Earth Matters the Newsletter of the Geology Section of the Woolhope Naturalists’Field Club the Geology Section Is an Affiliate Member of the Geologists’ Association
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Earth Matters The Newsletter of the Geology Section of the Woolhope Naturalists’Field Club The Geology Section is an Affiliate Member of the Geologists’ Association. No. 7 December 2010 The Woolhope Naturalists’ Field Club is a Registered Charity, No. 521000 MESSAGE FROM THE CHAIRMAN CONTENTS NCE again, I can say that we've had a good year Oand this despite some very wintery weather that Message from the Chairman ........................... 1 set in just when some of us were beginning fieldwork on an EHT programme. However, I want to digress Geology Section Programme .......................... 2 from the Herefordshire scene and look further afield. Last year I recalled Iain Stewart's remarks at the GA Editor’s Note ................................................... 2 Dinner in 2008. Iain gave an up beat and optimistic speech but things seem not to be working out quite Subscriptions ................................................... 2 so well as he anticipated. I refer to the current eco- nomic downturn; to the effects this is already having Annual General Meeting .................................. 2 on geology and geoconservation; and the likely out- come. We in the WGS may not appear to be greatly On-Line Geology Maps from BGS ................. 2 affected, possibly as individuals, but more certainly as a group of like-minded persons with a common ‘A Weekend in West Wales - September 2010’ interest. Unfortunately, this cannot be said for pro- by Gerry Calderbank .............................. 3 fessional geologists. Recent years have seen a steady decline in the universities, with geology departments ‘Meeting Reports, 2009-10’ either closing or the geological content subsumed by Geoff Steel and John Payne ............. 6 into other departments. In fact, this very theme arose repeatedly during our recent excursion to ‘The Burren’ Aberystwyth where exactly this had occurred. by Charles and Jean Hopkinson .......... 9 Earlier this year Julie Harrald, EHT Secretary, emailed her committee about cuts in Geological ‘Martley Pit’by Paul Olver ............................ 10 Conservation Review staffing at the Joint Nature Conservancy Committee; two of the three staff mem- ‘Changing rocks, changing ideas : bers had already been redeployed. We were asked to respond, presenting a reasoned case for opposing the 200 years of metamorphism’ cuts, rather than just expressions of dismay and gen- by Richard Edwards ........................... 12 eral disapproval. I promptly composed a letter on behalf of the WGS ‘Anatomy of a landslip: and, yes, I did express my genuine dismay, but I was the Darens, Olchon Valley’ also careful to formulate a number of detailed ques- by Richard Bryant ............................... 15 tions. I have just received a polite but bland reply, full of 'quango-committee-speak' that doesn't address Geology Section Committee .......................... 16 the specific questions I had raised. Instead, I now find that this letter is just a circular, identical to one Heritage Services News .................................. 16 that Sue Hay also received. Well, I'm sorry folks, but in view of the more recent developments, I fear it can Earth Heritage Trust News .......................... 16 only get worse! Gerry Calderbank, Chairman Page 2 Earth Matters No. 7 December 2010 GEOLOGY SECTION PROGRAMME ings. I wish to offer my thanks to all the contributors for their FOR EARLY 2011 E 2011 timely submission of what I perceive to be high quality ECTURES and the Annual General Meeting are held articles. Lin the Woolhope Room, Hereford Library, Broad John Payne, Editor Street commencing at 6:00pm unless otherwise stated. SUBSCRIPTIONS Friday January 21st. ‘A geological tour of North East S Greenland’ HE ANNUAL SUBSCRIPTION to the Geology st Lecture by David Rex. TSection is currently £7.00. This is due on 1 January (as for all other WNFC subscriptions). Please pay this Friday Febuary 25th. Section AGM followed by the directly, and on time, to the Section Treasurer, Beryl Section Dinner at Ascari. Booking forms for the dinner Harding, 'Bramley', Lugwardine, Hereford HR1 4AE. Do will be sent out electronically in January. not send it to the WNFC Secretary with your WNFC sub- Friday March 18th. ‘The Magallanes Basin in scription. Cheques should be made payable to ‘Geology Southern Patagonia’ Section / WNFC’. Members are encouraged alternatively Lecture by Dr Bill Fitches to pay by Standing Order; forms are available from Beryl. This talk will include Mesozoic-Tertiary turbidites and channel deposits (much like Aberystwyth and ANNUAL GENERAL MEETING Rhayader), oil and gas generation, huge mountains of EMBERS are asked to accept this as notification of granite and stunning glaciers. Mthe Geology Section AGM to be held on Friday Sunday April 3rd. Visit to Gore Quarry and Stanner 25th February 2011 starting at 6:00pm