Programme: 2005 - 2006

© Craven & Pendle Geological Society

Indoor Meetings

Friday, 21st October
Volcano-ice-water-interaction on Mars Alistair Bargery MSc., Planetary Science Research, University of Lancaster.

Friday, 18th November
Fire and ice: A geological and social perspective on volcanic activity in Alaska Diana Roman Ph.D., University of Oregan, U.S.A.

Friday, 16th December
Carboniferous Crinoids of Clitheroe
Paul Kabrna

Friday, 20th January
The Late Devonian mass extinction
Dave Bond Ph.D., University of Leeds.

Friday, 10th February
Disarming Dromaeosaurs
Phil Manning Ph.D., Manchester University.

Friday, 17th March
John Milne: the man who mapped the shaking earth
Paul Kabrna

Friday, 8th April
Members slides & Field Meetings

Field Meetings for 2006

Sunday, 21st May
Carboniferous limestones of Low Furness, South Cumbria
Steve Webster (CPGS).

Saturday, 24th June
Malham
Peter Chiles (CPGS).

Sunday, 16th July
Mineralisation around Greenhow, near Pateley Bridge
David Turner (CPGS) and Jean Chicken (CPGS).

Sunday, 20th August
Blackstone Edge and Rochdale Cemetery
Leaders: Paul Kabrna and Barry Smith

Saturday, 23rd September
Early Carboniferous geology of the Pendle Hill area
Paul Kabrna and Hed Hickling. This is a joint meeting with the Oldham Geological Society.


Volcano-ice-water-interaction on Mars
Alistair Bargery MSc., Planetary Science Research, University of Lancaster

The research work currently underway relies a great deal on assessing data gained by remote sensing. Tonight I will cover the following themes:

1. What evidence is there for ice and water on Mars?
2. What are the origin and fate of the water? (Current work)
3. What types of volcanism are there on Mars? (Current work)
4. How is the volcanism related to the ice and water? (Future work)
5. Summary

Mars: The Red Planet

Image courtesy of
NASA /JPL / M5

A wealth of new data from several recent missions to Mars have rapidly changed our perception of Mars’ volatile history. There is evidence suggesting that Mars has / had rivers of flowing water, shallow lakes, glaciers, active volcanoes of great size, and significantly, Mars may have seen the development of primitive life. The exciting new data has been obtained from observations by the Hubble space telescope together with the more recent arrival of Mars Pathfinder (1997), Mars Global Surveyor (1997), Mars Odyssey (2001) and Mars Environmental Rovers: Spirit & Opportunity (2004 - 2005).

This data for the presentation has been obtained via Remote Sensing: i.e. collecting data from orbiters & telescopes; in situ: Landers & Rovers and Meteorites (greatest petrological diversity, but <1.3 Ga (young!).

The present Martian environment is that of a cold arid desert, somewhat similar to Antarctica. There is low atmospheric pressure and global winds that readily transport large quantities of dust. There is also a 2-4km Cryosphere with a water aquifer beneath. The Martian terrane comprises of two distinct topographies: The Northern Plains and the Southern Highlands. An enormous escarpment several kilometres high separates them. The Southern Highlands (3 billion years old) are rough and highly cratered. The North is much younger, with extensive resurfacing, which happened about a billion years ago.

There are large volcanic shields which comprise ~ 20% of the planet’s surface area. The vast majority of volcanism occurs in the two regions, Elysium and Tharsis. Martian volcanoes are shield volcanoes, showing shallow slopes from tens of episodes of lava flow build up. Tharsis is the greatest volcanic region, rising 8-9 kilometres above the rest and hosting Mars’ greatest volcanoes of which Olympus Mons is perhaps the most well known.

Surface features on Mars

Image courtesy of : Alistair Bargery and Esa/DLR/Berlin/Neukum

As to why the volcanoes become so large is best explained by either / or a) lack of erosion, b) no plate tectonic movement, or c) long lived mantle hotspots.

The evidence for water on Mars is starts with the carbon dioxide that dominates the atmosphere. At ground level it exists as solid frost depending on the seasons. We are now satisfied that water exists in the ice of the North Polar cap (and may be the South Polar cap). As to whether there has been liquid water on Mars in the past is currently under scrutiny. To support the possibility is evidence of outflow channels, tear-drop formations and branching run-off channels.

