I had planned to walk on Axbridge Hill, but on arrival at Shute Shelve car park, an abandonment of cars left by a group of “ramblers” meant there was no safe place to park, so a change of venue was required.
Parked at the Shipham end of Winscombe Drove and followed the track westward to the junction with Callow Drove. Followed the track, up on to the hill, a bit mucky to start but it soon opens out to a section of walled drove.
The gatepost is conglomerate (Triassic), and the wall constructed from limestone (Carboniferous). It is possible, the conglomerate originates from Draycott.
Several of the trees along the drove have been ‘ring barked’. The height to which this occurs can be gauged by the livestock fence to the left of the image.
This boundary marker is located near the eastern end of the drove where the path splits around Callow Rocks Quarry.
There are fine views from the drove, from the eastern end looking through Longbottom towards Blackdown on the horizon.
5th February 2017: Walked up through Harptree combe towards Garrow Bottom. Passing the aqueduct, built c.1840’s, on the way. The weather, low cloud but, quite mild.
From Garrow Bottom followed a feint path, up the bank and through the woods to Smitham minery and the chimney. This is the last chimney remaining from the lead smelting industry on Mendip.
The chimney was built in 1867 by Cornish engineers. The smelting ceased in 1875 and a year later all the buildings, except the chimney demolished. The chimney was restored by the Mendip Society in the 1970’s.
From the chimney, followed the paths through the woods towards the car park, taking a detour to take a look at an old cave dig in one of the depressions. Water has been sinking here quite recently.
Across the road and into the field where Wurt Pit is located at NGR ST 558539.
The SSSI is an impressive site, it is one of the largest subsidence depressions in the Mendips. The silica-enrichment of the limetones and clays at Wurt Pit (known as the Harptree Beds, of early Jurassic age) is of considerable mineralogical importance since it took place as part of the main phase of mineralisation which emplaced the principal Mendip orefields during Jurassic times. The Harptree Beds show varying degrees of silica-enrichment, and also contain traces of other minerals, such as limonite and yellow ochre (hydrous ferric oxides), barite (barium sulphate), sphalerite (zinc sulphide) and galena (lead sulphide).
There are some good exposures of the rock type, access can be slippery when wet. The site falls within the Mendip Hills AONB.
29th January 2017: Not the best weather, donned the wet gear and set off up the hill to Charterhouse. Walked from Velvet Bottom, towards Longwood, then over to Piney Sleight.
Over the years stone has been cleared from fields and now fills small depressions, many with hawthorn growth.
Emmet butts in the rain. There is an accumulation of ant hills in this spot, perhaps the soil conditions are, particularly suitable here.
For a brief moment, the rain ceased and the low cloud lifted to give a fine view of the gorge.
Met some local browsers along the path, they kept a watchful eye on the dog.
The cliff top path on the west side of the gorge is suffering from footfall and is very eroded in places.
15th January 2017: A morning stroll around Stockhill.
In the woods there is plenty of evidence of the long gone mineral extractive industry. The landscape is pock-marked with pits and rakes. In this area the mineral of most interest was lead.
The ground here is tainted with the by products of the St Cuthbert’ smelting works and was given over to forestry many years ago.
Lichens and mosses have taken over the decaying stump of a felled tree.
There are several natural depressions found in this area, in the side of this one, a small stream sinks in a fissure in the underlying limestone shale.
There are plenty of fungi to be seen throughout the woodland.
Parked at Ellick Farm and followed the path keeping close to the boundary wall, then turning to head up to the trig on the top of Mendip – Beacon Batch at 325-metres. Passed a group of grazing ponies on the way.
I enjoy the sight of the ponies, and the cattle too, perhaps reminiscent of ancient herds in the past, a sentimental thought, of course.
Along the route from Beacon Batch to Rowberrow Warren the path follows the Blackdown pericline, the underlying geology comprises Devonian Old Red Sandstone (Portishead Formation).
As the path enters the warren and dropping down to the valley the geology is Triassic Dolomitic Conglomerate. In Rowberrow Forest I came across several examples of ‘angel’s hair’ an ice formation where water is extruded from fallen branches as it freezes.
Down the valley for a short distance before crossing the stile into the AWT reserve and a steep climb up to the hillfort at Dolebury Warren. Here leaving the Dolomitic Conglomerate and crossing the boundary between the Lower Limestone Shale and Black Rock Limestone of Lower Carboniferous age.
Across the warren and back onto Blackdown passing Reads Cavern, Rods Pot, and Bath Swallet along the way. As I approached West Twin Brook there are good views of the exposed limestone cliffs in Burrington Combe.
In West Twin Brook there are good exposures of the Lower Limestone Shale near West Twin Brook Adit.
Further down the stream is Sidcot Swallet, a cave in Black Rock Limestone.
There are interesting rocks in the stream bed too, such as this fossiliferous limestone.
From the bottom of West Twin Brook I followed the road passing Aveline’s Hole and the Rock of Ages before crossing the highway to gain the steeply ascending path behind the toilet block, stopping to look at the thin exposure of Dolomite in the car park.
At the top of the path is found Burrington Camp, a probable Iron Age univallate hillfort or religious enclosure. It is sub-rectangular, defined by a ditch and bank and appears to have been constructed in two phases.
