The Open University Geological Society Wessex Branch Newsletter
Website http://ougs.org/wessex
October 2017
Branch Organiser’s Letter CONTENTS Branch Organiser’s Letter Page 1 Hello All, 2018 AGM notice, 27 January 2018 Page 2 I hope that you have made the most of the Wessex Branch committee Page 2 good weather when we had it. We always Charnwood weekend, 3-4 June 2017 Pages 3-6 seemed to be lucky on our field trips though, Worbarrow Bay, 16 July 2017 Pages 7-9 and that should make us all happy. While we Trip to Lake District, 15-21 April 2018 Page 10 are waiting for the leaves to change colour and Minerals guide no. 26 – Labradorite Page 11 put on a special display for us, there is still Chilesaurus, a missing link? Page 11 plenty to occupy us. We have another excellent Other organisations’ events Page 12 trip to Lyme Regis with Sam Scriven on Sunday the 24th September as well as the Jersey trip in Forthcoming Wessex Branch events Page 13 early October (3rd to the 6th); the branch OUGS events listing Page 14 hasn't visited there since 2001. On Thursday 30 November we have a trip in the pipeline to had a volunteer step forward and they will be visit the British Ocean Sediment Core Research attending our September committee meeting to Facility (BOSCORF). You can see why everyone see the 'finer' details of working on the calls it 'Boscorf', can't you? It is Britain's committee. The brief, outline, job description is national core repository, offering researchers still available on the website (under both access to the most comprehensive suite of “Branch matters” and “Your branch committee state-of-the-art core logging facilities in the UK. members”). If the member does decide to stand Deep-sea sediment cores are an expensive and for election I shall make sure that relevant unique resource of immense scientific value. details of their qualifications and experience are This will be a fascinating visit. But before that made available at the AGM. we have a trip to Bowleaze Cove. It is an The AGM is, of course, is on the 27th January, excellent place for both the geology and the the notice is overleaf. As usual, the AGM will fossils. This is an ideal trip for those new to form part of a Day of Lectures, details of which geology and those that want to 'brush up', as are also overleaf. well as those of us that like finding fossils. Members who have marvelled at the Etches Looking further ahead, our week in the Lake Collection will want to join me in sending District next April has now been finalised and congratulations to Steve Etches, who recently you will find details and a booking form on page received an honorary doctorate of science from 10 of this newsletter. Southampton University in recognition of his Those of you who keep a sharp eye on these work on Kimmeridgean fossils. Steve was things will have noticed that our treasurer, awarded an MBE in 2014 for services to Rhiannon, will not be standing for re-election in palaeontology and his doctorate is equally well- 2018. Rhiannon has been our treasurer for deserved. seven years and I am pretty sure that we would Finally, if you haven’t been getting my monthly all agree that it is 'good stint'. She has email with updates and news about trips and provided outstanding support that runs through events, please check that I have your up-to-date all of the parts of the branch from daytrips and email address since I have a few that 'bounce'. longer trips through the newsletter to the AGM. Best Wishes Back in June I asked on the website if anyone would like to stand or is interested to please Colin Morley, Branch Organiser Wessex contact me. Well, we are lucky enough to have E-mail: [email protected]
Wessex Footnotes October 2017 Page 1
WESSEX OUGS AGM AND DAY OF LECTURES
“SLIP SLIDING AWAY”
10.15am to 4.00pm, Saturday 27th January 2018
D’Urberville Centre, Colliers Lane, Wool, Dorset BH20 6DL The AGM will form part of a day of lectures, with registration at 10.15am and a buffet lunch at 12.45am. There will be a charge of £8 for this event, including lunch - the AGM itself is free.
SPEAKERS Prof. Sanjeev Gupta: The Channel Megaflood Sam Scriven: The Jurassic Coast Dr Millie Watts: Storegga slides in the North Sea
Non-members are welcome to attend the day (but can’t vote at the AGM). Please contact Colin Morley if you plan to attend on [email protected] Please also let Colin know if you have a collection or display you would like to exhibit.
WESSEX OUGS AGM 1.45am to 2.30pm, Saturday 27th January 2018
AGM AGENDA All committee members will retire at the AGM.
