A tee is a basic shape used in the manufacture of stone artifacts .
Reductions are made from a larger starting piece, the core . The raw piece consists of hard, brittle , mostly very SiO 2 -rich, amorphous or very fine-grained rock , for example from rhyolite or obsidian , quartzite or silica slate as well as with flint , jasper or chalcedony also from cryptocrystalline varieties of pure quartz and sometimes also made of macrocrystalline quartz (including rock crystal). Because of their typical fracture behavior (so-called muscheliger or conchoidaler break ) can form these materials sharp edges and burrs.
The tuber (rarely a plate) is first cut, creating a fresh fracture surface (striking surface) with an acute angle to the outer surface. From this core, further tees are won with a hammer or mallet by carefully choosing the meeting point. The brittle fracture behavior of the material on the one hand causes the typical impact characteristics and on the other hand allows the shape and size of the tees to be influenced in a targeted manner.
Features of discounts
One speaks of so-called "striking features", which serve as clear criteria that the prehistoric flakes found are human products and not natural fractures. The point of impact (point of impact) on the remnant of the face and the resulting primary impact characteristics are characteristic: The energy absorbed in the rock creates a hump (bulb) on the ventral surface (the side facing the core ). The spread of the crack (actually crack propagation) creates concentric impact waves (also called wave rings or Wallner lines ) and radial rays leading away from the crack . If there are several successive cuts on a core edge, the fracture lines of the previously separated cuts can be seen on the dorsal surface (the side facing away from the core). These are called dorsal ridges and, in addition to the primary impact characteristics, are an important criterion for identifying man-made cuts.
Cut-offs can be both production waste (preparation cut-offs) and the goal of core dismantling , whereby target cuts of the Middle Paleolithic (Middle Paleolithic ) produced using the Levallois technique form a special shape with edges that are as sharp as possible. Reductions can be modified into devices by retouching the edge (see also: Prehistoric processing techniques ). As waste products, debris is created every time a stone is changed by cutting. For sizes under 1 cm, these are referred to as pleats .
Special shape: blade
In archeology , “ blade ” refers to a cut, usually made of silicate rock such as flint , which is at least twice as long as it is wide and has a regular, almost parallel edge course. Blades have been around since the Middle Paleolithic . Through a new processing technique, the creation of a guide ridge and a series-like mining along the core edges created with it , blades become the leading form of the Upper Palaeolithic .
- Joachim Hahn : Recognition and determination of stone and bone artifacts. Introduction to artifact morphology (= Archaeologica Venatoria. 10). 2nd Edition. Archaeologica Venatoria et al., Tübingen 1993, ISBN 3-921618-31-2 .
- John C. Whittacker: Flintknapping. Making and Understanding Stone Tools. University of Texas Press, Austin TX 1994, ISBN 0-292-79083-X .
- DC Waldorf: The Art of Flint knapping. 5th edition. Mound Builder Books, Branson MO 2006, ISBN 0-943917-01-8 .
- ↑ J. Hahn: Recognition and determination of stone and bone artifacts. Introduction to artifact morphology. 1991.