Mercia Rocks
OUGS West Midlands Branch Newsletter
Issue No 4 (2014) December 2014
Looking at the geology of the Severn Valley from Raggedstone Hill, Malvern
Branch Officers Contents
Branch Organiser – Sandra Morgan Branch Organiser’s report p 2 Branch Secretary - Vacant Branch AGM notice p 3 Branch Treasurer - Susan Jackson Field Trip programme p 4
Newsletter Editor – Susan Jackson Field trip report p 5 Branch Committee Other OUGS items p 8 Jo Barnett, Ian Kelly Other Society Events p 9 Alan Richardson, Dave Green
If you would like to join the committee please do get in touch [email protected]
Branch Organiser’s Report
Dear All,
Since the last newsletter we have held our last field trip of the year, to the Ercall on 12 October. This interesting and varied trip was attended by 9 participants. Thank you to Ian Kelly for organising and leading this trip.
The current newsletter includes a report on our field trip to Raggedstone Hill and Chase End Hill which took place on 20 September, led by John Payne. Thank you to John, and to Susan Jackson who organised the trip.
Our next event is the branch AGM which will be held at 11am on Saturday 24 January 2015 at Birmingham University. This is your opportunity to vote for committee members for the coming year, and to let us know your opinions. Do come along if you can. Susan Jackson will be circulating the AGM documents at the beginning of January.
The AGM will be followed by a free buffet lunch and then a talk given by Alan Richardson entitled “Training versus Teaching: what do geology field and lab work have to contribute in a digital age?” This is a very timely subject! Drawing on his 36 years of experience in designing and running field
courses Alan will be discussing whether there is a unique contribution that field work can make to
the education and personal development of students, and how can we evaluate field courses. So we
can look forward to an interesting event, and free of charge! Just contact me if you plan to attend.
Since our last newsletter, Alan Richardson and David Green have offered to join the committee – thank you both. We would still welcome more committee members, so do contact me if you feel able to do this.
I look forward to seeing many of you in 2015!
Best wishes
Sandra
2 [email protected] You are invited to the
WEST MIDLANDS BRANCH
ANNUAL GENERAL MEETING
On
SATURDAY 24th January 2015
at 11.00 am
Room G24 Department of Geography, Earth and Environmental Sciences University of Birmingham Aston Webb Building (Entrance is via the Lapworth Museum of Geology see map on next page)
Agenda 1 Apologies 2 Minutes of the previous meeting held on 18th January 2014 3 Matters Arising 4 Officers' Reports 5 Election of Officers * 6 Appointment of Committee 7 Any Other Business
PLEASE NOTE *Nominations are sought for all posts.
Lunch will be provided in G24 from 12.00 The after meeting lecture will be given by Alan Richardson G21
"Training versus Teaching: what do geology field and lab work have to contribute in a digital age?"
Is there a unique contribution that field work can make to the education and personal development of students? How can we evaluate field courses?
“I have 36 years experience of designing and running field courses. The talk arises from my current project, writing teaching materials to enhance the preparation of students before going into the field. Many geology and earth science departments in schools, colleges and universities are under ever increasing pressure to justify time spent with students in the field. I will explore the unique contribution that field work can make to the education and personal development of students, and will attempt to identify the criteria by which field courses should be measured. Digital materials can take us in one of two directions: they can either enhance or replace field and laboratory studies, and very often cost and administrative expediency will be the determining factors. I intend the talk to celebrate the advances that have been made in field-based education and illustrate many of its dimensions (especially its pitfalls) by reference to my own experiences.”
To help with the catering for lunch, please let us know if you will be attending the meeting. Contact Sandra Morgan [email protected]
University of Birmingham Edgbaston Campus
If you have problems finding us on the day please contact;- Sandra 07971 053626 or Susan 07773 943489
AGM 2014 information Due to our year end being the 31.12.2014 the branch accounts, accompanying Treasurer’s report and Branch Officers’ report will be emailed to everyone in early January ahead of the AGM on the 24th.
Field Trip Programme 2015
If you would like to attend any WMOUGS events please contact the Trip Organiser for full details. If you have difficulty in getting there please also let the Trip Organiser know as it may be possible to arrange a lift with another participant. There is a nominal fee of £2 on day trips (unless otherwise stated) to cover leader’s expenses. Always wear appropriate clothing and boots. Please note that it is a requirement that hard hats are now worn when examining rock faces. Yellow jackets may be required in some quarries.
Please check the branch’s website (http://ougs.org/index.php?branchcode=wmi) for the most up to date information. 2015 24th Jan Branch AGM
Branch field trip programme for 2015 is under discussion at the AGM and details will follow in the next newsletter or communicated by email if occurring before. If you have any suggestions or would like to help out please get in touch.