1. Apologies for absence Apart from the Treasurer, all those retiring are willing to stand for re-election. 2. Minutes of last meeting 3. Matters arising Nominations for the Treasurer and any other 4. Agenda items received post must be received by the Branch Organiser 5. Officers' reports: at [email protected] no later than 13 Branch Organiser (Colin Morley) January 2018. Treasurer (Rhiannon Rogers) Day Trips & Library (Jeremy Cranmer) DIRECTIONS
Newsletter (Hilary Barton) D’Urberville Centre, Colliers Lane, Wool, Dorset Website (Colin Morley) Postcode: BH20 6DL. Residential Trips (Mark Barrett) Map ref: SY 843 865. 6. The committee will then stand down for: Five minutes’ walk from the railway station in Wool. 7. Election of officers Train times at: www.southwesternrailway.com 8. Any other business
THERE IS NO CHARGE FOR THE AGM ITSELF
WESSEX BRANCH COMMITTEE CONTRIBUTIONS TO THE Branch Organiser Colin Morley [email protected] NEWSLETTER Treasurer Rhiannon Rogers [email protected] Day Trip Organiser Jeremy Cranmer [email protected] Is there anything you Newsletter Editor Hilary Barton [email protected] would like to tell or ask Residential Trips Mark Barrett [email protected] other members? All Website Manager Colin Morley [email protected] contributions welcome. Librarian Jeremy Cranmer [email protected] Hilary Barton, Editor Ordinary members: [email protected] Sheila Alderman, Ian Hacker, Linda Morley, Judith Purssell, Mike Grover, Gill Michaels
Wessex Footnotes October 2017 Page 2 WESSEX OUGS FIELD TRIP TO CHARNWOOD FOREST, 3-4 JUNE 2017 Leaders: Ian Williamson and Keith Ambrose Reports by Mark Barrett and Colin Morley DAY 1: Bardon Hill Quarry, Mount St Bernard Abbey, Charnwood Lodge Nature Reserve & Warren Hills On the Saturday morning our group met up with Ian Williamson, our leader for the day, and went to our first location, Bardon Hill and Bardon Hill Quarry. Charnwood Forest contains Precambrian rocks which, at 575 million years old, are the oldest rocks in England. At that time, Charnwood Forest area was located on a subduction zone on the northern edge of the Gondwana continent. The area was a volcanic island arc located in subtropical seas in the southern hemisphere and the environment would have been like Montserrat in the West Indies today. Bardon Hill Quarry As we climbed the hill towards the quarry, Ian drew our attention to some boulders that originated from the quarry. These were igneous plutonic rocks of varying complexities that belong to the Bardon Hill Volcanic Complex. They consist of andesites and diorites which can look similar when weathered and there is no sharp zonation between the two rock types. Some of the diorites have calcite in them and some quartz. On examining the rocks, we could see angular fractions of the original plutonic intrusion with pink feldspar phenocrysts in a black microgranite Simplified geological map of Charnwood Forest (Eastings and matrix. We also saw dioritic and Northings are British National Grid) From P.R.Wilby et al., basaltic rocks with little quartz. Palaeogeography, Palaeoclimatology, Palaeoecology 434 (2015) 14–27. http://www.sciencedirect.com/science/article/pii/S0031018215001649 An open access article under the CC BY license http://creativecommons.org/licenses/by/4.0/
These were intermediate and shallow magmas that intruded into wet muddy sediments below the seafloor. The magma chills at the edges and takes on lobate and stringy forms as it intrudes; the rocks formed at the chill margin are known as peperites. The andesites and diorites consisted of a micro breccia of devitrified volcanic glass which was formed by the rapid cooling; there were also phenocrysts present. Within the peperites there were porphyritic dacites, a black and white rock within which it is possible to see evidence of lava flow. Some boulders have slate intrusions which come from the seabed sediments. There Typical cleavage in the tuffaceous was evidence of some cleavage that was caused during the section of the Charnian Supergroup Caledonian Orogeny which occurred around 470 Ma, when the Photo by Colin Morley region was uplifted to form a range of low hills.
Wessex Footnotes October 2017 Page 3 Having climbed to the top of the hill we were rewarded with a panoramic view of the Leicestershire countryside and the quarry itself. Within the quarry we could see how the Bardon Hill Volcanic complex showed in relief as a ghost range of low hills that were formed at least 250 Ma. The shallow valleys were infilled by the Triassic Mercian Mudstone Member. At this time, the area was part of the supercontinent of Pangaea and was a desert environment with an extensive wadi system. It is possible to see where the Mercian Mudstone sags towards the centre of the shallow valleys due to compaction. Within these red sandstones are harder green bands that represent flooding surfaces. The green colour is due to reduction Wadi revealed in Bardon Hill Quarry whilst the red colouration is evidence of an arid Photo by Linda Morley oxidizing environment.
Mount St Bernard Abbey Mount St Bernard Abbey is a beautiful Cistercian Abbey that was built in the 19th century. After lunch, we examined the rocks within the abbey walls which contained examples of the Whitwick Volcanic Complex. We saw examples of the Peldar Dacite Member, which is a dacite breccia in a dark purple matrix of devitrified glass with large pink phenocrysts. This was formed when magma rapidly cooled when it was intruded into wet seafloor sediments. There were also volcanic breccias containing the Mercian Mudstone Country rocks together with stones from the St Bernard Tuff member, which consists of fine graded beds that fine upwards. By the abbey wall there is a large outcrop of the St Bernard Tuff that shows signs of cross-lamination. This member consists of a series of land-based pyroclastic flows: on reaching water, they eventually slumped into deeper water as a turbidite flow. During the Caledonian Orogeny, the rock became heavily faulted with a very steep cleavage. The roof of the abbey is covered with Swithland Slate; this rock consists of greywackes that were Mount St Bernard Abbey deposited in deep offshore water during the Cambrian. Photo by Linda Morley
Charnwood Lodge Nature Reserve – The Bomb Rocks In the afternoon, we examined a few rock formations that comprise the Maplewell Group, all of which were deposited in the Precambrian. A short walk in picturesque countryside brought us to the Bomb Rocks. This consisted of an outcrop of very blocky andesite clasts, varying in size from over one metre to small clasts in a mixed grain matrix, and represents a volcanic breccia. There is no evidence that any of these rocks were molten, as molten volcanic bombs tend to splat like a cow pat and can also produce spindle-like shapes as they cool and roll along the ground. It is now believed that the deposit formed in a cooling environment representing a gravity driven debris flow. It was probably caused by the collapse of a caldera and the rounding on the boulders is a result of abrasion in a high energy environment. On reaching a Charnwood bomb rocks Photo by Colin Morley change in gradient, the debris flow freezes but water will continue to run downslope.
