FOOTNOTES OUGS Wessex Branch Newsletter December 2017
ROM THE BRANCH ORGANISER Welcome to the last Footnotes of 2017, which has undergone a facelift. Hilary, our Editor, decided that it was about time! We hope that you like it. F I do not wish to pre-empt the committee members' reports to the AGM but I think that we had a good selection of activities arranged for the branch in 2017 with a varied local programme as well as residential trips further afield. We mustn't forget those members who made the effort to write the field trip reports for this newsletter. Hopefully reading them will make you decide to go on them in the future and those that can't get out there can at least get to see and read about the areas. We need members to make all this happen so please tell any like-minded friends about us and get them to join. Even if they just go on one trip, they will also have the newsletters, not forgetting the Proceedings of the OUGS (formerly known as the Journal), so they will have their money's worth. I should also remind you that the AGM will take place on Saturday 27th January in the D'Urberville Centre at Wool as usual. Full details are on the web and on page 8 of this newsletter. I put out a call some time ago for a suitably qualified (willing, able and spreadsheet savvy) replacement for Rhiannon, who has decided that it is time to step down as Treasurer. I am delighted to say that Chris Hawkes has volunteered, she seems a very suitable candidate. The names of all candidates for the committee will be put forward for you to vote on at the AGM. If you have a burning desire to 'throw your hat in the ring' you can still do so of course, just let me know by 13 January 2018. Please also contact me before the event if there are any questions that you would like answered. It gives us a chance to actually get the answer for you rather than say "we'll find out and get back to you". It is with great sadness that I tell you that we have lost one of our most active and popular members of the branch. Gwenda Brewer had been very ill for some time and passed away on Saturday 28th of October. Our sympathies have been passed on to her family. A short tribute to her life is on page 11. You will have read in the national newsletter that because of the changes to the data protection rules we need to ask you to fill out a membership renewal form for 2018, even if you pay by standing order. It is just this once – see page 11 for the details. Next year's programme is taking shape and I hope that you can find something that interests you and inspires you to join us on a field trip. We are always looking for new ideas and locations so if you can think of one please let us know, also if you know of a possible leader. It does actually work, that was why we had the Jersey trip. Remember this is your branch, so make sure that we are doing what you want us to do. Hmm, I suppose that does sound like a reason to come to the AGM, but meeting friends, sharing lunch and the talks too, is a pretty good incentive. Have a good holiday season, take great care near the cliffs and have fun. I hope to see you at the AGM. Oops, I mentioned the AGM again. Best Wishes, Colin Morley Branch Organiser Wessex E-mail [email protected]
Wessex Footnotes December 2017 Page 1 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day one, 4 October 2017
FOUR JERSEY GEOLOGY TRAILS Leader: Dr Ralph Nichols Reports and photos by Lizzie Davenport, Marion Phillips, Allen Fraser and Mary Barr le Messurier
LOCATION 1: LE PULEC (STINKY COVE) - JERSEY SHALES AND TURBIDITES According to the Jersey Geology Trail (Nichols and Hill, 2016), Jersey is part of the North Armorican Massif of France, with rocks ranging from late Precambrian to early Palaeozoic (c. 750 – 425 Ma). The Jersey Shale, the focus of our observations at this stop, is the oldest formation on the island. It was deposited in a late orogenic basin, the result of subduction when the Celtic oceanic crust was subducted southwards towards the Armorican Massif continental margin. It is Brioverian (c. 700 Ma) in age. The shale was intruded in a later extension phase by several plutonic complexes varying in age from 550 to 425 Ma. Geochemical evidence suggests that these were derived from mantle wedge melts in a later subduction episode with assimilation and fractional crystallisation at the base of the crust and during emplacement. Geological map of Jersey Brown et al, 1990
Locality 1a: Northern end of St Ouën’s Bay Our primary task here was to look at the varied bedding and load structures that are evidence of turbidite deposition. According to Bishop and Bisson (1989), this exposure shows parts of the mid to outer deposits (continental slope/foreset beds) within a deltaic submarine fan, with indicative associations of ripple lamination, cross-stratification and grading. The rocks here are laminated siltstone/greywacke rather than true shale. We found Laminates and lenses examples of ripples, cross-bedding, load- casting, boudinage, with later micro faulting (evidence of the deformation in tectonic and thermal events of the later Cadomian orogeny) and quartz veining. The beds dip at about 30° to the NE. Ripples and dip
Wessex Footnotes December 2017 Page 2 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day one, 4 October 2017
Locality 1b: Le Pulec Cove At this locality the Jersey Shales were intruded by granites which have been dated at 475 -438 Ma (Brown et al, 1990) and 480 Ma (Bishop & Bisson, 1989). We proceeded to Le Pulec cove to look at the shale granite complex, but as the cove was filled with seaweed we could not examine the rocks at close range.