The ancient crust of the Southern Highlands is dominated by basalt as detected by Mars GlobalSurveyor whereas the Northern Highlands appears to contain andesites as well. More recently some evidence for there being gabbro, peridotite and serpentinite has come to light. The magmas from which they crystallised are probably derived by partial melting of mantle material.

What does the future hold for further Martian exploration? In the pipeline there are the following key missions: Mars Reconnaissance Orbiter: (currently cruising to mars, arrives next March), NASA Phoenix module (2007), NASA Mars Science Lab (2009) and finally, Esa's Aurora programme: ExoMars (2011 - 2013).

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Fire and ice: A geological and social perspective on volcanic activity in Alaska
Diana Roman Ph.D. University of Oregan, U.S.A.

Violent geological activity is all too familiar to the people of Alaska. In fact the largest volcanic eruption on the Earth this century occurred at Katmai in 1912 and the second-largest earthquake of magnitude 9.2 in 1964 was recorded in Alaska.

Aleutian Arc

The restless nature of Alaska is related to the processes that formed the Aleutian Arc - a curve of mountains and volcanic islands extending from the Alaska Range west to Russia’s Kamchatka Peninsula.

The Aleutians are part of the Pacific Ring of Fire, with approximately twenty-four active volcanoes and frequent earthquakes, caused by the collision of two of the tectonic plates i.e. the Pacific plate is plunging under the North American plate. The volcanoes here are highly active, and have had negative economic consequences as the smoke and ash they produce interferes with the aircraft that follow Asia-North America-Europe flight paths overhead.

One such volcano lying in the Alaskan peninsula is Augustine Volcano - a 1200 metres high Pleistocene strato-volcano that forms an island in the Cook Inlet region. This volcano has erupted six times in the past 200 years, (the most recent being 1986), making it the most historically active volcano in the Cook Inlet region and currently on high alert. Augustine erupts both explosively and effusively, over a time scale of weeks to months typical of the most recent eruptions.

The 1986 eruption began explosively and ended with dome growth. Explosive activity lasted from 27th March to 8th April, 1986, and produced an ash column that reached a maximum altitude of 12 kilometres.

Augustine Volcano in Alaska

The erupted magma ranges from basaltic andesite to dacite. The addition and mixing of new magma to the storage region via a network of dykes may have destabilized the region and initiated the onset of the eruption.

Successful forecasting of volcanic activity requires a thorough understanding of the relationship between magmatic processes and measurable signals of volcanic unrest e.g. changes in gas chemistry, and geophysical signals such as ground deformation and increased seismic activity. Short-term forecasts of volcanic eruptions are often based on observed changes in seismic activity alone. It is interesting to note that episodes of unrest at active volcanoes do not always culminate in eruptions and it is therefore critical to be able to recognise “false alarms” and “impending” eruptions. The extensive seismic network in place along the Aleutian Arc is central to a successful early warning mechanism.

Research work in Alaska will no doubt continue in the development of techniques to predict the style of an impending eruption from precursory signals.

PS. Dr. Roman informed the audience that Augustine was on high alert. Now it's on Red Alert! In early January 2006 Augustine has begun erupting and once again aircraft have been guided away from the area.

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Carboniferous Crinoids of Clitheroe
Paul Kabrna C.Geol.

Introduction

Complete fossil crinoids have plant-like characteristics even though they are in fact animals. In the Clitheroe area entire crinoids comprising the stem, the head (theca or calyx) and arms are rarely found intact. However, in Swaledale, complete specimens have been recorded. Significant numbers of detached heads have been collected over the years from the Clitheroe quarries. As the late Stanley Westhead once said, “It is true to say that nowhere else in England have Carboniferous crinoids been found in such large numbers and also in such variety of genera and species”.

Amphoracrinus gilbertsoni

The Class Crinoidea consists of four sub-classes: the Inadunata, Flexibilia, Camerata and Articulata. Of the four sub-classes the Camerates dominate the Clitheroe limestone's.

Crinoids reached their highest generic richness and overall abundance during the Lower Carboniferous, which has thus been credited as the “Age of Crinoids.” Clitheroe has played an important part in the story. The greatest variety both of genera and species has come out of Coplow Quarry, but following the exposure of the Salthill Cover Mudstones in 1970, large numbers of exceptionally well preserved crinoids have been collected, together with many remarkably massive stems or columns. The adjacent Bellman Park Quarry has also provided many specimens and in the Hodder Valley, Knoll Wood has yielded some interesting crinoids. Further afield crinoids are recorded from Settle, Richmond in Swaledale, Derbyshire, Somerset and Bristol. Many fine specimens have been found at Hook Head, Co. Wexford in Eire; in Liddesdale on the Scottish Border, and from the Lowlands of Scotland.

