The Open University Geological Society Wessex Branch Newsletter

Website http://ougs.org/wessex

July 2015

Branch Organiser’s Letter CONTENTS Branch Organiser’s Letter Page 1 Dear All Mendips weekend, 18-19 April 2015 Pages 2-6 I attended the OUGS AGM in Bristol in April and the Minerals guide no. 15 – Hydrozincite Page 6 Branch Organisers meeting in June. You will be aware that there is a proposal that associate , 10 May 2015 Pages 7-8 members of OUGS (ie those who have not studied or Cullernose Point, Northumberland Page 9 taught at OU), who pay the same fee as full Wessex Branch committee Page 9 members, should now be given the same rights (eg be able to vote at AGMs and hold posts on the Other organisations’ events Page 10 committee). The next OUGS Newsletter will include Forthcoming Wessex Branch events Page 11 different views about this. For your information, OUGS events listing Page 12 Wessex Branch has a number of very active and supportive associate members - as have other branches. Once you have had time to consider this October and November. Contact Jeremy if you would please let me know on [email protected] what you like to attend field trips on [email protected] think. I’m looking forward to our residential trip to Anglesey The other point of discussion was health and safety in September (waiting list only). Mark Barrett has on field trips. A good point was made by someone also booked our trip to Mull, 14th to 21st May 2016. who is an events organiser and also a geology leader Dr Ian Williamson is the leader. Contact Mark about - undertake your own risk assessment at any site the residential trips on [email protected] you visit, by standing back and observing potential I have a title for our AGM and lecture Day on hazards and take necessary action to protect yourself Saturday 23rd January 2016: “Mars, Mull and in addition to noting what the leader says and what Mountains”. There will be an advert in the next is written on the risk assessment form. See page 12 Footnotes. Dr Susanne Schwenzer will talk about of this newsletter for information about insurance. Mars and the Curiosity mission (unless she is called Our two-day trip to the Mendips in April and geo- away on another Mars project). Dr Ian Williamson, walk around the Cerne Abbas area in May went who is leading our residential trip to Mull in May 2016, extremely well. The trip to see three chalk pits will cover the geology of Mull and Dr Tom Argles, our around Dorchester was really informative. Many OUGS President, will give a lecture on an aspect of thanks to our leaders Dave Green, Kelvin Huff and the geology of the Himalayas. Rory Mortimore. Also thanks to you as participants The 2016 Symposium will be at Exeter University for your enthusiasm and interest that makes it all from Friday 8th to Monday 11th July 2016, with worthwhile for the leaders and organisers. potential field trips for a few days before in Devon I’m putting the finishing touches to the trip I am and after in . The title is HOW THE WEST WAS leading up Ham Hill on Saturday 4th July in memory MADE. Prof Iain Stewart hopes to give our of Hugh Prudden, who led a number of trips there for introductory lecture and we have a number of us. We will to be able to visit the working quarry and confirmed lecturers from what was Camborne School stone masons yard in the morning, after meeting of Mines, Plymouth University, the Met Office and outside the Prince of Wales pub on Ham Hill. BGS. July 17th to 19th is the Symposium in Newcastle. I Do look at the website hope to see many of you there. http://ougs.org/index.php?branchcode=wsx where Colin will post any changes to events and also On August 2nd Jeremy will lead a trip to Worbarrow news items. near the abandoned village of Tyneham on the Dorset coast between Lulworth Cove and Best Wishes Kimmeridge. Sheila Alderman, Branch Organiser Wessex On September 13th Sam Scriven from the Heritage xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Coast Team will take us to see the ammonite xxxxxxxxxxxxxxxxx (evenings only) graveyard at Lyme Regis. We also have trips in E-mail: [email protected]

Wessex Footnotes July 2015 Page 1 WESSEX OUGS WEEKEND FIELD TRIP TO THE MENDIPS, 18-19 APRIL 2015 Leader: Dave Green Reports by Andy Mitchell and Mark Barrett

SATURDAY, 18 APRIL 2015: BURRINGTON COOMBE

Burrington Coombe [ST 477 588] By way of introduction, Dave Green explained that the upper Old Red Sandstone formed the core of an east/west asymmetrical anticline, flanked by Carboniferous deposits, which was created as a result of the Gondwana/Laurasia collision and the consequent Variscan orogeny, To view this part you should visit the Members only area with its push from the south creating a series due to copyright considerations. of periclines – all separated by synclines. Our aim was to walk a transect of the Carboniferous and Upper Devonian on the northern limb of the Blackdown Pericline. Log in using your membership number and surname

Location 1 – Quarry 1 [ST 477 590] Here we saw an exposure of the Clifton Down Limestone (CDL) with near-vertical dipping. It was a very fine grained variable biosparite/micrite with red stylolites and some crinoid and coral debris – indicative of a sheltered, low energy, lagoonal environment to the south of St Georges Land. The limestone produced a sulphurous smell when broken up (Stink Stone). The sulphur, on mixing with hydrothermal chlorides, gave rise to the lead ore deposits and mining history in the Mendips. The Clifton Down Limestone here was used for road base material and concrete supply. We saw evidence of blasting on the rock surfaces (plumose surface texture). The Clifton Down Limestone had been deeply buried, severely tilted and recrystallised.

