Next Meeting: Saturday 28^th January 2012: 2.00pm -5.00pm, Great North Museum:Hancock, Barras Bridge,  Newcastle upon Tyne NE2 4PT:
Foundations of the Northern Pennines: Rookhope - 50 years on: The Sir Kingsley Dunham Meeting: Joint meeting of the Natural History Society of Northumbria, the Yorkshire Geological Society and Friends of Killhope

Martin H P Bott, Department of Earth Sciences, University of Durham: North Pennine Mineralization

A Hercynian or later granite beneath the Alston Block was suggested by Kingsley Dunham 80 years ago in explanation of the zonal pattern of mineralization centred on Upper Weardale and Tynehead. 30 years later, gravity surveys gave convincing evidence for the Weardale granite with cupolas underlying the mineral zones. In 1960, the Rookhope borehole proved an  Early Devonian granite, stimulating major re-appraisal of the origin of the mineralization and of the influence of the granite on the stability of the Alston Block and subsidence of nearby deep Northumberland and Stainmore basins.  I review the discovery of the Weardale granite, and its thermal history in relation to origin of the associated mineralization.

Heat flow of ~95 mW/m² was measured in the Rookhope borehole which is about 65-75% above the continental average and the values in adjacent regions. This is explained by the high content of long-lived radioactive isotopes in the granite extending over its 10 km depth. Temperature-depth gradients are 32°C/km in the granite and 44°C/km in the Carboniferous due to differing thermal conductivity. Conductive heat flow appears to dominate.  Two sets of observations, however, suggest that heat flow several times higher than the present value occurred locally for a few million years above the Rookhope and Tynehead cupolas, both before and after emplacement of the Great Whin Sill. First, Creany showed that vitrinite petrography of thin Namurian coals indicates temperatures of 187°C or higher above the Rookhope and Tynehead cupolas prior to emplacement of the Great Whin Sill. Second, fluid inclusions in vein minerals such as quartz, fluorite and barite yield temperatures of crystallization ranging up to 210°C during the cooling phase of a thermal high subsequent to emplacement of the sill, with temperature in the barite zone of less than 50°C suggesting normal heat flow beyond the cupolas. The sharpness of these high thermal anomalies recording heat flow several times the present value indicates that they originated mainly from hydrothermal convection in the cupolas below rather than just thermal conduction. They may represent earlier and later stages of a single thermal event, but accurate dating of the mineralization is required to clarify. A modern example of this thermal scenario is provided by drilling for the Hot Dry Rock geothermal plant at Soultz-sous-Forêts in the Rhinegraben, where an excessively high conductive geothermal gradient occurs in the impervious cap above granite; in contrast, an excessively low gradient occurs in the granite itself where hydrothermal convection carries most of the upward flow of heat.

The source of the heat may have been high density Whin magma underplating the demonstrably lower density solid Weardale granite, consistent with the absence of Whin dykes above the granite. Phacolithic underplating might also explain the Teesdale dome.

Joe Cann, School of Earth and Environment, University of Leeds: The significance of the Rookhope Borehole and the North Pennine Orefield to models of the origins of lead ores

The origin of limestone-hosted lead-zinc ores found in many places around the world has long been disputed.  The dispute is still not settled, but the results of the Rookhope borehole had an important impact on the problem. Hydrothermal ores had traditionally been related to igneous intrusions, and especially to granites.  Such a relationship is clear in the Cornish orefield, where zones of mineralisation surround the granite intrusions. For example, tin ores are found close to the granites and lead ores farther away, suggesting an origin from granitic fluids that cool with distance as they percolate through the rocks.  In Cornwall this model still holds, and the same model seemed applicable when Sir Kingsley Dunham mapped the mineral zonation of the North Pennine orefield.  The ore fluids must have emanated from an underlying granite intrusion.

Further reinforcement came from Martin Bott’s gravity survey, showing a negative anomaly that coincided with the zonation of ores.  The Rookhope borehole found the granite at the predicted depth, but at the same time showed that the simple model did not hold, since the granite is overlain unconformably by the Carboniferous sediments that host the ores, and are 50 million years or so younger than the granite.  What alternative can there be? Detailed investigation of the ores showed that they formed from fluids that had reached temperatures of as much as 200°C, and that the fluids had been about six times as saline as seawater. Similar salinities are common in other limestone-hosted lead-zinc ore fluids, but the temperatures in the North Pennines are rather higher than is common.

Once freed from the need for fluids from a granite intrusion, alternative models were developed for the origin of limestone-hosted lead-zinc ores.  One group of models relate the ores to hot fluids expelled from the deep levels of sedimentary basins.  Such ideas arisen in other lead-zinc orefields, at first in outline, and later using computer models of fluid flow. Certainly such a model could be applied to the North Pennine orefield, deriving fluids from the deep Solway Basin to the northwest that contains evaporites at depth. An alternative group of models would source the ore fluids as surface seawater that had penetrated by thermal cracking deep into hot crystalline basement.  At those depths the fluids would have been heated and enriched in metals and then have risen to shallow levels again, convecting through the rock.  In this case questions arose about whether fluids could penetrate deep enough into the basement to be heated to 150-200°C.  The high heat production in the Weardale Granite would certainly reduce the necessary depths. The talk will explore the historical background and will assess the likely origin of the ores by comparing these two groups of models.

In 1961 the Rookhope Borehole proved the presence of the Weardale Granite, whose presence had first been postulated to account for the origins of Northern Pennine mineralisation, and subsequently to explain the results of detailed gravity and magnetic studies.  Surprisingly, however, the top of the granite was found to be overlain unconformably by Lower Carboniferous sediments and, although it had clearly been exposed during Carboniferous times, it was still hot.  It was later recognised that this heat was not residual after emplacement but resulted from the radiogenic decay of thorium and other elements.

The fiftieth anniversary of the Rookhope borehole in 2011 was marked by the drilling of the third modern geothermal well on the Weardale system by a Newcastle and Durham universities joint project.  The two universities are leading the way in the UK’s quest for geothermal energy – ahead of commercial concerns in Cornwall. Two wells have been drilled at Eastgate.  Both penetrated the Weardale Granite.  Eastgate 1 (2004) was drilled to 995m, entering the granite at about 275m and the flow rate tested at two intervals.  An open fracture encountered at 411m flowed at 37m³/hour (at 46ºC) and the interval below at 22m³/hour.  The former value is the highest ever recorded from a granite.  The thermal gradient was determined to be 38ºC/km.  The nature of the fracture system was uncertain.  The well had planned to intersect the Slitt Vein, part of the northern, bounding fault system to the Weardale (Block) Granite.  However, it was also considered possible that flow was coming from a weathering induced fracture system near the top of the granite.