in the Woolhope Rocks . Room. After the AGM we will retire for dinner to Ascari’s Led by Dr Geoff Steel. restaurant. Booking forms for the dinner will be e-mailed Both sites expose Precambrian rocks within the southern to members in January. part of the Church Stretton Fault Zone. The officials and committee for the coming year will be Meet at 10am at the quarry entrance which is located on a elected. All of the present committee members (see the small side road just off A44 about 1km north of back page of this issue) will stand for re-election. There is Stanner Rocks (SO 259 592). Hard hats and fluores- a vacancy on the committee for an additional member. cent jackets are needed for the quarry. Please bring a Section members are invited to submit nominations for packed lunch. election to this post. Nominations, with the names of the Further information for all events unless otherwise stated proposer and a seconder, must be received by the Section from: Sue Hay, 01432-357138 or e-mail svh.gab- Secretary in writing (letter or e-mail) before 25th January [email protected]. Please note until the Woolhope 2011. web site upgrade is completed the information shown there may not be accurate. ON-LINEINE GEOLOGY MAPS FROM BGS EMBERS may not be aware that the chief geology A further geological event: Dr Paul Olver is leading a maps of the British Geological Survey are now Geologists’ Association study trip to France 7th-19th M available on-line. (http://maps.bgs.ac.uk/geologyview- April 2011. This will be a circular geological tour by er_google/googleviewer.html) Both the 1:625000 and coach introducing a wide variety of sedimentary, 1:50000 scale maps are available. They may be viewed, igneous and metamorphic rocks. If interested please saved and printed superimposed, if desired, upon aerial contact Paul directly ([email protected] or photographs from Google Earth. This allows easy loca- 01432-761693). tion of geological features on the ground. Both superficial and bedrock geology are shown but not faults or made EDITOR’S NOTE ground. Nor is offshore geology included. ELCOME to the seventh issue of Earth Matters. Positioning the computer cursor at any point on the map WThis year, two of the articles deal with local reveals a text box showing the names of the bedrock and research activities. This is an aspect which I am keen to superficial deposit at that place. For the 1:50000 maps, a encourage, perhaps as preliminaries to full publication of stratigraphic key may be generated in an additional panel, research results in the Transactions. Indeed, Professor linking the map colours with stratigraphic names. Bryant is in the process of writing such a paper and his Unfortunately for those wishing to print the maps for field article in this issue is an early and abbreviated account of use, this key displays only about four stratigraphic units at his work in the Black Mountains. The work at Martley Pit, a time. described by Paul Olver, is less advanced but is intended to follow the same publication route. As you might expect, BGS do not allow each displayed map to cover a large area. At 1:50000, the frame covers Elsewhere, we have a geological holiday report, a valu- about 10 x 7 km2, big enough to cover many field excur- able write-up by Richard Edwards of a part of his lecture sions. on metamorphism and the usual accounts of WGS meet- Page 3 Earth Matters No. 7 December 2010 AA WWEEKENDEEKEND ININ WWESTEST WWALESALES -- SSEPTEMBEREPTEMBER 20102010 Gerry Calderbank Y EARLY EVENING on Friday, 3rd September, a meters; in effect, they may be regarded as dense, mobile, Bselect band of members had gathered at one of the homogenous bodies of 'slurry'. It is thought that the halls of residence on the Penglais Hill campus of avalanching was probably triggered by tremors and more Aberystwyth University; this was prior to meeting our severe earthquake activity, characteristic of the period - or guide for the weekend who joined us for supper. We imme- just, possibly, by severe storms. diately warmed to the presence of Bill Fitches, who had Other contemporaneous rock types associated with these kindly agreed to give up his weekend for our benefit by beds are, respectively, conglomerates and hemipelagites, conducting us on a tour of the local geology - and this com- with the latter tending to be fossiliferous since, unlike the menced with an introductory talk immediately after supper. turbidites, they were relatively undisturbed in transit so THE BRIEFING that any shelly fossil fragments were Bill explained that the weekend would less prone to damage. The conglomer- have two themes, with the Saturday ates represent pebbly in-filling of the taken up by an exploration of various turbidity channels, whereas exposures revealing basinal mud and hemipelagites include the dark grey turbidite shelf deposits of Silurian /black organic and sulphide-rich grap- age, and that these represent the deep- tolitic mudstones, laid down during water end of the Welsh Basin, rather periods when the coarse sediment sup- than the near-shore limestones and ply diminished.