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The Open University Geological Society Wessex Branch Newsletter

Website http://ougs.org/wessex October 2014

Branch Organiser’s Letter CONTENTS Dear All Branch Organiser’s Letter Page 1 I hope you have had a lovely summer and are Barton-on-Sea , May 2014 Pages 2-5 enjoying your geology. Wessex AGM 2015 notice Page 5 Northumberland Part 1, 2 June 2014 Pages 6-8 We have a couple of trips in October: West Bay Dinosaurs in the news Page 8 and on the Coast with Wessex Branch committee Page 8 Prof Chris Wilson on 12th October; and then the following week 19th October to Watership Down Minerals guide no. 11 – Sodalite Page 9 (Kingsclere Anticline) on the / Other organisations’ events Page 10 Berkshire borders with Dr Bernard Skillerne de Forthcoming Wessex Branch events Page 11 Bristow. Contact Jeremy on OUGS events listing Page 12 [email protected] Wessex Branch committee Page 12 We had a tremendous time in Northumberland In July 2016 it’s our turn to be involved in co- in June. Many thanks to Mark Barrett for ordinating the symposium. We have looked in organising the week and to Lesley Dunlop our detail at what the universities have to offer and leader. See the reports on day one on pages 6 have chosen Exeter over the weekend of 8th to to 8 of this edition; reports on the remainder of 10th July 2016. Participants can also book to the week will appear in subsequent newsletters. stay longer to make it a longer break. At the end of July I helped to organise a week in Kindrogan for NW and Wessex branches with The Wessex AGM and Lecture Day in Wool, near an expert in the Grampian geology Dr John Wareham in Dorset, is all arranged for Saturday th Mendum, retired from BGS Edinburgh. This 24 January 2015. The theme is: was hugely enjoyable. He did a tremendous “Hydrocarbons. How do they do it.“ As we have amount of preparation and explained an had such a successful year we have decided this extremely complex area very effectively. Look will be free of charge as a thank you. (See the out for reports in the National newsletter. AGM notice on page 5). th Do look at the events list as Jeremy has The National OUGS AGM is in Bristol on 25 arranged more day trips for next year. Also, April 2015 so we have plenty going on within Mark Barrett [email protected] has reach of us! arranged a Mendips weekend in April 2015 and Do let Hilary Barton know if you would like to is finalising details for Anglesey in September receive Footnotes by email rather than post so 2015. All in addition to Linda and Colin Morley’s you have the advantage of a full colour version trips to Arizona. and of course to cut costs. Her email address is [email protected] I thoroughly enjoyed the Canterbury Symposium and was pleased to see so many Also check the branch website for updates

Wessex members there including some for the http://ougs.org/events/index.php?branchcode= first time. In 2015 the Symposium is in wsx Newcastle - see http://ougs.org/symposium for details. It will be held at Northumbria I look forward to seeing you on future events th th University from 17 to 19 July 2015 with the Sheila Alderman, Branch Organiser Wessex title “PANGAEA: LIFE & TIMES ON A xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx SUPERCONTINENT - A celebration of Britain’s Tel. (evenings only) unique marine Permian strata”. E-mail: [email protected]

Wessex Footnotes October 2014 Page 1 WESSEX OUGS FIELD TRIP TO BARTON-ON-SEA, 11 MAY 2014 Leader: Ray Chapman Report by Giles Watts On a mainly sunny but quite chilly Sunday in May, 22 geologists met on the cliff top at Barton-on-Sea to take a look at the famous type section, the impressive but somewhat ineffectual sea defences and some very stormy seas left over from a series of strong south-westerly storms. The trip was led by Ray Chapman, who is a local expert on the geology of the area. We met near the Cliff House Hotel on Marine Drive West, which stands only about 25m from the edge of the cliff and commands imposing views across Christchurch Bay with Cliff House the in the west Hotel and in the Pebble Beach Restaurant east. In front of the hotel is Beachcomber Cafe an expanse of ocean that stretches 4000km to the coast Fig. 1 Map of Barton-on-Sea area http://www.openstreetmap.org/copyright of South America. Although storm waves are attenuated as they enter the shallow coastal waters, the high wave-energy pounds the coastline removing fallen material and destabilising the weak Tertiary cliffs. Erosion rates at the top of the cliff are between 0.5-1.5m per year and will soon be threatening the hotel. Further to the East, in an even more precarious position, stands the Pebble Beach Café and Beachcomber Café (Fig. 1) that lie right against the present-day cliff edge. Here the old café and adjacent Manor Lodge were demolished in 1975. Sadly, it cannot be long before the remaining buildings will also have to be abandoned. The trip began with a walk along the windswept cliff and an overview of the geomorphology. Ray set the scene with a description of the ancient East-West Solent river and how it captured a succession of local rivers such as the Frome, the Piddle and the Stour (Fig. 2), which now flow directly into the sea having left cliff cuts or “chines “ at their exit. We discussed the rising sea levels since the last ice age and the eventual break of the chalk ridge between the Isle of Wight and Old Harry Rocks. It is now thought that the first breach occurred during the Late Devensian some 12,000 years ago when the Frome and Piddle broke through the chalk from what is now Poole Harbour. One theory is that, as the temperature rose, a giant Fig 2. The Solent River of Early to Middle lake in Canada full of glacial meltwater broke its banks Pleistocene joining the Channel River sending a tidal wave across the Atlantic that breached Ian West ©2013 http://www.southampton.ac.uk/~imw/Solent- Introduction.htm the chalk ridge in several places. The group headed for the beach via Hoskin’s Gap where Pleistocene terrace gravels are well exposed along with the top of the Becton (Barton) Sands (Fig. 3). The stratification of the pebble and sand sediment was noted and the cemented iron staining. We walked down to the sea to look at the extensive landslips and slides, and the many attempts at protection that have been attempted over the last 80 years. The first coastal protection scheme, initiated in the 1930s, used timber groynes. These fell into disrepair during the war and in the 1960s a timber and rock revetment was constructed along with a series of timber and rock groynes along the shingle beach. At the same time, water flow through the cliff was Fig. 3 Hoskin’s Gap with Pleistocene stopped with a sheet pile cut-off wall and collected into a drain Gravels Photo Giles Watts before being piped down the cliff via rock drains.