Funds from DECC in 2010 allowed drilling of Eastgate 2.  A location was chosen 700m from Eastgate 1 specifically to test the two possible hypotheses regarding the fracture system.   The well terminated at 420m and although the temperature was as expected the well failed to flow; clear proof that Eastgate 1 had indeed penetrated a little mineralised section of the Slitt Vein.  Further funding from DECC, Newcastle Science City and the British Geological Survey in 2011 resulted in a third well.  The well was spudded in central Newcastle on the old Scottish & Newcastle brewery site. Like the Eastgate 1 well, Science Central 1 was planned to intersect one of the major bounding faults to the Weardale Block, this time the 90 Fathom Fault.  The well drilled to about 1850m having penetrated almost the whole of the Carboniferous section.  Evaluation is currently underway to determine both the thermal gradient and potential flow characteristic.  Evaluation of all three wells continues with the intention of determining whether the temperature and flow rates will support district heating schemes.   Such schemes could deliver low enthalpy heat with a  near zero carbon footprint.  Success in Eastgate and Science Central could pave the way for a geothermal revolution in the UK.

Brian Young, Department of Earth Sciences, University of Durham and F.W.Smith, FWS  Consultants Ltd, Spennymoor, Co.Durham: The Northern Pennine Orefield - Opportunities and Possibilities

Mineralisation in the Northern Pennine Orefield occurs in numerous veins and related replacement deposits of Mississippi Valley type, hosted in Carboniferous sediments and the Permo-Carboniferous Whin Sill. Over centuries of mining the orefield  has yielded around 4 million tonnes of lead, over 2 million tonnes of fluorspar, 1.5 million tonnes of barytes, 1 million tonnes of witherite (almost the entire world total), 0.3 million tonnes of zinc, a large,  though unrecorded, tonnage of iron ores, together with very modest amounts of copper ores and small but significant tonnages of silver, recovered as a by-product of lead smelting.  The 18^th and 19^th centuries saw the heyday of mining when, through ambitious programmes of exploration, innovative approaches to mining, mineral processing and smelting, the area achieved a prominent place at the forefront of the world’s lead industry. However, the collapse of world lead prices towards the end of the 19^th century forced the closure of all but a handful of mines. An almost contemporary rising demand for spar minerals, particularly fluorspar, and to some extent zinc ores, offered a lifeline for a few mines with reserves of these minerals. Whilst the earliest decades of the 20^th century witnessed the final demise of lead mining, by the second half of the century the area had become a major source of fluorspar, an industry that was to outlive the extraction of zinc, baryte and witherite. But, by the 1990s, a fall in the world price of fluorspar was to prove the death knell of the few surviving Northern Pennine mines and, since the closure of Groverake Mine in 1999, save for the extraction of cabinet specimens of fluorite, there has been no commercial mining in the orefield.

Although mining here may have been dormant for over a decade, thoughts of the industry’s resurrection have never been far away. Whereas changing economic, environmental and political climates will inevitably constrain any revival of mining, or even exploration, of fundamental importance is an understanding of   whether further workable deposits might exist and whether there may be realistic prospects of locating and exploiting them. Previous attempts to foresee a future for Northern Pennine mining have concentrated on the possibility of locating new deposits of the sorts long known here, or extensions of them. In the light of a modern understanding of the area’s geology and drawing also upon the legacy of observations of generations of Northern Pennine miners and mine agents, all brought into focus through the findings of the Rookhope Borehole, this review will explore the proposition that the Northern Pennine Orefield may be far from exhausted and will examine the prospects for new orebodies, including the possibilities of significant deposits in situations as yet unknown within the orefield.  Fifty years on, this important borehole remains a vital milestone in understanding ore forming processes worldwide  and may well offer important clues to where we might look afresh in the Northern Pennines for the means of reviving the very industry that helped inspire its drilling.

Summary Programme of the Yorkshire Geological Society for the remainder of 2012

Saturday 10th March, University of Leeds: Joint meeting with British Cave Research Association and Leeds Geological Association: "23rd BCRA Cave Science Symposium"

Sunday 27th May: Yorkshire Geology Month Field Meeting: "Permian carbonates in North-East England": Leaders: Mike Mawson and Noel Worley

Saturday & Sunday 23rd & 24th June, Field Meeting: Weekend programme to visit sites on the newly mapped BGS Hexham Sheet: Leaders: Dr David Millwards and BGS staff

Sunday 22nd July (date to be confirmed), Field Meeting: Ketton Quarry (Rutland) - Middle Jurassic Sequence: Leader: Dr Peter del Strother

Provisional: August/September Field Meeting: "Foundations of the North Pennines: 50 years on from the Rookhope Borehole": Leaders: Brian Yound and Friends of Killhope members

Friday 5th - Sunday 7th October - 3 day programme including provisional field meeting: "Sediments and Ecosystems - a celebration of continuing geology at Hull University", joint meeting with Hull Geological Society

Saturday 3rd or Saturday 10 November, British Geological Survey, Keyworth, Notts.: Provisional topic: "Mountains - all mountain chains are different, some examples"; joint meeting with East Midlands Geological Society

Saturday 1st December, Wakefield or Leeds: Celebration of the 175th Anniversary of the first meeting of the Society, including Annual General Meeting and 2nd Presidential Address of Dr Noel Worley

23rd British Cave Research Association Cave Science Symposium, Joint Meeting with the Yorkshire Geological Society and Leeds Geological Association, Leeds, Saturday 10th March 2012: Call for Papers and Presentations

The British Cave Research Association is pleased to confirm that its next one-day annual Cave Science Symposium will be held at the School of Earth and Environment, University of Leeds (www.see.leeds.ac.uk) on Saturday 10 March 2012. This will be a joint meeting with the Yorkshire Geological Society (www.yorksgeolsoc.org.uk) and the Leeds Geological Association (www.leedsga.org.uk) and will be hosted by Professor Simon Bottrell and Phil Murphy of the University of Leeds. Presentations are invited on any cave science topic. Those that fall within one of the four BCRA cave science themes (speleogenesis, cave archaeology and palaeontology, cave biology and cave technology) will be especially welcome (see the cave science policy via www.bcra.org.uk/detail/cstri_info.html), as will those from undergraduates and other students.

