significant ammonite finds are described briefly.
BENTONITES IN THE LOWER D BEDS (RYAZANIAN) OF THE SPEETON CLAY OF YORKSHIRE
Authors: O’B. KNOX R. W. , FLETCHER B. N.
Published: December 2009

Four volcanogenic mudstone beds totalling 50cm thickness occur in the lower D beds (Ryazanian) of the Speeton Clay in Filey Bay, Yorkshire. These structureless mudstones are composed essentially of smectite or kaolinite, with residual igneous grains suggesting that the clays have originated by alteration of a primary ash fall. Volcanoes of comparable age arc known at Zuidwal in the Netherlands and at the Wolf Rock off Cornwall but it is possible that the Speeton Clay ash was derived from an as yet undiscovered volcanic source.
CALCAREOUS NANNOFOSSILS FROM THE UPPER CALLOVIAN AND LOWER OXFORDIAN (JURASSIC) OF STAFFIN BAY, ISLE OF SKYE, SCOTLAND.
Authors: HAMILTON GILLIAN
Published: December 2009

Fifteen samples from a section in the Callovian-Oxfordian (Jurassic) part of the Staffin Shales, Isle of Skye, Scotland, were examined for their calcareous nannofossil assemblages. The results are compared with the ammonite zonal system, the ranges of other calcareous microfossils from the Staffin Shales and with analogous calcareous nannofossil assemblages from other areas.
PETROGRAPHY, STRATIGRAPHY AND WEATHERING OF LATE PLEISTOCENE TILLS IN EAST YORKSHIRE, LINCOLNSHIRE AND NORTH NORFOLK
Authors: MADGETT P. A. , CATT J. A.
Published: December 2009

A study of the vertical and lateral variations in particle size distribution, mineralogy and other petrographic features of tills in East Yorkshire, Lincolnshire and north Norfolk shows that the Devensian glacial succession in eastern England contains only two tills, for which the new names Skipsea and Withernsea Tills are proposed. The “Hessle Till”, recognised as a third member by most previous workers, is shown to be the postglacial (Flandrian) weathering profile on whichever of these two occurs at the surface. South of Flamborough Head, the upper (Withernsea) till occurs on land only in an arcuate area adjoining the coast of south-east Holderness. The Skipsea Till occupies the whole of Holderness, and extends westwards on to the lower dip-slope of the Wolds and southwards to the northern coastal strip of Norfolk, where in its weathered form it has previously been known as the Hunstanton Till. These conclusions agree with those reached by Bisat forty years ago, but hitherto unpublished.

The weathering of the tills involves decalcification, the softening and disaggregation of sandstone, shale, igneous and metamorphic erratics, clay alteration and translocation, and the alteration of micas and some heavy minerals in the sand and silt fractions. Reddish brown colours, previously regarded as characteristic of the “Hessle Till”, result from oxidation of pyrite and siderite to depths of approximately 5 m.
NEW BOREHOLES INTO PERMIAN BEDS OFF NORTHUMBERLAND AND DURHAM
Authors: MAGRAW D.
Published: December 2009

New evidence on the sequence of Permian beds off Northumberland and Durham from boreholes drilled between 1974 and 1976 is reported, and it is considered along with data obtained from earlier offshore bores. The bores confirm a rapid thinning and disappearance of the Hartlepool Anhydrite westwards towards the present coastline, a thinning northwards from an area of maximum accumulation lying towards the southeast, and lateral passage into bedded dolomites. This thinning is regarded as depositional rather than the result of solution at a much later date, although penecontemporaneous deposition and re-solution might account for some intra-formational collapse structures present onshore. No clear evidence has been found to support the former extension shorewards of significant thicknesses of bedded anhydrite corresponding to the so-called Hartlepool Anhydrite or Seaham residues, although these could have originated from resolution of deposits formed in ‘isolated’ evaporite pans.

In the light of the new data and subsequent re-examination of the cores from the Seaham Bore, some re-interpretation of the stratigraphy is proposed in which the Hartlepool Anhydrite is regarded as equivalent in age at least to the upper part of the reef, and possibly even to the whole, while the Seaham Beds revert to being part of the classic Concretionary Limestone. No correlation with either Yorkshire or the Zechstein basinal deposits is proposed in view of the uncertain value of
Calcinema permiana
(King), and further information is required.
THE DISTRIBUTION OF CALCAREOUS NANNOFOSSILS IN THE SPEETON CLAY (LOWER CRETACEOUS) OF YORKSHIRE
Authors: TAYLOR ROSANNA J.
Published: December 2009