Quarry 1 Photo by Andy Mitchell

Wessex Footnotes July 2015 Page 2 Location 2 – Quarry 2 [ST 476 588] The Burrington Oolite (BO) formed as a result of high energy wave action in water less than three metres deep. Older than the Clifton Down Limestone, the Burrington Oolite exhibits slickensides created by the action of competent rocks sliding over strata in order to accommodate folding. The central part of the quarry face is oolitic with two distinct dolomitic ribs forming local breaks in deposition with evidence of recrystallisation, pink staining and erosional surfaces. At the top of the north quarry edge was evidence of an unconformity, with red Triassic terrestrial conglomeritic flow deposits representing a wadi overlying part of the Burrington Oolite. Quarry 2 Photo by Andy Mitchell

The group then walked along the B3134 up the valley between the Barrington Oolite, past The Rock of Ages, to Avelines Hole (cave) where there appeared to be a confusion of bedding planes and jointing, and further on to the Black Rock Limestone (BRL). The dips at Quarry 1 were 65 NE becoming less steep with a 57NE dip at the start of the Black Rock Limestone, where evidence of localised calcite replacement by silica was seen in fossils. The Black Rock Limstone represents open shallow clear water seas and contains a good variety of fossils (Productus, Spirifer, crinoids, colonial corals etc). Rod Ward (public domain) Rock of Ages (legend has it that a local Continuing along the B3134, the road turns and follows the preacher wrote the hymn of this name strike of the Black Rock Limestone to join a footpath leading while sheltering from a storm here) away from the B3134 uphill to our third location.

Location 3 – East Twin Swallet [ST 479 580] East Twin Swallet is a cave where the Eastern Twin Stream meets the interface between an impermeable and a permeable rock formation - the Lower Limestone Shale (LLS) and the Black Rock Limestone containing thin impermeable chert beds. The path continues uphill following the stream where near-vertical dipping shales can be seen in the stream bed. We continued up the hill towards the core of the anticline to find the Upper Old Red Sandstone (UORS), a red quartz sandstone (Devonian under the Carboniferous). The red colour is due to oxidisation in a dry environment. The sandstone was most likely freshwater river deposits, close to a marine area – perhaps beach-type sands. The path swings back west along the Old Red Sandstone and back onto the strike of the Carboniferous sequences. A break in the trees enabled a view of the Great Scarp and Corner Buttress with its optical illusion of apparent dips and faulting on the scarp face. Also worth noting were the vegetation differences where the well-drained Old Red Sandstone is typical of bracken versus the limestone thin soil grasslands. At the 48S dip arrow on the map (ST475 580), the path joins the Western Twin Stream and follows the dip down towards the B3134 to see another swallet feature Great Scarp apparent dips near the pump house where the stream goes Photo by Andy Mitchell underground.

Wessex Footnotes July 2015 Page 3

Location 4 – Volvo Car Park, Gurney Slade [ST 622 491] After lunch we made a short visit to see an unconformity (~120 million year gap) of a Triassic dolomitic conglomerate (infill wadi deposit) and very irregular lower Carboniferous limestone surface (old land) having striking differences in colour. Trias conglomerate Photo by Andy Mitchell Location 5 – Velvet Bottom [ST 502 555] Here lead mine workings dating from Roman times have been re-worked at least three times since and reach maximum production in the mid-17th century. The lead was initially discovered by recognising surface mineral veins or ‘rakes’ and then excavating by hand. The mineralisation would have occurred as a result of deep hydrothermal mineral-rich solutions migrating up along faults and limestone jointing at great pressure. At one rake it was interesting to note the occurrence of flint nodules in the limestones (same as per chalk) on the bedding planes and silicified crinoid debris. The flints were only found on one side of a large rake working and apparent mineral pocket indentations on the other side “Gruffy ground” Photo by Andy Mitchell plus slickensides – indicating a separation due to faulting. The area of lead mining covered quite an extensive area with smelting works and a series of ore settling pools. “Gruffy Ground” is the local term for the broken-up landscape of pits and mine tailings. Andy Mitchell