This year’s partial theme will be ‘Cave science in the Yorkshire Dales’ (including relationships between karst and mineralisation and possible hypogene speleogenesis) and it is hoped to devote half the Symposium to this topic. Full papers are not required, but related submissions to Cave and Karst Science are also invited. To offer a verbal or poster presentation or a demonstration, please contact the lecture secretary, Dr. Trevor Faulkner, by email at: t.faulkner [at] bcra.org.uk or, for initial queries, by telephone at: +44 (0)1625 531558. Titles and abstracts of up to one side of A4 should be sent as Word files by email by Friday 6 January 2012. These should include full first names, contact details and affiliations of all authors, with presenters underlined, and may be ‘extended’ to include references. Talks will probably be allocated 15–20 minutes, and poster presentations 3–5 minutes.

 The Symposium will provide much of interest for academic and amateur scientists and for enquiring cavers. Registration will take place at the start of the meeting and is not required in advance. A £5 admission charge will cover the full programme and refreshments, with free entry to members of the sponsor organisations. Later visits to University departments will also be arranged. Further information, including directions to the venue, will be provided in the 3^rd BCRA Circular and YGS Circular 571 in February 2012 and on both the BCRA and YGS websites.   

Proceedings now fully digitised from vol. 1 (1839) to vol. 58 Pt.3 (May 2011) with free online access to individual YGS members

Instructions for YGS member access to the Proceedings of the Yorkshire Geological Society 1839 to 2011 in the Lyell Collection

This notice contains important information that will enable you to access the online.  Please make sure that you retain the address label from the envelope containing this Circular –
this contains your YGS membership number, which you will need to activate your subscription.

Latest part of Proceedings of Yorkshire Geological Society (vol. 58 Pt. 4 November 2011) has now been published in both print form
and on line on the Lyell Collection at: http://pygs.lyellcollection.org/content/current

Contents and Abstracts

A. Snelling, D. Bates and J. Zalasiewicz: Graptolite studies in honour of Barrie Rickards (1938-2009): an introduction

ABSTRACT: Barrie Rickards was a fisherman, biographer and, most pertinently in this context, a teacher of geology and palaeontology. As a fisherman, especially of pike, he was almost legendary, writing many books on the subject including some regarded as classics within the angling community. As a teacher of geology and palaeontology, he was known for his inspirational qualities in the field (and could, almost to the end, outpace his young protégés across hill and valley). In the narrower world of palaeontology, he was one of the world's leading researchers on those graceful, useful, but equally bizarre and baffling fossils, the graptolites.

D. Bates, A. Kozlowska, D. Chmielarz and A. Lenz: Excessive thickening of the cortical layer in graptolites

ABSTRACT: A number of graptolites with thickened periderm, both dendroids and graptoloids, have been examined with the SEM. The thickening is by the deposition of layers of ectocortical tissue, clearly as bandages in the graptoloids. In Colonograptus colonus and some ‘diplograptids’, the thickening is most pronounced in the proximal regions of the rhabdosome, and can lead to the partial or complete occlusion of the aperture of the sicula and proximal thecae, as well as thickening the virgella. This thickening is interpreted as an adaptation connected with an extra gerontic production of cortex, which might have served as a reinforcement of the rhabdosome, or as an adaptation to modify or retain, the centre of gravity in the water column, or both. In Amphigraptus sp. the thickening appears to be common, and is concentrated on the dorsal side of the stipes. In Dendrograptus sp. thickening is also common: the main branches become excessively thickened, uniformly around the stipes, the side branches less thickened. In Cyrtograptus, thickening is rare, and appears to be gerontic, with the exception of a new form tentatively identified as Cyrtograptus in which thickening is uniform throughout the rhabdosome, and may have been formed initially. In Colonograptus and several ‘diplograptids’, the thickened proximal part shows it is much heavier than the distal part, suggesting a downwards vertical direction of the proximal end. In Amphigraptus the asymmetrical thickening suggests an orientation with the ventral side uppermost.

R. A. Fortey: A critical graptolite correlation into the Lower Ordovician of Gondwana

ABSTRACT: The early Ordovician was a time of maximum faunal provinciality. Correlation between strata deposited at low palaeolatitudes and those deposited close to the Ordovician pole in Gondwana is accordingly particularly difficult. The graptolite used to define the base of the internationally accepted Floian Stage, Tetragraptus approximatus, is essentially a lower latitude species. The discovery of a closely related and coeval species, T. akzharensis, in the early Ordovician of the Montagne Noire is reported. It occurs at the same level as the acme of the trilobite Taihungshania miqueli. The new record permits a direct tie with the earliest part of the Floian Stage and the shelly faunas typical of much of western Gondwana.

D. Goldman, C. E. Mitchell, M. J. Melchin, J. Fan, S.-E. Wu and H. D. Sheets: Biogeography and Mass Extinction: Extirpation and re-invasion of Normalograptus species (Graptolithina) in the Late Ordovician Palaeotropics

ABSTRACT: Normalograptids constitute a distinctive but not easily identified group of derived axonophorans. A new study of Normalograptus morphology indicates that many Late Ordovician taxa previously identified as Normalograptus are actually referable to Styracograptus and related climacograptoids. These re-identifications have led to the recognition of a complex biogeographic history among normalograptids and their descendants, including an interesting pattern that had previously been overlooked – a late Katian disappearance of Normalograptus from the palaeotropics. Normalograptid palaeogeographic distribution in the Ordovician appears to comprise 5 main phases: (1) evolutionary origin probably in relatively high palaeolatitudes in the early to mid Darriwilian; (2) spread to global distribution in later Darriwilian time; (3) retreat from most low palaeolatitude regions during the early Katian, with perhaps a slightly delayed retreat from Laurentia; (4) a complete extirpation from the low palaeolatitudes by the mid Katian (Ea4); (5) reinvasion of the low palaeolatitudes that accompanies the remarkable ecological and evolutionary replacement of the Diplograptina by species of Normalograptus and their descendants during the latest Katian–early Hirnantian. We propose two sets of hypotheses to explain Late Ordovician Normalograptus distribution. First, given the low species diversity of Normalograptus, we suggest as a null hypothesis that the disappearance of normalograptids from low palaeolatitudes during the late Sandbian and early Katian as simply a stochastic outcome – a small clade simply went extinct by chance alone. The alternative is that the loss of Normalograptus species reflects some form of extinction for cause, either: (1) competitive exclusion; or (2) an inability to adapt to changing environmental conditions. In the case of the competitive exclusion hypothesis, the most likely competitors are species of the Diplograptina.

