Mercia Rocks OUGS West Midlands Branch Newsletter Issue No 4 December 2020 High Tor Limestone Reef, Matlock, Derbyshire. Jun 2015 - Mike Hermolle Branch Officers Contents Branch Organiser – David Green Branch Treasurer - Susan Jackson Branch Organiser’s report p 2 Newsletter Editor – Mike Hermolle Message on events p 2 AGM 2021 p 3 Branch Committee Quiz p 4 Emma Askew Summary of a research topic p 6 Sandra Morgan Local Geology p 9 Alan Richardson Geo-etymology p 11 Adrian Wyatt Other Societies P 14 Stop Press p 15 If you would like to join the Online Talks p 16 committee please do get in touch 2020 AGM Draft Minutes p 17 [email protected] [email protected] 1 Branch Organiser’s Report This year has been a year we may be remembering for quite a while, unfortunately the Branch has not been able to organise any events this year and is not likely we will be able to have any events until the lock down restrictions are lifted. You will see in this newsletter that the AGM will be held virtually via Zoom this time. The meeting is being held in February and I hope by then we may have some better news regarding what events we may be able to hold next year. I would be very happy to try to help anyone who would like to join the AGM meeting but is unsure of using ZOOM. It is easy to use to join in meetings and is not that hard if anyone is unsure. We will not be having a speaker this year so it will only take up an hour or so of your time. There of course will not be any travelling required to be at the AGM so hopefully members who may have been put off by having to give all day to the meeting may be able to log in to the meeting. As far as my activities this year as BO I have attended some Zoom meeting myself this year on behalf of the Branch as well as the Society’s AGM. For next year at the moment the AGM is also planned to be online and for the Branch we hope to be able plan for some day events and workshops just as soon as restrictions are lifted. I hope everyone is keeping well and will be looking forward to be seeing as many members as possible at the AGM in February Dave Green Forthcoming 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. An annual travel insurance may be the best solution for any member who regularly attends field events: this again is a matter of personal choice. Programme 20/21 – In abeyance due to COVID19 restrictions 20 February 2021 Branch AGM [email protected] 2 Notice of OUGS West Midlands Branch Annual General Meeting Saturday 20th February 2021 at 11:30 Meeting to be held virtually via Zoom Agenda 1. Apologies 2. Minutes of previous meeting on 25th January 2020 3. Matters Arising 4. Officers Reports 5. Election of Officers 6. Appointment of Committee 7. Meeting close Discussion of any items raised by members present If anybody would like to raise any matters to be included in the meeting please contact me on [email protected]. The details for the meeting are Join Zoom Meeting https://us02web.zoom.us/j/87016372237?pwd=SzZsakZpO GsvSjZuWXRzdWN1NkprQT09 Meeting ID: 870 1637 2237 Passcode: 717856 Draft Minutes of the previous meeting were published in the March Mercia Rocks and are available in the WMi Branch members Area of the OUGS website. [email protected] 3 Quiz Adrian Wyatt has sent photos that members might like to puzzle over: I don't think that there are many places in the Midlands that specimens like this are to be readily seen (Figs 1 & 2). Yes, it is from the Midlands, in particular from the Malvern Hills. Fig 1 Fig 2 This specimen has been well weathered so it has been a long time since it was in situ. The only location thought to represent this type of rock is a SSSI owned by the Malvern Hills Trust (MHT) and thus hammering and sampling is not allowed. [email protected] 4 The location, once a small quarry, has recently been 'freshened up' during a clearance session by volunteers supporting the MHT. This has given visitors the best chance of seeing the features shown in this sample in the actual rock face. During the clearance small patches of rock surface have been hand ground to reveal the structure. The sample photographed was found some distance away in loose scree but there is only one known quarry where it has been noted. The location has been described in the GA Guide No. 4 ^1 where it is location number 4 on Itinerary 1. Adrian Wyatt Which of the following best describes this type of rock? A) Folded