5th September: Last geo-amble of the season, back in the cars down to the Teme Valley, this time by kind permission of Sir Anthony Winnington, parking at his home. Brockhill Court, Shelsley Beauchamp. These ambles have attracted a smattering of history and archaeological buffs, most useful when looking at buildings and the stones used. Next to the court an old quarry, hidden under dense trees, entrance straight off the narrow Pard House Lane. We stepped into a dark world, cliffs on both sides, the middle, very hard rock having been removed for building and roadway constructions.
Ella from EHT kindly took the role of explaining about the site and the geological processes that had formed it.
The interest here is that in the Carboniferous, some 300 million years ago, possibly when after a period of mountain building and pressure, the plates relaxed allowing weaknesses in the crust to be exploited by molten magma. Forcing its way up, these ‘dykes’ acted as feeders to volcanic activity on the surface, but themselves cooled down a kilometer or so below. Cooling was therefore slow, of the order of 10 000 years, submerged as it was under a huge depth of other deposits subsequently eroded, leaving the remains of the dyke on the surface of ‘our’ world. The extreme heat affected the layers through which it travelled as it itself was affected. In the centre, the hottest and slowest to cool, Teschenite, a rock of altered basalt with easily visible crystals. Next comes the ‘chilled margin’, a black, very fine crystalline rock, basalt in all but name. Then we see a rock with rough yellow, horizontal tubes. This is the baked ‘country rock’, in this case Raglan Mudstone (from the end of the Silurian), and the tubes are gas escapes later filled with other materials. If you wish to read about the site, from an article written many years ago, it is HERE (thanks Ella). Here is a map again drawn years ago. We intend to explore the area further.
22nd August: by car into the Teme Valley to Southstone Rock, possibly England’s largest tufa deposit, a quarter of a mile up a steepish track, often muddy and slippery. In this dense, damp, primeval woodland it is hardly possible to even glimpse the gigantic deposit from the fork in the track, only 50m away.
Prepare to be amazed.
Cross the narrow wooden bridge that replaced an original brick arch, that itself was replaced by a slippy plank with no handrails. Recent work by Rights of Way has made the approach less intimidating. Venture under towering, rugged cliffs, note giant blocks that have cracked off the main massif, observe a clean break from 5 years ago when a block tumbled down the slope into the fern thronged cascade. Plenty to explore here, narrow passages between the blocks, caves and holes then around the corner the flat top of this huge formation. Sadly these days the top is covered in dense brambles and young trees, unlike a few years ago when remains of the old house could be seen alongside the rushing stream, the area almost lawn like. Work needed here. Even the easily audible gushing spring, in this high summer season, is inaccessible. We struggled to the edge where the stream tumbles in runnels down a moss covered fall, building tufa as it goes, petrifying the moss to form a lightweight stone. This stone is used in buildings in the area, perhaps the most beautiful being Shelsley Walsh church though we understand the stone for it came from quarries much closer.
Descending in the gloom of this grey evening, a rare pool of sunlight picked out the hills, opposite. See HERE a guide to Southstone Rock.
15th August: no cars only shanks’ pony, on yet another beautiful clear evening. By popular vote we set off over the Nubbins enjoying views to the Malverns as well as close ups of the Bromsgrove Sandstone quarry face with its cross bedding and gravelly interleaves. The latter, evidence of stormy events in a river flowing in a dry region with wind blown and river deposited sands. Exiting on to the top field, travelling on paths walked earlier in the series, the 360 degree view always a wonder. This takes in the Clent Hills in the North with their cap of Permian Breccia, the Lickeys and their Ordovician, the Jurassic Cotswolds and Bredon outlier to the East, in the South the Precambrian Malverns and then the Devonian Bromyard Plateau in the West. Finally, swinging to the North the Clee Hills capped with sills of Dolerite, heavily quarried, continuingly so, for roadstone and aggregates, as well as ironstone and sandstones. Nearer to hand are Martley’s Triassic Nubbins quarries, Permian Berrow, Silurian Rodge/Pudford Hills and the Severn plain. Truly a place to stop and spend a while.
We took a permissive path along the rim of the Teme valley (Kingswood Slide), on limestone now, steeply into a distinct water catchment basin to Kingswood Chasm and outcrops of the Silurian Coalbrookdale Formation. Noting local ground slumping we trekked to the river far below to check out Martley’s highest (dry !) waterfall (Kingswood Waterfall) a block of perhaps slipped Coalbrookdale.