The detailed stratigraphic ranges of 71 species of calcareous nannoplankton have been determined from the Speeton Clay at the type locality in Yorkshire. One new species,
Parhabdolithus reightonensis,
is described. Comparison with other Lower Cretaceous nannofloras provides evidence for provincialism during this period.
EUSTASY AND TECTONICS: SEDIMENTARY RHYTHMS AND STRATIGRAPHICAL UNITS IN BRITISH DINANTIAN CORRELATION
Authors: GEORGE T. NEVILLE
Published: December 2009

The six ‘Major Cycles’ of sedimentation formally recognised by Ramsbottom in the British Dinantian succession are based on alternations of rock types and facies, ascribed to ‘regression’ and ‘transgression’ of the sea. Conceptually interpreted on a hypothesis of eustasy, they are different in kind from the six regional stages of the recent Special Report of the Geological Society, which were empirically and arbitrarily founded on the basis of a biostratigraphical exercise and in another sense reflect contemporary episodes of earth-movement; and, in practice as in principle, cycle and stage diverge in their application to sediments of the several depositional provinces.

Where there are radical facies changes, the ‘Major Cycles’ may be uncertainly identified or completely misidentified, being without definitive internal criteria, and they have no place in most of the Scottish deposits or in the Culm. The six regional stages also have their shortcomings, of boundary stratotypes and of criteria in extended correlation.

A hypothesis of eustasy as a major control on sedimentation diminishes the place of contemporary tectonism in the palaeogeographical profile, whereas pulsed diastrophism during British Dinantian times was of a magnitude to subsume and obliterate most or all signs of oceanic changes in sea level and engendered stratigraphical variation and nonsequence in ways independent of a ‘universal’ or ‘world-wide’ eustasy. In the result, the sedimentary rhythms everywhere to be seen, including the ‘Major Cycles’, lack an intrinsic ‘universal’ parallelism between one tectonic province and another; and the systematic use of eustatic criteria in correlation, even if they could be locally recognised, is impracticable in such a structurally complex area as Britain. Still less are such criteria available for more extended application in terrain beyond Britain.
MINOR SEDIMENTARY CYCLICITY IN LATE ASBIAN (UPPER D1) LIMESTONES IN THE LLANGOLLEN DISTRICT OF NORTH WALES
Authors: SOMERVILLE I. D.
Published: December 2009

A detailed lithostratigraphical study of the upper Dinantian (Asbian–Brigantian) limestones in the Llangollen district of North Wales has been made. The identification of minor cyclicity of sedimentation has been used to establish a new lithostratigraphical framework to supersede the former lithological divisions of Morton (1870; 1878). The following new formations are recognised: Ty-nant Limestone (early Asbian), Eglwyseg Limestone (late Asbian) and the overlying Trefor Limestone (Brigantian). In the Eglwyseg Limestone the sequence is divided into 9 to 10 minor cycles by prominent master bedding planes. Each minor cycle suggests alternation of transgressive and regressive periods which led eventually to emergence. Repeated subaerial exposure of limestone is recognised by features including palaeokarstic surfaces, calcareous laminated crusts and K-bentonite clays (palaeosols). The palaeokarstic surfaces were formed by contemporaneous chemical dissolution and the laminated crusts developed by
in situ
modification of the limestone possibly beneath a soil.
STRATIGRAPHY AND PALYNOLOGY OF EARLY DINANTIAN (CARBONIFEROUS) STRATA IN SHALLOW BOREHOLES NEAR RAVENSTONEDALE, CUMBRIA
Authors: HOLLIDAY D. W. , NEVES R. , OWENS B.
Published: December 2009

Six shallow boreholes in the Ravenstonedale area, Cumbria, have proved strata near the base of the Dinantian succession and these are related to nearby outcrops. The marine Pinskey Gill beds are 45 to 50 m thick and the overlying fluviatile Shap Conglomerate is about 40 m thick. About 42 m of marine Stone Gill Limestones occur between the Conglomerate and the lowest limestones exposed in the Stone Gill section. The boundaries between the three formations are gradational and there appears to have been no major break in deposition. Miospore assemblages belonging to the CM zone occur in all three formations, but the higher part of the Stone Gill Limestones proved in the boreholes, may be of Pu zone age. The Pinskey Gill beds were deposited during a Courceyan marine transgression and most of the Shap Conglomerate was laid down in the succeeding regressive period. Renewed marine transgression, probably at the base of the Chadian, is indicated by the higher part of the Shap Conglomerate and the basal Stone Gill Limestones.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
THE AMMONITE ZONATION OF UPPER OXFORDIAN MUDSTONES IN THE VALE OF PICKERING, YORKSHIRE
Authors: COX B. M. , RICHARDSON G.
Published: December 2009

