Prepared-core technique

The prepared-core technique is means of producing stone tools by first preparing common stone cores that can then be shaped into the desired implement.

Although there had been different types of tools created prior to this technique, mostly that of handaxes and cleavers, this new technique was a great advancement for early man. Believed roughly to have been first used 200,000 years ago this technique involved a removal of flakes from a piece of stone to achieve desired shape and thickness. The use of this technique is believed to be a significant change in culture and shows an increasing growth of cognitive ability, as one that is using this method must be able to imagine the end product and maintain that image while conditioning the stone to the desired shape and end result tool.

Centripetal or radial core reduction technology encompasses a substantial range of archaeological variability, using pieces of raw material with natural convexities just as well as heavily prepared centripetal cores. The technique is defined by the characteristic direction of percussion from the perimeter of the core towards the centre, hence the term "centripetal". The perimeter of the circular to oval-shaped core served as a platform for striking off flakes, blades and points, which further shaped the face of detachment.

Several technological criteria characterise the definition of the centripetal cores.

Centripetal core reduction techniques are found in most Middle Paleolithic assemblages known from Africa and Eurasia. There are a number of different methods of technological actions involving centripetal core reduction, the most extensively documented of which is the so-called "Levallois" technology.

The recognition of Levallois as a distinct core reduction strategy dates to the late 19th Century. The term was used to describe specific flakes with certain surface attributes that were recovered during that period in northern France. These early descriptions were purely typological and based on the morphology of the flake products themselves. However, there was never a great deal of consensus among scholars, which typological attributes could be used to identify Levallois products. Gradually, more and more emphasis was put on the idea that Levallois flakes were the products of a particular method or process of production. Indeed, F. Bordes emphasised that Levallois was essentially a method and not a particular product. However, the shape and character of a Levallois blank is also thought to be "predetermined" by the elaborate Levallois core preparation process . While a shape control system undoubtedly exists for the Levallois cores, there remain a number of significant problems. Indeed, how applied force will propagate through a specific core is determined by a number of variables and not only by the will or the desire of the Middle Palaeolithic flintknapper. Fracture mechanic variables include size, shape and internal structure of a particular flint nodule, but also the mass and resilience of the hammer stone and finally the angle and force of the blow and the shape of the core's striking platform. Given the imprecision of hand-eye co-ordination , a rather high probability for only partial core reduction success is very real. Not only are there a number of significant problems with defining Levallois on the basis of predetermined blanks, but there is also considerable disagreement over what set of attributes should be used to characterise a Levallois product. Furthermore, it has also been demonstrated that very different core reduction strategies can produce seemingly diagnostic Levallois blanks.

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