(C) Historic Buildings & Monuments Commission for England.

Introduction

Ecton Hill, Derbyshire (NGR SK 09 58) has been known and mined for its relatively rich copper mineralisation from the Bronze Age (PDNPA 1998), with exploration reaching a peak in the 18th- and 19th-centuries AD before final closure in the 1880s.

Research is currently being undertaken to investigate the utilisation of local resources during the Bronze Age, and a geophysical survey was requested to try to find evidence of surface activity in the form of small smelting furnaces associated with the ore extraction.

Two areas were suitable for survey (see Figure 1), both on a local geology of Lower Carboniferous Limestone overlain by a thin layer of topsoil.

Method

Two Geoscan FM36 magnetometers were used to collect magnetic data at 0.25m intervals from survey lines separated by 1m within grids of 30m squares (see Figure 1). The grids were set out so that traverses could be made perpendicular to the steeply sloping sides of the hill. Magnetometry was considered to be the method most suitable for the survey on account of its ability to detect the thermoremanent signature expected of industrial features.

Results

Figure 2 shows greyscale and trace plots of the data collected from both areas, with a diagrammatic interpretation for each.

Area 1

Very little archaeological activity is revealed in either area, but Area 1 does show some magnetic variations which may be of archaeological interest. Two possible pit-like anomalies (approx 6nT) are present, one of which may be associated with a faint circular anomaly. A trackway has been detected, but other apparently linear anomalies parallel to the traverses must be explained by an accidental misalignment of the fluxgate sensors.

Also present are several anomalies which may be indicative of industrial activity connected with mine workings. The largest of these (A and B on Figure 2), are shown on Figure 3: they are both of diameter approximately 3.5m, with response strengths of 92.75nT and 101.5nT. For comparison, Figure 3 also illustrates the responses from probable and known pottery kilns which have strengths of 112nT (New Forest) and 70-350nT (Nuneham Courtenay). Although the sizes of anomaly in the latter cases are comparable to A and B their shapes are different: A and B have a prominent negative portion and show sharp changes over a single traverse. The kilns show a smoother response with a comparatively small associated negative deflection. This suggests that the anomalies found at Ecton do not originate from an intense heating of natural local materials as would be used for a small smelting furnace or kiln. The sharp responses of A and B are more usually attributed to the presence of ferrous metals. Another point to note is that the negative deflections are to the south, which suggests a dipolar source is present.

Although the results therefore do not indicate the presence of burnt features, the location of Anomaly B is coincidental with the end of a natural gully leading to the head of a blocked pipe working (see Figure 1).

Area 2

The data collected from Area 2 shows only general areas of disturbance; to the north, variation is caused by buried materials associated with the adjacent former engine house, and to the south more subtle variations may be due to irregularities caused by outcropping rock.

Conclusions

The steep slopes, irregular ground surface and the prevailing weather conditions made surveying at Ecton very awkward and have undoubtedly prejudiced the data obtained. Several anomalies have been located but none can be certainly linked with any prehistoric mining or processing activities.

E. Bray
T. Horsley

E. Bray Date of Report: 21/9/98

References

Barnatt, J., Rieuwerts, J., and Haddon Thomas, G., 1997. Early Use of Gunpowder in the Peak district: Stone Quarry Mine and Dutchman Level, Ecton, Derbyshire, Mining History: The Bulletin of the Peak District Mines Historical Society, Vol. 13 , No. 4 (Winter), p25.

Peak District National Park Authority News, 20th April 1998. "4000 Year Old Antler Digs up Bronze Age Copper Mine". Code 04:98/99.

List of Figures

Figure 1 Location of the survey grids

Figure 2 Magnetic data

Figure 3 Detail and comparison of magnetic anomalies