Worked Flint from Trench 42 at the Bradford Kaims

Franzi Leja – Assistant Supervisor and the University of Bamberg, Germany

During this season Trench 42, situated on the south-side of the Bradford Kaims excavation area, was extended to measure at 13 m by 5 m, intended to reveal potential structures related to a large pit and the post holes surrounding it in the centre of the trench, exposed in the 2016 season. Unlike in the western half of the trench, there was no burnt mound underneath the topsoil, which came straight down to the prehistoric land surface into which the trough and the other features were cut. In the south-east-corner, a modern horse-shoe was discovered in the topsoil, but shortly after this, sitting on top of the light and yellowish sand based land-surface that we were aiming for, a large worked flint point was discovered.

flint

It is triangular in shape with the two retouched sides being slightly convex. They have been knapped and retouched, with the bulb of percussion at the tapered end. As the flint is so thick, it suggests that the currently tapered end is in fact the base, with the point having snapped off leading to the discard of the tool. Our first assumption was that this was an arrow head, but the thickness and length of the tool, when complete, suggests it could be something like a spear head. Our provisional dating for the site suggests that this is a Bronze Age tool, but we wait for specialist analysis to further prove this.

Beyond this initial evaluation, the discovery of the flint lends credence to the idea that the land-surface which we came down upon is contemporary with, and associated to, the burnt mound in this area, and that the artefact scatter which also contained flint working debris, suggests an associated activity going on in the periphery of the burnt mound.

Geomorphological Survey at the Bradford Kaims

 Anna Finneran, Coring Supervisor and PhD Candidate, University of Durham

In 2017 the Kaims coring team has benefitted from many dry days, and persevered through some soaking days. Here’s a quick update on the accomplishments of Dr. Richard Tipping and field school students this season:

The Bradford Kaims branch of the BRP since 2010 has conducted a landscape-scale interdisciplinary investigation of a large fenland associated with our archaeological sites.  Excavations have uncovered multiple burnt mounds, structural remains, and artefacts.  Human activity spans at least the Mesolithic through the Bronze Age.  The features and material culture represent an industrial area.  Conspicuous in its absence, however, is evidence for domestic activity in the landscape. In contrast, palaeoenvironmental reconstructions present a rich aquatic environment, characterised by two large lakes throughout the Holocene and populated with unique flora and fauna, potentially attractive for long-term habitation.  The landscape surveys this season have sought to look beyond the Neolithic and Bronze Age by incorporating geomorphology, geophysics, soil micromorphology, and excavation to describe both the natural landscape and the human activity throughout the Holocene.

The main aim of the 2017 season in terms of this geomorphological mapping was coring and sediment description at locations known to contain or likely to contain layers of colluvial accumulation (or slopewash). Colluvial accumulation would result from episodes of erosion on slopes descending towards the fenland basin. Geomorphological analyses from previous seasons concluded that no natural sediment erosion occurred on steep slopes around the fenland. Any erosion on gentler slopes may then be ascribed to archaeological, and potentially agricultural, activity.

The coring team conducted coring transects across the landscape, inserting a metal tube (or sediment core) into the soils and sediments of the fenland and its surrounds, to chart the different types and depths of material.  We successfully identified layers of colluvium within layers of peat, representing episodes of agricultural destabilisation of the slopes, at numerous points. Following reconnaissance, five locations were selected for a combination of analyses including soil micromorphology and pOSL analysis (see Becky Scott’s blog in a few days for more detail on this!).

Another aim of the geomorphological investigations in 2017 was working in tandem with Graeme Attwood’s magnetometry survey to define buried anomalies. Coring and sediment description preceded excavation of 1 x 1m test pits over the most promising anomalies. The anomalies to the NW of Trench 6 proved to be burnt mounds, as hoped. However, the anomalies in the form of two parallel lines between Trenches 11 and 9 were found to be ditches for Victorian age drainage pipes.

Richard

Despite our pipe-related set-backs, one lost (but later retrieved) core, and numerous small injuries and sprains, the coring team successfully completed our aims for this season with positive and encouraging results for the future. Next season we hope to continue to investigate the natural landscape and the human impact upon the environment throughout the Holocene, and hopefully use the analyses of colluvial deposits and the dating material provided by the fenland to gain a more in-depth understanding of how people across the Bronze Age and Iron Age influenced their landscape.

