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Last time I posted about radiocarbon I reported on an unexpected Iron Age date from the New Laund enclosure. At the time I suggested that the charcoal we dated had been moved into an earlier layer and I fingered the earthworm Lumbricus terrestris as the probable culprit. I can now completely and unreservedly withdraw this accusation.

Just about two weeks ago we had another batch of radiocarbon results back. These were all on charcoal fragments that Denise identified from the excavations at the New Laund and Whitewell Enclosures. Now I’ve had chance to think about what these results mean it is clear that we need to radically reassess our ideas about the New Laund Enclosure.

We have being trying to do two things with radiocarbon at New Laund. First to get dates that were both earlier than the construction of the circle of posts in the middle of the enclosure and then others that were later than its demolition – giving us an idea of not only when it was built but how long it was in use for. We were also trying to get dates from the enclosure ditch, to confirm our suspicion that the circle of posts and the ditch were in use at the same time.

(Very) long term readers may just about be able to recall that early in the 2012 season, when we started to dig the New Laund Enclosure, we fleetingly considered the idea that the site might be Iron Age. Then we started to find large quantities of worked stone tools, showing that there had been lots of either Neolithic or Early Bronze Age activity on this bit of the hill, and came to the conclusion that the features we were digging were likely to be of that date too.

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One of our new dates comes from here, about half way up the fill of the New Laund Enclosure ditch, and it calibrates to somewhere between 390 and 205 BC, right in the middle of the Middle Iron Age.

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On the timber structure itself we have the date from the bottom of this posthole showing construction also started in the 4th or 3rd centuries BC.

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And now we have another one from this upper fill of the same feature with exactly the same calibrated date range: 395  to 350 or 305  to 210 BC. This is excellent,as it allows us to combine the archaeological information with the radiocarbon dates. One radiocarbon date on its own tells you that there is a 94.5% chance that the thing you are dating died between a given range of dates. So the date from the base of the posthole only really told us that the structure was built at some point after 395 BC. Now we have this second date, which should have gone into the ground after the posts were removed, we can now be much more confident that the building, use and demolition of the structure all falls into the period between 395 and 210 BC.

What is round, later prehistoric and made of wood? Now we have an Iron Age date for this structure then the temptation to take our former timber circle, imagine a big round thatched roof on it and call it a roundhouse is very strong. If it is an Iron Age roundhouse it is a very big one. And, of course, the date from the main ditch suggests that it has a big enclosure around it. I am off to look up possible local parallels, which should make a whole blog post all on their own. There is also the question of what was going on at the site in the Late Neolithic or Early Bronze Age to leave all the worked stone artefacts we have found. However, next week’s post, assuming I get all the dissertations marked before then, will be an update on the new results from the Whitewell Enclosure, where the finds and the radiocarbon dates are in much closer agreement.

Rick

As it has been a little while* since my last post I thought I had better try and sum up all the progress we have had with the various projects since I last posted. This will chiefly involve telling you about what other people have been up to. I have been supervising five dissertations based on work we’ve done. These are all due in during the next month, so they are doubtless evolving and changing all the time, but I thought I would try and give you a flavour of what each student is up to and how it feeds into our overall research.

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Phil is looking at the prehistoric pits in and around the Whitewell Enclosure for his BSc project. He is interested in how the objects we found in each layer got to be there and what the differences were between the different shapes of pit. Inspired by work on big Neolithic pit complexes in East Anglia, he has been spreading all the finds from each layer in each pit out on tables in the archaeology lab to look for similarities and differences. This should hopefully let us see which pits are roughly the same date and were used in comparable ways.

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James is using all the magnetometer surveys carried out at New Laund since 2011 to look at what effect a whole lot of different factors have on the effectiveness of this kind of survey. Apart from involving him and Scott spending a lot of last summer walking up and down the farm, he has been pulling together information about the geology, topography and excavated archaeology. The plan is to be able to use this detailed information to give a really precise interpretation of all of the surveys.