M. P. Howe: GrapEl - a simple spreadsheet application for managing and disseminating graptolite biozonal range chart data

ABSTRACT: Biostratigraphical data frequently consist of tables indicating the presence, absence or relative abundance of taxa in a sequence of rock units or time units such as biozones or various chronostratigraphic units. Spreadsheet programs provide a simple means for managing this data and can be used for archiving and disseminating it, in addition to manipulating it. A simple spreadsheet (‘GrapEl’) is used to link the biozonal ranges of graptolite taxa to illustrations of representative or type specimens. Use of the filtering function enables the rapid selection of species from particular biozones, or species belonging to particular genera, and is intended to assist workers with a limited working knowledge of the faunas concerned. This approach is briefly compared to other uses of spreadsheets and databases in the management, analysis and distribution of graptolite biostratigraphical data.

J. Loxton, M. J. Melchin, C. E. Mitchell and S. J. H. Senior: Ontogeny and Astogeny of the Graptolite Genus Appendispinograptus (Li and Li, 1985)

ABSTRACT: Graptolites of the genus Appendispinograptus feature prominently in Late Ordovician biostratigraphy and studies of biodiversity. Well-documented, but enigmatic, secondary structures extend along the basal spines in mature specimens of three of the four common late Katian species of the genus: A. supernus, A. longispinus, and A. venustus. Using SEM imaging of isolated, three-dimensional specimens of A. supernus, we provide a detailed description of its early growth, as well as confirm that its secondary structures are composed of hollow tubes extending from the sicular and thecal apertures (‘parasiculae’ and ‘parathecae’, respectively). We also describe a collection of Canadian (northern Yukon) appendispinograptids that possess a large heart-shaped, sheet-like basal structure. Detailed comparison (width, thecal length and thecal inclination) with immature specimens from our collection, as well as collections from Russia, China, and Nevada, identifies these specimens as A. leptothecalis, a species not previously known to exhibit any secondary spine modification. The observation of spine modification in A. leptothecalis allows previously unclassified specimens from China, Siberia, and Nevada to be assigned to this species, clarifying our understanding of appendispinograptid biogeography and diversity. However, these structures are difficult to explain functionally. Unlike structures found in other Appendispinograptus species, those in A. leptothecalis decrease usable thecal space, shift drag proximally, and provide no obvious feeding advantage.

A. A. Cullum and D. K. Loydel: The Rhuddanian/Aeronian transition in the Rheidol Gorge, mid Wales

ABSTRACT: Logs are presented through the upper Rhuddanian and lower Aeronian (Llandovery, Silurian) of the internationally important Rheidol Gorge section in Ceredigion, mid Wales. It is hoped that these will be of value to those engaged in future research on the section.

J. Maletz: Scandinavian Isograptids (Graptolithina, Isograptidae): Biostratigraphy and Taxonomy

ABSTRACT: The Lower–Middle Ordovician of Scandinavia is largely dominated by endemic Atlantic Province graptolite faunas, which are useful only for local biostratigraphy and paleoecology, but are difficult for correlation on an inter-continental scale. Isograptids, regarded as essential for inter-continental biostratigraphic correlations in the Lower–Middle Ordovician due to their wide palaeobiogeographic distribution, have rarely been recorded from the region. The Scandinavian Tøyen Shale and Bogo Shale formations bear a number of isograptids that range in age from the late Floian to the early Darriwilian, and these provide a good tool for inter-continental correlations of this interval. Isograptus caduceus norvegicus Monsen and Isograptus spinosus Spjeldnaes are interpreted as possible tetragraptid species. The following biostratigraphically important Isograptus species from Scandinavia are described as new: Isograptus spjeldnaesi n. sp., Isograptus rigidus n. sp. Isograptus mobergi n. sp. and Scandinavian zonal names in the Dapingian are revised accordingly.

M. J. Melchin, C. E. Mitchell, A. Naczk-Cameron, J. X. Fan and J. Loxton: Phylogeny and Adaptive Radiation of the Neograptina (Graptoloida) During the Hirnantian Mass Extinction and Silurian Recovery

ABSTRACT: Cladistic analysis of some Hirnantian (latest Ordovician) and Rhuddanian–Aeronian (early Silurian) biserial graptolites and basal monograptids has been undertaken in order to test hypotheses of the relationships among the Neograptina (‘normalograptids’ and their descendents) and to provide a phylogenetic framework for understanding the early Silurian adaptive radiation of graptoloids. It is clear that Silurian graptolite faunas are dominated by two major clades, here named the superfamilies Retiolitoidea and Monograptoidea. Several other lineages whose basal relationships are unresolved, including Normalograptus and Metaclimacograptus, persisted through much of the Llandovery. The Retiolitoidea includes some taxa previously assigned to the Normalograptidae, as well as petalolithids and retiolitids. The Monograptoidea includes akidograptids, dimorphograptids, the uniserial monograptids, as well as stem taxa previously regarded as normalograptids. Both of these major clades had their origins in Late Ordovician time and began their diversification within the Hirnantian–early Rhuddanian, in step with the two main phases of the Hirnantian Mass Extinction. The Neograptina also exhibit an additional interval of accelerated turnover in the Rhuddanian during which the characteristic Silurian fauna largely replaced the Hirnantian Neograptina. One new family, Neodiplograptidae, and four new genera are described: Avitograptus, Rickardsograptus, Korenograptus and Paramplexograptus.

L. A. Muir: An unusual specimen of Glyptograptus from Dob's Linn (Southern Uplands, Scotland), and a discussion of graptolite teratomorphies

ABSTRACT: A specimen of Glyptograptus from the Silurian of Dob's Linn is described that possessed a bifurcating virgula, with a biserial stipe along each virgula. The colony lived for some considerable time with this morphology, showing that at least some graptoloids could survive and grow with major modifications to the rhabdosome. The specimen is left under open nomenclature, but if further material is discovered it may be appropriate to name a new species. Growth abnormalities in graptolites are not common, but many examples of repaired damage, rhabdosome malformations, and abnormal growth of thecae, virgellae and virgulae are known. Growth abnormalities can provide important evidence about graptolite ecology, biology and evolution, and so should be described and illustrated whenever possible.