Turning down river, South, through woodland along a section of the Geopark Way. After the audit was produced we discovered an outcrop of Raglan Sandstone and though not now accessible due to a fallen tree, we had placed by the track, samples of this micaceous, sometimes blocky, sometimes finely bedded into very flat, thin sheets, sandstone. Raglan Mudstone is generally just that, mud, soft, clay, marly but it does contain lenses of more solid materials as sandstones and here we have one. There are two examples in the audit book but difficult to reach and on private land (Horsham River Cliff) and in the River Teme at Ham Bridge, River Teme Reef.
A steep walk took us back to Kingswood Lane and the small site there, near where the East Malvern fault crosses so the lane jumps +-150 million years at this point, from Triassic to Silurian (Raglan Mudstone).
Thanks for coming–next week Southstone.
(photos Angie Hill and J Nicklin)
8th August: 1st August rained off, stair-rod stuff, stalwarts turned up but seriously guys, no way, and boy were we wise to postpone, 8th turned out to be a simply glorious evening, clear, warm, the countryside in its harvest best, marvellous.
After the hall meet, in convoy to the driveway of Rodge Hill Farm, parking by kind permission of the owner. Immediately the greyish soil colour indicating we were in limestone country, actually where we parked the cars, the softer Ludlow Shales between the hilly Much Wenlock and the ridge of Aymestry to the west. The so called Ludlow series is one of four divisions in the Silurian Period and itself has three parts–Lower and Upper Ludlow Shales and between them in age, Aymestry formation. Nearly all of the rocks in Martley parish, indeed in the wider area are sedimentary, meaning they were deposited in layers in the sea, in rivers and deserts. This is over many millions of years and to be expected in such a long time period the environment changed dramatically. Sea levels rose and fell, climate changed and the quality of the deposits varied from a greater contribution by sea dwelling life (corals, shellfish, stromatolites, stromatoporoids as examples) to silty wash ins from rivers and volcanic ash falls, sand banks in marine estuaries and so on. In the case of the Ludlow group these changes are reflected as hard rock in well defined layers, sometimes nodular, to the softer, muddier, more easily eroded shales found in the lower ground between the ridges. All though have greater or lesser proportions of calcium carbonate from the then living organisms that inhabited those seas. Running through are veins of whitish, volcanic ash, a soft clay like material (Bentonite) with a great many industrial uses.
Leaving the car park, we followed the newly laid out (a most generous gesture by the landowner) permissive way, to the side of the main track, climbing up to the low ridge of Aymestry separated from the much higher ridge to the West. We turned North up to a low but excellent viewpoint then down a long track passing by one of the Martley sites, Rodge Hill Farm Track North. It was a splendid place to be on such a summer evening, the geology and Angie’s knowledge of plant life (thanks Angie) adding to the enjoyment. Puffing up on to the main ridge of Rodge Hill we joined the Worcestershire and Geo-Park Ways and started South climbing through dense woodland, mostly not present 20 years ago, to the highest point and a welcome resting and view site. En-route we made out the edges of the nearly vertical Aymestry strata outcropping as the foundation of the footpath (this is Rodge Hill Summit site).
At the seat, we took in views to the Malverns, Skirrid, Hay Bluff, Clee Hill and at our feet with evening shadows creeping, the incomparable valley of the River Teme. We spotted Shelsley Beauchamp Church, Clifton Church up on the Devonian across the river, the Shelsley Walsh Hill Climb, Homme Castle Motte and many old farmsteads now largely converted to fine homes for those with more money than the writer has.
Descending to a bridle path we stopped at an outcrop of Aymestry (Pudford Hill Bridleway Section) then through woodland and field to Lower Farm Quarry (aka Crinoid city) and its interpretation board. A short walk along the edge of a wheat field took us to the cars and back home.
25th July: 18 of us packed the minimum number of cars, parked at the Admiral Rodney (thanks–but Monday, no activity there) and walked under lowering skies down Horsham Lane then up on to the Berrow, along a ridge of Haffield (Permian) Breccia. There is a small pit, high on the ridge, in a spectacular position, only accessible by permission of the landowner. ‘Haffield’ because Haffield House near Ledbury is where the ‘type’ formation is situated, ‘breccia‘ because this formation is a jumble of angular and rounded rocks of all sizes set in a fine matrix that cements the whole together and this is what the word means. The deposit here is not so firmly concreted, presumably due to weathering; signs of faulting are present with distinct differences in the coarseness of adjacent deposits. Laid down in a dry land, in rugged but eroding highlands part of the giant continent of Pangaea, flash floods brought down debris of all sizes, rounding some of the boulders as they washed along, creating beds of rubble with finer and finer particles cementing it under the weight of subsequent events. At the time, this area was some degrees north of the equator; deposits of this Permian breccia (from a period 299-252 million years ago) are scattered across Worcestershire and Herefordshire, for example on the Clent and Woodbury Hills, on Berrow and on the top of Ankerdine and of course near Ledbury at Haffield House, among others. The deposit here is extensive–at the bottom of the hill near the lane is a much larger quarry, Permian Pit 2, heavily overgrown but previous investigations revealed that it too was Haffield Breccia.