SUNDAY, 19 APRIL 2015: Ebbor Gorge [ST 521 484] We met in the car park on a fine sunny day with a fresh northerly breeze. From just south of the car park you have a commanding view of the Vale of Avalon and the Quantock and Blackdown Hills in the distance. Dave Green explained that the small hills we could see perched above the alluvium in the vale would have been islands in an inland sea during the Pleistocene. Even more remarkable is the fact that the topography would have looked the same in the Triassic - except these hills would have been in a hot desert surrounded by salt lakes and a wadi environment. During the Jurassic some believe that the hills would have been islands in a shallow tropical sea, although this theory is not universally accepted for reasons that will become apparent later in the report. Ebbor Gorge Photo by Andy Mitchell Dave Green explained that the hills were either inliers or outliers. The inliers are the tips of thrust planes coming from the south and represent a series of overturned anticlines and synclines. They evidence the mountain building phase known as the Variscan Orogeny during the late Palaeozoic when Gondwana to the south collided with Laurasia to the north. This caused the Ebbor Thrust north west of Wells, whereby Carboniferous Limestone was thrust over the later Carboniferous Coal Measures. The inliers are nappes of Burrington Oolite, whilst the outliers represent the remnants of the Mesozoic cover that has been subjected to erosion. The outliers consist of Triassic Rheatic and Jurassic Lower Lias deposits. In the immediate foreground was a fault that was part of the Bristol Channel-Bray Fault along which the Bristol Channel and Levels have been eroded. This was a dextral fault that also happened to bring Devon, Cornwall, Dorset, Wiltshire and parts of Hampshire (that hitherto had been located south east of Paris) alongside the rest of .

Wessex Footnotes July 2015 Page 4 We then started to walk down into the gorge where initially we were shown an exposure of the Burrington Oolite that was dipping 45° south into the hillside. This rock contained stretched oolites and calcite veins, indicative of the great stress, heat and pressure that the rocks had undergone during the Variscan Orogeny. Eventually we found the Ebbor Thrust, where limestone had over-ridden the impermeable Coal Measures. The boundary was indicated by a boggy stream and Dave Green managed to find the coal-bearing sandstone in the root bole of a fallen tree. Most of the Coal Measure deposits originated from rivers to the north and, unlike here, were mostly incompetent shales and thus very susceptible to faulting and deformation. We then walked back up the gorge on the opposite side of the valley and back up through a sequence of limestone deposits, although here it was hard to differentiate between the Clifton Down and Burrington Limestone beds which were now dipping towards the north east. As we walked up the narrow gorge, our leader stated that the theory that it represented collapsed caves caused by the erosion of the overburden cannot be substantiated, as there is no evidence of cave roof within the gorge. The gorge also meanders across the strike of the rocks and is The narrowest point of Ebbor Gorge discordant to the structure. This was because the stream (not visited on this trip) that created it flowed across an alluvial flood plain that © Graham Taylor 2006, licensed for reuse under has since been eroded away. It reached the limestone Creative Commons Licence CC BY-SA 2.0 rocks during the Ice Age, when they were frozen and thus impermeable, therefore the melt water stream cut down through the rock following its original course. There is also a theory that around 400ka this area and south Wales were domed by the asthenosphere but not sufficient to create a volcanic hotspot, and the uplift helped facilitate the cutting of the gorge.

Downhead Quarry [ST 689 461] In the afternoon we visited a disused quarry in order to examine the Silurian rocks at the heart of the Beacon Hill pericline. The quarry is now overgrown with secondary woodland and the remains of a narrow gauge railway lead you to the quarry face. The rocks are intermediate volcanic andesites from the Wenlock series which are fine grained with evidence of iron staining. They represent lava flows and are extremely variable in structure depending on whether you are looking at the top or bottom of the flow. The top of the lava flow is indicated by darker clasts within the generally grey matrix, showing where the lava cooled and congealed on exposure to the air. It is also indicated by the presence of vesicles. The rocks contain small phenocrysts of either blue-green chlorite or pale green epidote, caused by the alteration of the original mafic materials either at the time of eruption or post-burial due to the effects of water percolating through the rocks. It is not known what caused the Silurian Volcanics but it is most likely caused by subduction around 420Ma. (Andesites are named after the Andes mountains which arose as a consequence of subduction). The rocks dip 50° to the south and at one exposure we found evidence of flow banding, which is caused by impurities being streaked through the lava as it flows. Upper Old Red Sandstone from the Devonian rests Flow banded andesite at Downhead Quarry Photo by Andy Mitchell uncomformably on the Silurian Volcanics.

Wessex Footnotes July 2015 Page 5 Holwell fissure exposures [ST 728450] We finished off the day by visiting this remarkable quarry face which consisted of Carboniferous Limestone that contained numerous fissures which could have been caused by tectonic faulting and tilting or due to solution as water percolated down and widened the rocks along joint planes. As stated at the beginning of this report, it was believed that the topography of the region was similar in the distant past as it is today. However, these fissures are filled with Triassic Mercian Mudstone and dog tooth calcite, which must have originally totally covered the limestone for it to fall down the fissures. Furthermore, these fissure deposits are topped by Jurassic Lower Lias with intact depositional beds. This demonstrates that the whole of the area was overtopped by Triassic Sandstone deposits laid Old Quarry Wall, showing fissures with Triassic down in a wadi-filled desert; subsequently the and Jurassic infill Photo by Andy Mitchell entire area was drowned by a shallow sea in the Jurassic. This challenges the theory that the outliers and inliers represented high ground in a Triassic desert and islands in a tropical Jurassic sea. This was a highly successful and enjoyable weekend. This was due to the enthusiasm of the participants and particularly the knowledge and enthusiasm of the leader, who also prepared an excellent accompanying handout. Mark Barrett