A.W.A.Rushton: Deflexed didymograptids from the Lower Ordovician Skiddaw Group of northern England

ABSTRACT: The type species of Corymbograptus, Didymograptus v-fractus, is discussed and a neotype is proposed. The zonal graptolites Didymograptus varicosus and D. deflexus, mainly from the Loweswater Formation of the Skiddaw Group succession, are discussed and illustrated as species of Baltograptus. Study of their proximal structure shows that the identification of D. varicosus in the Loweswater Formation is not correct, and the English specimens are here assigned to Baltograptus jacksoni sp. nov.

P. M. Sadler, R. A. Cooper and M. J. Melchin: Sequencing the graptoloid clade: building a global diversity curve from local range charts, regional composites and global time-lines

ABSTRACT: Even range charts from the best graptoloid-bearing sections can be improved by adding information from nearby sections. Traditionally this is achieved on a scale of discrete biozones. Zonal composites improve upon the taxon richness of individual sections but lose resolving power; they artificially cluster range-end events at zone boundaries. Graphical and numerical methods allow composite sections to be constructed on continuous scales that match or exceed the resolving power of individual sections. Using a database of 582 graptoloid-bearing sections that together preserve 2214 distinct graptoloid taxa, we show that constrained optimization algorithms can construct objective, reproducible, global time-lines for the entire Ordovician to early Devonian graptoloid clade. The underlying database of locally observed ranges allows standardization for sampling unevenness. The quality and geographic origins of support for composite taxon ranges are explicitly revealed. A high precision, interval-free, standing species richness curve derived by this approach reveals the diversity trajectory of the graptoloid clade and of the families of which it is composed. Major reorganizations of the clade at the family level took place after diversity minima in the late Darriwilian and Hirnantian. Glacial events recognized on sedimentological evidence coincide with diversity minima.

A. Snelling and J. Zalasiewicz: The evolutionary lineage of Petalolithus to Cephalograptus: evidence from Coalpit Bay, Northern Ireland

ABSTRACT: The evolution of graptolites is the basis upon which much of the Lower Palaeozoic is subdivided. Amongst the clearest evolutionary lineages within graptolites are those that show seemingly unidirectional trends in morphology, such as the sequence of stratigraphically successive taxa of Petalolithus and Cephalograptus, discussed here. Graptolite specimens collected in the 1960s from Coalpit Bay, Northern Ireland are consistent with the succession established in the Czech Republic by Boucek & Pribyl (1941) and Štorch (1998), and include the first UK records of P. aff. krizi. We recognise other intermediate forms within this lineage that may enable further subdivision of the convolutus Biozone.

J. Zalasiewicz, C. Russell, A. Snelling and M. Williams: The systematic relationship of the monograptid species acinaces Tornquist, 1899 and rheidolensis Jones, 1909

ABSTRACT: The relationship between the early Silurian (Rhuddanian) monograptid species rheidolensis Jones, 1909 and acinaces Törnquist, 1899 has been contentious, with debate as regards both their possible synonymy and their generic assignation. We have re-examined the type and associated material of rheidolensis, and conclude that this taxon is almost certainly a junior synonym of acinaces. Lacking ventral apertural processes, acinaces does not belong within Lagarograptus, as previously thought, but may be placed within Huttagraptus, as proposed by Koren' & Bjerreskov (1997). The confusion between these two taxa arose because the material that Jones assigned to rheidolensis includes two taxa, one representing non-topotype (and probably mis-localized) specimens of an undoubted Neolagarograptus. This is morphologically very similar to, and probably referable to, the late Aeronian species Neolagarograptus tenuis, the type material of which we show here to be tectonically distorted.

Special Offer on three new geological publications of the National Museum of Scotland and Geological Society of Edinburgh

The National Museum of Scotland has recently published three new geological guides in association with the Geological Society of Edinburgh, and is offering these post-free for orders received by 31st January 2012:

A Geological Excursion Guide to the North-west Highlands of Scotland edited by Kathryn M Goodenough & Maarten Krabendam with 12 contributors. Paperback (flexi-binding), £15.99. 224 pages,115 colour illustrations. This field guide describes the bedrock geology from Ullapool northwards, including many classic localities in the Moine thrust zone and it foreland: the area covered largely corresponds to the North-west Geopark.

An Excursion Guide to the Moine: Geology of the Northern Highlands of Scotland by  Rob Strachan, Ian Alsop, Clark Friend & Suzanne Miller. Paperback (flexi-binding), £17.99. 304 pages, 104 colour illustrations. This field guide describes the varied rocks and structures that occur within the largely metasediments of the Moine Supergroup of the northern and central highlands of Scotland. The excursions are, for the most part, along major roads, allowing easy access to some of the finest outcrops of deformed and metamorphosed sandstones in Scotland. Professional geologists will find the book invaluable as will the enthusiastic amateur and the undergraduate student.

The Paleocene Igneous Rocks of the Isle of Rum, Inner Hebrides by C H Emeleus and V R Troll. Paperback (flexi-binding), £12.99. 152 pages, 75 colour illustrations.  Rum, the largest of the Small Isles, is a National Nature Reserve, owned and managed by Scottish Natural Heritage since 1957; it has several geological Sites of Special Scientific Interest.   It is justly renowned for the ultrabasic cumulate magmas of its Eastern and Western Layered Intrusions of Paleocene age. Less well-known are the equally spectacular sidewall and roof contacts of the magma chamber, together with examples, rare in the geological column, of sequences through the caldera floor of the Rum volcano and the overlying volcano-sedimentary infill (with ignimbrites). The nine excursions in this A5-sized guide, each colour coded for easy reference, highlight all of the above and also illustrate the complex contacts of the Lewisian and thick Torridonian successions with Paleocene rocks, a feather-edge Triassic succession and Jurassic fault slivers, as well as a plant-bearing Paleocene sequence of lavas and conglomerates that demonstrates very rapid intra-Paleocene unroofing of the Rum Igneous Complex.