We could see the rain coming and come it did, the more sensible equipped with raincoats and umbrellas, others (me) drenching in a considerable shower as we walked along roads then through dripping woods to our next ‘site’, Hay Wood petrifying drip. In the Teme Valley there are many streams that deposit tufa owing to the preponderance of limestone and a spring line created by impervious layers below. In Hay Wood there is a small water outflow from a muddy, root bound patch trickling down a gentle slope until it meets a large tree that creates a small waterfall, ideal for teasing out of the lime laden water a precipitate of calcium carbonate. This coats objects in the stream bed and creates small terraces, similar to those on a much larger scale in for example Turkey. Prof. Fairchild explained that a storm event would easily destroy these deposits only for the process to start all over again.
The rain ceasing, long grass still soaking we tramped uphill to Collins Green Quarry, a long scar into Much Wenlock limestone formation topped, uncomformably, by the very same Breccia seen previously. ‘Unconformably’ means that there is a geological period missing in the sequence, in this case the Silurian is topped by Permian, with Devonian and Carboniferous missing. The assumption is that it was there but was later eroded away before the Permian was laid down. Unknowingly, drivers on the B4197 pass within a few inches of a sheer drop into this quarry and in the past, before the new landowner erected a tall fence, all sorts of rubbish was hurled into the void from the ‘out of sight out of mind brigade’ parking in the lay-bye. Without maintenance the face is losing clarity. At the foot of the slope can be found boulders from the Permian, themselves usually made up of a conglomerate of pebbles from yet a previous generation of eroded mountains. Limestone rocks in the scree, many with fossils typical of the Wenlock, are often stained red, washed down from the iron rich Permian above. In the right conditions a vein of bentonite is also visible, common throughout the Much Wenlock.
We wended our way in a glorious sunlit evening back up to the road thence to our fleet of ‘taxis’ at the Admiral Rodney and back to Martley. Another 5 sites tonight, taking the total to 17, I make it–over half way there.
18th July: 20 of us took to the hills on a very warm and gloriously sunny evening. This time we went a little way north, driving to and parking at the Martley’s main quarry site (by kind permission). A little introduction to this impressive Silurian, Much Wenlock formation face with its clear layers and the turned over section to the west, how it was formed over many millions of years in a warm sub-tropical sea. Life was booming in the sea with many types of corals, trilobites, bivalves and other shellfish, some of which might look familiar on your local fishmonger’s slab. These reefs were then around 2000 miles south of the equator not always far from shore, in sea the depth of which varied considerably, influencing the quality of the deposit. From the top of the old filled in quarry, wonderful far ranging views to the Malverns (south), Bredon Hill and the Cotswolds (south east and east), the Severn plain, the Lickeys south of Birmingham, Clent Hills and finally our neighbours, the Abberley and Woodbury Hills. Western views were obscured by trees and by the somewhat higher hills known as Pudford and Rodge Hill from the Aymestry formation. Dropping down to the public footpath that runs around the north end of the quarry, we descended ‘Stairway to Heaven’, explored ‘the Canyon’, passed by ‘Callow Track South’ exiting as if through a doorway from forest to grassland to a magnificent viewpoint over a vale of the softer Lower Ludlow Shales, seemingly towered over by the aforementioned Aymestry ridge along which run the Worcestershire and GeoPark Ways. Group decision took us back along the forest edge to Peter Weddell-Halls land and the fine face to the rear of his old farmhouse. So those of you who came along can tick off Penny Hill Lane, Quarry Farm, Quarry Farm House, Penny Hill Quarry, Penny Hill East, Stairway to Heaven, The Canyon and Callow Track South taking the total in two weeks to 12.
11th July: On an increasingly lovely evening, 28 gathered to commence the quest of visiting everyone of Martley’s 31 geology sites and maybe a few more too. It was a pleasure to meet many new faces, keen on a gentle ramble of exploration with some geology thrown in. The walk up the Worcestershire Way, then high above the river and into the top fields above the Nubbins was simply glorious, memorable, Worcestershire and counties beyond glowing in the evening sun. Sites visited: Martley Rock, Kingswood Slide, The Nubbins, Scar Cottage. Next week we’ll probably check out our limestone countryside and features.