SIMPLE GUIDE TO MINERALS 15 – by Colin Morley

Hydrozincite Zn5(CO3)2(OH)6 You have probably guessed from the name that hydrozincite is a basic zinc carbonate. It is really a secondary mineral from the oxidisation zone of zinc deposits. As an oxidation product it is often found in 'post mining' conditions. It is also known as zinc bloom. As usual the colour is not a good identifier; it can range from white, through a light yellow to a grey colour. The crystal form can also vary widely from tiny radiating slender monoclinic form to the much more common massive (also as stalactites). The best way to positively identify it is that it is just 2-2.5 on the Mohs scale, produces a white streak and best of all it fluoresces pale blue to lilac under shortwave UV. It does fizz well in hydrochloric acid even when cold and very diluted. If subjected to heat, the H2O and CO2 are lost starting at about 230°, leaving just ZnO. Scientists in Sardinia are exploring the precipitation of hydrozincite from a microbial community made up of cyanobacterium and microalgae for the natural removal of harmful metals, especially Zn, from the stream waters. Although first recorded in Austria in 1853, a very nice botryoidal form has been found in the Hilton Mine in Cumbria. Colin Morley

Hydrozincite in normal light (top) Note for readers of the printed copy of Footnotes and in UV light (bottom) To see the effect of UV light, check the website or sign up for the Specimen in the Sun City Rockhounds collection electronic version of the newsletter. Ed Photos by Colin Morley

Wessex Footnotes July 2015 Page 6 WESSEX OUGS FIELD TRIP TO CERNE ABBAS, 10 MAY 2015 Leader: Kelvin Huff Report by Geoffrey S Dearn The village of Cerne Abbas sits in a river valley in the chalk downland of Drift Clay with flints Quaternary mid-Dorset, some eight miles north Seaford Chalk Fm. Coniacian of Dorchester. This was a field trip Late Turonian - Lewes Nodular Chalk Fm. with a difference for although an White Chalk early Coniacian extensive quarry has been carved Sub-group New Pit Chalk Fm. Turonian out of Giant Hill in the past this is Late Cenomanian - now overgrown and no major Holywell Nodular Chalk Fm. outcrops are now to be seen. We early Turonian Grey Chalk were, however, not to be Zig Zag Chalk Fm. Cenomanian Sub-group disappointed. Cerne Abbas is built Upper upon an Upper Greensand Shaftesbury Sandstone Member Albian Greensand basement, the surrounding hills Fm. Cann Sand Member Albian being of chalk capped with clay with Gault Fm. Albian flints. The local lithology is summarised in the table at right. Having assembled at the Kettle Bridge picnic area we followed a footpath leading to Abbey Street, crossed the 19th century burial ground, passed through a hummocky field which was once the site of and ascended the western slope of Yelcombe Bottom. This is a dry valley formed by Quaternary solifluction and erosion. The remains of a lime kiln marked the beginning of what was once a large quarry cut mainly into New Pit Chalk. On the western face of the hill the well-known 17th century of the Cerne Abbas Giant is also carved into chalk of this formation. At the top of Giant Hill we encountered a field of clay with flints, the flints clearly derived from eroded White Chalk deposits. Less certain is the origin Kelvin Huff (far left) briefs members on the day's events at Kettle Bridge picnic area. of the clay although it has been suggested that it Photo by Geoffrey Dearn derives from Paleocene-Eocene laterites. At Minterne Parva Farm we stopped briefly to examine the building stones, mainly Shaftesbury Sandstone and Ham Hill Stone. Nearby was the stump of a preaching cross, also in Ham Hill Stone.

From Minterne Parva we continued on by road to Upcerne. Badger holes by the roadside revealed dark glauconitic and unconsolidated Cann Sand. From a distance we were able to view the Ham Hill Stone frontage of the 17th century manor house before leaving the road to cross a field. The basement rock here is a fossiliferous Shaftesbury Sandstone. This Fragment of Neithea gibbosa yielded a fragment of the flattened left valve of Neithea gibbosa Pultney 1813 in Shaftesbury embedded in the pale cream speckled sandstone. We returned to Sandstone from Upcerne Kettle Bridge picnic area on the edge of Cerne Abbas for a packed Photo by Geoffrey Dearn lunch before examining building stones used in the village.

As well as local stone, the buildings of Cerne Abbas incorporate material from further afield that was salvaged from the ruins of the abbey, largely destroyed in 1539. We began the afternoon’s village walk at Kettle Bridge, constructed with weathered Upper Greensand. Just upstream is the flood defence barrier - gabion baskets placed across the river channel to moderate the flow in the event of extreme rainfall. The next stop was Beauvoir Court, formerly North Barn, built with massive blocks of Holywell Nodular Chalk.