Wessex Footnotes October 2014 Page 2 These works subsequently failed in the 1970s but the remains of the sheet pile wall is still visible today (Fig. 4) with more in the lower cliff that have been overturned. In the 1990s the old drainage pipes were fully replaced and the timber revetment was upgraded with a rock one using 90,000 tonnes of Carboniferous limestone from the Mendips (Fig. 5). Finally, rock groynes or “strongpoints” were built in the foreshore. The idea Fig. 4 Remains of sheet pile was that “pocket” wall Photo Giles Watts beaches would form between the groynes helping to prevent erosion. Unfortunately the combination of storms and longshore drift is too strong and the pocket beaches are minimal. Nevertheless the extensive rock dumping has been efficient in dissipating wave energy and in preventing erosion of the cliff toe. However, cliff top erosion has not Fig. 5. Cross section showing stone revetment, been halted by the defences. and landslides now drainage and typical slip mechanism (from Coastal Protection information Leaflet) cover the undercliff path, preventing access and obliterating features of geological interest. The main process of cliff erosion is through percolation of water through the Pleistocene gravels and Barton sands until the impermeable Barton Clay is reached. As this becomes lubricated, the bedding becomes a horizontal shear surface allowing large blocks to move laterally (without much rotation) to form elongated ridges with a graben (ditches) behind. There is a strong correlation between rainfall and cliff failure due to the build up of pore water pressures. Ground investigation suggests that pore pressures are recovering which increases the risk of further cliff failures. Recent very wet winters in 2013 and 2014 will not have helped. In 2013 the District Council instigated a £300,000 scheme to monitor groundwater movement and identify options for the future management of the cliffs. 18 boreholes were drilled to a depth of 20-35m and fitted with inclinometers (to detect movement), piezometers (to measure groundwater levels) and pressure sensors (for pore pressures). A separate subsurface geological survey was also conducted Fig. 6 Map showing borehole locations for 2013 monitoring along the cliff top. Data is being programme Photo by Giles Watts of District Council sign at Barton-on-Sea collected for around 18 months. After a fabulous picnic on the cliff-top, the party drove 1km west to the car park at Highcliffe. Ray started by showing us a selection of fossils he had collected over the years (Fig. 12 on next page) which included large teeth from Palaeogene Odontaspid sharks (Stratiolamia Macrota), shell crushing teeth from the Common Eagle Ray (Myliobatis) and several spectacular bivalves and gastropods including the giant Clavilithes Macrospira (Fig. 7). The group walked down the local chine called Chewton Bunny (where Bunny is a local form of bourne or stream) to the beach (Fig. 8). Here the cliff protection scheme to the west ends in two large rock groynes and a “strongpoint”.

Fig. 7 Clavilithes Macrospira Cossman Photo Ray Chapman Fig. 8 Barton Beds behind the pocket beach in front of the “strongpoint” near Naish Farm Photo Giles Watts

