Cymraeg / English

	Back Home
	Projects index

Cwm Mawr Axe Factory, Hyssington
Archaeological Survey and Excavation 2007

Introduction

A programme of survey and trial excavation has now been completed in an attempt to confirm the source of the Group XII Bronze Age battle axes and axe hammers which have been found in Wales and the Marches. The axes are made from a distinct rock type known as picrite which is has a very limited distribution, with one of the known outcrops being a small hill near Cwm Mawr, just to the north-west of the village of Hyssington in eastern Montgomeryshire.

Cwm Mawr

Right: Cwm Mawr - the picrite outcrop occupies the hill in the foreground. Photo CPAT 00-c-0037

The Cwm Mawr area was first suggested as a potential source for the axes following a study in the 1950s, the results of which were published in a paper by Shotton, Chitty and Seaby in the Proceedings of the Prehistoric Society in 1951. They identified a number of likely rock sources around the hill, including a small quarry, and concluded that the site 'clearly calls for excavation'. Since the 1950s other products from the axe factory have been found over a wide distribution and a number of other local features such as picrite outcrops, boulders, and small quarries have been recorded.

The present project was undertaken with funding from Cadw in an attempt to define the extent of prehistoric workings and assess their potential, as well as considering their future management.

Field Survey

Cwm Mawr axe hammer and battle axe
(and a 50 pence piece)

Cwm Mawr

A programme of systematic field survey was undertaken covering the area of the picrite outcrop (c. 30ha) to identify and record those sites already thought to be potentially associated with the axe factory, as well as prospecting for further potential sites. At an early stage it became clear that not all of the potential sites were outcrops of picrite, as some small-scale quarries had also been recorded on an adjacent hill where the geology is dolorite. However, several small quarries and outcrops were confirmed within the area where picrite had been identified by the Geological Survey. Each of the sites was assessed and two areas were then selected for geophysical survey.

Geophysical Survey

Geophysics

Carrying out the magnetometer survey within the quarry on the south-east side of the hill

A limited programme of magnetometer survey was undertaken adjacent to two small quarries, one on the north side of the hill, and the other on the south-east side. The gradiometer has an on-board data logging device which enables readings to be taken at specific time intervals. These readings can then be correlated with geographical locations. Readings were taken along parallel traverses of a 20m by 20m grid, with a traverse interval of 1m. The speed of each traverse was controlled such that readings will be taken every 0.5m, thereby giving a total number of 800 readings per full grid. The survey grids were laid out and then located in relation to nearby field boundaries by total station surveying, using a digital laser theodolite.

It had been hoped that the surveys might provide some indication of occupation and activity, possibly identifying hearths or areas where the rock had been quarried using a technique known as 'fire-setting', where an outcrop is heated and then rapidly cooled with water, causing cracking. However, neither of the surveys produced any evidence which could help to target trial trenching.

Trial Excavations

Right: The small quarry on the south-east side of the hill. Photo CPAT 2485-026

A programme of small-scale, hand-excavated trial trenching was carried out in September 2007 to investigate three sites on the south-eastern side of the hill, including the small quarry which had been highlighted in the 1950s as a potential stone source. The quarry measures 11m by 8m overall and has a number of picrite boulders visible in the base, possibly resulting from later field clearance. A single trench was opened within the quarry which revealed a mass of voided stone filling the quarry base. It soon became clear, however, that the task in hand was beyond the limited resources available at this time and work concentrated instead on two small features 35m to the south-east, which had the appearance of quarry scoops.

quarry scoop

Left: One of the small quarry scoops. Photo CPAT 2485-047

In both cases an outcrop of picrite was visible, below which was a small, oval platform, the appearance of which suggested that spoil could have been removed from the outcrop and deposited downslope. The removal of the topsoil appeared to confirm the initial impressions in both trenches, after which excavations only proceeded in one trench. This revealed an outcrop 0.9m high, which had been fractured as a result of natural weathering and this appeared to have been exploited to extract stone. It is possible that the natural cracks in the rock had been expanded using wedges to separate large blocks, which had been removed. In all, the face of the small outcrop may have been moved back by at least 2m as a result of quarrying. It was interesting to note that there were a number of potentially axe-sized rocks which had been discarded in the general spoil. Unfortunately, the excavations did not produce any artefacts or other dateable material and it is therefore not possible to determine the date of the these workings.

outcrop

Right: Outcrop of picrite exploited by one of the small quarry scoops. Photo CPAT 2485-044

A programme of detailed topographical survey was also undertaken to record the earthworks and setting of those features thought to be related to the axe factory. This detailed examination identified a series of small outcrops on the south-eastern side of the hill, in the area of the trial excavations, which could have been exploited by small-scale quarrying.

Conclusions