The sequence of mudstones (c. 48 m thick) proved above the Corallian succession (Oxfordian) and below Kimmeridgian mudstones in boreholes at the western end of the Vale of Pickering has yielded an ammonite fauna of
Amoeboceras
and perisphinctids spanning the three youngest zones (Serratum, Regulare, Rosenkrantzi) of the Oxfordian. The macrofauna and lithology of these mudstones is outlined and specimens of
Amoeboceras
are figured.
THE INSTITUTE OF GEOLOGICAL SCIENCES BOREHOLE AT BECKERMONDS SCAR, NORTH YORKSHIRE
Authors: WILSON A. A. , CORNWELL J. D.
Published: December 2009

The Beckermonds Scar Borehole passed through 260 m of Lower Carboniferous strata of Asbian to Arundian age. These are mostly limestones but also include an attenuated representative of the Ashfell Sandstone. Underlying Ordovician strata were penetrated to 260 m rod length and consist of steeply dipping magnetite-rich siltstones, mudstones and greywacke sandstones. These contain acritarchs of probable Arenig age from a single horizon. Mineral flats consisting of barite, fluorite, calcite and chalcopyrite occur within late Asbian limestones. The homogenisation temperature of the fluorite was 190°C, an unusually high value for the Askrigg Block.

The magnetic susceptibility of the Ordovician sediments is equivalent to a magnetite content of about 1% and is capable of producing magnetic anomalies of several hundred nanoTesla amplitude. Remanent magnetisation is not likely to contribute significantly to the magnetic anomalies as its intensity is only about 20% of the induced magnetisation.

The sediment samples have a plane of maximum susceptibility parallel with the bedding planes, lending support to the idea that the magnetite is an original constituent.

The magnetite-bearing sediments are likely to extend near to or even reach the basement surface along the northern, western and southern sides of the concealed Wensleydale Granite.

A similar origin cannot be ascribed with confidence to adjacent anomalies which appear to indicate more deep seated magnetic bodies, but the results of the Beckermonds Scar Borehole cast some doubt on the conventional geological interpretation of aeromagnetic anomalies in the UK in terms of igneous or metamorphic bodies.
VITRINITE REFLECTANCE DETERMINATIONS FROM THE BECKERMONDS SCAR AND RAYDALE BOREHOLES, YORKSHIRE
Authors: CREANEY STEPHEN
Published: December 2009

Vitrinite reflectance values have been measured on material from thin coals and clastic sediments within the Great Scar Limestone in the Raydale and Beckermonds Scar Boreholes. Reflectance values increase rapidly down-hole (0.50%/100 m approx.) in both holes, with values ranging approximately from 1.30% to 2.25% (medium volatile bituminous to semianthracite). This rapid rate of increase is probably related to post-emplacement reactivation of the Wensleydale granite stock, which may have acted as a ‘chimney’ for a considerable amount of mantle-derived heat.
PERIGLACIAL INVOLUTIONS AND THE EVIDENCE FOR COVERSANDS IN THE ENGLISH MIDLANDS
Authors: DOUGLAS T. D.
Published: December 2009

Involutions from various sites are characterised by pockets and balls of medium sand contained within varying clay substrates – tills and lacustrine clays. Their spacing varies from 1–2 m and the involutions may extend downwards to a depth of 2.5 m. Mechanical analysis of sand samples and geomorphological context suggests that they are aeolian and the remnant of a previous layer of coversands. The involutions appear to be associated with permafrost and are likely to be late Devensian in age.
NEW DATA ON TETRAHEDRITE, TENNANTITE, CHALCOPYRITE AND PYROMORPHITE FROM THE CUMBRIAN AND NORTH YORKSHIRE PENNINES
Authors: SMALL A. T.
Published: December 2009

The occurrence and compositions of some copper ore-minerals are described from the Swaledale orefield and the surrounding region in the north of the Askrigg Block, northern Pennines. Tetrahedrite was found at Hanging Lund Scar in the quartz-chalcopyrite ‘feeder zone’ and tennantite at Fell End Clouds in the adjacent zone. Trace element contents in chalcopyrite are compared with those from the Groverake Mine on the Alston Block. A high cobalt/nickel ratio is found in chalcopyrite throughout, but no tin. A very pure pyromorphite was found at Gunnerside, this is thought to be the first record in the Askrigg orefield.
TRACE FOSSILS AS EVIDENCE IN THE EVOLUTION OF
CARBONICOLA
Authors: EAGAR R. M. C. , OKOLO S. A. , WALTERS G. F.
Published: December 2009

In Standedge cutting near Marsden, Yorkshire, the Butterly Marine Band, of late Kinderscoutian (Namurian R
1C
) age, is gradationally overlain by a small-scale (7 m) coarsening-upward sequence. This is characterised by parallel-laminated mudstone-dominated units at the base and by parallel-laminated fine sandstone/siltstone-dominated lithofacies at the top. The sequence, which probably reflects the infilling of a shallow interdistributary bay by sediment-laden incursions from distributaries, is truncated by erosion at the base of the Upper Kinderscout Grit.