Wessex Footnotes October 2014 Page 3 From here on to the east there is no protection for the cliff under Naish Farm Holiday Park until Barton-on-Sea is reached. As a Fig. 9 Highcliffe, Barton and Hordle Geological cross-section. Ian West ©2001 result there is an http://www.southampton.ac.uk/~imw/barton.htm excellent exposure of the Barton beds which are the world type section for the beds of the Upper Eocene. The geology is relatively simple with nearly flat-lying strata sloping at about 1-in-50 to the east (Fig. 9). The cliffs rise to a height of about 30 metres and generally comprise plateau gravels overlying sands and clays of the Upper, Middle and Lower Barton Clays. These are now divided into 14 beds in the Becton Sand Formation (Barton Sands), the Middle Barton beds (Naish Member) and the Lower Barton Beds (Highcliffe member) (Fig. 10). The Middle and Lower Barton Beds are well known for the abundance and excellent preservation of their fossils. More than 500 species have been recorded of which over half are molluscs; they include numerous turret shells and lamellibranchs, sharks teeth, solitary , fish, turtles and archaeocete whales. In the Headon Hill Formation, mammals, reptiles, birds and plant material are found; and in the 1840s an alligator hanytonensis was found in the so-called "crocodile bed". Although the geology is simple, multiple and complex landslides obscure the layers and cause beds to be juxtaposed in the wrong order. Here the fringe of debris flows is nearly 100m wide with three main individual terraces capped with flat areas, frequently with ponded water on the surface. The group walked along the foreshore looking out for fossils washed out of the Barton clay. Despite a dedicated search I was unable to locate any shark’s teeth although I was delighted to pick up a reasonably well- preserved silicified echinoid fallen from the Terrace Gravels above (Fig. 11). Also along the foreshore were a Fig. 11 Echinoid wide selection of impressive septarian nodules from Bed Photo Giles Watts C which are also clearly visible in aerial photographs. The group split up and started tramping over the muddy landslides, trying to stay upright. Here, the risks to geologists are less from rock falls and more from getting stuck and the indignity of a dirty bottom! Searching through the various mudslides, it was easy to pick up a large number of varied bivalves and gastropods. One or two members of the group managed to find examples of hand-sized Clavilithes macrospira ( Fig. 7 on previous page) although the ventricle was usually missing and the specimen I saw was poorly preserved along its side. The numerous tiny gastropods with intricate spines were spectacular. They were beautifully preserved with intricate designs so I picked up around 50 to add to my small collection at home. That evening I put them in a mug of water to clean them. Unfortunately my wife mistook it for a dirty Fig. 10 Stratigraphy coffee mug and threw them down the sink of the Eocene Barton Clay Formation, the Becton Sand such are the perils of an amateur collector! (Barton Sand) and part of the Our many thanks go to Jeremy Cranmer for Headon Hill Formation from Fig. 12 Ray Chapman, with Highcliffe to Barton-on-Sea superb fossils in his car boot organizing everything and to Ray Chapman Ian West T West & J Bentley Photo Giles Watts for leading us on this memorable field trip. ©2009 http://www.southampton.ac. uk/~imw/barton.htm

Wessex Footnotes October 2014 Page 4

Further Reading on the geology of Barton-on-Sea

 Managing the Cliffs at Barton-on-Sea. http://www.newforest.gov.uk/index.cfm?articleid=8095&articleaction=dispmedia&mediaid=1662  Barton-on-Sea Coastal Protection information leaflet. http://www.newforest.gov.uk/index.cfm?articleid=8095&articleaction=dispmedia&mediaid=23392 The Investigation and Monitoring of Coastal Landslides at Barton-on-Sea, Hampshire, UK. DS Foot, AR  Clark, DG Cliffe, High Point Rendel, London, UK. http://www.newforest.gov.uk/index.cfm?articleid=8095&articleaction=dispmedia&mediaid=13488  Ground investigation works and Barton-on-Sea cliffs. http://www.newforest.gov.uk/index.cfm?articleid=14349  Geology of the Wessex Coast of Southern by Ian West:  Barton and Highcliffe Eocene Strata. http://www.southampton.ac.uk/~imw/barton.htm  Barton and Highcliffe coast erosion. http://www.southampton.ac.uk/~imw/barteros.htm  History and future of coastal erosion and Barton-on-Sea, Highcliffe and Christchurch Bay. http://www.southampton.ac.uk/~imw/Barton-Erosion-History.htm  Barton Beds. Wikipedia. http://en.wikipedia.org/wiki/Barton_Beds Giles Watts

WESSEX OUGS AGM & DAY OF LECTURES Hydrocarbons . H o w d o t h e y d o i t . 10.15am to 4.00pm, Saturday 24th January 2015 Please contact Sheila Alderman if you plan to attend on [email protected] or zzzzzzzzzzzz Please also let Sheila know if you have a collection or display you would like to exhibit.

DIRECTIONS The whole day is free of charge as a “thank D’Urberville Centre, Colliers Lane, Wool, Dorset you“ to members for all their support.

Postcode: BH20 6DL. Map ref: SY 843 865. Non-members welcome, but can’t vote at AGM! Five minutes’ walk from the railway station in Wool. Train times at: http://www.southwesttrains.co.uk/ AGM AGENDA 1. Apologies for absence 2. Minutes of last meeting

PROGRAMME 3. Matters arising 4. Agenda items received 10.15 Registration 5. Officers' reports: 10.30 Andy Mitchell “Directional Drilling and What's  Branch Organiser (Sheila Alderman) Involved”  Treasurer (Rhiannon Rogers) 11.30 Ian West “Geology of Oil Shales and their Potential  Day Trips & Library (Jeremy Cranmer) in the South of England”  Newsletter (Hilary Barton) 12.45 Buffet Lunch provided by committee and members  Website (Colin Morley) 13.45 AGM (agenda in box on right)  Residential Trips (Mark Barrett)