Pioneers

Not until the beginning of the 19th Century did any serious investigation as to their significance take place. The first serious scientific work on crinoids appeared in 1821 by J.S. Miller “A Natural History of the Crinoids”. Miller’s specimens though came from the Bristol area. The real merit of Miller’s work is that the morphology and classification of the crinoids are discussed and the genera and species placed on a sound basis.

Clitheroe Crinoid Pioneers

Of more local interest and significance was the appearance in 1836 of John Phillip’s second volume of “Illustrations of the Geology of Yorkshire - The Mountain Limestone District” in which Plates III and IV contain figures of 32 species of crinoids from this district. Thereafter in this country, in the USA and in Europe, the study of the Carboniferous crinoids gathered momentum resulting in an extensive bibliography (Wright 1949). So far as the local fauna is concerned it is to James Wright and Stanley Westhead that we are indebted for their meticulous investigation into the Carboniferous Crinoidea of the Clitheroe limestones.

Except for the war years, James Wright came to Clitheroe every year for at least a week to collect. A native of Kirkcaldy in Fife, James Wright must rank as one of the great amateurs to whom both Geology and Palaeontology owe so much, and, over a period of 50 years he became internationally regarded as the foremost authority on the British Carboniferous Crinoidea. He wrote and illustrated, carrying out his own photographic work, some 40 papers on the Crinoidea and at the request of the Palaeontographical Society wrote the Monograph. “The British Carboniferous Crinoidea”. His extensive collection of crinoids, including many Clitheroe specimens, was bequeathed to the Royal Scottish Museum in Edinburgh.

New Research

Recent collecting in Salthill by PK has yielded two palaeoecological stories. Firstly, the biotic interaction of a well preserved Amphoracrinus gilbertsoni in close association with a solitary rugose coral has been described in a paper published in the Proceedings of the Yorkshire Geological Society last month (November 2005). See Donovan, S. K., Lewis, D. N. and Kabrna, P.2005. An unusual crinoid-coral association from the Lower Carboniferous of Clitheroe, Lancashire. Proceedings of the Yorkshire Geological Society, 55, Pt. 4, pp 301-304.

Secondly, we have described the palaeoecology of an infesting organism on another Amphoracrinus gilbertsoni calyx. See Donovan, S. K., Lewis, D. N. and Kabrna, P.2006. A dense epizoobiontic infestation of a Lower Carboniferous crinoid (Amphoracrinus gilbertsoni Phillips) by Oichnus paraboloides Bromley. Ichnos. This paper has been accepted for publication in ICHNOS sometime in 2006.

The search for a Platyceras gastropod attached to the anal tube of a Clitheroe crinoid continues!

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The Late Devonian Mass Extinction
Dave Bond Ph.D., University of Leeds

Introduction

The Devonian period (408-360 MA) saw the first appearance of sharks, bony fish, and ammonoids. The world’s oceans were dominated by reef-builders such as the stromatoporoids and corals which inhabited some of the world’s largest reef complexes ever built. Terrestrial newcomers in the Devonian included amphibians, insects, and the first true land plants, giving rise to the first forests. My research interest in the Devonian period centres on a major intra-Devonian extinction which occurred at the Frasnian-Famennian boundary. This extinction event constitutes one of the “big 5” crises in the fossil record.

The Lower and Upper Kellwasser horizons

The Lower and Upper Kellwasser horizons in the Rhein Slate Mountains of central Germany. The Frasnian-Famennian Boundary is located here.