Distant view of contact
The mineral veins that underlie the inlet (the cove follows the strike of the lode) contain silver, sphalerite (the gangue is ankerite) and pyrite, but were not considered as commercially viable propositions by the Cornish miners who assayed them. From a distance we could see the irregular contact between intrusion and shale along the edge of the promontory, and the felsite dykes that criss-cross the shale. Felsite dykes and granite/shale contact
Locality 1c: The slipway to Le Pulec From the slipway, a notable feature is a line of caves that marks the 8 metre raised beach at this locality. This is evidence of sea level fluctuations during and after the last glaciation, with the wave-cut platform produced during advance and the loess-head deposits (described below) during retreat. Along the slipway to the cove we saw that the bedrock (Jersey Shale that has been hornfelsed here by the intrusion) has been cut by 8m raised beach channels and gullies, filled at the base with rounded pebbles and in the upper layers with angular clasts of shale and loess. The upper deposit is produced by freeze/thaw processes (gelifluction) and gravity fill. Sea levels continued to fluctuate post-glaciation. When the tide goes far back, ancient peat beds are exposed (formed c 7-5 ka at a time of lower sea level); Gullies in the slipway trees were reported here in the 18th century. By 3-2 ka, the locality was covered by sand dunes.
Lizzie Davenport
References Bishop, A. C. and Bisson, G. 1989. Classical areas of British geology: Jersey: description of 1:25 000 Channel Islands Sheet 2. (London: HMSO for British Geological Survey.) Brown, M., Power, G. M. Topley, C. G. & R. S. D'Lemos, R. S. 1990. Cadomian magmatism in the North Armorican Massif. p. 181 - 213, in The Cadomian Orogeny. Eds. D'Lemos, R. S., Strachan, R. A. & Topley, C. G., 1990, Geological Society Special Publication No. 51. Nichols, R and Hill, A. 2016. Jersey Geology Trail: A Series of Explanatory Notes on Selected Traverses. Charonia Media.
Wessex Footnotes December 2017 Page 3 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day one, 4 October 2017
LOCATION 2: GREEN ISLAND VICINITY - DIORITES Our second locality was in the south-east of the island on the beaches and low-tide sea floor close to Green Island at La Motte, Le Croc and Le Nez. Here we found outcrops of diorites (c. 580 Ma) which are coarsely crystalline, intermediate plutonic igneous rocks with a speckled appearance. The black crystals are hornblende (frequently seen in the form of excellent needles and columns with hexagonal cross-sections) and the white ones are plagioclase feldspar. The diorites crop out within later pink granites of the La Roque group (c. 570 Ma). In places the diorites are also associated with gabbros. Diorite The diorites showed a complex relationship with each other: different textures of feldspar, black hornblende and augite layers graded into black gabbroic-looking layers. In some places Granitic veins within diorite quartz occurs as an accessory mineral and has produced quartz diorites. Elsewhere, the greater abundance of the amphibole has produced darkly-coloured hornblende diorites (melano-diorites) which contrast with the paler leuco-diorites. In some places the sequence is layered and very dark grey, gabbroic-looking rocks alternate with the lighter dioritic-looking rocks. The complex relationship between the diorites and gabbros together with the presence of the adjacent granites has led to questions about their genesis. Do they result from crystallisation of a dioritic magma, or from gabbros altered by the introduction of a granitic magma? Frankly I did not feel equipped to answer this question but I certainly enjoyed looking at the rocks on this beautiful stretch of coast! Many Granite dyke within diorite thanks to our excellent guide, Ralph Nichols, for such an enlightening outcrop and patiently-explained visit.
Marion Phillips
LOCATION 3: ANNE PORT - RHYOLITE HEXAGONAL COLUMNS AND SPHERULITES The third location was the picturesque bay of Anne Port, now part of an SSI. The bay is formed in Cambrian ash and lava outpourings that overlie the Jersey Shale we saw earlier. Erosion of the north side of the bay and the headland of La Crête exposes units of the St John’s Rhyolite Formation within the Jersey Volcanic Group. The lower unit in the bay is the Anne Port Ignimbrite with pumice fiamme but also includes xenoliths of the underlying Jersey Shale. The next unit is flow banded rhyolite overlain by heavily weathered agglomerate, which includes blocks of explosion breccia. Columnar jointed lava flow The headland of La Crête is formed from a thick (~15m) rhyolite lava flow of the Bouley Rhyolite Formation that overlies the St John’s units. This flow has flow-banding and flow-folding as well as areas displaying a spherulitic texture. Spherulites are of millimetre size and are indicative of rapid cooling. Overall the flow has cooled to form columnar joints. Jointing varies from pentagonal to hexagonal in cross-section. The stack of lava columns dip about 30° to the SSW but this is believed to be a post-cooling tectonic dip. This headland is known on the island as La Chaussée de la Crête - proof that Finn MacCool went to Jersey for his holidays. Flow folds in rhyolite, loose block Allen Fraser
Wessex Footnotes December 2017 Page 4 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day one, 4 October 2017
LOCATION 4: ST CATHERINE’S SLIPWAY, LA CRÊTE POINT – ROZEL CONGLOMERATE As soon as we arrived, Lizzie found what looked like a small flint implement, and Jersey resident Jane Edwards helpfully drew marks in the sand to help all drivers with directions and parking possibilities for the five cars and a minibus. Conglomerate or "puddingstone" occurs in the north east of Jersey. I have come across puddingstone in Hertfordshire where it can be seen in the wall of St Alban’s Abbey. The Rozel Conglomerate Formation is made of pebbles cemented together. It is widely thought to have been formed 400 million years ago and is the youngest hard rock formation on Jersey Island. It is generally thought that it occurred after uplift, folding and erosion of older rocks. Streams and torrents would have transported eroded bedrock and sand down Leader Dr Ralph Nichols valleys, producing these pebbles which inspecting Lizzy's flint tool cemented together after, perhaps, a flash flood. This would have been during the Cambrian to Ordovician periods. The pebbles we saw here varied in sphericity, size and shape. We saw rhyolite, granite and shale. Interestingly, the granite was not similar to any other local Jersey granite, which led us to believe that it must have been Pebbles piling up part of a granite mass which had largely disappeared, probably due to erosion. behind boulder Alan Fraser spotted a superb example of a large boulder blocking the flow of smaller pebbles and sand, which piled up behind a large boulder in this conglomerate.