Planolites
occurs sporadically in the 2 m of laminated silty mudstones lying immediately above the Marine Band. In the succeeding thin sandstones, siltstones and silty mudstones trace fossils are abundant and include ‘
Scolicia
’,
Cochlichnus
and hitherto undescribed forms.
Pelecypodichnus
and
Pelecypodichnus
escape shafts are extremely numerous in these beds and both are commonly connected to trails which are parallel to bedding planes. The association of trails with burrows indicates that bivalve movement was initially across the substratum, then steeply downward and finally more or less vertically upward. The structures fit the recently described marginally marine bivalves provisionally designated of.
Sanguinolites
Hind
non
M’Coy from the top of the Upper Kinderscout Grit in Sabden Brook, near Clitheroe. On the basis of comparative internal and external shell morphology this form appears to be ancestral to
Carbonicola
(Eagar 1977). Burrows and escape shafts at Standedge fit well into the sequence of burrow morphologies in which progressively longer escape shafts develop from the middle of the Shale Grit to the middle of the Marsdenian. Thence they merge upward into forms ascribed to
Carbonicola,
which are associated with trace fossils suggestive of fresher water. Escape shafts of
Carbonicola,
as far as they have been investigated, tend to show more pronounced current orientation of their long axes than shafts attributed to cf.
Sanguinolites.
LOWER CARBONIFEROUS
RENALCIS
FROM CUMBRIA
Authors: ADAMS A. E.
Published: December 2009

The microfossil
Renalcis
is described from the Carboniferous Limestone of Britain for the first time. Specimens occur unattached in fine-grained sediments between the framework organisms of small reefs of Arundian age in the Furness area of Cumbria. Although fairly numerous,
Renalcis
did not play an essential role in the construction of the reefs.
THE DISCOVERY OF THE DINANTIAN PRODUCTACEAN
SEPTARINIA LEUCHTENBERGENSIS
(DE KONINCK) IN THE BRITISH ISLES
Authors: MUNDY D. J. C. , BRUNTON C. H. C.
Published: December 2009

Septarinia leuchtenbergensis
(de Koninck), an unusual and rare productacean, has been recognised for the first time in the British Isles. A single specimen has been found in recent collections made from Asbian marginal reef facies at Cracoe, North Yorkshire and further specimens, from Castleton, North Derbyshire and Little Island, Cork were located in museum repositories. Search of the available de Koninck material has led to the discovery of the originally-figured specimen, in the British Museum (Natural History), which is here selected as lectotype. The species is redescribed and the genus is placed in the subfamily Septarininae nov.
THE RELATIONSHIP OF THE ELLER BECK FORMATION AND THE SUPPOSED BLOWGILL MEMBER (MIDDLE JURASSIC) OF THE YORKSHIRE BASIN
Authors: POWELL J. H. , RATHBONE P. A.
Published: December 2009

Recent mapping and the study of new exposures in the Hambleton Hills demonstrate that the Blowgill Member of the Middle Jurassic Cloughton Formation is equivalent to the mudstone and succeeding sandstone units of the Eller Beck Formation, and was deposited during the same marine transgression. The term ‘Blowgill Member’ is, therefore, rejected. The Ingleby Ironstone and Gormire Limestone are established as members of the Eller Beck Formation.

The revised correlation necessitates a reappraisal of the palaeogeography and sedimentation of the Eller Beck Formation.
GRAPTOLITE BIOSTRATIGRAPHY OF EARLY LAND PLANTS FROM VICTORIA, AUSTRALIA
Authors: GARRATT M. J. , RICKARDS R. B.
Published: December 2009

After a complete re-examination and reappraisal of all the plants and graptolites at the two critical localities of Limestone Road and Ghin Ghin, it is concluded that the overwhelming evidence indicates that the Lower Plant Assemblage of the Yea District, Victoria, Australia is Silurian (Ludlow) in age and that the earliest
Baragwanathia longifolia
Lang & Cookson occurs some 10Ma earlier than the unquestionably Devonian occurrences of the same species in the Upper Plant Assemblage in the same region.
RED BASAL PERMIAN SANDS: A NEW DISCOVERY IN NATIONAL COAL BOARD BOREHOLES OFF SUNDERLAND, NORTH-EAST ENGLAND
Authors: SMITH D. B.
Published: December 2009

