ramblingon

8th December: with Roz, Nick and Tav.

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.

1st December: with Tav and Nick.

The plan was to go up and check the water level in the dig at the top of Chamber 20 and then to search for Rob Harper’s passage.

The dig is still flooded, although the water has been much deeper it is at the level noted by Jake and myself a fortnight ago. There is not any sign of water flowing in so it may be receding slowly. There has been some slumping of material into the dig.

We went then, in search of Rob’s passage and after some rummaging around looking at, other potential leads we located the passage. A low, wide phreatic arch requiring some flat out crawling through puddles, strewn with boulders, plenty of calcification and some small formations, about 20m in length. We need to see a survey to see where it’s heading and then decide if it is a viable dig. A pleasant evenings stroll around though!

Roman building in Salisbury, Wiltshire. Image taken using Olympus TG_4 and Samsung Galaxy smartphone, Wi-Fi connection utilising Olympus Share App; camera mounted on a 12 metre telescopic pole. The building is north/south aligned through long axis, north is top left (image above) and bottom right (image below). Scales are 2m and 1m.

An assemblage containing an assortment of animal and bird bones and including a single pot sherd was found during clearance works to enable an adventure caving route in Wookey Hole cave. The pdf below is a summary of the assemblage.

17th November 2016: with Jake.

With hindsight, perhaps it shouldn’t have come with too much of a surprise to find the dig under a considerable depth of water. We didn’t really think there had been that much rain lately, but we knew that this area had flooded before.

There had been plenty of signs along the way to the dig, where there were drips before now was a trickle, it was noisier, the cascade was once again rippling with the flow of water, and a pool of water with a stream had appeared in the chamber just before the dig, the result of an overflow of water from a tiny flooded side passage.

As I approached the dig I could see the water, it’s probably 1.5m deep and there’s a small stream flowing in being fed, we suspect, by the tiny overflowing side passage previously mentioned.

We collected the tools together and stashed them up in the higher chamber. We will return when it dries up sometime in the future. Meanwhile we will have to find somewhere drier to dig!

10th November 2016: with Nick, Tav and Jake.

The bears are back – Ursus fibra glassicus!

Putting our excitement aside we had a steady jaunt up to the dig. Arrived quite warm and straight into digging so no chance to cool down. Nick was clearing back the skips as I filled them, Tav and Jake hauling and dumping. When I had suitably overheated I swapped places with Nick until he too, overheated, we swapped places with Tav and Jake. Dug out lots of sediment and at 21:20 we left for the pub!

3rd November 2016: with Jake, Tav and Nick. Duncan P. went to DW to check his dig there.

The ‘top of 20’ team had another warm trip up to the dig. Tav and Nick began the proceedings, Jake and Vince hauling and dumping the spoil. When Tav and Nick overheated we swapped roles.

It’s a big hole filled with silt and sand and it isn’t clear why there are no rocks as there are plenty on the approach and on both sides, perhaps they are lower down. There is some interesting banding ranging through yellow and red with alternating thinner bands of yellow and brown, probably signifying past flooding/filling events.

When we were all suitably warmed and thirsty we exited the cave and finished the evening at the usual local hostelry to discuss the dig and other plans ahead.

25th October: with Jake, Nick, Tav and Duncan P.

All went in through the ‘adventure caving route’ near the main entrance where I stayed behind to take some photographs, the rest of the team went on up to the dig at the top of 20.

After taking the photographs I then headed into 20 to join up with the others. I was distracted along the way and stopped to take even more photographs.

Then I got sidetracked by a passage that I thought might by-pass the climb, it didn’t, and I was glad to get back out as it was rather too snug in places and I was not convinced it was entirely stable among the rocks.

Eventually arrived at the dig and joined in with the team shifting spoil back and dumping it in various gaps in the floor of the chamber.

All too soon it was time to depart the dig and we made our way out of the cave exiting by the more traditional route along the tunnel.

Driving down the A38 to Burnham on Sea you can’t miss the prominent feature of Brent Knoll sitting atop a Lias inlier (c.139m AOD) standing out from the surrounding levels.

The Iron Age hill fort has produced evidence for Roman occupation to the 4th century. Enclosing an area c.1.6 hectares it has an inner bank with a second major bank just down the hillside. The original entrance was to the east, the west and south has been artificially shaped by terracing possibly during the Medieval period.