Mary Barr le Messurier
Day two, 5 October 2017 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017
ARCHAEOLOGY (and some geology!) LEADER: ROBERT WATERHOUSE Reports by Bob Spurgeon and Kathy Stott
LES MONTS GRANTEZ In geological terms, the dolmen at Les Monts Grantez was constructed at some time during the Holocene Epoch, which started about 9,700 years BCE and lasts to the present. The archaeological system dates it as 3,200 BCE (based upon time), late Stone Age (based upon tools) and late Neolithic (based upon subsistence practices). It was at a time when people remained in the same location so they could grow crops and raise animals, allowing them enough spare food and time to build permanent structures. The actual date will have been estimated by comparing the pottery fragments found on site with those from other sites around, because it was excavated before radiocarbon dating became available. Les Monts Grantez High sea levels before the Holocene shaped the island of Jersey. One particular episode 230,000 years ago left raised beaches and erosion slopes that are visible today. Glacial ice never reached the island, but the strong winds coming from the high pressure area above the northern and eastern ice sheets certainly did. They brought with them the fine clays, silts and sand, which covered the area as a deep
Wessex Footnotes December 2017 Page 5 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day two, 5 October 2017 layer of loess. We were fortunate to see cross-sections through this material when we visited Green Island the day before. At the start of the Holocene, there was dry land between Jersey and France, but as the sea level rose it became an island. During the Stone Age Jersey would have enjoyed these very fertile calcareous loess soils, perfect for an agricultural economy; but as time passed massive quantities of wind-blown sand began to cover everything. By the 19th century quarrymen were actively extracting granite from outcrops above the 230,000-year sea level. When one such rock was being extracted in 1839 they realised it was not a natural outcrop, but rather part of an ancient monument. Fortunately they stopped, which saved the site and allowed it to be properly excavated in 1912. The same unfortunately could not be said of the Dolmen du Mont Ubé in the south-east of the island, whose capstones were destroyed by quarrymen in 1848 before it could be examined by archaeologists. Other dolmens on higher ground probably met the same fate. When it was built, the dolmen rested on the yellow loess soil. It would have stood proud above the ground, but would not have dominated the skyline. After it fell into disuse the ground was covered with a thick layer of sand (visible in nearby molehills) and it now lies below the modern ground level.
In plan the dolmen is pear shaped. It A – J: Interments would originally have been completely 1 – 5: Pottery. covered with stone slabs, but those removed by the quarrymen were never replaced, leaving a narrow, low passage into the now open area. The alignment is such that the sun may have illuminated the west wall during the solstice. There is a side chamber in the north wall, constructed from local angular blocks, which is possibly a later addition. The structure is classified as a passage tomb. A total of seven bodies were found in the round section of the tomb: six adults and one child, lying on their sides in a crouched position. A further Plan of Les Monts Grantez (Hawkes 1937) Image courtesy of the Société Jersiaise, with permission. body was found seated in the entrance passage, with the scattered remains of a ninth in the side chamber. There were limpet shells, bones and teeth of cow, horse, sheep, pig and deer, colourful sea pebbles, three round-bottomed bowls, broken vase supports, a clay spindle whorl, stone rubbers, hammers, a fine flint pick and a steatite bead. Neolithic tombs were in use over many generations and typically contain selected body parts from a large number of individuals. So these complete bodies could well be a much later addition, although as they have never been carbon dated this cannot be proven.
Bob Spurgeon
LA COTTE DE ST BRELADE This is a Neanderthal cave or gulley in the granite cliffs at Ouaisne which was occupied around 190,000 years ago. Excavations by the Sociéte Jersiaise between 1910 and 1914 produced thousands of small artefacts and stone tools, a hyena skull and 11 mammoth skulls, some of which can be seen at the geological museum at la Hogue Bie. The cave is now considered unsafe to enter so our leader did the presentation outside on the rocks!
