Chemical characterisation of cherts from the valley of Serpis river (Alcoy, Alicante) for archaeological purpose

Mobility range and territorial control are central questions for Archaeology in the study of human groups’ life during Prehistoric Ages. A key point to get to grips with this set of problems is to understand the dynamics of supply of natural resources such as food and raw materials. Thus, the identification of the outcrops of chert and their characterisation is essential, due to the use of this particular rock as raw material for the production of several different tools. Since the nakedeye description of stone characters (colour, translucency, presence of carbonatation or patina, etc.) often lacks to identify different outcrops and to determine the provenance of a sample, in the last decades, scientists have tried to develop methods to improve the characterisation of this rock from the chemical, mineralogical and petrographic point of view [1,2]. This contribution shows the study of some chert varieties which were widely used since the Paleolithic by the inhabitants of the valley of Serpis river [3], in the southern part of the Valencian Community. Forty-three samples of Serrat, Mariola and Serreta chert were collected from different kinds of outcrops: from the wall rock, and from fluvial and colluvial deposits. The cortex or crust and the nucleus of each sample were mechanically separated and individually analysed to control the variability caused by the amount of cortex and consequently to develop a methodological approach that permits to identify different chert sources in a restricted area. For this purpose, Xray fluorescence and Inductively coupled plasma mass spectrometry analyses have been carried out to determine major elements, trace elements and rare earth elements [4] of cherts affected by different depositional and post-depositional conditions. [1] Luedtke, An Archaeologist's Guide to Chert and Flint (1992) 172. [2] Skarpelis et al., J. Archaeolog. Sci.: Rep. 12 (2017) 819. [3] Molina Hernández, El sílex del Prebético y cuencas neógenas en Alicante y sur de Valencia :su caracterización y estudio aplicado al Paleolítico Medio, tesis doctoral (2015) 902. [4] Murray, Sediment. Geol. 90 (1994) 213.