14.30 Giles Watts “Monitoring hydraulic fracturing for 6. The committee will then stand down for:

safer shale gas extraction” 7. Election of officers 8. Any other business

Andy Mitchell Dr Ian West Giles Watts Andy worked in the service sector of the oil Dr Ian West is a geologist who has Giles is a consultant Geophysicist industry over 35 years, predominantly in studied the Wessex Coast since the specialising in seabed seismic Norway, Middle East, Africa and South 1950s. He has long been a lecturer at acquisition, time-lapse seismic and America. He started out as a mud logger in Southampton University both at the reservoir monitoring. Previously he the North Sea in 1975. In 1984 he joined original Geology Department and later worked for 21 years for BP where he Teleco Oilfield Services in the US as a at the School of Ocean and Earth was senior Geophysicist at Wytch product development engineer involved in Science. He is now retired but Farm (1995-2000) and Seismic the roll-out of measurement while drilling working from home. He is a visiting Services Manager for the North Sea scientist at the university and still formation evaluation services. Since that (2008-2010). Giles has an MA in involved in some lecturing, field trip time he has worked primarily as an Physics (Cambridge) and a BSc in leading, etc. His knowledge of the operations manager for a variety of Geology (Birkbeck College) but he is geology of the south coast of England MWD/directional drilling service companies is unsurpassed. Visit his website at just as proud that he has taken and, most recently, two years in modules in Sedimentology and Song Kazakhstan. Since returning to the UK he http://www.soton.ac.uk/~iwm/ Writing with the Open University. has enrolled on a degree course with the OU.

Wessex Footnotes October 2014 Page 5 WESSEX OUGS FIELD TRIP TO NORTHUMBRIA, 1-7 JUNE 2014 Leader: Lesley Dunlop Reports by Tony Loftus and Alison Neil 2 JUNE 2014 (DAY 1): BOWDEN DOORS, BAMBURGH CASTLE AND LINDISFARNE Location 1 – Bowden Doors Our first visit of the week started appropriately with an examination of the Fell Sandstone at Bowden Doors – appropriate since Fell Sandstone is the main building material in this area of Northumberland. The locality – a west facing scarp face – is a cliff 0.5km long and 8-10m high. Following closure of the Iapetus Ocean at the end of the Silurian, extensional tectonics and fault reactivation led to the formation of a half graben to form the Northumberland Basin. In the Lower Carboniferous, uplift and erosion of mountains to the north led to deposition of sandstones into this basin via braided river systems flowing SSE. The sandstone contains over 90% quartz with feldspar and occasional mica. It was deposited in a humid tropical environment in the Arundian/Holkerian stages of the Dinantian Epoch ie ~335-340 Ma and was probably derived from weathered granites. Goethite (Fe3+) gives the red colour. Variscan compression in the late Carboniferous was E-W in this area and led to folding (forming the Holburn Anticline) and subsequent faulting. Extension in the Cenozoic reactivated these faults to give the N-S trending scarp face. The facies forming the lower part of the cliff shows water escape structures at the top but is otherwise generally featureless (Fig. 1). One interpretation is that the bed was deposited from a river with a high sediment load. With no grass to stabilise river banks in the Carboniferous, high sediment loading in times of flood was likely. The loosely packed sediment could then have been homogenised by an earthquake or by fluidisation from ingress of groundwater. This would explain the lack of structure. Loading which resulted in compression then caused the flame structures. The upper facies, in contrast, displays trough and planar cross stratification augmented by channel bed dune structures. Some structures Fig. 1 Bowden Doors Crag- sedimentary structures have been deformed and this has been Photo by Tony Loftus attributed to shear from heavily sediment laden flow in the river above. There are also signs of bank collapse. All in all, the picture is one of a highly sediment laden river, perhaps in flood. A short walk gave good views west towards the The Cheviot where the granite and other volcanic rocks have weathered to give a rounded dome. In the foreground the underlying softer cementstones had been eroded to form the Wooler valley while the scarp faces of the Fell sandstones could be seen arcing away to the south. Tony Loftus Location 2 – Bamburgh Castle This was our first view of the wonderful Northumberland coast and of the Whin Sill. Bamburgh Castle is spectacular, built directly onto the Whin Sill itself (Fig. 2). In fact any visible bit of the Whin Sill usually has some prominent structure built on it, Hadrian's Wall further south being the most famous. The castle is isolated and atmospheric, with splendid views over extensive Fig 2 Bamburgh Castle Photo by Linda Morley sand dunes and a long beach across the North Sea towards the Farne islands. It was once the seat of the kings of Northumbria and the first written reference to it was in 527 AD. It has been rebuilt many times since and part of it is still lived in.