Marine Faunas

One of the main groups which suffered during the Devonian event, (although the story is far more complicated than this) was the ostracods; a diverse and abundant group, which are still around in many environments today. They are water fleas, and look rather like potatoes when preserved in sediment. They suffered at least a 75% extinction at species level during the late Devonian. Other well known groups to suffer include rugose corals at species level and tabulate corals at generic level. Stromatoporoids (calcareous sponges) were the principal reef constructors of the Devonian but were heavily affected, with at least 70% of species becoming extinct. The extinction of other reef dwellers is clearly linked to their demise. Brachiopods saw a 75% generic extinction with mid to outer shelf tropical fauna being most affected. Trilobite losses through Devonian were partially offset by high origination rates, until an abrupt extinction of 75% of trilobite subfamilies at the F-F boundary. Bivalves and echinoderms handled the stressful environmental conditions better than most as did the gastropods, although detailed data is not available. Ammonites experienced high rates of extinction and radiation through their history, but the important Gephuroceritidae, Beloceritidae and Acanthoclymeniidae families were lost in the Frasnian crisis, with only a few genera surviving. The Devonian is known as “the Age of Fish”, with lots of fish evolving. Despite being largely unaffected by most extinctions, the late Devonian was a great crisis, with agnathans, placoderms, and acanthods - all suffering heavy losses. Those strange creatures called conodonts in almost all environments were affected, and their extinction appears to have occurred abruptly. Finally, the Tentaculitoids, those tiny cone shaped animals abundant during the Devonian, suffered total extinction at the Frasnian-Famennian boundary.

What happened on land?

The Devonian was a time of major development for land plants with the first tree Archaeopteris and the first seeded plants developing. A major decline in spores occurs in the Frasnian, but no diversity change is observed in plant megafossils.

Proposed Extinction Mechanism

A number of studies have looked at the timing and duration of the F-F extinction and also considered whether it was sudden or gradual? All have agreed that the extinctions occurred at the F-F boundary. As to the mechanism that drove the extinction below are some possible culprits:

a) Bolide impact
b) Global cooling
c) Global warming
d) Sea-level change, including regression
e) Eutrophication caused by plants
f) Widespread marine anoxia

Frasnian-Famennian Type Section in this French Quarry

My research work suggests that widespread marine anoxia – ‘poison from the deep’ – was the trigger for the F-F mass extinction. During the Late Devonian much of Euramerica and Gondwana lay at low latitudes. Temperatures were warm, and the period was characterised by widespread reef development in tropical oceans. Much of the evidence for the extinction comes from these latitudes. As part of my own studies I have visited sections in Poland, Germany, France, and the western and eastern United States, which provide data from the margins of three separate oceans.

In all the field localities I have visited there is abundant evidence that anoxic waters developed within epicontinental basins during the late Frasnian (e.g. the Kellwasser facies). There are classic black limestones and shales in the USA, Europe, N. Africa, Siberia, China, and Russia and there are also abundant geochemical proxies (e.g. trace metals, pyrite framboid analysis) and lithology (e.g. fine laminations) which together suggest that the most intense and widespread phase of anoxia occurred during the very latest Frasnian, together with the extinction amongst most, if not all groups.

Conclusion

So, have we solved the problem? Certainly there is abundant evidence that marine anoxia and extinction in the Devonian are causally linked. The ultimate cause? Perhaps a newly discovered Large Igneous Province in Siberia holds the answer!

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Disarming Dromaeosaurs
Phil Manning Ph.D., University of Manchester

Introduction

Dromaeosaur means “swift lizard”. They were a group of small carnivorous dinosaurs or theropods that included Velociraptor and Deinonychus. A distinguishing features of this group is the huge sickle-like claw on the second toe of its foot. Dromaeosaurs are in fact possibly the closest known relatives of birds. They gained some notoriety through their role in the Hollywood film Jurassic Park by Steven Spielberg as the vicious “raptors”. They were more than likely a family of small to medium-sized, lightly built and fast-running dinosaurs from the Cretaceous Period (146 MA to 65 MA) who appear from the fossil record to have been very smart predators. There is even evidence some, such as Deinonychus hunted in packs.

Dinosaur Tracking

A footprint is made when a dinosaur’s foot is impressed into the sediment. Usually the resulting footprint impression retains evidence of both motion of the foot and the physical state of the sediment. The footprint needs to be covered by later sediment in order to be preserved. By examining the footprints it is possible to determine if it was made by a quadrupedal or bipedal dinosaur.