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Dan is still working on the environmental evidence for his masters dissertation. Alongside the core he and Mairead took last summer he has been analysing a second core from further up the Hodder valley. We think that both the peat bogs sampled built up over the last 6000 years so together they should give a good picture of how the local environment changed during the period that the sites we have been digging were in use.

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Josh has been analysing the human and animal remains we excavated from Dunald Mill Hole in October last year for his BSc dissertation. He has discovered that the human bone from this site all seems to come from the same Romano-British child as the front of the skull first discovered by Di. Most of the bone is from the skull, although Josh has found a fragment of arm-bone too. He is sure that the original burial site was either at the entrance or even some way outside the cave and that all the bone was washed into the back of Pearl Passage, where we found it.

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Chelsea is re-analysing the human remains from George Rock Shelter, which Stephen and I excavated between 2005 and 2007. The bone and teeth from this site were originally studied by former students Gemma and Genvieve shortly after the dig finished. However, that was before we got radiocarbon evidence to show that although some of this bone is Neolithic there was also a much more recent burial at the site. For her BSc dissertation Chelsea has been trying to find a way to distinguish the ancient and (relatively) modern within the mass of mixed up fragments of bone.

*or if we are being strictly honest absolutely ages, apart from reblogging Julia’s lovely appreciation of Stephen, I now see that I haven’t posted anything here since October last year

HARN Weblog

In Appreciation – Professor Stephen Aldhouse Green

1945-2016

Stephen

It is with great sadness that I’m writing this appreciation of Stephen who lost his long battle (and it was a battle) with Parkinson’s disease in February. Matt Pope and Rob Dinnis have already written a short obituary for Salon which can be read here, and I know Professor W.H. Manning is writing an obituary for the Cardiff University Alumni magazine which I’ll link to when it’s published. This then is an intermediate account mixing personal reminiscences with some details about Stephen’s life.

Stephen was born in Bristol in 1945, attended grammar school before going to Cardiff University to study archaeology as an undergraduate and later as a postgraduate. After graduation he became a lecturer at the University of Khartoum, then returned to Britain and became a field archaeologist at Milton Keynes, before taking up the post of Assistant Keeper of Archaeology…

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Although I am a cave archaeologist, unlike some of my colleagues, I have never been a caver. When I go into a cave it is to dig stuff up and I generally don’t go in that deep or down very small holes. This is fine, except when the archaeology happens to be a long way down a very small hole. This weekend we have been working with some caving colleagues to excavate Late Iron Age and/or Roman human remains from a cave near Carnforth and I have been right at the very feeble limit of my caving skills.

Di, one of the caving team, discovered the front part of a human skull while digging at the end of a narrow passage last spring. She reported it to Lancashire Constabulary, who had it radiocarbon dated and discovered it died sometime in the first two centuries AD and therefore was slightly too old to be a live enquiry. We then took the bone to Preston, cleaned it up and discovered that is was the frontal bone (basically the face bit) of a young child between 3 and 4 years old. The aim of this weekend’s dig was to find out how the skull got into the cave and if anything or anyone else was with it.

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The passage where the find was made ends in a series of pools, dammed by flowstone curtains. This photo shows the view across them looking back towards the way out. What we needed to do was divide this area up into 30 cm blocks and excavate the sediment out of each block in 5 cm layers. Working like this means that when we sieve the mud we know where everything we find comes from. Sieving took place at the surface and to get the sediment out to be sieved involved a long chain of bodies.

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Di, because she made the original find and had the skills to get in and out of the chamber, did the actual digging and recording on site. She put all the sediment into 10 litre lidded sample buckets and passed them out to me.

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This is as far into the final chamber as I could get. I leant round the corner like this and passed archaeological advice in one direction and waited for Di to pass buckets of mud and finds in the other. I labelled them and took them backwards behind me to a slightly wider fissure where I could turn round and pass them on.

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This is Andy, waiting for the next bucket. He then had to crawl about 15 metres to pass them on to Simon at the entrance.

