It’s all over bar the backfilling

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One of Adam’s (AerialCam) wonderful photos from yesterday

It was our last day of digging and recording on site today, and we are all done, expect for backfilling and replacing the turf tomorrow. There were some last minute surprises, both good and bad.

First for the bad news. The rammed platform in Trench E which looked so promising contained modern finds – so that is not prehistoric. Underneath the platform we came down onto a steep-sided cut, which produced more modern finds from about 40cm down. So definitely not prehistoric. Precisely what a deep hole is doing right next to a dolmen is anyone’s guess: our best guess was a latrine!

But good news too. We found a cut for a socket for the single standing stone in the collapsed dolmen – this means that this stone was placed into a socket and probably stood before the dolmen was built – whether by a few minutes, a few decades or a few hundred years we don’t yet know. We have a sample of the fill of the socket and with any luck it will contain short-lived charcoal which should date the erection of the stone. The presence of a standing stone prior to dolmen construction is very interesting, and is paralleled with sites in Cornwall where a single standing stone formed the primary and key component of the dolmen monument (the doorstone at Trevithy Quoit being the best example).

We’re tired after a long day but I’ll post summaries of each of the trenches over the next few days and some nice pictures too.

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More archaeology, more rain

The reason I am able to write the Pressadfed blog at 2pm in the afternoon is that we have been rained off again. Yesterday was sunny and dry and we got a lot done, and progress was made this morning as well before we all got too soggy to continue. The rain isn’t all bad though – it is really excellent for showing up features, and with tomorrow set to be sunny again, we should be able to see the archaeology nice and clearly.

Trench E: we made some good progress with this yesterday. This is the little 3x1m trench by the standing dolmen, and a substantial rammed platform is also in this trench, just as in the main trench. We think it may be sitting in a cut which was where people extracted the glacial erratic which was used as the capstone. Tomorrow’s digging should reveal this.

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Trench D: the main trench by the collapsed dolmen continues to provide us with interesting archaeology, and a complete lack of finds. The hearth was excavated yesterday, and towards the end of the day as we cleaned up around the excavated area we started noticing more charcoal spreads. One of these represents a smaller, shallower hearth, which seems to pre-date the big main hearth. We managed to section that yesterday. Magnetic susceptibility also showed that while the two hearths represent in situ burning, there was no burning on the land surface around them.

We have also taken away parts of the rammed stone platform and this is turning out to be more complicated than we first thought. There are substantial deposits underneath them, which we were just starting to make sense of today when the weather closed in. This is tomorrow’s main task.

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We also have Adam Stanford (aerialcam) coming out tomorrow to take some shots from above. Fingers crossed for a kind day weather-wise.

Lots of archaeology, but not so many finds

Today it is pouring with rain and blowing a gale, but we’ve had some good weather which has meant we have been able to make good progress at Presaddfed. CADW kindly let us extend the trench next to the collapsed dolmen as we just picked up a feature in the edge of the trench. In order to understand this properly we needed more than the 10cm x 10cm bit that was exposed. So the trench was extended and as we suspected, this feature is a scoop hearth cut into the natural. Yesterday we sectioned this feature and it is packed with charcoal which is great news as we will be able to get the charcoal identified and radiocarbon dated. Next to the hearth is the remains of a fairly knackered post-hole. It appears to have once held a small post, which has then been wiggled out of place, making the sides of the original cut rather ragged. We also have a rammed stone platform round the edge of the dolmen, more of which is showing up in the extended trench. This has been planned and so first thing tomorrow when the sun is shining we will be able to excavate this. It almost certainly relates to the construction of the monument – which is our primary research objective. If we are really lucky this will also contain charcoal or other organic material which we can radiocarbon date.

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We have also opened a final trench at Presaddfed, just beyond the standing dolmen. This has been carefully placed so as not to disturb any surviving chamber deposits, and not affect the structural integrity of the monument. As such, it is quite a modest trench, just 1m x 3m. However, more of the rammed stone platform has started to appear here, as well as the edge of a pit which we think is where the capstone was cut from the earth (just as at Garn Turne) – and again, if we are really lucky we will be able to recover organic material for radiocarbon dating.