Kettle Bridge Photo by Geoffrey Dearn

Wessex Footnotes July 2015 Page 7 We followed the river to Mill Lane where exposed walls revealed a mixture of local and non-local stone. One that caught our attention was of dark red cross-stratified sandstone, possibly dune bedded and perhaps of Permo- Triassic age. The frontage of the New Inn in Long Street had a selection of material - Ham Hill Stone from the Upper Lias and Purbeck stone joined chalk and flint. Weathering of a block of chalk at the eastern end of the frontage exposed a Cenomanian ammonite Calycoceras and Inoceramus bivalves. The New Inn is roofed with split Purbeck stone and has a steep pitch reminiscent of buildings in the Cotswolds. Block of dark red cross-stratified sandstone Mill Lane, Cerne Abbas Photo by Geoffrey Dearn

The Old Bell, a former public house, has lower courses of Purbeck stone with flint and chalk courses above. The junction of Long Street and Abbey Street is dominated by the early 16th century Royal Oak Inn, its walls built of flint and rubble. Further along Abbey Street we paused to examine St Mary’s church with its tower and entrance porch of Ham Hill Stone. The church was built in the 13th century with 14thand 15th century and later additions. At the northern end of Abbey Street we followed the path through the burial ground to St Augustine’s Well. There are the remains Weathered block of chalk in frontage of New th Inn, Cerne Abbas with Calycoceras ammonite and of a 15 century Ham Hill Stone preaching cross in the Inoceramus bivalves Photo by Geoffrey Dearn graveyard. Hamstone seems to have been the material of choice for preaching crosses in this area. We had already seen one in Minterne Parva and the neighbouring village of Sydling St Nicholas also has one. The clear water of St Augustine’s Well is fed from a spring issuing from the Upper Greensand. A slab of ripple-marked limestone may be attributed to Purbeck Limestone. Our final stop within the village was a visit to the few remaining buildings of Cerne Abbey. The walls of the Hospice are of flint and Purbeck limestone with Ham Hill stone windows and the Abbot’s Porch incorporates Ham Hill Stone and Portland limestone. A short distance from Cerne Abbas is St Catherine’s Farm where we found a thriving industry in setting natural stone in concrete blocks as facing material for the building trade. In the yard were heaps of large flint nodules, basalt and Forest Marble, brought in from afar. There was even a paramoudra, a trace fossil that is found in only a few localities in Britain. As most of these are in Norfolk (Granville Bromley, R., et al, 1975, Paramoudras: Giant Flints, Long Burrows and the Early Diagenesis of Chalks. Copenhagen) its presence here may offer a clue to the source of the nodules. Paramoudra at St Cath- I gratefully acknowledge the information set out in Kelvin Huff’s field notes erine's Farm, Cerne Abbas for the OUGS Wessex Cerne Abbas Field trip 2015. Photo by Geoffrey Dearn Geoffrey S Dearn

Maps and further reading Postscript Ordnance Survey, 2010. Cerne Abbas & Bere Regis, Explorer Map 117. If you are planning to follow 1:25 000 (Southampton: Ordnance Survey). the progress of this field trip on BGS map 328 you British Geological Survey, 2000. Dorchester, England and Wales Sheet 328. will need the latest edition Solid and drift geology. listed at left. Based on 1: 50000. (Keyworth, Nottingham: British Geological Survey). resurveys made between Cerne Abbas. Jo Thomas Coast and County. Geological Walks in and around 1985 and 1996, this gives a Dorset. Dorset Geologists’ Association Group, 2003. wealth of detail not available on the older 1981 www.cerneabbashistory.org/pdfdocs/TheGeologyofCerne.pdf publication.

Wessex Footnotes July 2015 Page 8 CULLERNOSE POINT, NORTHUMBERLAND Following the Wessex Branch trip to Northumberland in June last year (see reports in the October and December 2014 editions of Footnotes), Alan Holiday stayed on to explore a few more geological sites, including Cullernose Point on 7 June 2014. The OUGS Symposium in July is another chance to visit this stunning county (see below). We were blessed with a gorgeous sunny day which showed the site at its best. We parked at GR NU25813 and walked along the coastal footpath to reach Cullernose Point after about 300 metres. The most striking feature at the site is the Whin Sill cutting the coastline (GR NU 260187) and exhibiting good columnar jointing (fig. 1). The cliff face is made of dark blue black dolerite and has proved ideal for nesting birds. The contact between the Whin Sill and the country rock can be observed (sandstone, shale and limestone units - Middle Limestone Group, Dinantian, Lower Carboniferous). The shale at the contact is quite rotted and the dolerite of the sill also looks to be rather altered. The sill changes horizon at beach level demonstrating its Fig. 1 Columnar jointing in Whin Sill transgressive nature, although generally it has a Photo by Alan Holiday concordant structure following the bedding. South of Cullernose Point the cliffs expose the sedimentary sequence of Yoredale cycles, rhythmic sedimentation associated with a deltaic and coastal marine environment which is characteristic of this section of the Northumberland Coast. There is a good wave-cut platform on the beach which exhibits good evidence of ‘whaleback’ folding with N/S strike to the fold axes (fig. 2). The limestone exposed on the lower beach also shows excellent honey comb weathering possibly exaggerated by the role of Fig. 2 Folds south of Cullernose Point colonising limpets. Photo by Alan Holiday Another feature is a Whin type dyke cutting across the beach with an ENE/WSW strike. In places it stands out positively but in others it has been eroded by recent processes (fig. 3). It has a typical sharp contact where it comes into contact with the country rock (sandstone) and develops a chilled margin. The country rock has been affected by thermal metamorphism although this is not very obvious. Fig. 3 Dyke cutting beach Nearby the sandstone shows good small scale cross-bedding features. Photo by Alan Holiday