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Once Simon got hold of them he then loaded them onto the fantastic Tyrolean ropeway which would carry them over the big drop into the main cave entrance and down to the streamway where they could be sieved and sorted.

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Josh and Tom spent all day getting very wet indeed sieving very intensively. By late afternoon they had gathered both an admiring audience and an alarming backlog of buckets. This is actually the hardest part of all. It is cold, wet, backbreaking work while everyone else is having all the fun digging or playing with rope tramways.

Thanks to everyone’s hard work we successfully removed all the sediment from the end of the passage. We discovered most of the rest of the original cranium and also quite a bit of animal bone. Because we didn’t find either the jawbone or any of the rest of the skeleton we are assuming that the original burial was much nearer the surface and that the cranium was later washed into the depths of the cave.

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Final shot of the day. Di emerging from the passage entrance as the last one off site.

Rick

Back to the Pleistocene this week, at least partly. At home we’ve been reading John Grant’s fantastic Littlenose books. Apart from being hilarious and giving a rush of TV Cream style nostalgia for Imperial phase Jackanory, I’d forgotten what a great fictional introduction to early prehistory the books are. Grant was sensibly vague about details of precisely when in the Ice Age all this was going on but the stories all turn on themes recognisable to Palaeolithic archaeologists. Hunting, gathering, shamanism, rock art and of course Neanderthal/modern human interactions all drive most of the plots. Our copy of ‘Littlenose and Two Eyes’ even has a useful one page chronological summary of the Quaternary at the back – something like the thing I give out in first year lectures but with better pictures.

A Neanderthal/modern human encounter as Littlenose and Father have to outwit the straightnoses with the help of a swarm of bees. (c) John Grant 1975 from Littlenose to the Rescue

We are still working on the floatation of soil samples from both sites but today I have been looking at the distribution of the stone tools and waste flakes across the site. All the worked stone finds have been washed now and I’ve been through them all checking that they are what they say on the bag. I’ve also checked that the recorded co-ordinates we have listed are right – which was mostly the case. There were one or two pairs of finds where the locations from one find had been transposed onto the other, which is the kind of thing which happens when you are doing complex recording in driving rain and wind, but fortunately there is enough built-in checks and repeats in how we record to let us unscramble all these mistakes at this stage. I’ve also thrown away about four pieces from each site which however hard I looked at them I couldn’t see any sign that they had ever been worked.

The results from today’s work are. One, just over 80% of the stone tools are various kinds of chert with the all the rest being flint. Two, there is quite a variety of different things subsumed under that broad label ‘chert’. Some of it is very fine and black and almost like flint: while other bits are grey and very very granular indeed. More detailed work on what all these rocks are is an obvious area where we need to do more research.

Once we’ve checked everything is as it should be it is possible to start looking at the distribution of finds across the site. After all, this is one of the major reasons for recording this locational information in the first place. The plot above is the distribution of worked stone from trench C, showing a big cluster of finds in the area of the ditch in the centre of the plot. There is also another little group in the bank to the right of this and another cluster towards the interior of the enclosure to the left.

This plot shows that at site D things are less clear-cut. At this stage of research all this really tells us is that there are finds from over the whole of the excavated area. Clearly there is more to do here.

Rick

Today we have been getting some of the soil samples ready for study. Or, to be more strictly honest, Megan and Vanessa have been up in the lab doing the sample processing while I was either swanning about with the camera taking the pictures for this post or downstairs in my office doing completely unrelated things. The samples they have been dealing with come from the bottom of various of the pits, postholes and ditches. We took 5 litre buckets of soil in all these cases to allow us to look for a range of different kinds of evidence. To divide them up into their constituent parts we use a device called a flotation tank. This should not be confused with the thing 70s Californians used to bob about in to get back to the womb. In environmental archaeology a flotation tank looks something like this.

