Category Archives: Pre-Cambrian

South Wales Geological Visit

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What a day!  What a day fortune bestowed (that is the word) on us for the S Wales Geological Society’s visit to Martley, one of five set up when Ian and I attended the GA annual meeting in November last.  As I write it does not look so good for the visit of Reading GS today, 19th April.

Worcestershire’s countryside shone in all its glory, ploughed and harrowed fields lay cropless at this time showing off the true colours of underlying strata, undergrowth just awakening, exposures easily viewable.

SWGS bought along 13 members, none of whom needed my simple introduction to the geology of the region, so using an experienced teacher’s trick I talked about other things.  We made our way to Martley Rock, then across Kingswood Lane, along the valley edge:  the change in the colour of the dry, tilled earth in the fields to our right, from Triassic red to Silurian grey, was distinct under the clear blue sky.

On top of Rodge Hill

Over the B4204 past the Tee and  up on to the ridge formed of upended, even over turned Aymestry limestone, above Pudford, glorious, Hay Bluff peeping over Bromyard Plateau, Brown and Titterstone Clee to the north west, valley of the Teme gorgeously spread below.  Lunch at the PONS seat, only one lunch mind, not like the Ramblers 9 mile foray a couple of weeks ago where Mike and I counted three.

Off the ridge to Lower House Quarry, Crinoid City to us,

Lower House

 

 

but under intense gaze isn’t that a fault face, aren’t those slickensides and not only crinoids but cephalopods too.

 

 

Orthocone (Cephalopod) at Lower House

 

 

 

 

 

 

 

From Lower House towards Woodbury

 

 

 

 

 

 

Old Faces near The Canyon

 

 

 

Down into the dip, old quarries on all sides and into dense woodland, past

crags we worked on last week, see previous post, to the Canyon.

 

The Canyon

 

Thick layer of bentonite squeezed by cascade folds, maybe this ancient access way into the quarry was forged

along an old fault line.

 

 

 

 

Continuing along the forest path, up the Stairway to Heaven, around Penny Hill and into the quarry proper, discovering fossils at the famous face (Observer’s Book of Geology from the 50s, picture of this, captioned Martley, Wilts(!)).

Upside Down Corals (50p IS the right way up)

My non geological colleague Colin found a striking example of the upside-downness of the formations hereabouts–a large piece of coral definitely growing towards the light but here at an angle of +-45 degrees down (see photo).

 

 

My constant mantra to the group, fascinated and intent as they were by each new exposure was that we were saving the best till last. This encouraged a steady pace

Analysing Calcite Veins at Scar Cottage

towards Martley and the pub with the last geological site being Scar Cottage and its incomparable quarry garden.  There certainly were a few wows and blimeys when the group rounded the corner and took in the view.  Here again the experts in the group came up trumps, seeing clear fault zones with fault debris between, proving with an acid bottle, the white veins were calcite.

At Scar Cottage

 

 

Back at the pub, drinks and yes, SWGS were made to walk through the TVGS shop (just as National Trust) and indeed purchased two of our geology audits–thanks!!  We hope to see you at our symposium in October geo-symposium.eu.

Coal and Water

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MARTLEY AUDIT
Coal

Silurian f/g, Permian Breccia b/g Collins Green

There be coal on that there Berrow! A longish afternoon and evening trip with Julie (in charge of Martley Geological audit) to check up on a few things (she said) led us into primeval swamps and exposed hillsides in quest of several holy grails. Quarries on Ankerdine, very close to the road edge, some type of conformity. I am not sure if it was ‘non’, ‘dis’ or ‘un’. Noduley Silurian underneath, not Triassic as documented, but very clearly Permian Breccia as on the Berrow, with its redness leaving classical staining in the underlying limestone. With a bit (lot) of cleaning this would be an excellent site but access is not available.

Petrified Twigs

From there, downhill, a bit of tramping about then bingo, the little petrifying stream, trickling away in its woodland glade, turning to stone twigs, moss and snailshells, no competition for Southstone Rock up the valley but a gem all the same.

Tufa Weirs, Ankerdine

Moving just a little way north on to the southern slopes of the Berrow, first we checked out the Permian pit–Haffield Breccia–where you can see tumbled, rounded boulders loosely cemented with angular gravels and fines. This pit, on a south reaching spur of the hill commands simply wonderful views down the Teme valley to the Malverns and Forest of Dean, with Cotswolds eastward. Spade on shoulder and with some anticipation we then headed up the steep hill and into the rough woodland.

Our Coal Pit on Berrow

Handful of Berrow Coal!