Wessex Footnotes October 2014 Page 6 The Whin Sill formed 295 million years ago – as dated from its strontium content. Stretching of the earth's crust caused magma, at over 1000°C, to rise and spread out along the easiest path, between layers of Carboniferous limestone, shale and sandstone, where it cooled and solidified underground. The sill forms a vast sheet of dolerite, in places up to 70m thick, and is only partly exposed now, after millions of years of erosion. The dolerite erodes more slowly than the rock around it and so can be seen as rocky headlands, foreshores, islands, and crags. Bamburgh Castle is situated on its northern edge. It stretches southwards to Teesdale, westwards to Cumbria and eastwards under the north sea, surfacing again to form the Farne Islands. We walked along below the castle, looking carefully at the sill which is about 10m thick there, massive, grey and blocky, with large vertical joints Fig. 3 Whin Sill, below (Fig. 3). At a spot behind a war Bamburgh Castle memorial we could see a layer Photo by Linda Morley of pinkish, cross-bedded, river- deposited sandstone under the sill, and a flat carboniferous limestone layer under that (Fig 4). In one place, behind the Fig. 4 Sandstone above limestone vegetation, we got a closer Photo by Linda Morley glimpse of the contact surface between the sill base and the sedimentary layer below (Fig 5). The sediment next to the sill looked baked, and the margin of the sill chilled (ie more finely grained than the rest, due to the flow crystallising more quickly than the cooler edge). This confirms that Fig. 5 Contact surface the Whin Sill is the younger rock! Photo by Linda Morley We then set off northwards to explore the beach, which was beautiful, stretching out peacefully along a calm sea. The sand under our feet covered the top layer of the sill itself and stray bits of sill stood proud on the beach. In some of these we found amygdales, where calcite and quartzite had precipitated in vesicles, formed from gas bubbles rising to the surface as the magma cooled. We also saw some of the sill showing a flow texture, looking shiny and wrinkled like cooling sticky toffee; it is thought to suggest an east to west flow (Fig. 6). Fig. 6 Flow texture Photo by Linda Morley Further up the beach we saw Harkess Rocks where the Whin Sill seems to have been formed in two pulses, with the second pulse flowing on top of an earlier slightly cooled layer, with vesicles on its surface. At the end of the beach we came to Stag Rock, so- called because people have painted a brilliant white stag on the rock face. The sill is only 3-4m thick here - to our right it was undercut, resting on softer shale, to our left it rose over a level layer on limestone. It was difficult to tell what was what (Fig. 7). In one place between layers we could see crushed material resulting from movement along a fault in an ancient earthquake. In some of the limestone we found small fossils, such as corals Fig. 7 A puzzle Photo by Alison Neil and crinoids. We also found some ripple marks. Finally it was time to walk back to the castle along The Wynding, a path through the sand-dunes, from where we had a good view of the layout of the land. Alison Neil

Wessex Footnotes October 2014 Page 7 Location 3 – Lindisfarne After lunch it was off to see Holy Island. Here the geology is Lower Carboniferous with cycles of marine limestone/ marine shale/deltaic sediments (these of non-marine shales/siltstones/sandstones/seatearth/coal - if you’re lucky). Subsequent Variscan compression was E-W, probably due to the presence of the Cheviot pluton nearby. Emplacement of the Holy Island dolerite dyke then occurred as part of the Whin Sill intrusion. The abbey merited a brief viewing largely because it is made of Fell Sandstone. However, the beach to the south proved far more interesting. Examination of the Acre limestone revealed plenty of fossils, especially crinoids and brachiopods. A xenolith of the Limestone, which had got Fig. 8 Contact between dolerite dyke itself nicely baked in the dolerite intrusion. also provided and Acre limestone Photo by Tony Loftus interest. Further on, the contact between dolerite and limestone (Fig. 8) showed the effects of fluid transfer when the hot, dry dolerite soaked up water from the limestone which in turn led to iron transfer. The effect of E-W Variscan compression was nicely displayed on the shore just to the south of the intrusion, with some nice gentle syncline/anticline pairs (Fig. 9). The Holy Island dyke “topped out” in this area as displayed by “ropey” structures on the top surface and amygdales a few centimetres below.

The castle beckoned in the distance, but time and tide Fig. 9 Folding from Variscan compression warranted a quick escape to end the day. Photo by Tony Loftus Tony Loftus

GEOLOGY OF THE MENDIPS GA FESTIVAL OF GEOLOGY Wessex weekend trip, 18-19 April 2015 10.30am-4.30pm on 1 November 2014

This weekend trip to the North Mendips will be led University College, Gower Street, London WC1E 6BT by Dave Green and include visits to Ebbor Gorge, Fossil and mineral displays, lots of stalls, lectures Downhead Quarry and Velvet Bottom. (including Richard Edmonds and Iain Stewart), activities for children, geological walks and field trips. Details at: http://ougs.org/events/index.php?branchcode=wsx For further information: www.geologistsassociation.org.uk Contact: Mark Barrett, [email protected] Tel. 020-7434 9298

IF DINOSAURS HADN’T GONE EXTINCT Dinosaurs have been in the news a lot recently, with research suggesting that feathers were more widespread than previously thought1,2 and that the evolution of therapods into birds involved shrinking for over 50 million years3. Recent discoveries include the 65 ton Dreadnoughtus schrani4 and the semi-aquatic Spinosaurus aegyptiacus5. One study suggested that if the asteroid strike 65Ma had happened just a few million years sooner or later then dinosaurs would not have gone extinct. This prompted speculation as to whether dinosaurs would have evolved intelligence on a par with Homo sapiens. Professor Simon Conway- Morris of the University of Cambridge gave the answer on BBC News6: "The experiment has been done and we call them crows." 1 www.bbc.co.uk/news/science-environment-28407381 2 Science, 25 July 2014, Vol. 345 no. 6195 pp. 451-455 http://www.sciencemag.org/content/345/6195/451 3 http://www.bbc.co.uk/nature/28563682 and http://www.sciencemag.org/content/345/6195/562 4 http://www.smithsonianmag.com/smart-news/meet-dreadnought-largest-dinosaur-world-180952612/?no-ist 5 http://www.bbc.co.uk/news/science-environment-29143096 6 http://www.bbc.co.uk/news/science-environment-28488044

Wessex Footnotes October 2014 Page 8 SIMPLE GUIDE TO MINERALS 11 – by Colin Morley