Kathy Stott Robert Waterhouse (arrowed) perched outside the cave Photo by Malcom Wright
Wessex Footnotes December 2017 Page 6 WESSEX OUGS TRIP TO JERSEY, 4-6 OCTOBER 2017 Day three , 6 October 2017
Leader: Derek Hairon Report and photos by Rhiannon Rogers
A WALK ON THE SEABED: LA ROCQUE TO SEYMOUR TOWER The South East Jersey coast is designated as a Ramsar Site (ie a wetland of international importance) to protect the high quality environment, which in turn supports tourism and the island’s economy. By early evening high tide would be a depth of 11.5 metres and the sea returns rapidly once the tide turns. So, with no time to lose, we donned our wellies and set off at low tide from La Rocque with our guide, Derek, to explore the large littoral zone with rocks, pools and shingle banks. The rock pools were clear and full of life. We carefully turned over a large stone and saw chitons, sea squirts, sponges, sea mat and a cushion star before placing the stone back as we found it. Other sightings were a stranded barrel jellyfish, which was returned to a rock pool. Seaweeds were abundant, including Egg Wrack (Ascophyllum nodosum) with tufts of Egg Wrack Wool (Polysiphonia lanosa) growing on it. Farmers would have taken their horse and cart to the shore to harvest “vraic” or wrack which was then piled up to let the rain wash out the salt. In the autumn the wrack was spread onto the fields adding minerals, improving both the soil and the flavour of the famous Jersey Royal potatoes. It was also noticed that the iodine in seaweed Rock pool species prevented stillbirth in cattle. We looked at the association of the array of yellow and green periwinkles and seaweed. When the periwinkles were placed on different seaweeds some of them blended in well, others less so, indicating a very successful method of survival on their favourite food plants.
There are a number of SW-NE channels between the granite reefs and some are just the right width for seaweed carts – perhaps natural gullies adapted by farmers? We also saw patches of crumbly sand and clay mix soil. Clay can be found 30-40cm below the sand, a remnant from when the land between France and Jersey was a land bridge. Elsewhere there was a single large conglomerate boulder from the Rozel Conglomerate Formation to the NE of the island. Jersey is well known for its regionality or “terroir”, influencing the flavour of its Conglomerate boulder, Rozel food. Limpets, winkles and Conglomerate Formation many seaweeds are edible, though perhaps not as popular now as they were in the past when there were fewer alternatives. Overfished European oysters have been replaced by Pacific oysters grown for the restaurant trade: Jersey has the only sustainable oyster fishery in the world. As Pacific oysters rarely spawn in European waters they grow quickly and can now be eaten all year round. Bass fishing and dredging have been banned and Shingle banks with limpets and there are strict minimum sizes for shellfish. The south of Jersey is periwinkle shells the northern limit for abalone (or ormer) which is a rare marine snail, considered to be a delicacy; numbers taken are carefully monitored. What an amazing place. Derek was incredibly knowledgeable and told us so many good stories as we walked. There was so much to look at it would have been easy to forget the impending return of the tide!
Rhiannon Rogers
Wessex Footnotes December 2017 Page 7 SIMPLE GUIDE TO MINERALS 27 OKENITE Ca10Si18O46 · 18H2O
The first thing that you should be aware of is that Okenite is white, or white with a slight hint of a colour. It is not a bright blue or red, but there are many dyed specimens being sold out of India and China. Did you notice the proportion of water in the formula? That is what makes it easy to dye.
It is a phyllosilicate which is found as bladed crystals, typically fibrous, clusters of curved crystals and radial balls. You can see in the photo that this specimen has both the radial ball shape and the fan of bladed crystals. The most common form is the 'cottonwool ball' shape. It is one of the zeolite minerals and is found in vugs, or cavities, in basalt. Basalt geodes frequently have these inside. It is a secondary mineral from the alteration of basalts. Okenite is fairly translucent, has a pearly lustre and streaks white. It has a hardness of 4.5 to 5. Specimens can be found wherever there is basalt and the one in the photo came from Durango in the US. The most common source of this mineral is India, but it was first described in 1828 for an occurrence at Disko Island, Okenite Greenland and named for German naturalist Lorenz Oken. Specimen in the Morley collection Photo by Colin Morley In 1802 he devised a new system of animal classification that demonstrated the path of evolution. He was also the first to recognize the significance of biological cell structure in 1805. If you give or receive okenite as a present, you should know that amongst its many metaphysical properties it is believed to aid those suffering from prudishness!