Alan Holiday

43rd OUGS SYMPOSIUM 2015, 17 - 19 JULY 2015, NORTHUMBERLAND PANGAEA: LIFE & TIMES ON A SUPERCONTINENT A full programme of lectures, field trips and entertainment, based at Northumbria University, Newcastle Contact: Paul Williams at [email protected]

WESSEX BRANCH COMMITTEE CONTRIBUTIONS TO THE Branch Organiser Sheila Alderman [email protected] NEWSLETTER Treasurer Rhiannon Rogers [email protected] Is there anything you Day Trip Organiser Jeremy Cranmer [email protected] would like to tell or ask Newsletter Editor Hilary Barton [email protected] other members? All Residential Trips Mark Barrett [email protected] contributions welcome. Website Manager Colin Morley [email protected] Hilary Barton, Editor Librarian Jeremy Cranmer [email protected] [email protected] Ordinary members: Ian Hacker, Tony Loftus, Linda Morley, Marion Phillips, Jane Mead

Wessex Footnotes July 2015 Page 9 OTHER LOCAL EVENTS – PLEASE CONTACT THE ORGANISERS DIRECT

DORSET GEOLOGISTS’ ASSOCIATION GROUP (DGAG) LULWORTH RANGE WALKS www.dorsetgeologistsassociation.com & TYNEHAM VILLAGE 18 Jul 2015 Chairman’s picnic, Poxwell pericline For information on opening times 15 Aug 2015 Fossil & Mineral Fair, Wimborne tel. 01929 404819 24 Oct 2015 Holiday Rocks, Broadmayne 21 Nov 2015 DGAG dinner, Dorchester (note change of date) OPEN EVERY DAY OVER HOLIDAYS 12 Dec 2015 Christmas workshop, Broadmayne 25 July – 1 September 2015 OUGS members welcome but check beforehand that spaces are 19 December 2014 – 3 January 2016 available. Contact: Doreen Smith tel. xxxxxxxxxxxx or e-mail OPEN EVERY WEEKEND EXCEPT: xxxxxxxxxxxxxxxxxxxxxxx 4-5 July 2015 26-27 September 2015 14-15 November 2015 HAMPSHIRE MINERAL & FOSSIL SHOW Saturday, 5 September 2015 DIGS: Dorset’s Important Geological Sites Group Lyndhurst Community Centre, Lyndhurst, Hants SO43 7NY More details from Alan Holiday: http://www.sotonminfoss.org.uk/smfsshow.htm xxxxxxxxxxxxxxxxxxxxxxxxxx Displays and sales of fossils, minerals books and maps. Website at: http://www.dorsetrigs.org.uk This year’s displays include minerals and fossils from the If you would like to be kept informed of forthcoming Natural Science Society’s collection and Isle conservation sessions, please contact Alan, who will be of Wight fossils presented by the Dinosaur Isle Museum. As happy to add your name to his e-mail circulation list always, DGAG will have a display and Adrian Smith will be showing some of his Barton-on-Sea fossils.

BOURNEMOUTH NATURAL SCIENCE SOCIETY 39 Christchurch Road, Bournemouth BH1 3NS RUSSELL SOCIETY, SOUTHERN BRANCH http://www.bnss.org.uk http://www.russellsoc.org/sbranch.html The Society covers all the branches of natural science, including geology and palaeontology. It has an Gary Morse: xxxxxxxxxxxxxxxx, tel. xxxxxxxxxxxx. extensive, and very impressive, collection of fossils, For anyone interested in minerals, the Branch runs summer field rocks and minerals which can be viewed on any trips plus winter lecture meetings on the second Thursday of the Tuesday morning (by appointment) and at drop-in month at Wyvern Technical College, Fair Oak, Eastleigh, Hants. sessions 7-9pm on 8 July, 5 Aug & 2 Sept 2015 This summer’s collecting trips include day trips to Cavendish Mill and plus an Open Weekend 10-11 October 2015. Standford Lane Quarry, plus a longer trip to Devon. Forthcoming field trips and lectures Contact Chris Finch at xxxxxxxxxxxxxxxxxxxxxxxx 16 July 2015 Field trip to Brownsea Island 28 Jul 2015 Lyme’s eroding coast Richard Edmonds) 22 Aug 2015 William “Strata” Smith (Ray Chapman) 27 Aug 2015 Field trip to Barton-on-Sea 2 Sept 2015 A traverse across Iceland (Alan Holiday) DORSET BUILDINGS GROUP 24 Sept 2015 Milford on Sea The Group aims to promote the preservation of Dorset’s YOUNG EXPLORERS’ CLUB (geology and more!) building traditions and so takes a practical interest in For children aged 7 to 12. £4 per child per meeting. building stones and local geology. Contact: 10am-12.30pm on 11 July, 8 Aug & 12 Sept 2015 http://www.bnss.org.uk/about/young-explorers John and Sue Rowntree, xxxxxxxxxxxxxxxxxxxxxx The summer programme includes visits to Wolfeton House (4 July), Milton Abbey, Druce Farm (15 Aug) and the Kingston Lacy estate (2 Sept). Plus an exhibition on “thatch and cob” at Wareham Library (11, 12 & 14 Sept). SOUTHAMPTON MINERAL & FOSSIL SOCIETY