Dating Funding Awarded to the Bradford Kaims

We are pleased to announce that the Bradford Kaims site has been awarded two small funding grants to undertake radiocarbon dating of some of our features across Trench 6, and to tie our coring activities in with the rest of the excavations. The funding was sought immediately after the end of the 2016 season to clarify the dates of certain areas of the excavation uncovered this year.

Primarily, we have been awarded £1500 from the Northumberland County Council Community Chest scheme to date a series of preserved hazelnut shells through our large wooden platform feature in Trench 6, following on from the £1,000 grant we received from this fund in 2015 to enable community volunteer involvement. We selected hazelnut shells as the datable component as they are a very short-lived ecofact, only absorbing base carbon from the atmosphere for a short period (<1 year), rather than over longer periods such as other carbon-storing ecofacts can do. Dating oak (Quercus) for example, can provide discrepancies of up to 500 years, as it can be such a long-lived tree. As the first grant from this fund allowed dozens of community volunteers to come on to site and work with us, especially on the platform area, we thought it appropriate to use the second grant awarded from the Community Chest to date that area of the site, to finalise the good work that our volunteers have done. Many thanks to the Community Chest fund and all of our volunteers for their support and help!

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Community volunteers digging the platform

Our second grant is slightly smaller, a total of £756 awarded to us through the Heritage at Risk and Northumberland County Council Conservation Grant for two more radiocarbon dates on our platform area, which will finalise its dating and allow us to tie this feature into our other chronologies across the site. Hopefully these two dating grants can be used as pump-primer funds on dates to help us get further funding from across the site and landscape. Hopefully we will have more good news for you all soon!

Tom Gardner

 

Bradford Kaims 2015 Interim Report Released

Since the end of the 2016 season we have been working hard to process and assess the material which we extracted from the Bradford Kaims, as well as dispersing to work on our other projects. However, we had a wee bit of catching up to do on the 2015 season, in the form of finalising our interim report. We usually try to get the interim reports done prior to the beginning of the next season, as we managed with our 2013 and 2014 season reports, but time ran away with us this year. However, we can now safely say that the 2015 interim report from the Bradford Kaims is available, open access and on our website!

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Trench 6 under investigation in 2015

I shows the highlights and the less glamorous sides of our 2015 scheme of investigation, and covers all the excavation which took place during out two month season, so please give it a look and let us know what you think!

Evidently it is a slightly slimmed down version of our activities, the full details of which will be presented in our end-of evaluation site monograph. However, it should provide details of our exciting finds, such as the Neolithic timber platform in Trench 6, the timber laid working area in Trench 11, and the stake-built building in Trench 9!

Now, a bit of time off to work on other projects, such as the exciting Blythe Beach work, and then the beginning of the 2016 interim report!

Tom Gardner

Trench 6 Update – Bradford Kaims

 

Trench 6 remains our largest and longest running trench to date at the Bradford Kaims. Each new context we uncover adds to the complexity and variety of information about prehistoric human activity in the area. Here, we highlight just two of the exciting features currently under excavation.

 

THE TROUGH

Over the past couple of weeks, we have uncovered our wooden trough in the northwest corner of the trench. After two years of sitting under tarp, the trough has now been fully excavated and cleaned, with its contents removed down to a beautiful clay base. The trough is made of a hollowed out oak tree and fills with crystal clear water, so may have been used as a well; however, within its fill, fire cracked stones have been found which means that this water was probably being heated.

 

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The trough being fully excavated after half-sectioning.

 

BUILDING A

Earlier in the season we uncovered a suspiciously rectangular-shaped dark fill in the northern side of Trench 6. Upon beginning excavation last week we found a series of four large postholes down one side as well as postholes in each corner. We believe that the colossal postholes suggest that this structure was a building. Lying within the structure is an oblong patch of burnt material, which could possibly be a fire pit. From this pit, we have removed a large pointed post, which could have been one of the posts supporting the structure.

Experimental Prehistoric Pottery

This week’s experimental blog is courtesy of Rachel Brewer, Bradford Kaims Assistant Supervisor.