The flotation tank in all its custom-built glory. As you can see it is a modified rainwater butt wearing a bridal veil and plumbed into the mains water supply. Water goes in at the bottom and rises through the tank to flow through the soil sample which is spread out on the net. Then it flows out of a spout at the back and through a nested set of very fine sieves. The water then drains through a set of traps to catch all the silt and keep mud from blocking up the University’s drains. We built it ourselves (except the silt trap which we had to buy) about three years ago after a big shopping trip to Berry’s of Leyland and we are inordinately proud of our workmanship. As well as the rainwater butt and the net curtain, which is semi-disposable, there is a steel grill, 3 m of plastic piping, about a kilometre of duck tape and two whole tubes of bathroom sealant hidden away inside it.

Each soil sample is divided into four parts during the process. First, about a handful (precision is everything in archaeology after all) is taken out and put into a separate sample bag. This will go through a completely different set of processes to extract any surviving fossil pollen. This microscopic evidence for the past environment will need a post to itself to explain – and probably someone other than me to write the post.

The second stage is that all the rest of the sample is tipped into the top of the flotation tank. Here Vanessa is adding a sample, in this case from the bottom of one of the postholes, on top of the net. Under the water is the metal grill which supports the weight and under that is the water source. Note the stylish sequins on the net, which are an essential part of the whole process.

Once the water is turned on then the floatation process can begin. Megan is floating a sample by gently agitating it with her fingers. Macroscopic plant remains and charcoal which have been preserved in the soil float to the top (we hope) and are carried by the flow of the water out of the spout and into the coarse and fine sieves below. Stones and other heavy particles remain behind in the net and the rest of the sediment sinks down to the base of the tank: where it remains out of sight and mind until the sad day about once a year when the whole thing fills up and has to be drained down, emptied and cleaned out.

From this process we get three more fractions to add to the pollen sample taken at the beginning. From the two sieves we get a ‘coarse flot’ and a ‘fine flot’ – i.e. small and very small bits of preserved organic material that need to be parcelled up in lab towel and hung up to dry. Once they are dry then the will be examined under a microscope by an archaeobotanist and identified. The last fraction is the ‘flot residue’. All the stones and heavy particles are removed from the net curtain and put on more lab towel in trays to dry – we have a drying rack to aid this process – before being hand sorted. This involves a lot of patience, sharp eyes and tweezers. The reward is usually embarrassingly large fragments of worked stone, bone and sometimes even pottery.

Rick

After a week of serious getting down to it in the evening this year’s interim report is completed. Well the Paralympics is over and, now there is no need to spend every night applauding Iwan Thomas’s dedicated fight against the ‘casual friday’ look for sports presenters, what else was I going to do with my time? I’ve uploaded it as a pdf on the interim reports page. There is still a lot of research to be done on the results of this summer’s work but at least we have now got an interpreted framework of what happened on site and in which order to work around.

There is a certain amount of environmental science that I would like to get moving over the next few months, in particular we will be looking at the preserved pollen from both the caves we dug last year and from all the features in the enclosure. I also need to make a start on a detailed analysis of all the worked stone. There are lots of tools, but just as importantly there are lots of waste flakes from making those tools which need to be measured and compared with the finds from last year and from Reginald Musson’s excavations in Fairy Holes cave in the 1940s.

We have also got a new toy here at UCLan: a robotic total station with an in-built differential GPS. Yes dear, very nice, you are thinking. This is a survey instrument which allows us to take and record measurements to the same accuracy as the total station we used over the summer (about +/-5 mm if we are doing it right and anyone cares) but automatically and in vast numbers. I want to use this to make a very detailed contour model of the whole hill. There are two reasons for doing this. One is because I can and think it will look cool in the final report. But the other is that this level of very detailed survey may show up little changes in the topography of the site that show where buried features, such as the missing bits of the ditch, may be.

I want to extend it over the whole hill because when I was on top of the hill taking this picture of the dig in progress there were a lot of very intriguing humps and bumps which may be other monuments. One in particular, right on the summit, looks as if it may be a barrow or a cairn.

Rick