Sauropod Footprint from the Saltwick Formation

There are many examples of dinosaur tracks and trackways known around the world. The prints are usually in sandstone, limestone or mudstones. The original track may be seen or an undertrack in which parallel laminae beneath are pushed down i.e. deformation of sediment. The footprint or track may be seen as a mould or a cast or as both. They may be classified into one of three categories: 1. Sauropod Footprints - usually made by the large quadrupedal dinosaurs such as Brachiosaurus or Diplodocus; 2. Ornithopod Footprints - tridactyl (three-toed) usually made by the bipedal herbivorous dinosaurs like Iguanodon; 3. Theropod Footprints - tridactyl footprints of narrower type, with claws, made by the bipedal carnivorous dinosaurs.

Dinosaur tracks are abundant in the Middle Jurassic non marine rocks of Yorkshire. Recent ongoing work by Whyte and Romano of Sheffield University (1993 to 2003) has provided evidence for several varied footprints thus indicating a presence of varied dinosaur communities. The track distribution suggests that the Yorkshire dinosaur communities were made up of between 7 - 10 common types, belonging to sauropods, stegosaurids, ornithopods and theropods. The area is a megatracksite of global importance.

Dinosaur killer claws or climbing crampons

Dromaeosaurid theropod dinosaurs, such as Deinonychus, possess a strongly recurved claw. It is commonly suggested that, in combination with strong kicking / slashing actions of the hindlimb, this claw functioned to disembowel prey, in particular large herbivorous dinosaurs, such as the contemporaneous Tenontosaurus. This hypothesis has been tested using evidence from comparative pedal ungual morphology and by construction of a robotic model of a dromaeosaurid hindlimb that was used to simulate the forces acting at the ungual / flesh interface during attacks on prey. The data suggests that, contrary to the existing consensus, dromaeosaurid claws were not designed for slashing through flesh, but were used to grip the hides of prey many times larger than themselves in an analogous fashion to climbing crampons.

Killer Claw or Climbing Crampon?

The robotic limb built to test the disembowelling hypothesis was designed and constructed by Pennicott Payne Models and Special Effects (London) in connection with a BBC television production (The Truth About Killer Dinosaurs). The dimensions for the hydraulic limb were constrained by using the limb dimensions, articulations and functional morphology of the dromaeosaurs. The mechanical limb mimicked the sort of kick that might have come from a 2m-long, 40kg Velociraptor. The Kevlar and carbon-fibre-coated aluminium claw was thrust into the flesh from pig and crocodile carcasses.

Skin impact

Instead of producing the expected slashing wounds, the robotic impacts created only small, rounded punctures. What is more, the way the skin tissue bunched under the impacts prevented the claw from withdrawing easily. The punctures had a depth of about 30-40mm. It seems highly unlikely that wounds of this depth would have posed a danger to the vital organs of a large herbivorous dinosaur, though they would obviously be fatal to small prey, It’s effectively like a fatal embrace. These claws were used to hook into the flanks of prey larger than them so the jaws could do the despatching. This fatal embrace is analogous to the hunting technique used by many species of big cat that use their protracted claws to cling onto their prey.

Introduction

The cause of earthquakes has historically been attributed to mythical beasts or the wrath of Gods! However, the first rational explanation of earthquakes is from Greek natural philosophers. Aristotle (4th Century BC) attributed earthquakes to the shaking of the Earth due to dry heated vapours underground or winds trapped in its interior trying to leave toward the exterior. In the 17th Century A. Kircher (1678) related earthquakes and volcanoes to a system of fire conduits inside the Earth. In the 18th Century M. Lister and N. Lesmery suggested that earthquakes were caused by explosions of flammable material concentrated within the Earth's interior.

The destructive Lisbon earthquake and associated tsunami (1st November 1755) ultimately proved to be the starting point of modern seismology (a term derived from two Greek words: Seismos = Shaking and Logos = Science or Treatise). In 1760, J. Mitchell (a Cambridge astronomy) was the first to relate earthquake shaking to the propagation of elastic waves inside the Earth.

An Irish engineer, Robert Mallet (1857), made an important contribution by mapping earthquake zones around the Mediterranean. He suggested that earthquakes are elastic waves of compression caused by the sudden flexing and fracturing of the Earth’s crust.

John Milne: UK

Born in Liverpool in 1850 and spending his early years in his home town of Rochdale. Milne had an eventful career quite unlike any of his peers. At the age of 13, he entered Liverpool Collegiate Institute where he gained many prizes, one of which was a sum of money which he used it to fund a trip to the Lake District.

