Provider: Moravian Museum, Brno, Czech Republic

TY  - JOUR
JO  - Anthropologie (Brno)
TI  - Comparative heating experiments on flint from the Côte Chalonnaise, Burgundy, France
AU  - Frick JA
AU  - Hoyer CT
AU  - Herkert K
AU  - Floss H
Y1  - 2012
VL  - 50
IS  - 3
PB  - Moravian Museum, Brno, Czech Republic
SN  - 0323-1119
SP  - 295
EP  - 321
KW  - Use of fire
KW  - Middle and Upper Palaeolithic
KW  - Flint from the argiles à Silex
KW  - Germolles
KW  - Grotte de la Verpillière I and II
KW  - Saône-et-Loire
KW  - Colour measurement
KW  - RGB values
N2  - 
N2  - During the last 50 years, heating experiments on different variations of siliceous rocks have been conducted. In the beginning, the primary focus was on North American variations, whereas varieties deriving from sites in Europe were largely disregarded. The aim of this article is to contribute to filling in some of the gaps in current knowledge through experimental heating of flint from the argiles a Silex of the Cote Chalonnaise in southern Burgundy, France. Samples of the raw material were exposed to different temperature levels for a specified time span under controlled conditions in a muffle kiln. The goal of these experiments was to define the features of raw and heated flint and to find relationships between the appearances of those features at different temperatures. Apart from global observations and characteristics occurring under the exposure to heat, we show a new comparative method concerning the colour change of the samples. Hereunto, we use the RGB-colour values of specific parts of the samples (before and after the heating) and visualise the colour change in tree-dimensional vector graphics. The results indicate that nearly all of the pieces' surfaces show a colour shift. This experimental research indicates a trichotomy of the heated material. In the lower temperature spectrum (200°C and 250°C) the pieces are nearly in the colour range of the raw pieces, the middle ones (300°C and 350°C) show a colour shift (reduction in brightness and a shift into the spectra of higher red and blue content) as well as fragmentation. In the higher temperature range (above 350°C) the pieces tend to be more greyish and are often complete disintegrated.
ER  -