Thursday, November 6, 2008

A flint mine at Grimes Graves. Material for a new shaft was back-filled into a disused one. Exhausted galleries were also backfilled. The freshly mined flint was hauled to the surface where it was roughed-out into the shape of required implements. (Tracey Croft)

About 160 filled-in flint mine shafts can be seen in this aerial view of Harrow Hill, Sussex. The rectangular enclosure was used in the Iron Age for cattle slaughtering. (Cambridge University)

Plan of the galleries at Pit No. 2, Grimes Graves (Norfolk), ranged round the central access shaft. The position of deer antlers used in mining have been indicated. (Source: Armstrong, 1926)

Flint was used for making axes and other implements. Whilst the raw material can frequently be found lying on the hillside or seashore in southern Britain and north-eastern Ireland, and was at first used for axe manufacture, it is usually of poor quality due to frostfracturing, and the lumps often too small to make the sort of tools required. The best rock lies buried in seams often 5–15 m. (5.5–16.4 yd) deep which formed in the upper chalk, so mines were developed to extract it (fig. 13). When agriculture reached western Europe flint mines were quickly developed in France, Belgium, the Netherlands and Denmark. In England at least a dozen mining sites are known from Sussex (Harrow Hill (plate 10), Cissbury) and Wessex (Easton Down) to the Chilterns (Pitstone) and East Anglia (Grimes Graves). A possible site has also been located at Ballygalley in County Antrim. Radiocarbon dating shows that the earliest mines were in Sussex and must be contemporary with the first agriculturalists from 3100 to 2700 bc. The East Anglian mines at Grimes Graves span the period 2300 bc to 1600 bc with the greatest activity between 2000 and 1800 bc. One wonders how people knew that there was flint buried deep in the chalk. It can of course be seen outcropping in the cliffs at the seaside, and may have been encountered when ditches were dug for earthworks.

Archaeological excavations were recently carried out at Grimes Graves in Norfolk and the mines are typical. In a number of places the flint outcropped in narrow bands and could be quarried by opencast working which might involve only a few days’ digging. Where the seams of flint dipped deeper into the chalk, shafts had to be sunk from above. There are more than 340 of these deep shafts close together at the site. They are from 5 to 12 m. (5.5 to 13 yd) in diameter and can be as much 15 m. (16.4 yd) deep, depending on the depth of the best seam of flint. The stone occurs in three bands; the upper two known as the topstone and wallstone are fragmentary nodules and were not usually of much interest to the miners who made for the lowest layer, the floorstone. This seam is 5 to 10 cm. (2 to 4 in) thick.

Using pickaxes of red deer antler and shovels made of ox shoulder blades or shaped pieces of wood, the miners dug down until they reached the floorstone. Access would have been by ladder. Sometimes if the shaft was deep they inserted a platform about half-way down, enabling miners to descend in two stages. Occasionally small galleries might be dug to retrieve the wallstone if it seemed worthwhile but normally it was only at floorstone level that a series of galleries radiated out from the base of the shaft. These could be as much as 2 m. (6.6 ft) wide and 1.5 m. (5 ft) high at first. From these, smaller tunnels, less than a metre high, penetrated about 5 m. (5.5 yd) from the foot of the shaft. Often the galleries of one mine communicated with those of an adjoining abandoned shaft, the whole area being honeycombed with hundreds of tunnels. The miners worked lying on their sides in the galleries, removing the chalk with their picks and levering out the blocks of flint which lay buried beneath them. They passed the material back down the tunnel and other workers removed it into baskets which could be hauled to the top of the shafts. Galleries and shafts already cleared were back-filled with rubble. The galleries would have been hot and stuffy with limited air supply. Although we have no evidence for this, the miners must have worn protective clothing, especially for the hands, since the flint is razor sharp and the chalk very abrasive. Lamps, made by hollowing out a block of chalk and filling it with animal fat, have been found in a number of British mines, though not at Grimes Graves. It is possible that daylight reflected from the white walls was sufficient when the miners’ eyes became accustomed to it, providing the galleries were not too long. In the Sussex mines, where soot marks have been found on the roofs and ashes on the floor, faggots or tapers were also used for lighting.

It is likely that about a dozen men worked at each mine. A new shaft was dug every one or two years, though the actual digging time may have been only about two months. An average mine produced a total of around 45 tonnes (44.3 tons) of flint. This would have been roughly trimmed and shaped close to the top of the shaft. The rough-outs were then transported to would-be customers who we imagine were responsible for shaping the finished tools. These would include not only axes but adzes, arrowheads, scrapers, knives and sickles. Men engaged in mining may have had little time for agriculture unless the quarrying was carried out after the harvest. Perhaps they exchanged their flint for a large part of their food supply?


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