This flint ‘livre de beurre’ blade core is from France. The core is made from Grand-Pressigny flint, which outcrops in the Loire Valley. Exceptionally long blades were struck from these cores by indirect percussion. The blades were used as knives and were traded extensively across Europe. The peak of production at the quarries occurred ca. 4450-4650 BP, during the Neolithic period.
The core in this model measures about 22 cm long, and was discarded at the end of its productive life. One large blade was removed from the reworked core face. The platform end of the core appears to have been flaked after the removal of the long blade, perhaps to re-prepare the core for more removals, but the core was abandoned.
The Neolithic period in the Near East and Europe saw the emergence of a blade industry focused on manufacturing extremely long blades, up to about 40 cm long. These blades have been discovered in burials and caches dating from about 4000 to 7000 BP. They appear to have originated in northwestern Greece and spread to production centres in Syria, Sardinia, Bulgaria, France, and Portugal. The flintknappers in these production centres produced similar long blades, but by different methods. Long blades persisted into the Chalcolithic in some regions.
One of the production centres for long blades was at the Grand-Pressigny flint source in France. The cores found there are called ‘livre de beurre’ because local farmers thought they resembled a ‘pound of butter’. The peak of production was about 4450-4650 BP at Grand-Pressigny. Blades from this source are found in large numbers on French Neolithic sites but were also traded to Switzerland, Germany, Belgium, and Holland. The ‘La Creusette’ cache of about 138 blades from the Grand-Pressigny workshops was discovered in France in 1970. The blades measure from 25 to 38 cm long. They were not from one reduction event—if this were the case, the blades should conjoin (fit back together), but few of them do. Rather, they are part of an original production of between 500 and 800 blades struck from between 50 and 80 cores, representing from 1 to 2 months of work by one flintknapper. This gives some indication of the scale of the trade in these items. One archaeologist estimated that 750,000 long blades were made at Grand-Pressigny.
Grand-Pressigny flint occurs abundantly as slabs of honey-coloured stone from 30-100 cm long. Initial reduction involved preparing a boat-shaped bifacial core measuring up to 38 cm long, 15 cm wide, and 9 cm thick. It was made by hard-hammer percussion. A domed surface was prepared on one face, and the opposite face was minimally flaked, with blades struck lengthwise down the domed face. To do this, a special platform was prepared at one end. This involved careful flaking to produce a dihedral surface with the ridge oriented in line with the central mass down the centre of the core face. The platform surface was oriented at about 80-85º to the face, so at nearly a right angle. The apex of this ridge was lightly pecked to create a crushed zone measuring about 7 mm long and 2 mm wide. Pecking roughened the surface and embedded microcracks; when the platform was struck, one of these microcracks would expand to create the blade, requiring less force. Blades were detached by indirect percussion using soft punch.
The dorsal surface of the first blade consists of the negative scars that defined the central dome on the core face. The core at this point was marked by a single scar down its length. The second blade was detached down one of the arrises bounding one side of that initial scar, and the third blade was detached down the arris bounding the other side. The dorsal surfaces of these two blades are marked by negative scars on one side from the core preparation, and the long negative scar from the previous blade detachment on the other side. The next blade was detached down the long arris created by the prior two removals; this blade has a triangular cross section. The platform was re-formed prior to removing each of these blades, a process that incrementally shortened the core (and the length of the blades that could be removed from it). Blade removal also flattened the core’s domed surface, so the next step involved percussion flaking along the core’s sides to re-form the dome at the middle. Reshaped cores may also retain traces of previous blade removals. Once the reshaping was completed, the knapper could remove another series of blades. The core could usually be reshaped at least twice, and from 10-12 blades might be produced from a good core.