Further details are available on the National Museum of Scotland website at: http://shop.nms.ac.uk/categories/Books/Natural-Science-/ which also has a link for on-line purchases. 

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  University of Liverpool: Herdman Symposium: Geoscience Frontiers - 3: Saturday 18th February 2012
(The Herdman Society is the undergraduate society of the Earth and Ocean Sciences Department at Liverpool University; William Herdman was the founder and benefactor for the original Department of Geology)

Speakers:

Dr Bryan Lovell (Cambridge) ‘A pulse in the planet: hot blobs in the mantle and yo-yo tectonics’.

Prof John McCloskey (Ulster) ‘Evolution of stress on the Sunda megathrust, West Sumatra: Implications for future earthquakes and tsunamis’

Dr Clive Oppenheimer (Cambridge) ‘Mount Erebus: an exceptional volcano laboratory in Antarctica’

Dr Richard Shaw (British Geological Survey) ‘The disposal of radioactive waste – a geological perspective’.

Dr Jan Zalasiewicz (Leicester) ‘Exploring the Anthropocene’.

The full programme with abstracts, times, location of the Sherrington Lecture Theatre,and ticket charge will be circulated in December.  The charge to non-students will, subject to sponsorship, probably be ~£10, which includes programme, buffet lunch, tea/coffee and wine reception. Persons interested in attending should contact Helen Kokelaar, e-mail: herdman@liverpool.ac.uk

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Otley Chevin Project: A Joint Venture Between West Yorkshire Geology Trust and Leeds City Council

The West Yorkshire Geology Trust has been working on a project with Leeds City Council at the Chevin for the past year. We were asked to produce a geological trail taking in the main features of the local geological site and write a leaflet to illustrate it (see the front cover, reproduced on the left). The trail is marked by large stones, which have been carved in local sandstone by a local sculptor and depict various geological features, such as plant fossils, cross-bedding and tidal laminites. The start of the trail, in East Chevin Quarry car park, is marked by an enormous boulder, carved with many geological features, including the words ‘Variscan orogeny’. This will provide something for the general public to ponder! There is an excellent geological interpretation board at Surprise View, which overlooks Wharfedale from the top of the Chevin. Leeds Geological Association originally provided the splendid drawings, diagrams and photos, but we have been asked to update some of the information, particularly geological dates. A large landscape photo also needed to be retaken, as the view from the top of the chevin has changed over the last decade. West Yorkshire Geology Trust’s final contribution to the project is the production of a professionally produced audio trail, which will be available to download from the Friends of Chevin Forest website http://www.chevinforest.co.uk and the WYGT website, http://www.wyorksgeologytrust.org, to accompany the geological trail. Many walkers now want to know more about what they see, having downloaded some information from a website beforehand. Then they can walk the trail listening to their MP3 player, or use the leaflet to locate themselves. We look forward to hearing the recording, which should be finished in a few weeks time. Alison Tymon, West Yorkshire Geology Trust

 

Quaternary Research Association/British Cave Research Association Joint Field Meeting: Cave archaeology and karst geomorphology in NW England
21st to 24th June 2012, Dalesbridge Centre, Austwick, North Yorkshire

This field meeting is jointly organised by the Quaternary Research Association and the British Cave Research Association, including the newly-formed BCRA Cave Archaeology Special Interest Group. It will consider recent research into cave archaeology and aspects of karst geomorphology in Cumbria and the Yorkshire Dales, where the latest results are informing us about glaciations since MIS15 or earlier, the later stages of the Devensian glaciation, and human influences since the Late Glacial.  

Preliminary programme

Three field days are planned, preceded by introductory talks on Thursday evening. Additionally, other visits and talks will be arranged each evening.

Thursday 21st June - evening:

Registration and introductory talks

Friday 22nd June:

The Quaternary development of Kingsdale. Leader: Tony Waltham

Drumlins at Ribblehead and the Whernside glacier. Leader: Wishart Mitchell

Archaeology, sediments and speleogenesis at Jubilee Cave and Victoria Cave. Leaders: Tom Lord and Phil Murphy

Friday evening - exhibition about Victoria Cave at the Museum of North Craven Life, Settle. Leader: Tom Lord

Saturday 23rd June

Archaeology of caves at Grange-over-Sands in Cumbria. Leaders: Hannah O'Regan and Ian Smith

Lowland limestone pavements and grike erratics in the Arnside and Silverdale AONB: Hale pavement and Gait Barrow. Leaders: Peter Standing and Helen Goldie

Sunday 24th June

Cosmogenic dates and pedestal studies from Norber and OSL dates from loess at Winskill. Leaders: Peter Wilson and Helen Goldie  

Recent palaeoecological and archaeological work in the Settle area.   

Accommodation: The meeting will be based at the Dalesbridge Centre, Austwick, near Settle, North Yorkshire. 

Further information from: Trevor Faulkner  (trevor[at]marblecaves.org.uk or Hannah O'Regan   H.J.O'Regan@ljmu.ac.uk

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University of Hull Centre for Lifelong Learning: Geology Courses 2012

Rocks and Minerals through the Microscope Course, starts on Wednesday 18th January 2012

This course provides an opportunity for students to discover the exciting world of rocks and minerals as they appear through the polarising microscope. Students will use equipment that is not normally available to the amateur and specimens from the University's collection, to reach a deeper understanding of the rocks and minerals. Ten Wednesday evenings from 7-30pm until 9-30pm at the University of Hull, Department of Geography.

Collecting Rocks, Minerals and Fossils Course, starts Wednesday 18th April 2012

Collecting rocks, minerals and fossils is an exciting way to study the history of our world and is a rewarding hobby in itself. This course will show you - what to look for - where to go - how to collect safely - how to take care of your collection - where you can get help and advice on identifications Four Wednesday evenings from 7-30pm until 9-30pm at the University of Hull, Department of Geography and three half day field trips at weekends. Rocks and Fossils of the Yorkshire Coast The course will include four half days of fieldwork to study the rocks of the Early Jurassic, Middle Jurassic, Cretaceous and the Quaternary. We will see how changes to sea level and climate have produced the diversity of rocks and fossils we now see on our coastline. Course starts on Wednesday 18th July 2012 and is followed by four half day field trips at weekends.