4 [email protected] Field Trip Report
Raggedstone Hill and Chase Hill Quarry, Malvern, Worcestershire 20th September 2014
We began the day meeting our leader John Payne on the Eastnor Estate car park at the Hollybush in the southern Malvern range. Introductions were made and John outlined the day.
Location 1 – The Earth House We began at ‘The earth house’ a construction started 12 years ago by Mariana and Simon in a small disused quarry where they have built their home in a very large hole in the ground. John had arranged for us to visit because the site not only has some unusual architectural features but also something of geological interest. A low angle 30 degree thrust fault could be seen in the quarry wall to the far wall of the patio area. The fault occurred during the late Carboniferous Variscan orogeny the origin of many of the thrust faults in the Malvern Hills. The site is of interest as most of the thrusts are covered in topsoil or undergrowth so you can’t see them.
Location 2 We then began to ascend Raggedstone Hill. We were due to stop half way up the hill but unfortunately the mist has not risen on this autumnal day and our view of the Severn Valley below was obscured. If we could, we would have seen how the soft muds and sandstones deposited in the Triassic form a very flat expansive area from which the ridge of limestones and hard sandstones of the Jurassic formed the Cotswolds beyond. John explained that the rocks moving eastwards become younger and younger, a result of tilting causing younger rocks to be exposed going down a slight dip to the east. This dip is believed to have been caused by tectonic activity at the end of the Cretaceous period.
Location 3 – Top of Raggedstone Hill By this time we reached the top the mist had cleared a little so John gave us an over view of the formation of the Malvern Hills. A ridge of Precambrian rocks running north to south for around 12 miles. The hills began when the rocks were thrust up during the Variscan orogeny with the overall shape a result of the East Malvern Fault. This fault appears to have been formed when two micro-continents (terrains) merged in the Precambrian and runs from the Bristol area into Cheshire. John explained that the rocks were only thrust up in the Malvern area probably as a result of undulations on the fault meaning that when pressure was applied the rocks could only go in one direction – upwards creating a flower structure.
We examined an outcrop of rocks at the summit, a metamorphic gneiss, light in colour and rich in quartz. This is unusual in igneous rocks so it is thought that they may be
metamorphic Precambrian sedimentary rocks.
We then moved a little further along the ridge to look out westwards. Here the rock layers have been pushed upwards during the Variscan orogeny tilting to the west (see diagram ‘Section through the Cambrian Vale below’). Originally overlaid by the Silurian sandstones these have been eroded away by large braided rivers revealing a window in some areas of the Bronsil Shales of the Ordovician and the Cambrian White leaved Oak shales slightly to the north.
Location 4 – Whiteleaved Oak Quarry We then descended Raggedstone Hill calling half way down into the top half of Whiteleaved Oak Quarry. This quarry is an important geological site as it was here that two Victorian theories were demonstrated. Consisting of mainly Malvernian igneous rocks there are also exposures of Cambrian sedimentary material. Fossil records have now been used to age the Cambrian sandstones but in the 1860s the age of the Malvernian below were unknown. They were unsure whether their presence, next to those of the Palaeozoic was as a result of a fault or an unconformity. It was in this quarry that the answer was provided. Pebbles of Malvernian rock were found within the Cambrian sandstone so it follows that the Malvernian was of Precambrian age. The boundary is an unconformity not a fault as there is no planar junction between the two rocks.
The other evidence to support an early Victorian theory was the proof of the theory of dynamic metamorphism. In 1893 Charles Calloway discovered a collection of rocks showing the progression from a pure igneous rock to a schist. This showed that metamorphism could also be
6 [email protected] caused by tectonic activity in a very small area and didn’t need the heat of a large magma chamber as had been seen at other metamorphic sites.
We then descended to the bottom of the quarry where John showed us another example of a schist in the form of a grey chlorite phyllonite. Shiny due to its mica content it was well laminated along defined planes.
We then walked through the delightful hamlet of Whiteleaved Oak and had a late lunch in a nearby field.
In the afternoon we walked to Chase End Hill stopping off on the way to examine a number of outcrops along Whiteleaved oak valley where dolerites of Ordovician age had intruded into the older but less resistant White-leaved Oak (Cambrian) and Bronsil Shales (Ordovician). Theses shales were very fine grained sediments, originally deposited in deep water some way off land.
Location 5 – Chase end Hill Quarry The quarry lies within a fault-bounded inlier (an area of older rocks surrounded by younger rocks) composed of the rocks of the Malverns Complex. This inlier forms the southernmost extent of the Malvern Hills and, as such, the quarry is the most southerly exposure of the 680 million year old Malverns Complex. The rocks began as igneous intrusions of molten dioritic rock thought to have occurred in an area of subduction. Over millions of years they have been changed by pressure and heat and have recrystallized into courser-grained metamorphic gneiss. About 600 million years ago hot quartz-rich fluids opened up lines of weakness within the gneiss. These fluids cooled very quickly to form pegmatite veins which we could clearly see in the quarry face (see picture to right). These veins appear to have been further deformed causing them to pinch and swell and become broken up into a feature know as a boudinage.