Then followed the path over the common to return to the van at Ellick Farm.
Some observations on a walk from King’s Wood to Crook Peak and back.
Wavering Down, looking east from Crook Peak. Along the southern flank Burrington Oolite of Lower Carboniferous (Dinantian) age is exposed through thin soils. The lower slopes comprise Triassic Mercia Mudstone and pockets of Quaternary Head. The summit of Wavering Down is Lower Carboniferous Black Rock Limestone.
Looking back, west, to Crook Peak from Wavering Down. Here a short sequence of Lower Carboniferous limestone’s (from left to right in the image). To the south side of the peak is Clifton Down Limestone. The peak is formed from an outcrop of Burrington Oolite, this overlies Black Rock Limestone, on the north side.
To the south west of Wavering Down, the inlier, Brent Knoll can be seen. Formed of Jurassic Lias rocks and surrounded by younger Quaternary deposits.
Alongside the hill top path is a fine re-constructed drystone wall, this re-construction is an ongoing process. Look closely and there are interesting rocks to be seen, like this colonial coral, Lithostrotion, admittedly it’s out of context.
This is a fine ridge top walk with extensive views, on a clear day, across the Somerset Levels to the south, and the hills and mountains of south Wales, across the Severn Estuary to the north.
After yesterday’s wet and miserable weather, today started with a frost, it was dry and the sun was shining in a blue sky.
Followed the Mells river valley from Great Elm down to Vallis Vale, near Frome to take a look at a Mendip geo-classic; the ‘De La Beche’ unconformity.
Described in the 19th century by Conybeare and Buckland, and illustrated by Sir Henry De La Beche in the first memoir of the Geological Society in 1846.
Horizontally bedded, yellow Inferior Oolite limestone of Jurassic age overlies massively bedded, steeply dipping grey Carboniferous Vallis Limestone. There no intervening Triassic or Lower Jurassic rocks.
Then to Tedbury Camp.
Here the eroded unconformity surface is better exposed.
On the way from De La Beche to Tedbury Camp passed this good example of a lime kiln in a quarry near to the river.
Reference: Farrant, A.R. 2008. A walker’s guide to the geology and landscape of eastern Mendip. Book and map at 1:25 000 scale (Keyworth, Nottingham: British Geological Survey).
Our first destination was to the location of Tickenham Rock Shelter, unfortunately this turned out to be more difficult than anticipated. Tav wanted to check the co-ords and description for the MCRA, Alex was interested in a possible glacial origin, and there was an archaeological interest for me, including Cadbury Camp.
The current MCRA grid ref. is wrong and we spent quite a bit of time wandering about. Eventually I googled ‘Rock Shelter’ and found a property of that name in the right location, unfortunately the owners were out, so this will have to wait for another day.
Next destination was the Clevedon estuary shoreline. First to Margarent’s Bay to look at the carvings in Babyface Cave, the cave is really a gap in amongst some large blocks of conglomerate.
There is also some good geological features around here, including an unconformity between Triassic conglomerate and Devonian sandstones.
Then along to Ladye Bay to peer into the cave sites there, more great geology and we noted some more possible carvings of uncertain date close to a small cave.
As time was running short Tav decided to give Swiss Valley a miss today and so, our final excursion was to check out a couple of sites on Strawberry Hill, Clevedon. We, quickly located the first target, recording was completed and we moved on to the next.
After a good deal of scrambling we located the second site, then proceeded to check out the rock exposures along the top of a steep and precarious hill slope. When this had been achieved we returned to the car.
An enjoyable day out in North Somerset done we returned home, and we didn’t go to the pub!
A steady trip up through Chamber 20, stopping for a while to point out the entry to ‘Attila the Hun’s Sardine Cannery’ to DP so that he can add it to his survey at a later date.
At the dig, it was rather disappointing to find that it was full of water again. I can’t remember when it rained but Tav seemed sure it was around the 23rd. On the way out we noted that the pool in the chamber was deeper and a trickle of water was coming from the solutional slot in the roof, filling the small side tube that was overflowing and trickling into the pool.
Hopefully, the weather will remain dry and the water will drain away so that we can resume digging next week.
A steady jaunt to the end of Chamber 20 where we continued the construction of the stepped wall. First lowering the sediment, then I collected rocks for Nick to build up the wall.
By the end of the session the retaining wall was just about completed, now we are ready to resume digging.
The dig at the end of Chamber 20 has dried up, it’s a bit claggy on the top but underneath it is relatively dry, at least it was where we reduced the level for the drystone wall. Nick decided to roll some rather large boulders down the slope for use in the next stepped wall and some of them took quite a lot of effort to position. It was very warm work indeed.
We plan to return on Thursday evening to continue the project.
At the dig the water has all but receded, just a small puddle and some slop remain. We began the task of cleating spoil so that a retaining wall can be built to try and prevent any further slumping in should the dig flood in the future.
The plan is to build a series of stepped dry stone walls as we dig deeper, first of all though we will consolidate the depth we have already gained. A number of large rocks, and some medium sized ones, were moved into location and by the end of the session the first stage was almost completed.
As ever it was warm and thirsty work and soon time for some refreshment.
