Identifying pottery fire-pits in the archaeological record

Cloghabreedy, Co. Tipperary Site 125.3

Probable pottery fire-pits at Cloghabreedy, Co. Tipperary Site 125.3. Image from McQuade et al. 2009.

Thanks to the work of the UCD Centre for Experimental Archaeology it may now be possible to identify the pottery fire-pits of the Irish prehistoric pottery industry.

One of the most characteristic artefacts of the Irish Bronze Age is pottery. It was produced in large quantities and is found at all types of sites from settlement and ritual to industrial. Until recently no prehistoric pottery fire-pits, where the clay is heated until it becomes pottery, had been identified in the Irish archaeological literature (see for example Ó Faoláin and Northover 1998, 73). Even where quite large settlement sites have been investigated like Corrstown, Co. Derry, where over 9,000 sherds of pottery were recovered, and Chancellosrland site A, where over 2,000 sherds were found, no fire-pits were identified.

UCD Centre for Experimental Archaeology fire-pit.

UCD Centre for Experimental Archaeology fire-pit with charcoal and pottery in situ. Photo Aidan O'Sullivan

Now thanks to the work of the UCD Centre for Experimental Archaeology it looks as though firing sites can be identified. At UCD Aidan O’Sullivan, Conor Mcdermott, Thomas Cummins and John Nicholl have been making vessels of various periods and types and firing them in sub-rectangular shaped fire-pits. Once the contents of the pits have cooled and the finished pots are removed what is left is a fire-reddened pit filled with charcoal and any sherds of failed pots. The great value of this experimental work (and documenting it with images and video through media like Facebook) is that it helps archaeologists identify these features in excavation reports. Aidan O’Sullivan and the others have not only demonstrated how pottery can be made in a simple fire-pits, but Aidan has noted that the field archaeologist will find.

“Charcoal, ash, burnt stones, and pieces of fire-reddened and blackened soil. You might also find heavily fired and black, sooted pottery fragments, the fragmentary remains of previously failed pots that have been through several kiln fires.”

He also noted:

“The effect of a north-easterly breeze, meaning that only centimetres away on the ‘wrong’ side, the fire was essentially cool”.

So some method of blocking the prevailing airflow across the surface of the fire-pit is needed to maintain a constant temperature. As Graham Taylor who writes pottedhistory has noted:

“If the wind is gusting it can cause huge temperature fluctuations which destroy pots.”

The wind can be mitigated by the erection of a simple wattle screen across the path of the prevailing wind.

As Graham Taylor points out:

“A common technique would be: fairly serious fire in the pit allowed to burn down to charcoal, green brushwood directly onto this, pots on to this, then more dry fuel, close over with green brush and clay leaving a few small air holes around the edge. Walk away and leave it for a couple of days. If you’ve got it right, and it doesn’t go out, it’s a gentler way to fire larger pots and get them black.”

The sealing material may be dug from a pit or pits next to the fire-pit which may be refilled with the waste charcoal and sherds of any failed pots from the fire-pit.

Therefore the elements that one might expect to find at a pottery firing site are a fire-reddened pit or pits filled with charcoal, ash, sherds of failed pots with a windbreak to the west or south and pits from which soil has been dug to seal the fire-pit. These pits can be back-filled with the sooty failed pot sherds from the firing.

Plan of probable pottery fire-pits at Cloghabreedy, Co. Tipperary site 125-3.

Plan of probable pottery fire-pits at Cloghabreedy, Co. Tipperary site 125-3. from McQuade et al. 2009.

At Cloghabreedy, Co. Tipperary a site appears to fulfil all of these criteria. The site was excavated under the Direction of Colm Moriarty in advance of the construction of the N8 Cashel to Mitchelstown Road Scheme and is published by Colm in M. McQuade, B. Molloy and C. Moriarty (Eds.) In the Shadow of the Galtees. Archaeological excavations along the N8 Cashel to Mitchelstown Road Scheme. NRA Scheme Monographs 4, 30-31. The site consists of two sub-rectangular pits set in a line and aligned north-west to south-east with concave profiles that measure 1.37m and 1.65m long by 0.97m and 1.25m wide and 0.25m deep. The sides and bases of the pits were fire-reddened and contained charcoal fills.

Just to the east of the fire-pits was a pair of pits also filled with charcoal-rich deposits and sherds of food vessel vase and urn. Charcoal from the primary fill of one of the pits was radiocarbon dated to 2289-2014 Cal BC (UB-7377). Set 3.3m south of the fire-pits and aligned roughly east-west were nine stake-holes that appear to have supported a windbreak 7m long. This appears to have been a pottery firing site in which the leather hard vessels were placed into the fire-pit, fired under a layer of soil from the pits and then, after cooling, the material from the fire-pits was deposited back into the pits along with sherds of failed pots.

Cloghabreedy is a good example of a fire-pit because it has a number of elements, is a single period site without the complication of earlier or later features and was well excavated and published. However, where fire-pits lack associated pot sherds or windbreaks or are separated from these features by later elements recognition becomes more difficult. The conclusion is that using the insights being gained at the UCD Centre for Experimental Archaeology it will be easier in future to identify the firing sites of the prehistoric pottery industry.

References

Ó Faoláin, S. and Northover, J.P.  1998. The Technology of Late Bronze Age Sword Production in Ireland, The Journal of Irish Archaeology, Vol. 9 (1998), pp. 69-88

About the author

Dr. Charles Mount has been involved in research on the Irish Bronze Age for more than twenty years and carried out his post-graduate and doctoral research on the period. Since then he has published extensively on the burials, monuments and artefacts of the period. This blog post is partly based on research he is preparing for a book on the period. You can learn more about Charles Mount’s publications here.

Cite this post as:

Mount, C. Identifying pottery fire-pits in the archaeological record. The Charles Mount Blog, 9 May 2012. http://charles-mount.ie/wp/?p=825.

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