Sodalite - Na4Al3(Sio4)3Cl

Sodalite is a silicate. We could call it Sodium aluminium silicate chloride, which makes sense but is a bit of a mouthful so it is just known as Sodalite. It was discovered in Greenland in 1811. The crystal system is isometric, usually dodecahedral. I say usually, but it is rare to find it in crystal form. The crystals can be found in the calcareous lavas of Vesuvius, but I have only seen it in a compact mass where its blue colour is prized. It isn’t usually all blue though, it is also mixed with white or gray (see picture). A variety of Sodalite known as Hackmanite (from Afghanistan and the Myanmar Republic aka Burma) has the ability to change colour in sunlight (most humans do Specimens of Sodalite in the Morley Collection the same thing), a phenomenon known as reversible Above: massive. Below: a cabochon. photochromism or tenebresence. Hackmanite can make Photos by Colin Morley a good addition to a fluorescent collection as it shows a patchy orange under UV light. Its Lapis-like blue colour is its main identification point in the field, but as Lapis usually has a pyrite content it feels heavier than Sodalite. It is quite hard, 5.5 – 6, has poor cleavage and is relatively fragile. It has a vitreous lustre and is described as translucent but, as I have only seen the massive form, I would call it opaque. It streaks white rather than blue and can be found in under-saturated plutonic rocks such as nepheline seyenites and phonolites. It is associated with leucite and metasomatised limestones and volcanic blocks. Bancroft in Canada has beautiful coloured massive specimens that are prized for jewellery and carved ornaments. It also occurs in Brazil, Russia, Portugal and the US. Colin Morley ARIZONA, USA with Linda and Colin Morley 16 - 25 March 2015: Basin & Range 19-28 Oct 2015: Colorado Plateau Discover the geology of the desert areas of Arizona Visit the Grand Canyon, Meteor Crater, Painted Desert, along with its plants, birds and animals. Sunset Crater etc and search for minerals and fossils. Estimated cost of each trip: £800 excl. flights Further details and itineraries for both trips at: http://ougs.org/events/index.php?branchcode=wsx To express an interest or book a place, contact: zzzzzzzzzzzz

FOSSIL FORAY AT WRITHLINGTON SCIENCE FESTIVAL 2 - 4pm, 27 October 2014 12-19 October 2014 The Somerset Earth Science Centre is organising a fossil This year the festival has a special focus on foray at Writhlington Batch for local families and is looking geology and there is an extensive for any geologists who would like to go along and help programme of displays, talks, walks and identify peoples’ finds. If you are interested, contact other activities. [email protected] There is even a competition to produce the This event is part of the Mendip Rocks! Festival of most attractive, tasty and scientifically Geology, which runs from 27 September to 30 October. entertaining cake with a geological theme! For the programme of events, which includes sites not usually open to the general public, see: Full programme at: http://www.somersetwildlife.org/rocks http://www.sidmouthsciencefestival.org/