http://www.sotonminfoss.org.uk Gary Morse: xxxxxxxxxxxxxxxx, tel. xxxxxxxxxxxx The Society runs indoor meetings, field trips and other WIN SOME, LOSE SOME activities relating to the collection of minerals and fossils, and the sites where they are found. Monthly evening Dorset County Museum has secured a grant of over £10m meetings are held at The Friends' Meeting House, from the Heritage Lottery Fund to help with its expansion. Ordnance Road, Southampton (guests welcome). www.dorsetcountymuseum.org/discovery-centre 17-20 July 2015 Collecting trip to Weardale, N Pennines But Jurassica was unsuccessful in its initial bid for £16m 21 July 2015 Spot the Fake (Gary Morse) to develop a dinosaur-themed museum in a quarry on the 18 Aug 2015 Swap and sale evening Isle of Portland and intends to try again later this year. 15 Sept 2015 Early history of Geological mapping 10-11 Oct 2015 Trip to Bakewell Rock Exchange www.jurassica.org/

Wessex Footnotes July 2015 Page 10 WESSEX BRANCH FIELD TRIPS – DETAILS

Ham Hill, Somerset Saturday, 4 July 2015

HAM HILL – IN MEMORY OF HUGH PRUDDEN (08/01/29 to 08/01/2015)

with Sheila Alderman To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxxx Hugh studied geology and geography at Cambridge and took up a career in teaching. He taught at Yeovil Grammar School and Yeovil College - with the claim to fame of teaching OU’s Dr Angela Coe and palaeontologist Neville Hollingworth amongst others. He was awarded the Halstead Medal by the Geologists’ Association in 1994 and the R H Worth prize in 2007 by the Geological Society. The R H Worth Prize rewards those who make distinguished contributions to geology as amateurs, or whose work encourages amateur geological research. He passed away in January 2015 and this field trip is in his memory. There is sudden change in environment at Ham Hill to the west of Yeovil from the relatively soft sandstone of the Yeovil Sands with few fossils, to the thick pile of shell debris that comprises the 15- 20 metre thick deposit of bioclastic limestone of Ham Hill Stone. There are disputes as to how the shell debris occurred. Some think there was a wide channel in the sea floor along which shells were swept and broken up. Others think there was a shell-bank where currents washed away the lighter particles leaving a mass of broken shells. Many thanks to Hugh Prudden for giving me the knowledge to take us on this trip.

Worbarrow Bay, Dorset Sunday, 2 August 2015

A JOURNEY THROUGH THE CRETACEOUS with Jeremy Cranmer To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxxx Jeremy Cranmer is an amateur geologist who lives in West Dorset very near to the Jurassic Coast. He is OUGS Wessex Branch day trips organizer. By starting at the summit of the Purbeck Hills we shall gain an overview of their geology, the Frome syncline and the Weymouth anticline. We shall then visit the coast at Worbarrow Bay to follow the Cretaceous succession through its various climate and sea level changes between the Portland stone and the Chalk. Jeremy says “I have never visited this location without noticing something new.”

Monmouth Beach, Lyme Regis, Dorset Sunday, 13 September 2015 GEOLOGY AND FOSSIL HUNTING WITH SAM SCRIVEN To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxxx Sam Scriven was born in Weymouth and studied geology at the University of Plymouth to gain a M.Geol. He spent four years as the geologist at Charmouth Heritage Centre. He has now worked for five years as the Earth Science Adviser to the Jurassic Coast team at . Needless to say Sam has an intimate knowledge of the Jurassic Coast and its fossils. He lives in Bridport. Wessex branch has traditionally held fossil-hunting trips each year at Charmouth/Lyme Regis in December. This year there is a change of format. We shall look at the Lias west of Lyme Regis with the Cretaceous beds lying unconformably on the top as well as the Triassic/Jurassic boundary. There is a wealth of geology here and we shall still be able to visit the “ammonite graveyard” and, with extra daylight hours, there will be plenty of opportunity to collect fossils. The total distance is about 3 miles on varying beach material. Some slippery conditions must be expected - a walking pole can aid stability. Hammer and hand lens should be brought and collecting bags will be useful.

