Stenalderens grubedrift

Resumé

Stone Age Mining

Almost everywhere in Denmark it was possible to obtain the most important raw material of the Stone Age, flint, either from the deposits left in Ice Age moraines or from nodules washed out by the sea from the chalk cliffs ¹). But a more rationalised exploitation of flint deposits was later adopted by Stone-Age man, and by the Dagger Period well-organised mines were in operation. They were first discovered at Skovbakken near Aalborg in North Jutland (Fig. 1) and have already been published ²). Since these first discoveries the Aalborg Historical Museum has from time to time undertaken further investigations on Skovbakken and a connected picture of the mining operations has gradually been built up.

In September 1950 excavations for a house foundation on the southern slopes of Skovbakken revealed the round mouths of mine shafts filled with chalk debris (Fig. 2) and a hurried excavation was made. Shaft 1 was the only mine fully excavated, its greatest depth being 3 meters. Its shape and layout was similar to those found in the previous excavations, but on a larger scale corresponding to the greather depth, allowing several men to work at one time.

On a layer of chalk covering the entrance to Shaft 2 was a chipping site, presumably chosen as a sheltered spot, and here the uncomfortable layers of chips had been covered with sand as they accumulated. In the sand lay several of the discarded blanks which were the chief item of manufacture on Skovbakken.

Shaft 4 was not completely emptied but was measured 2.15 ms. below the surface. At this depth, and again at a depth of 1 m. below the surface a heap of chippings was found. These do not necessarily betoken chipping sites. One may imagine that the nodules were roughly shaped after quarrying at the foot of the shaft, and that the more delicate work was done on the surface. The chips were then swept into the discarded shaft when new mines were to be opened. A chipping site was found above Shaft 4, just as above Shaft 2. It included a hearth.

Shaft 5 was 1.20 ms. in diameter at the top and reached its greatest depth in the NE gallery which descended to 3.20 ms. In the southern gallery the flint vein was still visible and a number of holes driven in to a depth of 3-4 cms. just above the flint had presumably been made by a pointed antler pick (cf. Fig. 10).

Shaft 6 was dug to a depth of 2.30 ms., at which depth the skeleton of a 3 month old pig was found.

In 1952 a further excavation was carried out on Skovbakken. All measurements given are taken from the present surface level. A trial trench showed that the original surface was very uneven with heaps of chalk lying everywhere. Not every shaft which was discovered was excavated, so that Fig. 10 gives no true picture of their closeness together.

Shaft 1 was 3.5 ms. deep and 1.7 ms. wide at the mouth. It had a poorly developed gallery system and its floor was covered with discarded flint.

Shaft 2 was 4.05 ms. deep and 1.6 ms. wide at the mouth. A chipping site Jay at the top of the shaft filling.

Shaft 3 was 3.85 ms. deep and 2.00 ms. wide at the mouth. Here too a chipping site lay at the top of the shaft going down to a depth of 1.5 ms., where a hearth was found. The deposit of chips contained 15 half-fabricated objects and two hammer stones. The galleries here broke through to the neighbouring shafts to the north and south (Fig. 11). The southern gallery was filled up to the ceiling with chalk and flint debris, showing that when one gallery was worked out it was filled up in the course of cutting another.

Shaft 4 (Fig. 14) was 4.20 ms. deep and 2.30 ms. wide at the mouth, with a chipping site at the top of the shaft filling. The galleries opened into Shafts 3 and 5 (cf. Fig. 11). Remains of the seam of flint with traces of mining from both sides at these entrances shows that the galleries were not driven for the purpose of connecting the shafts but were the result of unplanned pursuit of the veins of flint.

Shaft 5 was the northernmost and deepest, and its construction shows that the fear of collapse prevented mining further north. Digging was stopped as soon as the first flint layers were taken up at a depth of 4.70 ms., and only a single short gallery ran eastwards to Shaft 4. This shaft was the narrowest of them all.

Shaft 6 was the southernmost, where the seam of flint comes up to the surface. The shaft is one meter deep and its greatest diameter 2.90 ms.

Shaft 7 was 1.50 ms. deep and its greatest diameter 1.40 ms. The galleries were here very low, in one the last half meter being only 20 cms. high. In this shaft were found many fragments of flint nodules which could be fitted together, showing that the unusable portions of the flint were broken off immediately after mining within the actual mine shaft.

Shaft 8, 1.85 ms. deep and 2.50 ms. wide, lay 5 ms. north of Shaft 7.

It is clear that Skovbakken has been the scene of intensive and probably highly organised mining, while sporadic investigations at points one and two kms. distant suggest that the mining area stretched at least that far. The production consisted mainly of a rhombic shaped blank suited for manufacture of knife or spear blades (Fig. 4), and only one axe blank was found. Production must have far exceeded local demand and a guild of merchants would seem a prerequisite of this 3500-year-old Aalborg industry.

Sylvest Grantzau.