John and Toné Mile

Not content with viewing the natural splendour of the Lakes, he crossed over to Ireland and made his way to Dublin by existing on apples and what he could earn by playing the piano at pubs on route.

Having moved south and now aged of 17 he entered King's College London where he studied Maths, Mechanics, Divinity, Geology, Chemistry, Mineralogy, Geometrical Drawing and Surveying. This was followed by a spell at the Royal School of Mines (London) and Freiburg, where he studied more on Mineralogy.

In the early 1870's he was fortunate to have visited Iceland, Newfoundland and the Sinai Peninsular. This widespread experience as a field geologist specialising in minerals and mining significantly contributed to Milne being appointed consulting engineer to the newly-formed Public Works Department of the Japanese Government. Milne was not a keen sailor so to many peoples surprise he made the journey to Tokyo overland via Scandinavia, Russia, Siberia, Mongolia, China and finally Japan.

John Milne: Japan

In Japan Milne worked on Japan’s Volcanoes (plus volcanoes of the Kurile Islands), their formation and geological distribution. Milne concluded that: ‘the majority of earthquakes which we experience do not come from volcanoes nor do they seem to have any direct connection with them’.

The origin of the Japanese people captured Milne's attention. He struck up a friendship with Morse (USA) although in time Milne's opinions on the Stoneage Japan differed considerably from those of Morse. Much of his recorded work took place in and around Hakodate where on Hokkaido, the northern-most island along the Japan arc.

The Tokyo - Yokohama earthquake of Sunday, 22nd February 1880 proved to be the turning point in Milne's career where one might say Milne the Seismologist was born! Milne founded the Seismological Society of Japan and was a guiding force in the development of the seismograph alongside Thomas Gray and James Ewing.

In June 1871 Milne was elected to the Royal Society.

The Mino-Owari earthquake of 28th October, 1891, with its spectacular faulting, helped convince Milne that faulting caused earthquakes by the release of strain energy which had been stored in rock through the slow deformation of the Earth's crust (Milne, 1898b, p 24-38). This earthquake is sometimes referred to as the Nobi Earthquake of 1891.

Milne collaborated with W.K. Burton and K. Ogawa in completing a photographic record of the 1891 earthquake (The Great Earthquake of Japan, 1891) and also The Volcanoes of Japan (part 1 Fujisan).

On leaving Japan in 1895 with his wife Tone, Milne was presented with the Order of the Rising Sun from the Meiji Emperor - an honour rarely accorded to any foreigner.

John Milne: Isle of Wight

In 1895, on his return from Japan, John Milne set up his observatory in an old stable. Milne made sure the concrete foundation was put in place prior to the first seismograph being put into operation on 16th August, 1895. At the nearby Carisbrooke Castle, another seismograph was installed in 1896. His friend and assistant, Shinobu Hirota collected daily details from the Carisbrook seismograph. By 1900 Milne had added a laboratory. Sometimes several seismographs at a time were in operation, however, the principal one was the Milne horizontal pendulum.

Milne became the driving force of the BAAS Seismological Investigation Committee and fulfilled his goal by setting up the first global network of seismograph stations. The observatory closed following his untimely death in 1913.

BAAS REPORT ON THE STATE OF SCIENCE 1914

The death of John Milne in July 1913 creates a situation of some difficulty and anxiety. He organised a world-wide seismological service with very little financial help from others. In many of the outlying stations the instrumental equipment was provided either by himself or by one of his friends, and the care of it has been generously undertaken by a volunteer who is often busily engaged in other work. The collation of results was in the early years untaken by Milne himself, with the able help of Shinobu Hirota. Of late years a subsidy of 200/ a year from Government Grant Fund allowed of paid assistants; and Shinobu Hirota thus obtained a well-deserved official position; but for many years the only salary that he received was paid from Milne's own pocket.

Professor John Milne, D.Sc. F.R.S., F.G.S.,
Hon. Fellow of King's College, London.

30 December, 1850 - 31 July, 1913

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Field Meetings

Carboniferous limestones of Low Furness, South Cumbria
Leader: Steve Webster

Time & Date: 10:30 am, Sunday, 21st May 2006

Meeting at: the crossroads at the northwest corner of Birkrigg Common Grid Reference [280 746].

Practical details: the first part of the excursion is on Birkrigg Common, 4 km south of Ulverston, on open land with easy access and parking. In the afternoon we shall make our way to a coastal section to see evidence of the Devensian ice age in the form of kame terraces and erratics. Appropriate clothing and suitable, strong footwear are recommended.