Wessex Footnotes October 2017 Page 4 Warren Hills We then walked a short distance to Warren Hills which consists of three rocky knolls and we were able to examine Middle Knoll and South Knoll. These rocks are part of the Bradgate Formation which is younger than the Charnwood Lodge Formation and represents a time when volcanic activity was diminishing and finer-grained sedimentary rocks and tuffs were being deposited. Middle Knoll represents a pyroclastic flow that has continued under water and the very coarse- grained sandstones contain fragments of siltstones and mudstones from the seafloor forming a breccia. At the South Knoll, still within the younger Bradgate Formation, we are lower down in the same subaqueous debris flow in deeper water. Here the sandstones are finer-grained with Warren Hills bedding Photo by Linda Morley fining upwards; thereby showing more of the features of a turbidite flow. Ian pointed out the North Knoll that lies on private land. He told us that the rocks there consisted of coarse-grained tuff and lapilli tuff and were again pyroclastic in origin, representing the top of the Charnwood Lodge Formation. Mark Barrett
DAY 2: Bradgate Park and Sliding Stone Crags The second day started in Bradgate Park where we headed off to Old John Tower. Towers are frequently on a hill, and this was no exception. On the way we were walking over unconsolidated glacial deposits. We stopped to examine the outcrops of rocks; they were volcaniclastic deposits of mainly siltstones and mudstones. This was the Bradgate Formation, which is a part of the Charnian Supergroup and is described by the BGS as fine to medium and coarse-grained volcaniclastic sedimentary rocks with locally abundant tuffs and volcanic breccias. In Charnwood Forest it is intruded by massive to brecciated andesites and dacites of the Whitwick Volcanic Complex and the Bardon Hill Volcanic Complex. The rocks are fractured, cleaved and have only very low-grade metamorphism in the Nuneaton area and low-grade upper greenschist metamorphism in Charnwood Forest itself. On the way up to the tower the cleavage was easy to see but the bedding planes were less obvious. A little study showed varying thicknesses and slight colour changes. I could also see that there were distinct differences in grain size between the layers. The colour changes could have been due to varying grain sizes but it was a little too weathered for me to make that out even through a hand lens. These sediment layers would have been deposited by turbidite flows. As the sediment-laden current loses its energy and slows down, the sediment is allowed to settle with the larger grains settling first, and gives us the fining upwards effect. It isn't uncommon for fine-grained beds to show good cleavage planes and this cleavage was at a very high angle (circa 80 degrees?) to the bedding planes. Our next stop was not very far away. It was our chance to see the world famous Charnia fossils. The best specimens have been preserved and can be seen elsewhere but here the rocks seemed very similar to our previous stop. At first it seemed like a huge slab sloping away from us with widely spaced jointing. This fossil- bearing bedding plane covers a large area about 20m long by about 2-3 m high. It took a while but, looking at the low relief faint patterns, we started to be able to pick out the fossils. It wasn't easy because we didn't have good oblique sunlight - that may have helped. But it became obvious that they weren't all small and there were quite a few. Photographs, like our eyes, Charnia masoni, holotype in the New didn't pick them up that clearly so I have included one that I took Walk Museum, Leicester in the local museum last year (unfortunately they have followed Photo by Colin Morley the modern trend towards 'artistic' lighting.)