 

Following on the heels of the beer brewing experiment, our Week 5 experimental archaeology project was an effort to make a variety of pottery vessels using only raw clay sourced from our prehistoric site here at the Bradford Kaims. We knew from previous seasons that the trenches and test pits often turn up natural clay deposits of varying colours and quality. We’ve also had a few examples of possible Neolithic and Bronze Age potsherds surface during excavation; so this summer’s experimental archaeology program seemed like a perfect opportunity to test out our prehistoric potting skills! Altogether, processing the clay, forming the pots, and the subsequent firing turned out to be a messy, fun and educational experiment for all involved.

 

Step 1: Gathering the clay

While digging a series of shovel test pits earlier in the season, we hit upon a substantial deposit of clay about 50cm below topsoil. Seeing a source of raw material for our pottery experiment, I dug out a bucket’s worth to begin processing. Though the clay was mostly light orangey-brown, there was a thin layer of grey overlaying that; it also gathered a good amount of silt and peat on its way out of our 20cmX20cm shovel test pit. Through processing, these colours and textures blended together as shown in the later photos.

 

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The raw clay.

 

Step 2: Processing the clay

This was the longest part of the process, due in part to my own inexperience and also to the wet conditions on site. I knew from research that the best way to process raw clay is often to dry it out completely, grind to a powder, sieve, and slowly reintroduce water until the clay reaches a workable consistency. I also knew how unlikely it would be that we could completely dry out that amount of clay in a timely manner, particularly when it was raining almost daily. So I opted instead for wet processing, which involved the help of several pairs of hands pulling all of the clay into small lumps and mixing/mashing it up with added water in a large plastic box. This part worked better than expected, and after a couple of days of minimal stirring, nearly all of the clay was liquefied.

 

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Slaking the clay on site.

 

At this point we poured the slip (liquid clay) through a sieve to remove the largest inclusions, mostly small stones and twigs. We could have used smaller screens and sieved multiple times for greater purity, but I chose not to since examples of prehistoric pottery found at this and other sites indicate that prehistoric people were not processing their clay to a high degree.

 

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Sieving the slip.

 

For about a week I attempted to do a daily pouring-off of the water that would accumulate on the surface, hoping that between evaporation and pouring off that the clay would thicken a bit every day. The couple of days I was able to let the boxes sit out in the sun did help, but it wasn’t working quickly.

 

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The slowly thickening slip.

 

On one sunny day I cut open a bin liner and laid it out on the grass like a small tarp, then I poured the thickened slip out on the plastic. This increased the surface area the sun could reach and it was noticeably thicker by the end of the work day, but it still wasn’t drying out fast enough. We had to rearrange the experimental schedule and move pottery back a week – I had only a week to get some workable clay and I was running out of ideas!

 

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Spreading out the clay to increase the surface area for evaporation.

 

My final effort involved pouring the clay into an old pillowcase, tying it closed with string and hanging it from a tree to allow the water to drain out with gravity and air. The better part of the week passed before I noticed much of a change, but much to my relief, the night before we were scheduled to make the pots we had somewhat sticky but relatively workable clay!

 

 

Step 3: Forming the pots

Before beginning our pot making, the students used rocks to crush up a few soft pieces of sandstone sourced from Trench 6; we used this sand as temper.

 

 

Since wheels were not used by prehistoric potters, the students learned to use the two most common methods of building pottery without a wheel: the pinch method (formed by pinching a solid ball of clay into the desired shape) and the coiling method (rolling out rings of clay, stacking the rings, and smoothing them together). A small amount of temper was added by each individual to their own allotment of clay. Of course we had some creative minds in the mix who ventured beyond the utilitarian forms like bowls and jars, and by the end of the day we had quite a collection of unique creations! We set everything we made on two log disks that would be easily moveable and would absorb moisture. After that we just had to let everything dry out completely to prepare them for firing.

 

 

Step 4: Firing

When it was time for firing, we began by building a small fire in our fire pit on site. Pottery has to be heated very slowly, so we began by placing the dried pots around the edge of the pit and then slowly moving them in close to the fire. Once the pieces were against the central fire, we began placing larger branches over and around the pots, completely covering them and creating a kiln effect. We kept a large fire burning for about an hour and a half, then allowed it to die down to coals. Since our time on site was limited to 5 hours and the pots needed to be cooling before we left site, we weren’t able to keep the pots firing for the ideal amount of time, which for our purposes would have been around 4 hours.

