These axe grinding grooves are on a boulder behind the church at Villemaur-sur-Vanne, Forêt d’Othe, Aube, France. The grooves likely date to the Neolithic period.
The boulder in this model was moved from its original position to behind the church where it now resides. The grinding grooves were first described by the famous French archaeologist Adrien de Mortillet in 1906. The boulder has 7 grooves across the top thought to be from grinding stone axes—probably made of flint—during the Neolithic period. The grooves are relatively deep and V-shaped in profile. They measure about 20-40 cm long. In contrast, the grooves in Madsen’s grinding slab are broad, shallow, and U-shaped in profile, measuring about 90-100 cm long. This suggests that very different grinding methods and techniques were used by the Neolithic axe-makers in France.
The last stage of manufacturing a stone axe during the Neolithic period was to grind it on an abrasive stone, usually sandstone. In 1983 the flintknapper and archaeologist Bo Madsen undertook experiments at the Lejre Research Center in Denmark to grinding edges and faces on thin-butted flint axe blanks . The thin-butted axes from the Danish Neolithic period were usually completely ground on both flat faces and the narrower sides. Madsen used three types of grinding to complete the axes in his experiment. Heavy grinding was achieved by securing the axe in a split-wood vise and pulling it back-and-forth across the fixed sandstone slab by two people while a third person positioned in the middle helped the movement and monitored the axe. The area above the axe was weighted with a large stone weighing 52 kg. Lighter ‘hand grinding’ involved one person pushing and pulling the axe across the fixed sandstone slab. ‘Area grinding’ was achieved with a hand-held piece of sandstone which was rubbed across the axe to sharpen the cutting edge. An experiment involving hand-grinding of a 22 cm-long flint axe blank required 11,800 strokes against the sandstone, with each stroke measuring about 50-60 cm long on average. The blank moved an estimated 6.6 km against the grinding stone, which took 5 hours and 30 minutes. The edges of the blank were not ground, and final sharpening was not conducted. In a second experiment using the weighted vise, a flint blank measuring 24 cm long was completely ground on both faces and edges after 10,600 80 cm-long strokes, 6.8 km of movement, and 4 hours and 30 minutes of work time. About 3.5 mm of stone was removed from the width of the blank, and 7.7 mm from the thickness, with a loss of 6-15% of the axe’s original weight. From these experiments, and two others, Madsen concluded that a medium-sized thin-butted axe could be ground in one day’s work, with breaks for rest. Less time was necessary to grind finely-flaked blanks with shallower flake scars than coarser blanks with deeper flake scars. Madsen concluded that it would be easier to made an entirely new finely-flaked axe blank (which takes him about 2 hours) than to grind a coarsely-flaked blank—assuming flint was abundantly available. His experiments created two long grooves in the sandstone slab he was using.