For more information and a registration form please contact: Centre for Lifelong Learning, The University of Hull
49 Salmon Grove, Hull, HU6 7SZ. Tel. 01482 465415; e-mail Cll@Hull.ac.uk

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Some British Geological Survey Memoirs for Yorkshire to download

In a major new development for the Society, the British Geological Survey (BGS) had made available to the Society's website full facsimile copies (in PDF format, including all illustrations) of some earlier Geological Survey Memoirs, listed below. These are now available for downloading for personal, academic, educational, non-commercial research and other non-commercial use, from the Yorkshire Geological Society website http://www.yorksgeolsoc.org.uk/ only. All users must agree to the BGS terms and conditions before downloading each Memoir.

 

Go to Geological Survey Memoirs index page

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Searchable Indexes to 138 years of the Proceedings of the Yorkshire Geological Society (1837-1995) now available on line!

The Society has been publishing its Proceedings since 1837, and its many thousands of pages contain a great deal of original research and other unique material relating to the earth sciences, especially in respect of Yorshire and adjacent regions, both also nationally and internationally.  Complete reference sets of the PYGS are held by many leading regional and national libraries including the British Library, the Geological Society LIbrary, and the Society's own library, now part of the University of Leeds Library (which members of the Society can apply to use as a benefit of membership via the General Secretary of the Society).

Over the years the Society has published three cumulative indexes to the Proceedings, but it has been an aim of the Society's Council to make these indexes available on line via this website to help members and others to search and explore the rich resources available in the Proceedings. 

We are delighted announce that thanks to the generous help of Pinpoint Digital of Winsford, Cheshire, which has undertaken the necessary scanning of the published indexes free of charge, these are now available as searchable PDF files as follows:

Index to PYGS volumes 1 to 25 (1837-1946)

Index to PYGS volumes 26 to 37 (1947-1970)

Index to PYGS volumes 38 to 50 (1970-1995

To access each index click on the appropriate link above to open or download the file. (Each is very large - over 2Mb - so unless you have a fast broadband connection it is advisable to download the files onto your own hard disk, and then search from there.  Whether using an index on line or from a downloaded file simply open the file in  Adobe Acrobat and then use the normal Acrobat "Search" (or "Find") facility.  Any geological term, placename or author name can be used to search each index: Acrobat will then give you a list of occurences in the subject or author indexes, and each occurence is highlighted in colour within ePDF (facsimile) image of the index page. 

Very many thanks to Pinpoint Digital Document Management and Storage Systems for their sponsorship,and particularly John Hatton for his advice and practical assistance.

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Yorkshire Rocks and Landscape – the popular YGS Field Guide, Third Edition, is now available

Yorkshire, famed for its scenic beauty and its rich industrial heritage, contains some of the most interesting geology and scenery in England , from the moors to the coast, including the Yorkshire Dales and North York Moors national parks. The influence of the geology on the landscape and on the industrial development in the region is profound.  

This book is a stimulating field guide to twenty-one locations selected to give comprehensive coverage of the geology, minerals, rocks, fossils and landforms of the area. Excursions vary from easy half–day walks to longer outings. Some are in moorland areas such as the Craven Inliers and the Pennines; others cover the Dinosaur Coast, famous for its rugged beauty and natural history, and coalfields adjacent to the major cities.

 Aimed at beginners and more experienced geologists, the book includes a general introduction to the area’s geological history, detailed location maps, a full glossary of terms, and details of local museums.

  Yorkshire Rocks and Landscape will be used and enjoyed by all those interested in the geology and natural heritage of this exciting and diverse region, especially the links between landscape and the underlying geology,

 About the Authors: The field guide, edited by Drs. Colin Scrutton and John Powell, has contributions from knowledgeable academics, professional geologists and dedicated amateurs, many of them members of the Yorkshire Geological Society. Together in this book they provide the most up-to-date and authoritative guide to the geology of Yorkshire and surrounding areas currently available.  

Published: September 2006; 224 pp, 22 figures.  Price £9.99, plus postage and packing (£2.00); cheques should be made payable to "Yorkshire Geological Society".  Please send your order form to: Dr J H Powell, British Geological Survey, Keyworth, Nottingham, NG12 5GG

  Also available at indoor meetings of the Yorkshire Geological Society (no p&p) and from selected bookshops.

Click here for more details, including the full Contents List

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A major Yorkshire Geological Society Publication!

Carboniferous Hydrocarbon Geology: the southern North Sea and surrounding onshore areas

edited by

John Collinson, David Evans, Doug Holliday & Neil Jones, 2005

Click here for full details and samples
of the full colour illustrations!

Price now reduced to £10 plus £5 p. & p. Cheques should be made payable to Yorkshire Geological Society. Please send your order form to: Dr J H Powell, British Geological Survey, Keyworth, Nottingham, NG12 5GG

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Important Notice to Members and others:Short Communications: Proceedings and Circular/Web Site

Rapid publication of short papers is common amongst journals, particularly those published weekly, monthly or bi-monthly, as a way of disseminating information quickly on topical or contentious issues, exceptional new discoveries or major developments.   Given its publication schedule, the adoption of such a publication strategy is not appropriate for the Proceedings.  Nevertheless, as a way of encouraging the membership to make more use of the Proceedings, and for that matter the Society’s other vehicles for publication, the Circular and web site, Council would welcome more short communications. Short communications submitted to the Proceedings might include anything for which it would be worth having a permanent published record, for example descriptions of new and/or temporary exposures.  Those intended for the Circular or web site could include more topical or newsworthy items, including brief reports of field meetings, new fossil/mineral occurrences, photographs of interesting geological features with a brief description or the work of RIGS groups. Short communications to the Proceedings should not exceed two published pages, approximately 2,000 words (or equivalents including figures) and will be subject to the normal review and editorial procedures, although a Summary will not be necessary. Please send your contributions in the usual manner to the Editors (see ‘Instructions to Authors’ in the PYGS as a general guideline).

For the A5 format of the Circular (and web site), contributions should be 300-400 words, but can include colour photographs and figures; these will also be subject to editorial review. These items should be sent to the Circular Editor in the first instance (see back page of the Circular for details).

Stewart Molyneux, Principal Editor PYGS
Keith Park, YGS Circular Editor
Patrick Boylan, YGS Web Editor

New Edition 2004 with minor revisions: price £9.99 plus £2.00 postage and packing Click here for further details

Field Trip Safety Issues

1.   The YGS takes the safety of its members extremely seriously. However, attendees of field meetings must also take responsibility for their own and other participants’ safety. In order to ensure the safety of all participants the YGS reserves the right to limit or refuse attendance at field meetings.