Anglesey, North Wales Tues – Sat, 22 – 26 September 2015 PLATE TECTONICS AND PALAEOZOIC GEOLOGY IN ANGLESEY Leader: Dr Margaret Woods, GeoMon Contact: Mark Barrett [email protected] (waiting list only) Three full days in the field, concentrating on plate tectonics and Palaeozoic geology. Based at the Gwesty Victoria Inn, a small hotel overlooking the Menai Straits. The cost for bed & breakfast and leader’s expenses only are £169 per person for shared/double rooms and £228 for the limited number of single rooms. The hotel has a licensed bar and restaurant and there are other shops and bars locally. A limited number of day trippers can attend at a total cost of £30 for all three days.

Wessex Footnotes July 2015 Page 11 THE OPEN UNIVERSITY GEOLOGICAL SOCIETY, WESSEX BRANCH – FORTHCOMING EVENTS This listing covers events in the Wessex area and general Society events. However, members can attend events organised by any OUGS branch - the full listing is at http://ougs.org/events/ Wessex Branch field trips Places are filled on a first come, first served basis. Non-members are welcome to attend events, but members will be given priority if places are short. Please contact the organiser to confirm details and to ensure there are spaces. Packed lunches, hard hats, strong footwear and waterproofs are usually required plus reflective clothing in working quarries. Please take note of the safety issues, which the leader will outline at the start of each trip. For day trips there is usually a charge of £2.50 per person to cover expenses. Events shown in italics are joint ones – please contact the host organizer as shown. Last-minute contact on the day, if you’re not coming or late: Jeremy’s mobile xxxxxxxxxxxx ONCE YOU’VE SIGNED UP FOR A WESSEX DAY TRIP, JEREMY WILL E-MAIL THE HAND-OUT TO YOU A FEW DAYS BEFORE THE EVENT SO THAT YOU CAN READ IT IN ADVANCE. DATE EVENT LEADER(S) CONTACT Jeremy Cranmer Saturday Ham Hill, near Yeovil, Somerset Sheila Alderman [email protected] 4 July 2015 (in memory of High Prudden) tel. xxxxxxxxxxxx OUGS Symposium Fri - Sun Lectures and Paul Williams Pangaea: Life & Times On A Supercontinent 17 - 19 July 2015 entertainment [email protected] Northumbria University, Newcastle Jeremy Cranmer Sunday Worbarrow Bay Jeremy Cranmer [email protected] 2 August 2015 tel. xxxxxxxxxxxx Jeremy Cranmer Sunday Monmouth Beach, Lyme Regis Sam Scriven [email protected] 13 Sept 2015 tel. xxxxxxxxxxxx Tues - Sat Dr Margaret Mark Barrett Anglesey 22–26 Sept 2015 Wood, GeoMon [email protected] Jeremy Cranmer Sunday A Dorset Important Geological Site Alan Holiday [email protected] 4 October 2015 Conservation tel. xxxxxxxxxxxx Jeremy Cranmer Sunday Lulworth Cove, Dorset Tony Cross [email protected] 11 Oct 2015 tel. xxxxxxxxxxxx Linda and Colin Colin Morley 19 - 29 Oct 2015 Northern Arizona, USA Morley [email protected] Beginning Geology at Bowleaze Cove Jeremy Cranmer Sunday Weymouth Alan Holiday [email protected] 29 Nov 2015 (suitable for those new to field geology) tel. xxxxxxxxxxxx Sheila Alderman Saturday Wessex Branch AGM and lecture day Sheila Alderman [email protected] 23 January 2016 Wool, Dorset Tel. xxxxxxxxxxxx INFORMATION ABOUT INSURANCE ON FIELD TRIPS AND EVENTS Each person attending a field meeting does so on the understanding that he/she attends at his/her own risk. The OUGS has Public Liability Insurance Cover for field and indoor meetings, but Personal Accident Cover and Personal Liability cover remain the responsibility and personal choice of the participant. There may be an element of appropriate cover included in house insurance or in travel insurance: although OUGS activities are not particularly dangerous, members are advised to check whether exclusions apply to activities in which they plan to participate in case they wish to arrange further cover. Annual travel insurance may be the best solution for any member who regularly attends field events: this again is a matter of personal choice. Please note however that all members participating in overseas events will be required to have travel insurance for the duration of the event: this is so that participants are covered for Medical, Repatriation and Personal Liability expenses. The Personal Accident element remains the personal choice of the member and again members are advised to check exclusions so that they can make an informed decision about the cover. Sheila Alderman, Branch organiser Jeremy Cranmer, Branch Day Events Organiser

CAN YOU HELP WITH OUGS SYMPOSIUM 2016? Exeter University, Friday to Sunday, 8 -11 July 2016 https://www.exeter.ac.uk/ Contact Sheila Alderman on [email protected] if you would like to be involved in helping to organise the Symposium or to assist over the weekend.

Wessex Footnotes July 2015 Page 12