Wessex Footnotes October 2017 Page 5 The impressions in the rock have resulted from fairly soft-bodied organisms coming to rest on the silts, with rapid burial covering them in sediment. The preservation of some discs was pretty good and that may indicate that they may have been formed of a less soft, organic substance. They were not all of one type. One seemed to have several fronds, possibly Bradgatia linfordensis. Other fossils on this bedding plane seemed to have one large frond (Charnia grandis?). There were also a number of disc-like fossils that didn't seem linked to fronds (Charniodiscus concentricus?) although they could have simply been the 'holdfast discs' to fronds that were difficult to see. Some of the Holdfast fossil impressions may have been two or more specimens overlaying each other Photo by Colin Morley so I cannot be certain about applying the correct names to any of them. The fossils are believed to have been benthic and sessile, anchored to the sea floor. According to the current hypothesis, they probably lived in deeper waters, below the wave base. This means they could not have photosynthesised. Precisely how deep they lived is critical, because below 200m in modern seas is the disphotic zone, where plants can't grow. Also, they have no obvious feeding apparatus (mouth, gut, etc) so their relationship with their habitat remains somewhat enigmatic. It is believed that they survived either by filter feeding or directly absorbing nutrients, and this is currently the focus of considerable research. We also visited the outcropping that showed the Sliding Stone Slump Breccia Member at Sliding Stone Crags. The first thing we noticed was the obvious ripped up and folded clasts in the rock and dewatering features, but the general matrix of the rock was the now familiar volcaniclastic sediments. The hypothesis is that the chaos was caused by earthquake shocks from the volcanic activity to the north west; it probably represents the proximal debris flow. This member can be traced westwards across the area and, being easily recognisable and at the base of the Bradgate Formation, it is an important marker horizon. Rip-up clast Photo by Colin Morley
Slide slump Dewatering structures Tension gashes Photo by Colin Morley Photo by Colin Morley Photo by Colin Morley
The Stable Pit Member was quite clearly sandstone (arenite), not quartzite as I would have expected in something that old. It was not well consolidated, nor did it display that sugary look of a quartzite. It was previously thought to be Precambrian but has been reclassified as Lower Cambrian. The rocks do show some signs of deformation and there are numerous tension gashes that resulted from shearing. In the Ordovician a substantial diorite dyke intruded. The deformation wasn't extreme though because there were still quite convincing ripple marks on the upper surface. All in all it shows deposition in a nearshore environment, along or close to the shoreline of the Iapetus Ocean. Unfortunately everything cannot be adequately covered in this report. The mineralisation and the slickensides, the pebbly hanging rock formation, cleavage defraction in the Holgate member, the South Charnwood Diorite and the Swithland Slate will have to serve as an extra reason to get on the next trip up there. Our thanks go to our two excellent leaders who really knew the area well. Colin Morley
Wessex Footnotes October 2017 Page 6 WESSEX OUGS FIELD TRIP TO WORBARROW BAY, DORSET, 16 JULY 2017 Evidence of climate and environmental change in the Cretaceous Leader: Jeremy Cranmer Report and photos by Bill Hinton
The view from the Hill Twenty members assembled at Povington Hill, Purbeck, which commands panoramic views. The area was bustling with walkers and cyclists taking part in organized events. Jeremy Cranmer outlined the local geology with the help of a geological map, a 3D model and features on the horizon in all directions. The wind was from the southwest and humidity was high. Jeremy explained the formation of orographic clouds which were visible to the southeast over St Aldhelm’s Head. In contrast, inland to the north there were only Orographic clouds over St Aldhelm’s Head (left) These clouds scattered high clouds. form as the air cools when wind pushes moist air up a hillside. We were standing on chalk, a rock that is resistant to erosion. Looking south we could see limestones on the horizon with the Vale of Tyneham in the foreground. The Vale is the result of erosion of the relatively weak Wealden Beds, which were deposited in deltaic conditions. Alpine orogenic forces from the south have tilted the rocks asymmetrically to form the Portland syncline. On Portland the upper Jurassic Portland Stone dips gently (4°) to the south; the Upper Cretaceous beds dip steeply (60°) to the north. The orogenic forces probably arose before the Cenozoic. These formations are all plunging very gently towards the east. Sediment was transported mainly from the west, and the vale broadens towards the east in the Weald where it links with the Paris basin. The mass of sediment lowers the strata in the east isostatically. Before leaving the Hill, we noted the Isle of Wight, the continuation of the chalk to the east. Looking north, the woods on the horizon were also on chalk exposed by the Frome Valley syncline. Though not visible, the most westerly outcrop of the Gault clay was considered to be not far away near Sutton Poyntz. We took our cars down to Tyneham and walked to the coast at Worbarrow Bay. We descended to the pebbly beach at Pondfield Cove to the east of Worbarrow Tout. The Worbarrow Bay, Wealden Beds oldest outcrop, the Kimmeridge Clay (KC), would have been visible had the tide been out. We were told that the KC is fine and black. It is rich in organic material, predominantly belemnites and ammonites that lived in the upper part of the water column. They are preserved because they sank into an anoxic environment on death. There is much less fossil evidence of a benthic fauna. The KC is the source rock for North Sea Oil. Question: why is the KC not oil-rich in this locality? Answer: in the North Sea grabens take the clay deeper where temperature and pressure are higher.
Wessex Footnotes October 2017 Page 7 Walking westwards on Worbarrow Bay is walking forward in time
Ma at STAGES Dorset outcrop Inferred environment PERIOD start 74 Mastrichtian Not exposed Portsdown Fm 83 Campanian
White Chalk Culver Fm
Group Newhaven Fm 86 Santonian Seaford Fm
88 Coniacian Lewes Fm Upper
Cretaceous New Pit Fm 90 Turonian Holywell Fm Grey Chalk Zigzag Fm Deepening sea 97 Cenomanian Group West Melbury Fm 112 Upper Greensand Gault Relatively deep sea ?anoxic Albian Shallow sea, well-
Lower Greensand oxygenated, high energy.