white marble, a metamorphosed limestone sediment. B) Angular style micro-folding in quartz-plagioclase-mica schist. C) Malvern 'gneiss', a rock having a 'gneissic' texture. D) Mylonite, a rock that has been subjected to metamorphic alteration. Answer on page 12 References: ^1 Geologists' Association Guides No. 4: The Malvern Hills, Penn & French, 1971. Rocks and Minerals, C. Pellant, Dorling Kindersley, 2000, p211. [email protected] 5 The hyperthermal events of the Palaeogene - a summary of my research topic for the OU Earth Science MSc I retired in 2013 having decided that I wanted to fulfil a lifelong desire to learn more about geology. I began my studies by following several L2 and L3 course with the Open University and by joining the Open University Geological Association (OUGS). Attending meetings and fieldtrips organised by the OUGS enabled me to learn more about the landscape and its evolution from people who like me had a keen interest in the subject. In 2016 I enrolled on an online course at York University entitled - The geology of Yorkshire and northern England and it was whilst studying this course that I visited Whitby and learnt about the effects of the Toarcian Oceanic Event (TOAE). Schangler and Jenkyns, (1976) described Oceanic Anoxic Events (OAEs) as episodes of widespread marine anoxia during which large amounts of organic carbon were buried on the ocean floor under oxygen-deficient bottom waters. In the case of Whitby, the most extreme episode of this event was seen in the deposition of Whitby Jet (Fig 1), a finely laminated black bituminous shale which is been used to make ornaments and jewellery. Fig. 1. An image of Whitby Jet. (Geology.com, 2017 The trigger for the TOAE is thought to have been volcanogenic and/or methanogenic sources which caused a rapid release of carbon dioxide into the atmosphere resulting in global warming, a warming of the oceans and a fall in oxygen levels leading to the deposition of the dark shales. The link between the environmental changes during the TOAE and present-day global warming has attracted many researchers. Often major warming events are associated with the release of large amounts of igneous material which formed large igneous [email protected] 6 provinces (LIP). In the case of the TOAE, the Karoo- Ferrar LIP was the likely source. An excellent book by Paul B. Wignall – The Worst of Times (2015) provides detailed information on mass extinction events during the late Permian and Triassic Periods. A further example of severe environmental disruption associated with igneous activity is the more recent Palaeocene-Eocene Thermal Maximum (PETM) ~56 Ma. Fascinated by LIPs, mass extinction events and OAEs and their environmental consequences I decided to explore this as my research topic for the OU Earth Science MSc which I submitted in September 2020. I was advised by my tutor to define a series of objectives that could be measured and evaluated through appropriate data. In 1985, the Ocean Drilling Programme (ODP) commenced. Analysis of a number of marine sediment cores extracted by these programmes have revealed that in the early-mid Palaeogene (65 to 40 Ma) many global warming events occurred. The first and largest event to be identified was the Palaeocene-Eocene Thermal Maximum (PETM) by Kennett and Stott (1991) in their study of ODP Site 690 in the South Atlantic. ODP records show changes in temperature and the carbon cycle and reveal a large number of short rapid warming events, termed hyperthermals. Hyperthermals are described as intervals of rapid, pronounced global warming associated with negative excursions of oceanic δ13C and with clay-rich layers indicative of reduced sedimentary calcium carbonate (CaCO3) content commonly interpreted as a response to increased CaCO3 dissolution. The hyperthermal events of the Palaeogene became the focus for my research. I established four objectives: (i) To identify the major hyperthermal events of the Palaeogene based on the criteria identified in the definition above. (ii) Using ODP data measure the magnitude, duration and shape of these events. (iii) Determine the cause of the events. (iv) Describe the environmental consequences of the events. My research identified over 50 hyperthermal events but 10 events, including the PETM, met the criteria and the availability of data and previous research enabled an evaluation of these events.