Location 6 – Westfields Quarry We then retraced our steps and took a path following the contour of Raggedstone hill stopping off on the way at Westfield Quarry; a small quarry at the northern extension of an intrusion into the Hollybush sandstone of spilitic andesite.
We then headed back to the car park after a great day of geology. Our thanks again go to John for leading this excellent excursion.
7 [email protected] Other OUGS items
Society AGM 2015 & Social Weekend: Bristol
Friday evening 24th to Sunday 26th April 2015
At the DoubleTree by Hilton, Bristol City Centre
The hotel is easy to get to: just 5 minutes' walk from Bristol Temple Meads train station, frequent buses from Bristol airport stop outside its doors and it is reached from the M4 by the M32 spur into the city centre. The DoubleTree is within walking distance of Bristol’s main attractions and city centre; the hotel has free WiFi. Draft programme: Friday evening: Talk by Mike Benton, Professor of Vertebrate Palaeontology, University of Bristol. Saturday morning: Explore Bristol - look at www.visitbristol.co.uk to see what you can do whilst here – much within easy reach of the hotel. A weekend won’t be long enough!! Saturday afternoon: 2:00 pm AGM followed by tea, the Geoff Brown lecture given by Kathy Cashman, Professor of Volcanology, University of Bristol, and the Moyra Eldridge Photographic Competition. Saturday evening: 7:30 pm AGM Dinner followed by a Quiz Sunday: Field trips to be arranged in Bristol and area Contact: Jan Ashton-Jones [email protected] See society website for booking form
43rd OUGS Symposium Newcastle July 2015
PANGAEA: LIFE & TIMES ON A SUPERCONTINENT - A celebration of Britain’s unique marine Permian strata
Northumbria University, 17th - 19th July 2015
Field Trips: Delegates will have the opportunity to survey some dramatic coastal & inland locations, replete with features of international geological significance. Our, largely unspoilt, SSSI Permian coast line is home to a large stromatolite biostrome together with evidence of possibly the greatest subsea landslide on the planet, when 100 million cubic metres of semi-lithified mud went on the rampage. The magnesian limestone grasslands and adjacent ‘pillars of silt’ (OK, coastal stacks) are also host to species of rare & unique flora...... You may also discover the two little known secrets concerning our Marl Slate?!?
Potential speakers to include: Dr Paul Williams, Prof Maurice Tucker, Prof Ken Glennie, Dr Mike Mawson, Ken Bradshaw & Lesley Dunlop.
Entertainment: Together with lively presentations, stunning scenery and fabulous geology, your evening entertainment will include a general knowledge quiz in the student bar, a Ceilidh (Saturday) and the opportunity to play Bridge.
Your accommodation is within walking distance of the University bar & restaurant, and also near to Newcastle’s vibrant town centre.
Contributions to the Newsletter are very welcome. The subject matter can be anything geological that you think other members would like to read.
Items for inclusion in the next Newsletter, by email to: [email protected] by 28th February 2015
Other Geological Societies in the West Midlands Please see the individual websites for events
Black Country Geological Society For details go to www.bcgs.info Lecture meetings are held at Dudley Museum & Art Gallery, St James’s Road, Dudley, DY1 1HU, 7.30 for 8 o’clock start unless stated otherwise. Those wishing to attend field meetings please contact the Field Secretary, Andy Harrison email: [email protected]
Shropshire Geological Society For details go to:- www.shropshiregeology.org.uk/SGS/SGSintro.html Lectures are held at Shire Hall, Shrewsbury, commencing at 7.15pm for 7.30pm A nominal charge is levied for attendance by non-Members.
Warwickshire Geological Conservation Group For details go to www.wgcg.co.uk/ Lectures are held monthly from September to April, Starting at 7.00pm free to WGCG members with non-members £2.00 per lecture.
North Staffordshire Group of the Geologists’ Association For details go to www.esci.keele.ac.uk/nsgga NSGGA is the regional group of the Geologist Association North Staffordshire. The winter lecture programme takes place on the second Thursday of the month from October to March at 7.30pm. All talks are held in the William Smith Building, Keele University.
Woolhope Naturalists Field Club For details go to www.woolhopeclub.org.uk The geology section of the club is an affiliated member of the Geologist Association. Lectures are held in the Woolhope room, Hereford Library Broad Street. Field trip programme also available. For further information on all events email Sue Hay [email protected]
Teme Valley Geological Society For details go to www.geo-village.eu Meetings generally held at Martley Memorial Hall Martley Worcestershire