125 Aptian Start of marine transgression Lower
Cretaceous Wealden Shales “Dry” land 132 “Wealden” Wealden beds High rainfall 146 Ryazanian Purbeck Beds Tidal lagoon, arid Portland Stone Shallow sea, arid Upper 152 Portlandian Portland Sand Jurassic 154 Kimmeridgian Kimmeridge Clay Start of marine regression
Observations on a smaller scale Our study of the “bigger picture” was supplemented by numerous smaller features revealed by Jeremy’s lieutenants, mainly at Pondfield Cove. • Steeply dipping Portland Stone containing a large ammonite Titanites gigantus. This is a type fossil for Portland Stone. • Purbeck Beds were thinner than those of Portland Stone implying a more changeable environment. • Broken Beds: spaces were originally filled with evaporites which have dissolved or are less competent. Broken Beds • Ostracods: bivalves whose different species define habitats. • Purbeck Marble, containing fresh water snails. • Piddocks: holes made in Purbeck Stones by a modern snail which secretes acid and has a rasping foot. • Cinderbeds: oysters. • Bioturbation. • Symmetric and asymmetric ripples. • Stromatolite: fossil algal mat developed around a tree trunk. • A dinosaur footprint which didn’t wish to be photographed! Symmetric ripples
Interpretation of environmental conditions giving rise to the sequence Portland Sand and Portland Stone were laid down in shallow seas at about 40°N, where wave and current action agitated the water resulting in fragmenting of shells and formation of ooliths. The change from shallow seas (Portland) to tidal lagoons (Purbeck) is explained by a marine regression and arid atmospheric conditions. At the end of the Ryazanian (Purbeck), there was a significant change from aridity to high rainfall. This change is marked by the end of evaporite deposition and the increased presence of clay minerals. The kaolinite content of clay minerals increases with increasing acidity, which is itself a consequence of high rainfall. However the acid conditions must have been persistent and tempered because carbonates are still present in the deposits.
Wessex Footnotes October 2017 Page 8 The marine regression continued and resulted in dry land with extensive terrestrial flora and fauna deposited in the Wealdon Beds. These beds contain river deposits, lake deposits, fossil vegetation and cross-bedding. Diagenesis resulted from groundwater, and environmental change altered the lithology. Terrestrial conditions didn’t last beyond the Aptian when a marine transgression commenced. By the Albian, the Gault Clay (tranquil, probably anoxic conditions) and the Lower Greensand (relatively shallow, high-energy, well oxygenated seas) had been deposited. These are visible at the western end of the beach. Continuing deepening of the seas resulted in the deposition of the Grey Chalk of the Zigzag Formation and ultimately the white chalks of the Holywell, New Pit and Lewes Formations. We were unable to see the upper reaches of the Chalk due to a major landslip at Cow Corner. Observations of colourful deposits As we walked forward through time from east to west along the edge of the cliff we observed many features. Purple Beds where carbonate nodules are stained by manganese and ferrous compounds in silty clay. Iron cemented sandstone. Lignite in clay with yellow colouration. This was due to the action of bacteria metabolizing selenite (gypsum needles). Elemental sulfur remains as the bacteria use the oxygen in sulfate.
White silty clay which was cross-bedded. The clay minerals Purple Beds were derived from feldspars to the west in Cornubia. The cross-bedding was of different thickness due to deltaic meander. Red and brown sandstone. Iron-rich groundwater has changed the rocks after deposition. Coarse quartz sandstone with some mica, evidence of an origin to the west (Dartmoor). More lignite with whole pieces of fossil wood. Rip up clasts resulting from a storm event. White clay stone (Cretaceous). Sandstone, influence of iron-rich Echinoids, bivalves and bioturbation in the Upper Greensand. groundwater We discussed the formation of a hardground (former sea floor) between the Upper Greensand and the Chalk. A marine transgression resulted from the displacement of seawater due to increased mid-ocean ridge formation and an increase in atmospheric temperature caused icecaps to melt. A special message of appreciation Colin Morley gave a vote of thanks on our behalf. At the outset Jeremy admitted to being “less mobile” than he would have wished having injured his leg a few days before. He thanked members of the group who had helped him by finding interesting features and for helping with their explanations. Bill Hinton References Cranmer, Jeremy: OUGS (Wessex) trip handout House M R: “Geology of the Dorset Coast” Mortimore R N: “Logging the Chalk” and “Cretaceous gems of the Jurassic Heritage Coast of England” OU SXR260: “Geological History of the British Isles” Raggett, George: OUGS (Wessex) trip handout West, Ian: website http://www.southampton.ac.uk/~imw
SULPHUR OR SULFUR? I used to think that “sulfur” was the US spelling and always preferred to use “sulphur”. I now realise that the nomenclature of chemical elements and compounds is decreed by the International Union of Pure and Applied Chemistry (IUPAC), which decided some time ago that it should be “sulfur”. In fact there only two elements for which the IUPAC allows alternative spellings – so we can safely continue to use aluminium and caesium, rather than 'aluminum' and 'cesium'. Ed.
