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Branch Organiser's Bit
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On behalf of your Branch Committee I do hope you will find this, the second issue of the new newsletter, both interesting and informative. As I stated in the first issue in February, if you have any comments or suggestions then please make them known to your Branch Committee.
We have now had a number of very good field trips, one to Ryton Pools Country Park and the surrounding area (see report on page 7) and the other to the Wren's Nest and Dudley Canal Cavern. Both well supported. The branch’s weekend trip to the Lleyn Peninsula was a great success and the weather I understand did clear up for you in the end. I look forward to reading a field trip report in the next newsletter.
I now turn to an important matter which needs our attention. Due to postal delays beyond our control, I was informed by the Chairman of the National Committee, that my membership subscription had not been received in time for our last AGM and the election of Branch Officers. Therefore, we are required to hold a Special General Meeting in order to confirm the election of the Branch Organiser. I can only offer my apologies to you all for of the situation, since this will involve us in additional time-consuming administration and costs.
However, rules are rules and to comply fully with the Constitution, I now give formal notice of a Special General Meeting which will take place immediately before the Ercall quarry visit on the 23rd September to confirm the election of a Branch Organiser. Full details are enclosed in this newsletter on page 5. It is absolutely imperative that we have a quorum at this meeting and that means we need at least 6 current members of the Branch, i.e. members in good standing, able to attend so please come and join us for the visit.
I am quite willing to stand for the position but if anyone else would like to be considered please let the committee know via the branch e:mail.
Alasdair
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Help us out for a time
West Midland OUGS
Special General Meeting
23rd September 2012, 10am
Branch members are invited to a special general meeting on the morning of the 23rd September, to elect our Branch Organiser. We encourage as many members as possible to join us (and stay for the field trip!) The meeting will start at 10am at the Buckatree Hall Hotel (TF6 5AL).
Tea and coffee will be provided.
Following the short meeting, we will set off on our trip to the quarries
Ercall Quarry field trip
23rd September 2012
The Ercall quarries are a group of quarries cut into the lower slopes of the Wrekin, primarily for roadstone, for which Ercall Quartzite was particularly prized.
The site is prefect for beginners and the more experienced, with extrusive and intrusive continental and oceanic volcanics, a very visible strike/slip fault, igneous/sedimentary contact, a half billion year old beach, a great opportunity to do field sketches and lots to think about and discuss!
The site is managed by the Shropshire Wildlife Trust, is well looked after and there is nothing too strenuous. Suitable footwear is highly recommended and hard hats are essential near the quarry face.
The site is accessed in much the same way as The Wrekin nearby; exit the M54 motorway at J7 (last exit) or the last junction of the A5 from Shrewsbury before it becomes the M54. From there The Wrekin is signposted; follow this road until you reach The Wrekin, then follow the sign for the Buckatree Hotel. There is a small car park across the road from the hotel and the entrance is clearly visible. If this car park is full, head back towards the Wrekin and use the Forest Glen car park.
We will be starting at 11am (after the SGM) and aim to be finished by 3pm.
We will be stopping for a break, so bring a packed lunch.
Any questions or queries please email me
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Programme 2012
If you would like to attend any WMOUGS events, but have difficulty in getting there, please contact the Trip Organiser, or any member of the committee and we will try and arrange a lift.
23 September / The Wrekin Area - Ercall QuarriesLeader - Ian Kelly
Precambrian Uriconian Volcanics, Cambrian and Ordovician sediments.
Contact: Ian Kelly,
October / Snailbeach Lead Mine, Shropshire – Postponed until spring 2013
NB A nominal charge, depending on the event, is made to cover the Society's expenses.
Programme 2013
The committee are at present putting together the programme for 2013 and it is hoped that some details will be available in the next newsletter.
26January / Annual General Meeting
The committee hereby gives notice that the 2013 AGM will be held on this day at the University of Birmingham.
More details will be available in the next newsletter.
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.
WARWICKSHIRE'S QUATERNARY GEOLOGY EXPOSED
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Around 500,000 years ago the Bytham River flowed through the Midlands. The river's ancient route has been studied and well documented by Professor Jim Rose. Professor Rose's study found that the Bytham River flowed in a north easterly direction from Warwickshire, passing through Leicestershire and circumventing Northamptonshire, before "dog-legging" eastwards towards East Anglia. From there to somewhere east of Great Yarmouth, the Bytham River joined the Thames and the Rhine and then headed north towards the contemporary coastline. At this time, Britain was not an island and the sea reached only part way down the east coast of Britain.
In the Pleistocene, the Bytham River was possibly the largest river in Britain, cutting channels into the underlying Mercia Mudstone (formerly the Keuper Marl Series), depositing a distinctive red sand, or a very durable quartzite-rich sand and gravel, with minimal clay - the Baginton Formation. Research has shown that these deposits were derived from the Sherwood sandstone and Kidderminster Conglomerate (formerly the Bunter Pebble Beds). Up to 8 metres was deposited in the Bubbenhall area. Plant and animal remains found in the river channels indicate a temperate climate. Andesitic hand axes have also been found suggesting that there were a number of settled hominin communities living along the river's banks, most likely they were a species known as Homo heidelbergensis.
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Some 450,000 years ago temperatures plummeted and Britain experienced the Anglian Glaciation, during which the ice advanced and retreated twice. Ice sheets moved down from the north to cover most of the Midlands and glaciers overrode the Bytham River, eroding the sediments and burying it beneath glacial deposits - the Thrussington Till.