Geological setting: the Lake District is partly flanked by Lower Carboniferous rocks which here at Furness are represented by several lithological formations, five of which are dominated by limestones that were deposited in warm, clear, shallow seas as Britain drifted northwards through tropical latitudes. Their varying character is due to changes in depositional conditions, particularly in water depth, wave and/or current action and the amount of muddy sediment carried by streams from the landmass to the northwest. Corals and brachiopods may be seen.

The Devensian cold stage did much to shape the Lake District. It is a period of earth history dominated by major climatic changes and characterised by the growth large ice caps in temperate mid-latitudes.

O.S. Maps:
1:25 000 Sheets SD 27, Barrow in Furness (North)
SD 37, Grange over Sands.

BGS Maps:
1:25 000, Classical areas of British Geology series, Dalton in Furness.

Reference:
Cumberland Geological Society 2000: Lakeland Rocks and Landscape - a Field Guide.

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Malham
Leader: Peter Chiles

Time & Date: 10:30 am, Saturday, 24th June 2006

Meeting at: Malham village car park.

Practical details: the excursion is entirely within the confines of the Yorkshire Dales National Park; thus hammering of the exposures is strongly discouraged. Carry packed lunch, have stout footwear and be prepared for any inclement weather.

Geological setting: this excursion will highlight Carboniferous (Dinantian and Namurian) stratigraphy and structural relations at the southern margin of the Askrigg Block along the line of the Mid-Craven Fault (MCF) and the North Craven Fault. Features relating to mineralization, Quaternary geology and geomorphology may also be observed during the day.

Local industries took advantage of geological resources. Copper and calamine (zinc carbonate) were mined on Pikedaw (SD 884 636). Lead was mined locally and smelted at the mill where a chimney still stands (SD 883 659). Unusually coal was found on the top of Fountains Fell (600m).

O.S. Maps:
1:50 000 Sheet 98, Wensleydale & Upper Wharfedale.
1:25 000 Outdoor Leisure Map 10, Yorkshire Dales-Southern Area.

BGS Maps:
1:50 000 Sheet 60, Settle.

Reference:
BGS Memoir, Settle (Arthurton et al., 1988).

The Craven Fault Zone - Malham to Settle.” in Yorkshire Rocks And Landscape: a Field Guide Edited by Colin Scrutton, 1994 (to be reprinted in 2006).

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Mineralisation around Greenhow, near Pately Bridge
Leaders: David Turner and Jean Chicken

Time & Date: 10:30 am, Sunday, 16th July 2006

Meeting at: Grid Reference [SE 128 643] where cars can be parked at the Toft Gate Lime Kiln.

Practical details: the excursion covers 6 miles (9.7km) on paths and tracks with 5 stiles. Carry packed lunch and be prepared for the vagaries of Pennine weather. Boots are recommended for this excursion.

Geological setting: the Greenhow Mining Field is one of Yorkshire’s oldest and most productive lead and fluorspar mining areas. Some of its more recent remains can be seen alongside the Grassington to Pateley Bridge road. Lead mining passed continued until the 1930s, with sporadic attempts at fluorspar working until the 1980s. Owing to its elevation, Greenhow differed from the usual Dales’ practice of using waterwheels and instead used steam engines for winding and pumping. The most spectacular example of this was at Cockhill Mine, where a 250 foot deep shaft was used as a chimney for boilers fixed in an underground engine house.

Lead-zinc-fluorite-baryte veins have been worked in most Dinantian shelf limestone areas. The most productive have been the Northern and Southern Pennine Orefields (lead-fluorite-baryte). Fluorite and baryte replaced lead as the main economic minerals in the Greenhow field.

O.S. Maps:
OS Explorer 298 Nidderdale.

Reference:
Morrison, John 1998: Lead mining in the Yorkshire Dales.
Dalesman Publishing company, Skipton, North Yorkshire.

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Blackstone Edge and Rochdale Cemetery
Leaders: Paul Kabrna and Barry Smith

Time & Date: 10:30 am, Sunday, 20th August 2006

Meeting at: the White House Inn public car park at Grid Reference [968 178] on the A58 Rochdale to Halifax road about 2 miles east of Littleborough.