2. You must declare to the field trip leader, at the start of the field trip, any disabilities or medical conditions that may affect your ability to safely attend a field meeting.3. Inform the leader if you leave the meeting early.

4. The Leader is not expected to provide First Aid – ensure that you have adequate supplies for your own needs.

5. Wear appropriate clothing and footwear for the locality and time of year. Anticipate potential changes in weather conditions.

6. Children must be accompanied and supervised by a responsible adult at all times.

7. The Leader’s decision is final on any matters relating to each field meeting.

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Corresponding Societies

(Please contact the society representatives and/or websites for the latest information)

CRAVEN & PENDLE GEOLOGICAL SOCIETY: Contact: Paul Kabrna e-mail: paul_kabrna@hotmail.com or http://www.cpgs.org.uk/ (usual meeting place for indoor lectures: The Rainhall Centre, Barnoldswick)

CUMBERLAND GEOLOGICAL SOCIETY: Secretary: Rosemary Vidler, 11 Blencathra View, Threlkeld, Cumbria, phone no 017687 79326, e-mail: rosevidler@freeuk.com; http://www.cumberland-geol-soc.org.uk/, For details of excursions please contact Alan Smith on 01768-771.068

EAST MIDLANDS GEOLOGICAL SOCIETY: Janet Slatter, tel. 01509-843.297; e-mail: sec@emgs.org.uk or http://www.emgs.org.uk (usual meeting place for indoor lectures: Lecture Theatre B3, Biological Sciences Building, University of Nottingham)

EAST MIDLANDS REGIONAL GROUP OF THE GEOLOGICAL SOCIETY: Secretary: David Bailey, British Geological Survey, Keyworth, Nottingham <deba@bgs.ac.uk>

EDINBURGH GEOLOGICAL SOCIETY: e-mail: secretary@edinburghgeolsoc.org;   http://edinburghgeolsoc.org/ (usual meeting place: Hutton Lecture Theatre, Grant Institute of Geology, University of Edinburgh: click on speakers' names for further details of each lecture)

THE GEOLOGISTS' ASSOCIATION: http://www.geologistsassociation.org.uk/: The schedule of field meetings for 2011 includes the following in the wider YGS region: 
(For further details and to book places please e-mail or telephone Sarah Stafford at the GA Office: geol.assoc@btinternet.com, tel. 020 7434 9298)

HUDDERSFIELD GEOLOGY GROUP: Julie Earnshaw (Secretary). Telephone: 01484 311 662 or e-mail: earniehome@ntlworld.com

HULL GEOLOGICAL SOCIETY: Mike Horne. Tel: 01482 346 784 or e-mail: secretary@Hullgeolsoc.org.uk web: http://www.hullgeolsoc.org.uk (Usual meeting place for indoor lectures: Department of Geography, University of Hull, at 7.30 pm. N.B.   for security reasons the door is locked at 7.40pm). Please contact the Society if you wish to come to a field meeting so that the leaders will know how many people to expect. The Society reserves the right to exclude people who are not wearing the necessary protective clothing/equipment. For further information 'phone 01482 346784. Hull Geological Society Website - http://www.hullgeolsoc.org.uk

Thursday 19th January 2012 - Members' Evening

hursday 16th February 2012 - (evening lecture) Richard Lamb on "Mineralogical Misfits: Minerals formed through Biological Intervention, and Anthropogenic Substances such as Slag ".

Thursday 22nd March 2012 - (evening lecture and AGM) Dr Cath Neal of the University of York on "People and the environment: a geoarchaeological approach to the Yorkshire Wolds landscape"

LANCASHIRE GROUP OF THE GEOLOGISTS’ ASSOCIATION: Secretary: Jennifer Rhodes, e-mail: sjrhodes@hotmail.com

LEEDS GEOLOGICAL ASSOCIATION: Anthea Brigstocke (General Secretary). Tel: 01904 626 013: E-mail:  lga@brigstocke.myzen.co.uk Field Meetings: Judith Dawson Tel. 0113 270 1069 e-mail: dawsonemail@tiscali.co.uk or http://www.leedsgeolassoc.freeserve.co.uk (usual meeting place for indoor lectures: Rupert Beckett Lecture Theatre, Michael Sadler Building, Leeds University at 7pm)

LEICESTER LITERARY & PHILOSOPHICAL SOCIETY - SECTION C GEOLOGY: Chairman Mark Evans, 0116 225 4904, mark.evans@leicester.gov.uk Publicity Officer: Dr. Joanne E. Norris, 0116 283 3127,
j.e.norris @ ntlworld.com; Website: http://www.charnia.org.uk/ (usual meeting place for indoor lectures unless otherwise stated: Lecture Theatre 3, Ken Edwards Building, University of Leicester at 7.30pm. 

NORTH STAFFORDSHIRE GROUP OF THE GEOLOGISTS ASSOCATION: Eileen Fraser Tel: 01260 271505 email: fraser@fraserco.co.uk http://www.esci.keele.ac.uk/nsgga/ (usual meeting place for indoor meetings: William Smith Building, University of Keele at 7.30pm

ROTUNDA GEOLOGY GROUP (SCARBOROUGH): contact Sue Rawson, tel. 01723-506.502, email: suerawson@yahoo.co.uk (usual meeting place Room CG7, Scarborough Campus of the University of Hull, Filey Road, Scarborough)

SORBY NATURAL HISTORY SOCIETY: Ken J Dorning, Geologists Group Secretary,  e-mail: geology@sorby.org.uk; website:  http://www.sorby.org.uk/

WESTMORLAND GEOLOGICAL SOCIETY: contact:  E-mail: mail@westmorlandgeolsoc.org.uk http://westmorlandgeolsoc.org.uk/ Meetings start at 8 pm (unless otherwise stated) and are held in the Abbot Hall Social Centre, Kendal.

YORKSHIRE REGIONAL GROUP OF THE GEOLOGICAL SOCIETY: Contact: Chris Evans <thomasne14le@yahoo.co.uk>

(With thanks to Paul Kabrna, the YGS's first Web Editor, for photographs, and the present banner heading and other images, and to Clare Gordon, Librarian, Earth Sciences, University of Leeds, for assistance in maintaining the YGS archive site on the Leeds University server from 1999 to 2007).