Colin Morley
AGM AND DAY OF LECTURES: “SLIP SLIDING AWAY”
Saturday, 27 January 2018 at the d’Urberville Centre in Wool, Dorset
PROGRAMME AGM AGENDA
10.15am Registration 1. Apologies for absence 10.30am Sam Scriven: Scientific discoveries 2. Minutes of last meeting
and insights of the Jurassic Coast 3. Matters arising 4. Agenda items received 11.30am Millie Watts: Storegga slides in the North Sea 5. Officers' reports: Branch Organiser (Colin Morley) 12.45pm Buffet lunch (provided by committee and friends) Treasurer (Rhiannon Rogers) Day Trips & Library (Jeremy Cranmer) 1.45pm AGM (agenda at right) Newsletter (Hilary Barton) 2.30pm Prof. Sanjeev Gupta: The Channel Website (Colin Morley) Megaflood Residential Trips (Mark Barrett) 4pm Close The committee will then stand down for:
The charge for the whole day, including lunch, 6. Election of officers is £8 per person (no charge for the AGM) 7. Any other business
All committee members will retire at the AGM. DIRECTIONS Apart from the Treasurer, all those retiring D’Urberville Centre, Colliers Lane, Wool, Dorset are willing to stand for re-election. Postcode: BH20 6DL. Map ref: SY 843 865. Nominations for any committee post must be Five minutes’ walk from the railway station in Wool. received by the Branch Organiser no later Train times at: www.southwesternrailway.com than 13 January 2018, [email protected]
Wessex Footnotes December 2017 Page 8 WESSEX OUGS TRIP TO LYME REGIS, 24 SEPTEMBER 2017 Geology and fossil hunting
Leader: Sam Scriven Report by Mark Barrett
We met Sam by the RNLI station by the Cobb on a warm, muggy Sunday. By way of introduction, Sam explained why the Jurassic Coast had been given world heritage status in 2001. The Jurassic coast extends for 95 miles and gives a near complete record of the Mesozoic with exceptional examples of rocks, landforms and fossils. Around 250 Ma, the world supercontinent of Pangaea started to break up. This tension caused the land in the Jurassic Coast region (known as the Wessex Basin) to stretch and sink. It was inundated by the sea and throughout the Mesozoic Era sediment was deposited on the seabed. The Wessex Basin was subsequently upraised and tilted downwards from west to east. Subsequent erosion meant that there was a continuous record of sedimentary rocks from the Triassic in the west to the Cretaceous in the east. Around 100 Ka the English Channel formed and cut through these rocks, allowing us to see this wonderful and unique geological record. We walked westwards onto Monmouth Beach where Sam then introduced us to the rocks that could be found on the beach. The major constituent on the beach and in the cliff face was the Blue Lias. Sam stated that Blue Lias with laminations was best for fossils. There was also chert on the beach from the Greensand Formation and Chalk with flint, both fossiliferous Cretaceous deposits from above the Lias. The chert and flint was often precipitated within sea urchin tests as well as around sponges. Between these two deposits, fossiliferous Cenomanian limestone was laid down in shallower seas. On the beach there were some hard, maroon quartzite pebbles, these originated from the Laminations in the Lower Lias cliff Budleigh Salterton Pebble Beds in Devon and had Photo by Ralph Bonsall Inset: Detail of Lias shale-mudstone-limestone been transported by longshore drift. The quartzite sequence Photo by Mike Grover was formed by metamorphosis when sandstones were buried during the formation of a mountain range over modern Brittany. Around 250 Ma a large river eroded the mountains and transported these pebbles northwards across a barren desert where they were subsequently deposited in the Budleigh Salterton area. Sam then showed us the famous ammonite pavement. This consists of numerous ammonite fossils and it has been suggested that the larger ones are females while the smaller ones are males. There are many theories on its origin; some believe than it was an anoxic death assemblage whilst others believe it to be a lag deposit. It has also been proposed that the very slow rate of sedimentation at the time meant that large numbers could have been deposited over a lengthy period and thus this pavement need not be indicative of any dramatic event. Sam pointed out that the deposit was in the middle of a rock layer and thus not in an area of environmental change. He said that we don’t know the answer and that any of these theories were equally valid - the fact that we will never know all the answers adds to the fascination of deep time. Anoxic events were a recurring feature throughout the Jurassic because, when the Wessex Basin flooded at the end of the Triassic just over 200 Ma, it became part of a European shallow tropical sea, sheltered by surrounding land masses. There was consequently little circulation which meant that the sea could become virtually stagnant at times, thereby promoting anoxic events. The lack of oxygen resulted in a virtual absence of benthic fauna which enabled fossils to be well preserved. Ammonite pavement and The Lias rocks are black because of their high organic content. detail Photos by Linda Luckhaus
Wessex Footnotes December 2017 Page 9 WESSEX OUGSOUGS TRIPTRIP TOTO LYMELYME REGISREGIS,, 24 24 SEPTEMB SEPTEMBERER 2017 2017 Geology Geology and and fossil fossil hunting hunting
The Blue Lias is a limestone sequence rhythmically interspersed with marl and shale. This indicates that the environment was alternating between two extremes, from limestones with large numbers of fossils to shales with very little fossiliferous evidence. It has been suggested that it is related to one of the Milankovitch Cycles, namely obliquity; this occurs every 41,000 years, as the Earth’s axial tilt varies from 24.5° to 21.5°. As we wandered along the beach we could see a few trace fossils caused by burrowing fauna and a small number of ammonite, brachiopod and bivalve remains. The most impressive was the fist-sized bivalve Plagiostoma giganteum. Chert – and trace fossils? Photo by Chris Hawkes Having gingerly negotiated our way around the rocky headland to Pinhay Bay, Sam was able to show us the Triassic/Jurassic boundary. The former was represented by White Lias, a marly limestone deposited in a lagoon environment. There is a complete absence of fossils in this rock, due to the mass extinction event at the end of the Triassic. The cause of the extinction event is believed to be massed volcanism caused by the break-up of the super continent of Pangaea; this is known as the Central Atlantic Magmatic Event when throughout the world about 60% of all species were wiped out. The Blue Lias shows the start of the Jurassic period, although some authorities believe it starts 3 metres above the White Lias and is defined by the bio- stratigraphical unit denoted by the Psiloceras planorbis ammonite. At the base of the Blue Lias there are no fossils The Triassic/Jurassic boundary lies or evidence of bioturbation but they slowly reappear as the above the White Lias at the base of the marine ecosystem recovered. cliff at Pinhay Bay Photo by Mike Grover Sam concluded by saying that the Jurassic coast not only enabled us to appreciate what was happening locally in deep time, but also gave us a better understanding of global events.