Basal Permian (Yellow) Sands in two NCB boreholes drilled east of Sunderland in 1982 are partly red, and thus differ from all other major provings of this formation in north-east England; they are also generally cemented by poikilitopic gypsum but in all other respects are lithologically normal. It is suggested that the red colour is an early diagenetic effect that formerly was more extensive and has survived there because of preservation by later cements.
THE MINERALOGY OF BRICKMAKING AT BROOMFLEET, NORTH HUMBERSIDE.
Authors: DUNHAM A.C. , MWAKARUKWA G.M.
Published: December 2009

The mineralogy and chemistry of three clay raw materials and three types of brick product have been examined by transmitted light and scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis. The clays contain varying proportions of illite, kaolinite, vermiculite, quartz, calcite, rutile and hematite. The bricks consists of mullite, cristobalite, quartz, feldspars, spinel, rutile, illite and glass. The calcium-rich brick also contains wollastonite and gehlenite. Electron microprobe analyses of relict feldspars, new pyroxenes and matrix have been made, leading to an estimation of the glass composition. Examination of heated test pieces of each clay has shown the sequences of mineralogical change. This preliminary appraisal provides a basis for further work to elucidate the mineralogical reactions taking place in brickmaking.
Whin Sill in exploratory boreholes from Newbrough, Northumberland
Authors: BATESON J. H. , JOHNSON C. C.
Published: December 2009

Four exploratory boreholes at Newbrough near Hexham, Northumberland, intersected the Whin Sill and in three of the holes sections of extensively altered quartz-dolerite were observed with a small amount of Ba-Pb-Zn mineralisation. Chemical analyses (both trace and major oxide) of altered and unaltered quartz-dolerite are compared with results reported in previous investigations. Trends in the geochemistry between the extreme end members of fresh Whin Sill and ‘White Whin’ can be identified. Abnormal local features are attributed to interference with the normal sill development at this location.
A palynological investigation of Toarcian to early Aalenian strata from the Blea Wyke area, Ravenscar, North Yorkshire
Authors: RIDING J. B.
Published: December 2009

A palynological investigation of the uppermost part of the Whitby Mudstone, the Blea Wyke Sandstone and the Dogger formations (Toarcian,
Hildoceras bifrons
Zone to Aalenian,
Leioceras opalinum
Zone) exposed on the foreshore and in the cliffs of the area around Blea Wyke Point, Ravenscar, yielded thirteen dinoflagellate cyst taxa. They all appear to be biostratigraphically significant, and in this respect are superior to other associated palynomorph groups (e.g. miospores), despite being numerically subordinate. The genus
Phallocysta
Dörhöfer & Davies 1980 and the species
P. eumekes
Dörhöfer & Davies 1980 are emended. The dinoflagellate cyst floras from Blea Wyke are compared with other published accounts of similar ages. Despite the existence of several cosmopolitan taxa in the Northern hemisphere, two cyst-provinces, the North American province and the north-west European province are recognised.
Discovery of Tremadoc rocks in the Lake District
Authors: Molyneux S. G. , Rushton A. W. A.
Published: December 2009

Acritarchs and trilobites of late Tremadoc age have been found in beds hitherto mapped as the Skiddaw Group, close to the outcrop of the Latterbarrow Sandstone in the River Calder, western Lake District. These Tremadoc beds are older than any graptolitic Skiddaw Slates. The new discovery means that a simple conformable relationship between the Latterbarrow Sandstone and the underlying Skiddaw Group is unlikely.
New information on the Dinantian stratigraphy and structure of Tynedale, Northumberland
Authors: FROST D. V.
Published: December 2009

The Northumberland Trough is dominated by numerous east-north-eastward trending Caledonoid faults. A recent geophysical survey has indicated the presence of another dislocation of similar trend, but this is related to the Whin Sill and its associated dykes and probably acted as an important feeder in the Roman Wall area.

New boreholes in the Settlingstones-Newbrough area show the Whin Sill to be intruded at an horizon close below the Colwell (=Single Post) Limestone, and confirm the variability of the Brigantian sequence in this part of the Northumberland Trough. These new data have thrown doubt on the correlation suggested by Frost and Holliday (1980, p. 34) for the Settlingstones Mine area.

The development of minor rhythms towards the top of each cyclothem in these Brigantian sediments is compared with those pre-Asbian sediments proved towards the base of the Stonehaugh Borehole. They are considered to have formed under similar conditions of deposition.