Wessex Footnotes October 2017 Page 9 OUGS WESSEX TRIP TO THE LAKE DISTRICT Sunday 15th April - Saturday 21st April 2018 Leaders Prof Chris Wilson, Emeritus Professor of Earth Sciences, Open University John Rogers, President, Cumberland Geological Society Organizer and contact Mark Barrett, 7 Lawrence Close, Amesbury, Wiltshire, SP4 7RP. Tel. 01980 624111. [email protected] Itinerary Five full field study days from Monday to Friday covering the Keswick, Shap and southern Vale of Eden areas. We will look at the Lower Palaeozoic and glacial history of the Keswick area including the Borrowdale volcanics, the Shap granite and turbidite sequences and finally the Carboniferous/Permo-Triassic succession in the Vale of Eden We will be walking over exposed and uneven ground. Hard hats, strong walking boots and both warm and wet weather clothing are required. Accommodation We will be staying at the very scenic Derwent Independent Hostel. This is a Georgian House overlooking Derwent Water. We have secured accommodation for twenty people. This is a hostel so accommodation will be in shared single sex rooms, which hold either 4 or 6 persons. There are only two twin rooms allocated to our party. Derwent Independent Water, Barrow House, Borrowdale, Keswick CA12 5UR www.derwentwater.org Booking The total cost will be £285 per person which includes the leaders’ expenses, breakfast, evening meal and accommodation. Packed lunches will cost an additional £30 for the week and need to be booked in advance. Participants will need to make their own travel arrangements. We will be using our own vehicles throughout the week and car sharing will be encouraged as parking is restricted at some locations. To secure a place please send the application form below and a deposit of £50 per person to Mark Barrett by 1 January 2018. Cheques should be made payable to Wessex OUGS number 2 account. The deposit is non- refundable unless another member can take your place. The balance will be due by 1st March 2018. Title Forename Surname
Address Tel. Mob. E-mail Postcode
DETAILS OF EMERGENCY CONTACT Name Tel. Address Mob. E-mail Postcode Please use a separate sheet for any special needs or information the organiser and leader should be aware of.
I/We acknowledge that this does not constitute a holiday under the Package Travel Regulations Yes/ no 1992 and that I need to book my own travel insurance Any special dietary requirements (If so e-mail [email protected] and advise accordingly) Yes/no Packed lunches - £30 (£6 per day) Yes/no I am prepared to car share and willing for my name to be passed to other participants from the Yes/no same area as me. If there is a surplus of less than £10 per person I am happy for this to be paid to a charity. Yes/no
I enclose a NON-REFUNDABLE payment of £50 per person Cheque Number (Cheques payable to Wessex OUGS number 2 account)
SIGNATURE DATE
Wessex Footnotes October 2017 Page 10 SIMPLE GUIDE TO MINERALS 26 - by Colin Morley
LABRADORITE (Ca, Na)(Al,Si)4O8 Labradorite is a feldspar. In the plagioclase series, it occurs towards the mafic end, with about 50 - 70% anorthite. As a rock, the colour can vary, but it is normally gray and displays the standard feldspar cleavage planes. Like most silicates it streaks white and, with a specific gravity of 2.68 to 2.72, it isn't particularly heavy for its size. As with all plagioclase it is triclinic and it is a hard rock, at 6 on the Mohs scale. Tabular twinning is common, and that is what gives it the schiller (iridescence) that makes it such a popular mineral. If the specimen has a high degree of schiller it can be called 'labradorescence' and then the specimen can even be called spectrolite. If you want more complicated, in-depth scientific information about the cause of the iridescence, look up Bolton et al, 1966. Labradorite was named after a find near Nain in Labrador, Canada, but as it occurs in mafic rocks, it can be found in many locations worldwide. The specimens in the photo came from Newfoundland, Canada. The better specimens are highly prized by collectors. The Labradorite photo shows rough rock as found but with a small polished Specimens in the Morley collection Photo by Colin Morley piece in the middle in order to show the schiller or iridescence. [Readers of the printed edition can check the website to see the iridescence. Ed.] With this mineral, some believe that you can reduce your stress and anxiety and have better insight into your destiny. Just what you need for an OU course. Colin Morley
CHILESAURUS – A MISSING LINK IN THE DINOSAUR FAMILY TREE? Research on recently discovered fossils of a fairly small dinosaur, Chilesaurus diegosuarezi*, provides support for the proposed new dinosaur family tree mentioned in the May 2017 edition of Footnotes. Chilesaurus fossils occur in the Late Jurassic, about 150Ma, and show a bizarre mix of anatomical features. Prof. Paul Barrett of the Natural History Museum, a co-author of the report, said: “I don't use the term lightly, but this does look like a genuine missing link between more standard- looking meat-eating dinosaurs and early plant-eaters.” Chilesaurus has bird-like hips that look like those of an ornithischian dinosaur. This pelvis design facilitates the evolution of the larger gut required for the digestion of plant material.