 

The final step of firing is allowing the pots to completely cool before removing them from the pit. Before we left site for the day, we dug the pots (none of which had broken!) out of the coals, stacking them against one wall of the fire pit and shoveling the coals to the opposite wall. We then covered the pots with a layer of grasses and sedge, placed a couple of metal sheets over the pit to protect the pots from rain, then left for the night.

 

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The fired ceramics hot from the fire.

 

Upon examining the cooled pottery the next day, I was pleased to see that none of the vessels had cracked or exploded during firing. Additionally, the pieces had fired, if not completely through, then most of the way through despite the shortened firing time. The fired pots are noticeably brittle and not completely water tight, but with a little more practice we could probably produce vessels that would be more serviceable. Since we accomplished our goal of using only raw materials from site and a fire to create prehistory-inspired pottery – and we had fun doing it – I’m calling this experiment a success!

 

Bradford Kaims – Trench 14 Update

Trench 14 is actually a combination of two earlier trenches: 8 & 11. 

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Trench 14 and the stone feature within it.

Trench 8

Trench 8 was opened in 2013 and contained an artificial mound comprised of larger stones (30-45 cm in diameter) underneath a layer of smaller stones (4-10 cm in diameter). 

A quarter section was dug out to determine the depth of the mound, and we discovered a thin layer of peat under which lay a brushwood platform. As the season ended, we backfilled the quarter section and left it to future investigations.

Trench 11

Trench 11 was opened in 2015 in an attempt to further understand the stone mound feature by examining the surrounding area, as well as determining if any relationship existed between Trench 8 and the western end of Trench 9 – where a large post was discovered in situ at the end of season 2015. 

A paleochannel with layers of sand and brushwood was discovered at the southern end, which was less than a metre from the north end of Trench 8. One side of the channel edge looked like it may have been cut intentionally though further investigations are required to determine if that was the case. 

Also within the trench, we discovered over 10 pieces of wood around 6 cm wide & ranging from a half metre to one metre in length lying within the peat layer. Two had potential cuts in them, giving us an indication that at least a couple of them were used by early humans. 

So far this season…

We have expanded Trench 14 to include both Trenches 8 and 11, and are in the process of expanding the quarter section to give us a fresh understanding of the stratigraphy of the artificial stone mound and the brushwood platform lying under the peat layer. We also plan to expand the trench into the western edge of Trench 11 to understand if a relationship between 8, 9, 11 and 14 exists. Our plans are to extend into the palaeochannel to determine if it was cut intentionally and to excavate at least partially into the edge of the peat layer to discover if more worked wood exists. 

Season Intro and Week 1 Diary – The Bradford Kaims

A slightly belated blog which is intended to be read in conjunction with yesterday’s post regarding the promontory area.

Written by Tom Gardner, Tom Lally, and Becky Brummet.

 

And so we are back to work at the Bradford Kaims, and thought it would be a good idea to outline our plans for this seasons excavation. We are nearing the end of our evaluation phase on site, and have some areas which we need to finish and wrap up. Our investigations are divided into three areas, the north of the site in Trench 6, the south of the site in Trench 9, and the promontory area with small excavations in Trench 12, Trench 13, and Trench 42.

 

Trench 6

Trench 6 finished last year with a focus upon our wooden platform and a complex pit sequence below the burnt mound deposits. We kicked off this season with a trench clean and photograph, before re-opening an area from 2014 over a series of Neolithic wooden troughs associated with our earlier burnt mound deposits. These troughs pose an interesting sequence of site use, abandonment, and re-use, and are impressive pieces of architecture in themselves. The latest in the sequence is a large and intact oak trunk, which has been hollowed out vertically all the way through, and set in the ground as a trough or well. This is cut into an earlier plank lined trough, and the whole sequences is surrounded by a series of post-holes and pits, with capping burnt mound deposits slumping over the lot.

 

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Trench 6 oak trough.

 

Beyond finishing this sequence, the plans for Trench 6 involve expanding to the north to excavate a later burnt mound identified last year in the section, removing the earlier mounds onto the subsoil, and working out the interface between our burnt mound sequences and the wooden platform from 2015. With this, and the other areas of work, we have a busy summer ahead!