While the archaeology has started to appear, one of the most remarkable things about the excavation is the lack of finds. We have just 5 pieces of flint, two of which were from trench B (the quarry). We’ve collected both black chert and quartz, but none of these pieces looks convincing. We have a few likely-looking hammerstones, but otherwise this is not a site with much material culture. While this may seem to be disappointing, actually this seems to support our idea that these sites were all about the construction of the monument, and not its subsequent use – although of course things were probably put in the chamber, and we have not investigated these here.

We’ve got a week left and it looks like we will know quite a bit more about this site by the end. With the planning done, tomorrow should be an exciting day for learning more about the construction of these dolmen monuments.

Geological knowledge!

We have been eagerly anticipating the arrival of Roger Anderton, the geologist, at Presaddfed. We had lots of questions for him, and he had lots of answers for us!

First, he was able to tell us that Trench A, with the lovely swirly schist, has been quarried in one area. Likewise, Trench B over another outcrop in the field is also definitely quarried. This is excellent news. However, the stones coming these quarries are not large enough to be the big schist capstone at Presaddfed.

The other type of stone at Presaddfed, including the capstone of the standing dolmen, is almost certainly a glacial erratic, as are the two uprights of the same material. Roger also suggested that the large schist capstone was a glacial erratic too, since the quartz lines on this stone are not mirrored on other schists in this field. This means that the builders of Presaddfed may have used stones lying around where they were to make the monument, and undertaken only small amounts of quarrying in order to acquire stone not available on the surface. We wonder if the stone being quarried was used as part of the construction process, perhaps to assist with lifting up the capstone/s into place prior to placing the uprights.

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We opened up another trench at Presaddfed today to explore the possible outcrop/quarry close to the dolmens as shown in the geophysics, but there was no archaeology, or outcrops, to be seen in this trench.

Attention is now turning to the trench next to the dolmen in order to find evidence for construction. The weather was beautiful yesterday but a cold wind made for chilly work today.

The construction of dolmens

The reason we are digging at Presaddfed is to try and understand how these monuments were constructed. Our work in North Wales will not be restricted to Presaddfed however. We are also visiting other sites and having a look at the geological composition of sites. The geologist is arriving next week to help us out with this. Were all the stones acquired locally, or were stones being brought in from elsewhere? Were people utilising erratics in these sites, and can we work out which these are? In order to make sure that the geologist has a fine range of sites to visit, we’ve been doing a little bit of reconnaissance in preparation. Here is a picture of the site of Ty Newydd. It’s a little bit knackered, and has a modern support in it, but is nevertheless a nice example of a dolmen constructed of different stones.

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Yesterday we got quite a bit of work done at Presaddfed before the rain set in in the afternoon. Trench B is finished, and we have found another candidate for the source of the capstone…..We’re taking the weekend off now and back on site next week.

Prehistoric finds and megalithic quarries

Trench A is all done. It’s not a site of megalithic quarrying, but it does look lovely.

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In our trench next to the dolmen, prehistoric finds have started to come up. A piece of chert was followed by flint and hammerstones.

A new trench (B) has been opened up over another potential quarry site. It is looking good as prehistoric flint has started to be found here already.

The weather has been super today. Fingers crossed for more of the same!

 

So far, we have found stone…..

We started work at Presaddfed yesterday. We opened a 4x4m trench over an outcrop which we thought might be one of the quarries for some of the stones in the monument. The dolmens at Presaddfed are made from two types of stone – one, a lovely swirly rock which is a mica-schist, and the other, a conglomerate. There is an outcrop of schist about 20 metres from the monument which looked a likely source of the mica-schist, hence the 4x4m trench here. Yesterday we found post-med finds in the plough soil, and a large chunk of a metal plough right up against a chunk of rock. Today, as we came down onto the glacial till with not a prehistoric find anywhere in the trench, it seems that this outcrop was not the source of the stones in the monument.

Today we also opened the 3x3m trench next to the collapsed chamber. This is to try and get a better sense of how the monument was constructed. Was it, like Carreg Samson, Garn Turne and Pentre Ifan, set into a pit, or are there signs of sockets for some of the stones? Is there any debris from the construction process to be found? Is there anything we can acquire which will help us date construction (as opposed to use)? We spent much of the day, however, removing the thick layer of gravel added (we can only assume) by the ministry of works, and we found various bits and pieces leftover by the workmen, including a wrapper of Wrigley’s juicy fruit chewing gum.

We have also had visitors the past two days, and are more than happy to show anyone around who might like to come out and visit us.