Although the head and two-fingered arms are more reminiscent of a By Danny Cicchetti (own work), via tyrannosaur, the jaws possess flat teeth designed for shearing plant Wikimedia Commons. CC BY-SA 4.0 food. However, it lacks the beak that subsequently evolved in bird-hipped dinosaurs like Triceratops and Stegosaurus. It also has some other features, such as the structure of the ankle, that even hint at a relationship with some of the long-necked dinosaurs, like Plateosaurus. It may take a few years for the palaeontological community to decide whether the proposed new family tree provides a better explanation of dinosaur evolution but in the meantime Chilesaurus is a fascinating dinosaur in its own right. Hilary Barton (with help from Mark Barrett) * Matthew G. Baron, Paul M. Barrett. A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs. Biol. Lett. 2017 13 20170220; DOI: 10.1098/rsbl.2017.0220. Published 16 August 2017 http://rsbl.royalsocietypublishing.org/content/13/8/20170220 http://www.nhm.ac.uk/discover/what-was-chilesaurus-diegosuarezi.html
Wessex Footnotes October 2017 Page 11 OTHER LOCAL EVENTS – PLEASE CONTACT THE ORGANISERS DIRECT
GEOLOGY LECTURES AT DORSET COUNTY MUSEUM High West Street, Dorchester DT1 1XA LULWORTH RANGE WALKS 11 Oct 2017 Environment (Martin Munt) & TYNEHAM VILLAGE 8 Nov 2017 Life and Times of Dippy (Paul Barrett) For information on opening times tel. 01929 404819 13 Dec 2017 Ignite! (Christmas party) Lectures start at 7pm. All welcome. Free, suggested donation of £3. OPEN EVERY DAY OVER HOLIDAYS Further information: tel. 01305 262735. 16 December 2017 – 3 January 2018 http://www.dorsetcountymuseum.org/events OPEN EVERY WEEKEND EXCEPT: 7-8 October 2017 DORSET GEOLOGISTS’ ASSOCIATION GROUP (DGAG) 18-19 November 2017 www.dorsetgeologistsassociation.com 9-10 December 2017 7 Oct 2017 Durlston Bay, Swanage (Alan Holiday) 18 Nov 2017 Annual dinner, Dorchester 9 Dec 2017 Christmas workshop, Broadmayne BOURNEMOUTH NATURAL SCIENCE OUGS members welcome but check beforehand that spaces are available. Contact: Doreen Smith tel. 01300 320811 or SOCIETY AND MUSEUM 39 Christchurch Road, Bournemouth BH1 3NS e-mail xxxxxxxxxxxxxxxxxx http://www.bnss.org.uk The Society covers all branches of natural science, and has an extensive, and very impressive, collection DIGS: Dorset’s Important Geological Sites Group of fossils, rocks and minerals which can be viewed More details from Alan Holiday: [email protected] every Tuesday morning and also on the: http://www.dorsetrigs.org.uk OPEN WEEKEND If you would like to be kept informed of forthcoming 10am – 4pm, 14 – 15 October 2017 conservation sessions, please contact Alan, who will be happy to add your name to his e-mail circulation list. (free entry, donations welcome) Forthcoming lectures include 7 Oct 2017 Life in the Mid Jurassic Coast (Will Fisher) RUSSELL SOCIETY, SOUTHERN BRANCH 14 Nov 2017 The Big 5 Mass Extinctions (Ray Chapman) http://www.russellsoc.org/ YOUNG EXPLORERS’ CLUB (geology and more!) Gary Morse: xxxxxxxxxxxx tel. xxxxxxxxxxxx For children aged 7 to 12. £4 per child per meeting. For anyone interested in minerals, the Branch runs summer field trips 11 Nov 2017 Famous scientists plus bi-monthly winter lecture meetings at Wyvern Technical College, www.bnss.org.uk/about/young-explorers Fair Oak, Eastleigh, Hants. 12 Oct 2017 Vanadium minerals and Scottish minerals 14 Dec 2017 Baryte and Italian minerals GA FESTIVAL OF GEOLOGY Weekend of 4-5 November 2017 SOUTHAMPTON MINERAL & FOSSIL SOCIETY UCL, Gower Street, London WC1E 6BT http://www.sotonminfoss.org.uk Something for everyone – and all for free! Lectures, Gary Morse: xxxxxxxxxxxx tel. xxxxxxxxxxxx fossil and mineral displays, books, maps, equipment, jewellery, stonecraft, tours of the UCL Earth Science The Society runs field trips and other activities. Monthly Labs and activities for kids. evening meetings are held at The Friends' Meeting House, Ordnance Road, Southampton (guests welcome). Plus field trips and a building stone walk on the Sunday 17 Oct 2017 Heavy Spar (baryte) (Gary Morse) https://geologistsassociation.org.uk/festival.html 21 Nov 2017 Mining emeralds (Rob Bowell) 19 Dec 2017 Recenseo Annus 2017 (Gary Morse) SUSSEX MINERAL SHOW 10am to 4.30pm, Saturday, 18 November 2017 DORSET BUILDINGS GROUP Clair Hall, Haywards Heath, West Sussex John and Sue Rowntree, xxxxxxxxxxxx Admission £2.50 (children 50p, Rockwatch members free) The Group aims to promote the preservation of Dorset’s building Displays and sales of minerals, gems, fossils, traditions and so takes a practical interest in building stones and meteorites, books & accessories. Illustrated talks. local geology. Winter lectures are held in Holt Village Hall, Children’s workshops. Refreshments and bar. Dorset. www.smls.online/show