The interior has been damaged by extensive quarrying for the Lias limestone lowering the interior by at least 2 metres. The outer defences to the north have been used for military purposes in recent times.

From the top there are extensive views of the Mendip Hills, the Poldens, and across the Severn estuary to Wales and the Somerset Levels. There would also have been views of the now lost River Siger to the south.

Reference: Adkins, L and R. 1992. A Field Guide to Somerset Archaeology. The Dovecote Press Ltd. Wimborne, Dorset.

20th October: with Jake and Tav.

Well what do you know! Should have brought the camera as all the Hallowe’en decorations were out, there were ghosties, ghoulies, skellies, coffins and things floating in the sump pool. What can you say!

Up at the dig the skip was trimmed to shape, the rope was attached, the slope smoothed over and ready to go. It’s very warm work swinging the mattock, then shovelling the sediment into the skip for removal, keep going until you start to overheat and then swap around. A lot of spoil was shifted and there’s a whole lot more to shift!

The Hunter’s was a welcome stop on the way home.

Three days of field schools with Peter Hardy, author of ‘The Geology of Somerset’ and Gill Odolphie, Adel Avery and Juliet Lawn from the Somerset Earth Science Centre. In conjunction wit the Geological Society’s Earth Science Week.

Day 1, 12th October:

After an introduction to the chronology of Mendip Rocks from the Silurian c.443 million years ago to the end of the Jurassic c.142 million years ago, and discussions regarding the formation of the Mendip Hills during the Variscan Orogeny we jumped onto a mini-bus for a tour of some local quarries.

At Moon’s Hill we examined the Silurian pyroxene andesite, lavas, fault features and breccias, agglomerates,etc.

Onto the Torr Works super quarry to look at the Carboniferous rocks found there. We had some very good views of the unconformity where Jurassic rocks can be observed to overlie Carboniferous rocks.

Fossils included horn corals, brachiopods and trace fossils left by burrowing animals, we also noted fault features.

The last visit of the day was to Doulting Stone Quarry to examine the Jurassic rocks found there.

The machine pictured above is used to ‘saw’ into the rock. We found more evidence for burrowing animals, there were fossil belemnites too. A discussion of the Doulting rock type established that it did not appear to be made of ooliths but is made up of calcite crystal that are likely to be remnants of Carboniferous crinoid being reworked and incorporated into the later rock formation.

Day 2, 13th October:

The day started with a slideshow presented by Juliet on the ‘Geology of the Mendips’. Peter then organised a closer look at fossils from the Coal Measures.

Field trips to Ubley Warren and Burrington Combe including lunch in the Burrington Inn ensued thereafter.

At Ubley Warren we discussed the evidence for mining that remains how the ores were formed and looked at the fossils seen in the limestone.

After lunch we explored Burrington Combe looking at corals, dolomite exposures and moving up to the lower Limestone Shales in West Twin Brook, at the base of the Old Red Sandstone.

Day 3, 14th October:

The day was spent exploring Carboniferous volcanics and associated rock and structures at Swallow Cliff and Middle Hope on Sand Point, unfortunately you have to go through Weston Super Mare to get here.

The things discussed included raised beach deposits, pillow lava, basaltic tuff, volcanic ash, the relative relationship of these events with the Variscan Orogeny – the volcanic activity pre-dates the mountain building period when uplift occurred.

Fossils found included Michelina, a colonial coral; Spirifer and Rhynconellid brachiopods, etched out of the rock and deep red in colour; solitary corals such as Zaphrentis; and the burrows made by escaping Lingula brachiopods as they became buried by successive layers of volcanic ash.

The weather was glorious for mid-October far better than had been predicted.

There was some interesting archaeology as well including field systems, dry stone walls, and mounds, a lot of this is probably associated with Woodspring Priory, and there were some small sea caves!

13th October: with Jake and Tav.

Tav headed to the rift to retrieve a skip and rope while Jake and I went on to the dig at the end of 20. There we continued where we left off last week just using the mattock to loosen the fine sediment, silty sand with some interesting colour bands but no large rocks. When Tav arrived with the skip and rope I set about removing boulders along the skip run using the capping gear.

At the end of the session the skip run was clear, just requires a few skips of sediment to smooth it over, and there was a very large hole where Jake and Tav had been active.

As ever it was very warm, thirsty work!