It was these, and the remnants of the ancient Bytham River deposits, that attracted members of WMOUGS and the Warwickshire Geological Conservation Group (WGCG) to Ryton Pools Country Park on 17 March 2012. Martyn Bradley, from WGCG, explained the Quaternary Geology of that part of Warwickshire and the geo-conservation work undertaken by his Group to preserve the deposits at the country park.
After briefly describing the local drift deposits and explaining the sites we were to visit, Martyn led us off to Waverley Wood Quarry where we were met by Quarry Manager, John Green, who was very knowledgeable and helpful during our visit. John had brought along some of the finds from the quarry including a hand axe, mammoth tooth and fossil wood.
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We spent some time exploring the deposits and quarry waste hoping to find more mammoth remains, hand axes or other archaeological artefacts, but were unlucky in that respect. The Thrussington Till deposits, however, yielded well-rounded pebbles of various rock types - dolerite, volcanic tuff, jasper, flint, quartzite and fossilised wood.
After a lunch break back at the Country Park, we travelled the short distance to Wolston village where Martyn showed the WGCG interpretation board explaining the geology of the area. The board was erected in memory of Professor Fred Shotton, former Professor of Geology at Birmingham University (see February 2012 newsletter). Professor Shotton spent much time in the Wolston area studying the glacial deposits and his research made a significant contribution to understanding the Quaternary.
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Professor Shotton also proposed that during the glaciation, the ice sheets blocked the Bytham River to form a large glacial lake which he named "Lake Harrison" covering Leicester, Nuneaton, Coventry, Warwick, Stratford and Rugby. Shotton pointed to the geomorphology of the area which showed examples of wave-cut platforms similar to the parallel tracks found at Glen Roy. Further evidence, he claimed, could be found in the sedimentary studies which confirmed lacustrine deposits. This, he proposed, proved that a glacial lake had existed in the Midlands. We then set off for Fenny Compton, which according to Shotton was located at the southern end of the lake.
Martyn pointed out a stepped feature running parallel to a section of the Oxford Canal. Could this be interpreted as a shoreline bench and evidence of an ancient grand lake? Others, however, have pointed out that the existence of lacustrine clays, on their own, even when found at strategic locations, was insufficient to prove the existence a large pro-glacial lake. They could also prove the existence of a series of glacial lakes. The debate continues.
It was there that we ended our day. I think I can speak for all of use, if I say that the visit was most interesting, sometimes demanding but always enjoyable. Our thanks must go to Martyn Bradley who was very generous with his time and his extensive knowledge of Warwickshire's geology.
Patrick Joyce
Linda Tonkin
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References:
Rose, J"Bytham River Aggregates" QM November 2006
www.AHOB project.org
www.wgcg.co.uk
Sumbler 1983a:Old et-al 1987
Harwood, D Mercian Geologist, Vol 11, No 3, 1988
The Deep Carbon Observatory – interesting website
Most of us will have met the carbon cycle, where carbon moves through reservoirs such as the atmosphere, oceans, land and living things, in a more-or-less balanced system. But, what about carbon in the deep Earth? Some carbon is subducted into the mantle with oceanic crust, and some is released from the mantle via volcanic degassing, but, remarkably, these quantities are not in balance – the carbon which leaves the mantle via volcanoes is equivalent to only about 5% of the carbon which enters the mantle via subduction1. Is the carbon from the Earth’s surface being permanently removed? What happens to the carbon when it has arrived in the mantle?
In fact, very little is known about carbon in the deep Earth, and this is the motivation behind the Deep Carbon Observatory, a 10 year international project funded by the Alfred Sloan Foundation. The project is supporting a wide range of research to investigate aspects of deep carbon such as reservoirs and fluxes, physics and chemistry, and deep life. The project website https://dco.gl.ciw.edu provides information about the project and related material, including a long list of publications relating to deep carbon.
1. Banks M (2012) ‘Understanding the element of life’. Physics World Vol. 25 No. 3 (March 2012)
Sandra Morgan
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From "Sky News" on 1 May 2012
"World's Largest 'Fossil Forest' Found In US
Scientists have found a 300-million-year-old subterranean 'fossil forest' in the US, believed to be the largest fossil forest ever discovered
preserved over tens of square kilometres.
Researchers uncovered the forest, which is believed to extend for up to 100 miles, encased in shale above coal seams in the state of Illinois. Complete trees, delicate ferns and even cockroach wings were fossilised during the Carboniferous. The forest is entombed in eight working coal mines in depths that vary from 250ft to 800ft below ground level and researchers believe the forest may extend for 100 miles.
The compacted remains of these forests are preserved above the coal seams and built on compressed layers of peat. After the coal is extracted the fossils can be seen in the mine ceiling.
Because of the remarkable preservation of delicate organic matter in the sediment that eventually turned to shale, scientists believe the forest was repeatedly flooded by rising
water levels. Researchers have found a river as wide as the Mississippi snaking its way through the forest. Few animal fossils have
been found - except for cockroach wings - as the creatures could flee the slow floods.
Researchers have traced a five-mile route through the forest, stopping to measure huge fossilised trees still stand rooted in their original but compacted soil, surrounded by fallen leaves. Seed ferns prevail close to the river, but further away from the ancient watercourse tree ferns and huge scale trees dominate. One fallen scale tree, measuring more than 100ft long, was traced by researchers until it disappeared into an as yet unexploited coal seam.
Scientists say birds had not evolved during the era but insects grew immense in the
oxygen-rich environment - with dragonflies the size of magpies and 6ft millipedes - although the vegetation was not as vulnerable to insect attack as present day foliage is.
Academics hope to explore as far as possible to provide an ecosystem mapping and analysis on an unprecedented scale to help them with predictions of modern global warming.