BLAST FROM THE PAST ON THE ISLE OF WIGHT Weekend of 18-19 November 2017 Fossil and collector’s event at Dinosaur Isle, Sandown, Isle of Wight. www.dinosaurisle.com/events.aspx
Wessex Footnotes October 2017 Page 12
WESSEX BRANCH EVENTS – DETAILS
Weymouth, Dorset Sunday, 15 October 2017 CONSERVATION AT UPWEY CUTTING, ONE OF DORSET’S IMPORTANT GEOLOGICAL SITES (RIGS) with Alan Holiday
To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxxx
Alan Holiday taught geography and geology in Weymouth from 1971 and most recently worked at Weymouth College. 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. In the morning we shall carry out conservation work on this exposure of the Jurassic/Cretaceous boundary, which is part of the Bincombe SSSI. In the afternoon we walk through Bayard Dairy land looking at another cutting and exposures in former quarries within the Purbeck Beds, which expose various strata and evidence of local tectonic effects. Walking distance 2 km. If time allows we can look at a RIGS site at Bincombe which exposes the Upper Greensand/Chalk boundary.
Weymouth, Dorset Sunday, 12 November 2017
BEGINNING GEOLOGY AT BOWLEAZE COVE with Alan Holiday Please note new date – originally scheduled for 5 November 2017 To book a place, contact: Jeremy Cranmer at [email protected] or tel. xxxxxxxxxxxx
Alan Holiday taught geography and geology in Weymouth from 1971 and most recently worked at Weymouth College. 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. This is an ideal trip for those new to geology and those who want to 'brush up'. The more experienced are, of course, also very welcome. It is conveniently located for access by 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.
National Oceanography Centre, Southampton Thursday, 30 November 2017 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. xxxxxxxxxxxx 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, 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 Dr Thomas Gernon, Associate Professor in Earth Science within Ocean and Earth Science, at the National Oceanography Centre will lecture on “Snowball Earth”. This will be a fascinating day. The number of those attending is limited to twenty.
Wessex Footnotes October 2017 Page 13 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 07531 318314
DATE EVENT LEADER(S) CONTACT Jeremy Cranmer Sunday RIGS site conservation session Alan Holiday [email protected] 15 October 2017 Upwey Cutting, Weymouth tel. xxxxxxxxxxxx Chris Phillips Sunday The Etches Collection, Kimmeridge Steve Etches [email protected] 29 October 2017 A guided tour with Oxford Branch tel. xxxxxxxxxxxx Beginning Geology at Bowleaze Cove NEW DATE Weymouth, Dorset Sunday Alan Holiday (suitable for those new to field geology) 12 November 2017 Jeremy Cranmer Originally scheduled for 5 Nov 2017 [email protected] Visit to The British Ocean Sediment Core Millie Watts & tel. xxxxxxxxxxxx Thursday Research Facility (BORSCORF) Dr Suzanne 30 Nov 2017 NOC, Southampton Maclachlan Saturday Wessex Branch AGM and day of lectures Colin Morley Colin Morley 27 January 2018 Wool, Dorset [email protected] Jeremy Cranmer Sunday Introduction to Mendip Geology Alan Holiday [email protected] 18 February 2018 Vallis Vale, Somerset tel. xxxxxxxxxxxx Sunday - Friday John Rodgers & Mark Barrett A week in the Lake District 15-20 April 2018 Prof. Chris Wilson [email protected] John Gooch [email protected] Friday - Sunday OUGS AGM and social weekend OUGS tel. xxxxxxxxxxxx 20-22 April 2018 Shap Wells Hotel, Penrith, Cumbria Maggie Deytrikh [email protected] Sunday Geology, fossils and coastal change David Bone 29 April 2018 around Selsey, West Sussex Sunday The Chalk of Durdle Cove Prof. Rory 13 May 2018 Dorset Mortimore Jeremy Cranmer [email protected] Saturday Geology of the Winscombe area Andy Bradley tel. xxxxxxxxxxxx 16 June 2018 Mendip Hills, Somerset Sunday Valley of the Stones Kelvin Huff 1 July 2018 Dorset 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 October 2017 Page 14