Practical details: bring a packed lunch or you can visit the Moorcock Inn which is open for food all day. Be prepared for all kinds of Pennine weather! Boots are recommended at least for the Blackstone Edge part of the excursion.

Geological setting: Blackstone Edge is situated on the crest of the north-south trending Pennine Anticline. It is composed of thick Kinderscout Grit which forms rough crags. Nearby stream outcrops in Red Brook (by Lydgate Mill) expose Coal Measure strata. As you follow the brook downstream you go down succession into older Namurian rocks (this is similar to traversing Paul Clough in the Cliviger Valley). Blackstone Edge is also one of the best exposures of weathered regolith (grus) in northern England and is important for the study of weathering processes, landscape evolution and tor formation.

The afternoon session at Rochdale Cemetery will demonstrate a unique and remarkable survival of an early attempt to promote geology (1855). There are a series of 30 geological specimens of varying age arranged along one side of the carriageway which surrounds the SE portion of the grounds from Bury Road to Sandy Lane.

O.S. Maps:
OS Explorer 287 West Pennine Moors.

Reference:
Broadhurst, F.M., Eager, R.M.C., Jackson, J.W., Simpson, I.M. and Thompson, D.B. 1970 No. 7: The Area around Manchester. Geologists’ Association Guide.

Baldwin, A and Alderson, D.M 1996 A remarkable survivor: a 19th Century geological trail in Rochdale. Geological Curator Volume 6, No. 6

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Early Carboniferous geology of the Pendle Hill area
Leaders: Paul Kabrna and Hed Hickling


A joint meeting with Oldham Geological Society

Time & Date: 10:30 am, Saturday, 23rd September 2006

Meeting at: Nick O’ Pendle lay-by [SD 772 860]. In the afternoon we shall meet at Salthill Quarry, Nature Trail car park [SD 7550 4265].

Practical details: this area around the Nick O’ Pendle is very exposed to inclement weather and members should be suitably equipped. Localities will be visited along the A59 so care must be taken. Bring a packed lunch or visit the Swan With Two Necks pub in Pendleton. No hammering in Salthill as it is a SSSI.

Geological setting: the Dinantian sequence in the Craven Basin is very thick (over 6km) and accumulated in an actively extending asymmetric rift basin, trending ENE - WSW. Marine sedimentation in the early Dinantian began on a carbonate ramp which subsequently fractured into a series of tilted fault blocks which actively controlled deposition during the Dinantian. The rift basin is bounded by the Askrigg Block and the Southern Lake District High to the north, and the Central Lancashire High to the south. During the late Dinantian there was an influx of deltaic sediments into the Craven Basin (Pendleside Sandstone) and in Pendleian times (Namurian) there was a huge influx of deep water turbiditic sandstone into the basin.

O.S. Maps:
1:50 000 sheet 103 Blackburn and Burnley.
1: 25 000 sheet SD 64 / 74 Clitheroe and Chipping.

Geol. Survey 1:63 360 Sheet 68 Solid Clitheroe.

Reference:
Earp, J. R., Magraw, D., Poole, E. G., Land, D. H. & Whiteman, A. J. 1961. Geology of the Country around Clitheroe and Nelson. Geological Survey of Great Britain Memoir, England & Wales, Sheet 68.

Miller, J. & Grayson, R. F. 1972. Origin and structure of Lower Viséan “reef “ limestones near Clitheroe, Lancashire. Proceedings of the Yorkshire Geological Society, 38, 607-638.

Riley, N. J. 1990. Stratigraphy of the Worston Shale Group (Dinantian), Craven Basin, north-west England. Proceedings of the Yorkshire Geological Society, 48, 163-187.

Donovan, S.K. 1992. A field guide to the fossil echinoderms of Coplow, Bellman and Salthill Quarries, Clitheroe, Lancashire. North West Geologist, 2, 33-54.

Donovan, S. K., Lewis, D. N. and Kabrna, P. 2005. An unusual crinoid-coral association from the Lower Carboniferous of Clitheroe, Lancashire. Proceedings of the Yorkshire Geological Society, 55, Part 4, pp 301-304.

Donovan, S. K., Lewis, D. N. and Kabrna, P. 2006. A dense epizoobiontic infestation of a Lower Carboniferous crinoid (Amphoracrinus gilbertsoni Phillips) by Oichnus paraboloides Bromley. Ichnos 13: 1 - 3.

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