Wessex Footnotes October 2014 Page 9

OTHER LOCAL EVENTS – PLEASE CONTACT THE ORGANISERS DIRECT

Dorset Natural History & Archaeological Society LULWORTH RANGE WALKS GEOLOGY LECTURES AT DORSET COUNTY MUSEUM High West Street, Dorchester DT1 1XA & VILLAGE For information on opening times 8 Oct 2014 Treasures from Space (Dr Caroline Smith, NHM) tel. 01929 404819 12 Nov 2014 Landslides (Dr Helen Reeves, BGS) 10 Dec 2014 Ignite! (Christmas party) OPEN EVERY DAY OVER HOLIDAYS 14 Jan 2015 Dinosaur Feathers (Dr Paul Barrett, NHM) 20 December 2014 – 4 January 2015 11 Feb 2015 Climate Change (Dr Felicity Liggins, Met Office) 3 – 12 April 2015 11 Mar2015 Lecture by Tom Sharpe, National Museum of Wales 2 – 4 May 2015 8 Apr 2015 A Long, Long Road (Steve Etches, Museum) 23 May – 1 June 2015 25 July – 30 August 2015 All welcome. Lectures start at 7pm. 19 December 2014 – 3 January 2016 Donation of £3 suggested to cover speakers’ expenses. Further information: tel. 01305 262735. OPEN EVERY WEEKEND EXCEPT: http://www.dorsetcountymuseum.org/events 15-16 November 2014 17-18 January 2015 7-8 March 2015 9-10 May 2015 DORSET GEOLOGISTS’ ASSOCIATION GROUP (DGAG) 4-5 July 2015 26-27 September 2015 www.dorsetgeologistsassociation.com 14-15 November 2015 4-5 Oct 2014 Dorset Inferior Oolite, leader Robert Chandler 14 Nov 2014 DGAG Annual Dinner, Dorchester 6 Dec 2014 Christmas Workshop, Broadmayne 10 Jan 2015 AGM, Wool SOUTHAMPTON GEOLOGY GROUP Meetings start 7.30pm at the National Oceanography OUGS members welcome but check beforehand that spaces are Centre, Dock Gate 4, Southampton SO14 3ZH available. Contact: Doreen Smith tel. or e-mail xxxxxxxxxxxxxxxxxxxxxxx 17 Oct 2014 Prof John Marshall: The Frasnian – Famennian Mass Extinction 21 Nov 2014 Dr Andy Gibson (Portsmouth Univ) Everybody welcome. For directions, please contact: DIGS: Dorset’s Important Geological Sites Group Lawrie Bubb tel. xxxxxxxxxxxx or More details from Alan Holiday: Tony Holmes tel. xxxxxxxxxxxx zzzzzzzzzzzzzzzzzzzz Website at: http://www.dorsetrigs.org.uk If you would like to be kept informed of forthcoming BOURNEMOUTH NATURAL SCIENCE SOCIETY conservation sessions, please contact Alan, who will be 39 Christchurch Road, Bournemouth BH1 3NS happy to add your name to his e-mail circulation list. http://www.bnss.org.uk The Society covers all the branches of natural science, including geology and palaeontology. It has an RUSSELL SOCIETY, SOUTHERN BRANCH extensive, and very impressive, collection of fossils, rocks and minerals which can be viewed at: http://www.russellsoc.org/sbranch.html OPEN WEEKEND AND DROP-IN EVENINGS Gary Morse: , tel. zzzzzzzzzzzz. zzzzzzzzzzzz 10.30am to 4pm on 11 and 12 October 2014 For anyone interested in minerals, the Branch runs summer field 7pm to 9pm on 5 Nov 2014 and 3 Dec 2014 trips plus winter lecture meetings on the second Thursday of the Forthcoming lectures include: month at Wyvern Technical College, Fair Oak, Eastleigh, Hants. 1 Nov 2014 2.30pm Dinosaurs (Darren Naish) 2 Dec 2014 7.30pm Gold in the UK (Gary Morse) YOUNG EXPLORERS’ CLUB (geology and more!) DORSET BUILDINGS GROUP For children aged 7 to 12. £4 per child per meeting. The Group aims to promote the preservation of Dorset’s 10am to 12.30pm on 8 Nov and 13 Dec 2014 building traditions and so takes a practical interest in http://www.bnss.org.uk/young-explorers building stones and local geology. There is a winter lecture series plus summer outings. Contact: John and Sue Rowntree, zzzzzzzzzzzz 5 Oct 2014 Visit to Sandford Orcas Manor SOUTHAMPTON MINERAL & FOSSIL SOCIETY 30 Nov 2014 Talk on Badbury Rings (Nancy Grace) http://www.sotonminfoss.org.uk Gary Morse: zzzzzzzzzzzz, tel. zzzzzzzzzzzz The Society runs indoor meetings, field trips and other BLAST FROM THE PAST activities relating to the collection of minerals and fossils, Fossil Festival on the Isle of Wight and the sites where they are found. Monthly evening meetings are held at The Friends' Meeting House, 10am-4pm, 15 & 16 November 2014 Ordnance Road, Southampton (guests welcome). Dinosaur Isle, Culver Parade, Sandown Isle of Wight PO36 8QA 25 Oct 2014 Rob Bowell: Liroconite and Wheal Gorland Tel. 01983 404344 for further details. 18 Nov 2014 Ben Dye: White Watson’s Web www.dinosaurisle.com/events.aspx#nov14 16 Dec 2014 Schofield and Morse: Review of the Year

Wessex Footnotes October 2014 Page 10 WESSEX BRANCH FIELD TRIPS – DETAILS

West Bay & Burton Bradstock, Dorset Sunday, 12 October 2014 INTEGRATING FIELD AND SEISMIC DATA IN with Professor Chris Wilson To book a place, contact: Jeremy Cranmer at [email protected] or tel. zzzzzzzzzzzz Please note that this trip is limited to 30 members. Prof. Chris Wilson joined the OU in 1969 as a founding member of the Faculty of Science & Dept. of Earth Sciences. Chris first visited Dorset in 1958 on a sixth form geology trip, returned to undertake his degree mapping project, and completed his PhD on the Corallian Beds of Dorset in 1965. He retired to Dorset in 2003. During the trip we will examine the Jurassic succession between the Bridport Sands and the Forest Marble and observe the Mouth Fault. Seismic data will be used to gain a deeper understanding of faulting in and adjacent onshore areas and the origin of the Bridport Sands. We shall visit Burton Bradstock in the morning and Eype’s Mouth in the afternoon. Don’t miss opportunity to visit outstanding part of the “Jurassic” Coast. Chris’s field trips are always memorable because of the vast amount you learn – you’ll be amazed.

Kingsclere, Hampshire Sunday, 19 October 2014 KINGSCLERE ANTICLINE with DR B J SKILLERNE DE BRISTOWE To book a place, contact: Jeremy Cranmer at [email protected] or tel. zzzzzzzzzzzz Dr Bernard J Skillerne de Bristowe spent most of his life working in the Oil Industry and is now retired. His specialist interests are in metamorphic and structural geology in relation to mountain building but finds himself living in the South of England where there are few mountains. The present field trip is a response to frequently being asked to lead trips by local geologists and it follows a line of thinking termed 'Regional Geology and Tectonics' often employed by the Oil Industry. The North Wessex Downs do not feature in many geological textbooks but they are important tectonically in so far as they mark the northern margin of the Variscan Orogeny. We cannot observe this directly due to the thick cover of Mesozoic and Tertiary sediments but recent work by the London Basin Forum has showed that neotectonic features can be recognised which provide insights into the deep geology. On this trip we will examine neotectonic, structural and stratigraphic evidence from sites on either side of the Variscan front including the Pang Valley and the Kingsclere anticline. We will use this evidence to develop a model for the tectonics of the whole of the South of England including popular sites such as the Weald of Kent, Mendips, , Kilve and Hartland Quay. This will involve thinking about processes such as basin inversion and fault reactivation. We will see that to understand what is going on we need to reverse Lyle’s dictum of 'the present is the key to the past' and think more in terms of 'the past is the key to the present'.