Immediately we came upon a volcano like crater, 2m deep, 15m across, reputed to be an old coal pit. We dug small test holes to find grey carboniferous deposits. Moving west, around the hill fifty or so metres we again dug and this time struck gold, black gold! Small glistening lumps of coal, in support of the ancient records that state that there were coal pits years ago. Julie took samples for EHT to check out and I was thrilled because it had been an aim of mine for some years to find Martley coal.
After a break, the indefatigable Julie decided on a high speed tour of limestones on Rodge Hill

Rodge Hill Silurian–Strata Vertical

and also on the track north of the farm of the same name. Loaded down with samples we called it a day as dusk settled. Thanks for the tour, Julie! All of the evidence she collected will go towards greater accuracy in the audit of the geology of Martley.

 

 

 

 

 

 

 

 

Water
It has rained a great deal lately, hasn’t it?

Pumping at Martley Rock

Do you think we should change the name, as some wag suggested, from Martley Rock to Martley Rock Pool(s)? OK so we’ve bought a pump and with Mike’s generator successfully drained the area on May 6th. It rained again this week, didn’t it? Can you see a pattern developing?

Interpretation Boards–one is up, the others should be very shortly, but the weather has delayed site work; the intention now is to wait for fine weather then go fix not only the two remaining interpretation displays but also the boundary signs that have been received from Graham Signs in Malvern. These will be fixed so it is clear to our visitors where one geological period ends and the next commences.

First Working Party

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Work at Martley Rock–Saturday afternoon,

Cleaning up the west trench, Mike and Alan

7th April TVGS’s first work party descended on Martley Rock. Armed to the teeth something like a bunch of brigands, the foot soldiers, rakes and shovels on shoulders, led into battle by Skinny’s trusty old Merry Tiller. Old it might be but it did the job wonderfully. Hardened soil softened under its caress as Skinny manfully wrestled the bronco so that the rakers and trampers could follow on behind, levelling and firming prior to seeding.
A group of agriculturists had stayed at The Chandlery during the week, up to meet with Dave Richards at Ridgend Farm to advise on better production from cattle and field. Not knowing what hit him, the expert in grass seed gave up the struggle quickly and was soon on the phone requesting a free sack of ‘the right stuff’ to seed this scenic corner of Worcestershire. Thanks LIMAGRAIN of Market Rasen (http://www.limagrain.co.uk/index.php), your generosity and expertise is very much appreciated by TVGS.
Apart from preparing the ground for seeding, we attended to the whole of the long trench, cleaning up the lips by rounding them off, and removing spoil from the east, Triassic, end. By the time we had finished after a couple off hours we were really pleased with our efforts. Just shows what can be done with a small group in a short time. Mike Install brought along some bean poles and we erected a temporary fence to stop traffic on seeded areas by the road. Andy cleared overhanging branches and during the week Mike (Dunnet) had sprayed the nettles and dogs mercury so that by the time we arrived on site it looked pretty ill. I think its the nub of why we do it when you can draw in people with different skills to get the job done–Mike D is from a gardening background, many of you know him from the Hort Soc and his wonderful open gardens up on Ankerdine. Everyone knows Skinny, don’t you? It seems that way to me–whether in the Teme Valley or downtown Martley, Skinny is well known as tree surgeon, grafter and keen to assist with community projects. The rest of us have all done a bit of raking and tramping in our time so played our part in the exercise. Good job–thanks Ian, Mike, Skinny, Alan, Andy.

Ian Spreading Seed

Sunday 8th–Ian and I managed to get up to the site and seed the whole area, afterwards raking it in.

With some spare time we also managed to clean out the east end of the exposed quarry, down to solid rock, using spoil from there to fill in the depression on the next level.

Quarry Cleaned

We aim to clean out all of the this pit, in order to expose solid rock and any features that it might exhibit.

 

 

 

 

 

Yellowstone–On Monday 26th March, Dr Ian Sutton presented ‘Yellowstone’ to a mid thirties audience (number not age). Those who had been to Yellowstone had their enthusiasm for this unique and varied park rekindled; those who have never been, myself included, renewed their vows to go there asap. How long do you need? There is so much to see, and though we focus on geology in our group, Ian, in a beautifully illustrated talk, showed that it’s not only steam and hisses, but wild life, scenic wonder and just wide open spaces–with the threat of doom through mega explosion not far down in one’s consciousness. Actually Ian discounted that and latest research suggests that the magma chambers underneath are not so large as to pose an ‘end of the world’ threat to North America. Thanks Ian!

Mapping Course–One more reminder for the Mapping Course starting 15th May, call Nat at EHT 01905 855184

The Martley Geology Project–the team is considering the way forward, i.e. the current project has some months to run and a number of milestones to achieve but can we now start to think of more? The audit of Martley geology lists over 40 sites in the parish and a handful of these meet the criteria of accessibility, interest and relevance. Given our aim of making Martley a European Geo Village, with trails and representative sites, we need to keep this in mind. Anyone reading this and interested in taking part in anyway whatsoever in our future projects, please speak up!