Mark Barrett
WESSEX BRANCH WEEK IN THE WESSEX BRANCH WEEK END ON THE LAKE DISTRICT NORTH NORFOLK COAST
15 – 21 April 2018 22 – 24 June 2018
Leaders: Prof Chris Wilson and John Rogers Leader: Dr Fiona Hyden (OUGS tutor)
Five full field study days covering the Keswick, The Norfolk coast reveals part of the history of Shap and southern Vale of Eden areas. Staying glacial and interglacial processes during the last at the very scenic Derwent Independent Hostel. 2.6 million years as well as oceanic and biogenic processes during the mid-Cretaceous. The The total cost will be £285 per person which proposed itinerary includes coastal cliffs at includes the leaders’ expenses, breakfast, Overstrand, West Runton and Hunstanton. evening meal and accommodation. Packed lunches will cost an additional £30 for the week Accommodation will be on a full-board basis at
and need to be booked in advance. Participants the modern, well-appointed Sheringham Youth will need to make their own travel arrangements. Hostel, in twin or double rooms. The price is
expected to be £120-£150 and a £30 deposit by To secure a place, a deposit of £50 per person is 31 December 2017 will secure your place. needed by 1 January 2018. Further information and an application form are Full details, and an application form, are on page on the website. The trip will only run if there is 4 of October’s Footnotes and also on the website. sufficient interest so contact Chris Hawkes soonest Contact: Mark Barrett, [email protected] xxxxxxxxxxxxxxxxxx
Wessex Footnotes December 2017 Page 10
A TRIBUTE TO GWENDA BREWER (1944 – 2017) It is with sadness that I have to announce that Gwenda recently lost her battle with cancer. She knew she had a poor prognosis but was determined not to burden anyone with the knowledge, so only a few of us were aware. Gwenda joined Wessex OUGS in 1998. She was always a very active member and supportive of others. She joined Wessex committee in 2007 and amongst other things organised a highly successful Climate Change Day of Talks in Weymouth and a residential trip in Snowdonia, an area she loved. Gwenda then went on to organise our AGM banquet annually. Gwenda was very enthusiastic about her geology. She was a real asset on field trips, taking detailed photographs which regularly featured in Footnotes. This also meant she was the one right at the back of the group so when we saw Gwenda we knew we had not lost anyone! Ours thoughts are with her husband Richard and son Duncan. Gwenda will be very much missed by us all. Her funeral was a wonderful celebration of her life. Sheila Alderman
AN IMPORTANT NOTICE FOR ALL MEMBERS
For this year only, all members are asked to complete a membership renewal form – even if you have already set up a standing order for the correct amount. This is because the rules regarding data protection are changing and the Society can no longer assume you are happy for us to communicate with you by e-mail unless you give explicit consent.
More information, and the forms, are on pages 14-16 of the November 2017 edition of the OUGS Newsletter, or on the website at http://ougs.org/files/ouc/general/Membership_Renewal_2018.pdf. If you pay by standing order, please ensure that it contains the appropriate amount, which is £22.00 for Full and Associate members and £32.00 for Joint members.
Please note that if you do not pay by 31 January 2018 your membership will lapse and this will be the last copy of Footnotes that you receive.
145Ma FOSSILS FROM DURLSTON ARE EARLIEST HUMAN ANCESTORS
Teeth of tiny shrew-like creatures found on the beach at Durlston are the earliest undisputed fossils of mammals belonging to the line that led to humans. They were discovered by Grant Smith, then an undergraduate at Portsmouth University, when sieving samples from the Purbeck Group “Mammal Bed”, bed number DB 83. Two new species have been identified. One has been named Durlstotherium newmani after Charlie Newman, landlord of the Square & Compass in Worth Matravers, who has his own fossil museum there. And the other is named Dulstodon ensomi, after Paul Ensom, former curator at the Dorset County Museum. Outline geological map of Durlston Bay and If you'd like to have a go at finding your very own the southern part of Swanage Bay, east ancestor, the grid reference is SZ 03673 78377. The Dorset, UK showing the locality. Arrows indicate dip. public have free access to the foreshore here and Inset Stereo scanning electron micrographs permission to collect fossils is not required. of: A Durlstotherium newmani gen. et sp. Hilary Barton nov., NHMUK PV M 99991; B Durlstodon ensomi gen. et sp. nov., NHMUK PV M 99992 Sweetman, S.C., Smith, G., and Martill, D.M. 201X. Highly derived eutherian mammals from the earliest Cretaceous of southern Britain. Acta Palaeontologica Polonica XX (X): xxx–xxx. Available online 7 November 2017, https://www.app.pan.pl/article/item/app004082017.html
Wessex Footnotes December 2017 Page 11 OTHER ORGANISATIONS’ EVENTS Elsewhere in the area