Bowleaze Cove, Weymouth, Dorset Sunday, 23 November 2014 BEGINNING GEOLOGY: , WEYMOUTH with Alan Holiday To book a place, contact: Jeremy Cranmer at [email protected] or tel. zzzzzzzzzzzz Alan Holiday has taught geography and geology in Weymouth since 1971. He is now retired but spends much of his time leading field trips! Over the years he has been involved in a range of OUGS activities as well as now being Chairman of the Dorset GA Group and Dorset RIGS Group. The trip is suitable for those new to field geology. This site is a great location to start to understand geology in the field and tie it into course written material. It is conveniently located for people wishing to use public transport. Bowleaze Cove is a fascinating area demonstrating an abundance of classic sedimentary features and structures of the Upper Jurassic in the World Heritage Site. We shall study the beach section either side of Bowleaze Cove including part of the Oxford Clay and the Corallian succession. The section is affected by mass-movement so we will study current processes as well as attempts to protect the coastline. We will also study the rocks exposed to consider the environment in which they were deposited. Both body fossils (shells) and trace fossils will be studied. A trip not to be missed.

Charmouth/, Dorset Sunday, 7 December 2014

FOSSIL HUNTING with SAM SCRIVEN To book a place, contact: Jeremy Cranmer at [email protected] or tel. zzzzzzzzzzzz 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 Heritage Centre. He has now worked for four years as the Earth Science Adviser to the team at Dorset County Council. Needless to say Sam has an intimate knowledge of the Jurassic Coast and its fossils. He lives in Bridport. This is an annual event and this year the walk will start from Charmouth. The exact itinerary will depend to some extent on what the autumn storms have done to the cliffs. We shall either walk eastwards towards Stonebarrow or westwards towards Black Venn. We should be able to visit the Heritage Centre at lunch time. We may even visit Lyme Regis. The total distance of the excursion 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. Alan Holiday taught geography and geology in Weymouth. He is now retired but spends much of his time leading field trips! Over the years he has been involved in a range of OUGS activities as well as now being Wessex Footnotes October 2014 Page 11 Chairman of the Dorset GA Group and Dorset RIGS Group. In the morning we shall carry out conservation work on this exposure of Purbeck Limestone of the Lower Cretaceous. This is a shelly limestone (Broken Shell Limestone or Burr) used for building and nearby Purbeck 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 zzzzzzzzzzzz DATE EVENT LEADER(S) CONTACT Integrating field and seismic data at Jeremy Cranmer Sunday Prof. Chris West Bay & Burton Bradstock [email protected] 12 October 2014 Wilson (Limit: 30 members) Tel. zzzzzzzzzzzz Dr Bernard Jeremy Cranmer Sunday Kingsclere Anticline, Skillerne de [email protected] 19 October 2014 Berkshire Bristowe Tel. zzzzzzzzzzzz Colorado Plateau in Northern Arizona, Linda & Colin Colin Morley 20 - 29 Oct 2014 USA Morley zzzzzzzzzzzz Sunday Beginning Geology, Bowleaze Cove, Jeremy Cranmer 23 November Weymouth, Dorset Alan Holiday [email protected] 2014 Suitable for those new to field geology Tel. zzzzzzzzzzzz Jeremy Cranmer Sunday Fossil hunting at Charmouth, Dorset Sam Scriven [email protected] 7 December 2014 Tel. zzzzzzzzzzzz Wessex Branch AGM & Lecture Day. Sheila Alderman Saturday Wool, Dorset. Sheila Alderman [email protected] 24 January 2015 “Hydrocarbons. How do they do it.” Tel. zzzzzzzzzzzz Jeremy Cranmer Sunday Introduction to Mendips Geology Alan Holiday [email protected] 8 February 2015 Vallis Vale, Somerset Tel. zzzzzzzzzzzz Jeremy Cranmer Sunday Studland, Dorset TBA [email protected] 15 March 2015 Tel. zzzzzzzzzzzz 16 – 25 March Arizona, USA Linda & Colin Colin Morley 2015 Basin and Range Morley zzzzzzzzzzzz Sat - Sun Mark Barrett Mendips weekend Dave Green 18-19 Apr 2015 [email protected] OUGS AGM weekend, Bristol Lectures and Jan Ashton-Jones 24 – 26 April 2015 (AGM on Sat 25 April 2015) field trips zzzzzzzzzzzz OUGS Symposium Lectures and Paul Williams 17 - 19 July 2015 Pangaea: Life & Times On A Supercontinent entertainment [email protected] Northumbria University, Newcastle 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

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 October 2014 Page 12