 

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Trench 6 at the end of the 2015 season.

 

Trench 9

Trench 9 finished with a flurry at the end of the 2015 season, and we aim to pick up right where we left off. The trench edges have been redefined, the backfill emptied out, and the flurry of features found last season are visible once again. It’s time to get things started for 2016.

With 2016 likely being the final season that we have Trench 9 open, we have a lot of work to do. Last season ended with the discovery of a possible sweat lodge, Mesolithic hearth and a possible man-made water channel, all of which will need to be investigated this season. As a result of time constraints and having more precise areas to excavate, the dimensions of Trench 9 have been slightly altered to accommodate for this. We will now focus heavily on the middle of the trench where the main features lie, as well as extending the trench out into the fen, in order to determine the purposes of the wooden features and timbers that were cutting into the section in 2015.

 

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Trench 9 at the end of the 2015 season.

 

The specific aims this season are to investigate the heavily wooded area in the North-West corner, excavate our Neolithic post-hole and post further to determine its function, determine the age and function of the wooden ‘plank’ which has been visible since T9 was first opened in 2014, and then focus most of our efforts into the central areas where the hearth, channel and sweat lodge are located. We need to determine the functions of these features individually and then whether they are contemporary with one another. Despite a burnt mound being the reason why this trench was opened to begin with, there is every chance that these features could be the whole reason why prehistoric people were drawn to this location in the landscape in the first place.

 

Trench 9 start of 2016

Trench 9 at the start of the 2016 season.

 

 

An Excerpt from the Promontory – Bradford Kaims

Trench 12, 13 & 42 were opened (reopened, in T42’s case) this season for sampling & investigations into the burnt mounds located on the promontory.

T12 is a 2m x 3m trench located on the southern end of the promontory. Shortly after opening the trench, we began to find some really interesting artefacts. In the peat layer, we found a piece of burnt quartz & when we continued down through the peat onto the burnt mound layer, we found more: two pieces of worked flint & two pieces of burnt bone! Quite exciting finds for a trench originally opened up for sampling.

 

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A piece of worked flint from trench 12.

 

Trench 13 is 1m x 2m trench located just off the edge of the promontory, near the waters edge. Like T12, it was opened for sampling & has also produced some really interesting finds! Just below our peat layer, we discovered a layer which consists of shells & sand moulded & formed together. In that layer, we uncovered two pieces of charcoal, nine small (4-10cm sized) pieces of worked wood & one log roughly 1m long. We think the smaller wooden pieces may have been stakes & considering their proximity to the waters edge & the fact that a couple were orientated at a 45° angle, it could indicate fencing.

 

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A piece of worked wood from trench 13.

 

A 2m x 4m portion of trench 42 was reopened for sampling, with the focus being on the burnt mound, the trough & the limestone piece. A 1m x 2m spit was dug out of the north end. We expected the burnt mound material to continue at least a half meter, but we quickly uncovered an interesting mottled orange clay layer only 4-5cm into the burnt mound layer.

 

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The re-opening of trench 42.

 

Since the weather has turned more amiable for excavations to continue in our other trenches, we have taken a break from our work on the promontory, but plan on returning to it to as soon as feasible.

Another week in the Finds Department

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The Windmill during a brief respite from the rain.

Good morning from the post-excavation department! We have had a busy few weeks processing some intriguing finds including a possible iron stylus, a worked stone bead, several bits of unidentified burnt clay discs, and a potential lead pendant, to name a few.

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Finds Illustration

Environmental supervisor Thomas Fox has kept our students engaged at the flot tank processing environmental samples from last year while Post-ex supervisor Jeff Aldrich has been taking advantage of the poor weather to give students the a chance to illustrate and process our finds.

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Students Katie and Kelly sorting environmental flotation samples.

The students have also had the opportunity to learn a bit of post-excavation from Bradford Kaims processing finds, including a plethora of worked wooden stakes and the resultant paperwork led by trench supervisor Becky Brummet. Because of its distance from civilisation, it is a separate process at each site: the Castle and the Kaims.

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Students Joe and Rachel filling out timber recording sheets.

With the sun shining and the winds calmer, the students and staff will have ample time in the trenches to find us some new artefacts, hopefully further fleshing out the story of Bamburgh Castle.