GEOLOGY LECTURES AT DORSET COUNTY MUSEUM LULWORTH RANGE WALKS High West Street, Dorchester DT1 1XA. Tel. 01305 262735 AND TYNEHAM VILLAGE https://www.dorsetcountymuseum.org/dcm/events/ For information on opening times tel. 01929 404819 13 Dec 2017 Ignite! (Christmas party) OPEN EVERY DAY OVER HOLIDAYS 10 Jan 2018 How best to manage fossil collecting on the 16 December 2017 – 3 January 2018 Jurassic Coast (David Sole) 30 March – 15 April 2018 14 Feb 2018 In search of dinosaurs in the Moroccan Kem Kem 26 May - 3 June 2018 (Prof. David Martill) 27 July – 2 September 2018 14 Mar 2018 The science of palaeoart: the life appearance of 22 December 2018 – 7 January 2019 fossil animals (Dr Mark Witton) OPEN EVERY WEEKEND EXCEPT: Lectures start at 7pm. All welcome. Free, suggested donation £3 9-10 December 2017 13-14 January 2018 DIPPY IN DORCHESTER 24-25 February 2018 19 February - 8 May 2018 17-18 March 2018 Dippy, the Diplodocus cast that for many years greeted visitors as 13-14 October 2018 they entered the Natural History Museum in London, will be on 10-11 November 2018 display at the Dorset County Museum. 8-9 December 2018 Entry is free but non-members need to pre-book a time slot. BOURNEMOUTH NATURAL SCIENCE SOCIETY DGAG AND MUSEUM
Dorset Geologists' Association Group 39 Christchurch Road, Bournemouth BH1 3NS www.dorsetgeologistsassociation.com http://www.bnss.org.uk 9 Dec 2017 Christmas workshop, Broadmayne The Society covers all branches of natural science, and 13 Jan 2018 AGM and talks, Broadmayne (note changed venue) has an extensive, and very impressive, collection of fossils, rocks and minerals which can be viewed every Feb 2018 Building stones of Salisbury Cathedral (Kelvin Huff) Tuesday and also over the Christmas period. 18-21 May 2018 Weekend in Shropshire CHRISTMAS OPEN DAYS OUGS members welcome but check beforehand that spaces are 10am – 4pm on 20, 22, 27 & 29 December 2017 available. Contact: Doreen Smith tel. xxxxxxxxxxxx or e-mail xxxxxxxxxxxxxxxxx (free entry, donations welcome) Forthcoming lectures include: DIGS 30 Jan 2018 Treasures of the Fells (Michael Brooke) 10 Feb 2018 Lecture (Prof. Vincent May)
Dorset's Important Geological Sites Group 27 Mar 2018 Minerals of Europe (Gary Morse) http://www.dorsetrigs.org.uk YOUNG EXPLORERS’ CLUB If you would like to be kept informed of forthcoming conservation (geology and more!) sessions, please contact Alan, who will be happy to add your For children aged 7 to 12. £4 per child per meeting. name to his e-mail circulation list. 9 Dec 2017 Highlights of the year More details from Alan Holiday: xxxxxxxxxxxxxxxxxxxx www.bnss.org.uk/about/young-explorers
RUSSELL SOCIETY, SOUTHERN BRANCH SOUTHAMPTON MINERAL & FOSSIL SOCIETY http://www.russellsoc.org/ http://www.sotonminfoss.org.uk For anyone interested in minerals, the Branch runs summer field trips plus The Society runs field trips and other activities. Monthly bi-monthly winter lecture meetings at Wyvern Technical College, Fair Oak, evening meetings are held at The Friends' Meeting House, Eastleigh, Hants. Ordnance Road, Southampton (guests welcome). 14 Dec 2017 Talks on baryte and Italian minerals 19 Dec 2017 What we got up to in 2017 (Gary Morse) 8 Feb 2018 AGM plus display of the best finds from 2017 16 Jan 2018 AGM and mini-display competition field trips 20 Feb 2018 Annual photographic competition Gary Morse: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Gary Morse: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
DORSET BUILDINGS GROUP JURASSIC COAST ART EXHIBITION John and Sue Rowntree, xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 95 miles of coastline, 3 years of art The Group aims to promote the preservation of Dorset’s building 10am – 5pm, 8 January - 12 May 2018 traditions and so takes a practical interest in building stones and local geology. Winter lectures are held in Holt Village Hall, Dorset County Museum Dorset. High West Street, Dorchester DT1 1XA 7 Jan 2018 Decorative tiles in Dorset buildings (Jo Amey) An art exhibition by Colin Bentley, who is collaborating 4 Feb 2018 Highlights from the Bankes Archive (Emma Munn) with the Jurassic Coast Trust to explore the geology of 4 Mar 2018 Historic England: who are we and what are we? this World Heritage Site and tell its story through (Eve Van Der Steen) landscape drawings and paintings.
Wessex Footnotes December 2017 Page 12 FORTHCOMING WESSEX BRANCH TRIPS More information
Vallis Vale & Tedbury Camp, Somerset Sunday, 18 February 2018
INTRODUCTION TO GEOLOGY: VALLIS VALE AND TEDBURY CAMP
with Alan Holiday To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxx 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 being Chairman of the DGAG and Dorset RIGS group.
The trip is aimed at OU students who are beginning to study geology. It will also be of interest to students studying environmental subjects as there is evidence of sea level change. This site is a great location to extend the knowledge gained on the Introduction to Geology field trip to Bowleaze Cove on 12 November last year. However, while it is complementary, it is not necessary to have attended the earlier one. We will study the Carboniferous limestone and its unconformable relationship with the overlying Triassic and
Jurassic rocks, providing evidence for the effects of the Variscan Orogeny. The famous De la Beche unconformity is a classic. Conservation work on Tedbury Camp has exposed the structures for all to see.
