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.

History of prepared-core processing

First evidence

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.

Geographical spread

Methods for reducing cores

Centripetal core reduction

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.
* The primary reduction surface is shaped such that the morphology of the product is a function of the lateral and distal of the surface, which serve to guide the shock wave of each flake.
* Centripetally worked cores may possess either one or two faces of detachment and striking platforms can vary from unprepared, cortical to faceted "chapeaux de gendarme" shapes.
* Centripetally-reduced cores were made via hard hammer percussion, which was probably necessary when attempting to work steep platform angles.

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.

Levallois Core Reduction

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 .

The fact of the matter is that the "Levallois" Method is a term, which has a different meaning according to context. The "Levallois" Method concerns the productivity of a Levallois surface, which can be exploited according to a "lineal" or "preferential" method with the production of a single "Levallois" product, or which can be exploited according to a recurrent method with the production of several "Levallois" products. The lineal or preferential Levallois method corresponds best to the classic definition of "Levallois" . The recurrent "Levallois" method can be unipolar, with only one striking platform, bipolar, with opposed striking platforms, or centripetal, with two or more adjacent striking platforms. The unipolar, bipolar or centripetal recurrent "Levallois" technique is marked by the detachment of a series of large "Levallois" flakes, such that the preceding removals ready the surface for the subsequent ones, thus eliminating the need for extensive repreparation. The centripetal recurrent "Levallois" technique also includes pseudo-"Levallois" points and sometimes side-struck pieces as well. In some contexts, on the other hand, the "Levallois" Method denotes the specific organisation of scars and ridges on a "Levallois" surface, with one method focusing on the production of flakes and the other method focussing on the production of points. Contrary to Boëda , Van Peer further concludes that the recurrent bipolar and centripetal "Levallois" methods do not exist. Only the notion of one preferential striking platform is the most essential characteristic of the true "Levallois" reduction strategy. Van Peer also claims that a separate "Levallois" method for blade reduction does not exist either.

There are thus serious problems and implications of the now widely accepted processual definition of the "Levallois" method . The presence of the "Levallois" criteria on a blank or a core do no longer necessarily guarantee the real "Levallois" character of a specific core reduction. So, we should not only study flakes and cores, since blanks and cores cannot be identified as "Levallois" by their own morphology. We should thus also try to reconstruct the dynamic reduction process by refitting. However, many Middle Palaeolithic assemblages do not allow these extensive reconstructions. So, analysis based on discarded cores and flakes can be problematic, since most of the flaking patterns that preceded a core's discard are simply not observable on them. But, if we cannot be sure of the status of a seemingly diagnostic "Levallois" product, can we then be sure of the "Levallois" or non-"Levallois" intent of the core reduction process? The centripetal or radial core reduction scheme, which is used in this study, functions independently of the other characteristics, which define the "Levallois" method. In "Levallois" and non-"Levallois" centripetal core reduction, flakes are struck from the perimeter of the core towards the centre. This is the only attribute, which both reduction strategies have in common. Three major variants within the centripetal core reduction strategy are distinguished: (1) unipolar [one striking platform] , (2) bipolar [two opposed striking platforms] and (3) centripetal [two or more adjacent striking platforms] . The preparation of these cores is thus always centripetal. However, the removal of the major flakes can be unipolar, bipolar or centripetal. The term "Levallois" only refers to specimens, which clearly bear evidence of the production of a limited number of large central-positioned flakes on the core, which have been struck off from individual proximal striking platforms, and which were usually prepared several times. "Levallois" thus only refers to preferential or linear (recurrent or not) centripetal core reduction. Only a very small percentage of the centripetal cores and flakes will thus be classified as true "Levallois" products, by virtue of the presence of a single flake scar covering more than 60% of the reduction surface . Core reduction strategies are by necessity dynamic processes, since they must manage an ever-decreasing amount of raw material. Variability in centripetal core reduction strategies can be explained by dynamic adjustments made during the process of core reduction. Indeed, flintknappers always had to respond to the often-unpredictable nature of stone fracture.

References

#Bringmans, P.M.M.A., Vermeersch, P.M., Gullentops, F., Groenendijk, A.J., Meijs, E.P.M., de Warrimont, J.-P. & Cordy, J.-M. 2003. Preliminary Excavation Report on the Middle Palaeolithic Valley Settlements at Veldwezelt-Hezerwater (prov. of Limburg). Archeologie in Vlaanderen - Archaeology in Flanders 1999/2000 VII: 9-30.

#Bringmans, P.M.M.A., Vermeersch, P.M., Groenendijk, A.J., Meijs, E.P.M., de Warrimont, J.-P. & Gullentops, F. 2004. The Late Saalian Middle Palaeolithic "Lower-Sites" at Veldwezelt-Hezerwater (Limburg - Belgium). In: Le Secrétariat du Congrès (eds), Acts of the XIVth UISPP Congress, University of Liège, Belgium. September 2-8, 2001. Section 5: The Middle Palaeolithic. Oxford. British Archaeological Reports (BAR) International Series 1239: 187-195.