The 2 km walk is mostly flat, with a slight incline to Tedbury Camp and a steep incline with steps to return to cars.
National Oceanography Centre, Southampton Thursday, 15 or 22 February 2018
VISIT TO THE BRITISH OCEAN SEDIMENT CORE RESEARCH FACILITY
with Millie Watts & Dr Suzanne Maclachlan
To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxx We visited this facility on 30 November 2017. The event was so popular that some members were unable to attend and remain on the waiting list. The NOC have very kindly invited us to a second visit.
Our guide will be Millie Watts. She obtained her BSc at the Open University and her MSc at Swansea University. She is currently completing her PhD on "Submarine mega-landslides from the Storegga Slide complex, and their relationship to climatic change" at Southampton University, where she is a curatorial assistant at the NOC. The Facility`s curator, Dr Suzanne Maclachlan PhD, will also be showing us around. We shall view the core storage facility, the logging laboratory, core scanning equipment, the thin section laboratory and have a tour of the research facility. The cores are taken from various places worldwide and are of sediments from the continental shelves, continental slopes and the abyss.
After lunch there will be a lecture by one of the academic staff of the NOC. This will be a fascinating day. The number of those attending is limited to 27. If you are already on the waiting list there is no need to re-apply.
WESSEX BRANCH COMMITTEE Branch Organiser Colin Morley [email protected] FROM THE EDITOR Treasurer Rhiannon Rogers [email protected] Is there anything you would Day Trip Organiser Jeremy Cranmer [email protected] like to tell or ask other Newsletter Editor Hilary Barton [email protected] members? All contributions Residential Trips Mark Barrett [email protected] welcome, including feedback on Website Manager Colin Morley [email protected] the "new look" Footnotes. Librarian Jeremy Cranmer [email protected] Hilary Barton, Editor Ordinary members: Sheila Alderman, Ian Hacker, Linda Morley, [email protected] Judith Purssell, Mike Grover, Gill Michaels
Wessex Footnotes December 2017 Page 13 Open UniversityUniversity Geological Geological Society, Society, Wessex Wessex Branch Branch FORTHCOMING EVENTS
WESSEX BRANCH FIELD TRIPS OTHER BRANCHES’ EVENTS Places are filled on a first come, first served basis. Non- This listing covers OUGS events in members are welcome to attend events, but members will be the Wessex area and general Society given priority if places are short. Please contact the organiser events. However, members can to confirm details and to ensure there are spaces. Packed attend any event organised by any lunches, hard hats, strong footwear and waterproofs are usually OUGS branch - the full listing is at required plus reflective clothing in working quarries. Please http://ougs.org/events/ take note of the safety issues, which the leader will outline at Events shown in italics are joint ones the start of each trip. For day trips there is usually a charge of – please contact the host organizer. £2.50 per person to cover expenses.
Last-minute contact on the day, if you’re not coming or late: Jeremy’s mobile xxxxxxxxxxx
DATE EVENT LEADER(S) CONTACT Wessex Branch AGM and day of Saturday Colin Morley lectures: “Slip Sliding Away” Colin Morley 27 January 2018 [email protected] Wool, Dorset Jeremy Cranmer Sunday Introduction to Mendip Geology Alan Holiday [email protected] 18 February 2018 Vallis Vale, Somerset tel. xxxxxxxxxxx 15 or 22 Visit to The British Ocean Sediment Millie Watts & Jeremy Cranmer (to be confirmed) Core Research Facility (BOSCORF) Dr Suzanne [email protected] February 2018 NOC, Southampton Maclachlan tel. xxxxxxxxxxx Sunday - Friday John Rodgers & Mark Barrett A week in the Lake District 15-20 April 2018 Prof. Chris Wilson [email protected] John Gooch Friday - Sunday OUGS AGM and social weekend [email protected] OUGS 20-22 April 2018 Shap Wells Hotel, Penrith, Cumbria tel. xxxxxxxxxxx Maggie Deytrikh [email protected] Sunday Geology, fossils and coastal change David Bone 29 April 2018 around Selsey, West Sussex Jeremy Cranmer Sunday The Chalk of Durdle Cove Prof. Rory [email protected] 13 May 2018 Dorset Mortimore tel. xxxxxxxxxxx Saturday Geology of the Winscombe area Andy Bradley 16 June 2018 Mendip Hills, Somerset Chris Hawkes Friday – Sunday Weekend on the north Norfolk coast Dr Fiona Hyden xxxxxxxxxxxxxxxxxxx 22-24 June 2018 tel. xxxxxxxxxxx Jeremy Cranmer Sunday Valley of the Stones Kelvin Huff [email protected] 1 July 2018 Dorset tel. xxxxxxxxxxx Friday – Sunday OUGS Symposium http://ougs.org/society- OUGS 10-12 August 2018 Worcester events/
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. Colin Morley, Branch organiser Jeremy Cranmer, Branch Day Events Organiser
Wessex Footnotes December 2017 Page 14