标题：El sílex en su contexto geológico: Un corpus de datos para el Pirineo centro-oriental [Chert in its geological context: A data corpus for the central-eastern Pyrenees]
摘要：Chert in its geological context: A data corpus for the central-eastern PyreneesThe analysis of lithic raw materials from an archaeopetrological perspective is essential if the aim is to better understand human groups who used this resource. Archaeopetrology considers lithic tools as natural and cultural remains, taking into account both natural (e.g. petrographical, micropaleontological, and geochemical) and cultural (e.g. technological, typological and traceological) aspects.We have focused our attention in the Pyrenees Mountain Range, as a specific geographical space, strategic by its location and understood long time ago as a barrier and now as a place of human interaction. This research area is an ideal location for the analysis of lithic raw materials.The Pyrenees correspond to the portion of the Pyrenean chain that extends between the Gulf of Lion and the Bay of Biscay. From North to South three major areas have been identified: the Norpyrenean Zone, the Axial Zone and the Basque Massif and Southpyrenean Zone (Vera, 2004) (Figure 1). For this study, we have analyzed the geological formations with chert located in the Central-Eastern Pyrenees.To achieve our goals, first we consulted the existing geological mapping, to see what formations included chert. Having detected the areas potentially containing chert, a series of field surveys took place. The goal was to detect and describe outcrops and proceed to sampling chert for latter characterize them at the laboratory. To accomplish this research at the laboratory, petroarchaeological methods were applied. These methods use descriptions and classifications from the natural sciences, such as petrology, to characterise, define and name rocks used by past societies. Initially a petroarchaeological characterisation of more than 300 chert evidences recovered from up to 75 outcrops was undertaken. This characterization was done in terms of two scales of analyses. First, a macroscopic examination of the entire set was carried out using a binocular microscope. Afterwards, a petrographic and micropaleontological characterization of those materials was performed by analysing them in thin sections.As a result of the fieldwork carried out, a total of 20 geological formations containing chert were identified: 10 outcropping in the Northern Pyrenean slopes and 10 in the Southern Pyrenean slopes. As it has been said, more than 300 chert evidences recovered from up to 75 outcrops were analyzed, obtaining the results we present below.In this paper we present the 20 geological formations with chert outcropping in the Central-Eastern Pyrenees. The textural, petrographic and micropaleontological analysis of these cherts has allowed us to document different siliceous varieties with a variable knapping aptitude.According to their special features and appearance in the archaeological record of distant sites, two long distance tracers have been identified. These are the Agua-Salenz Formation cherts and the Nankin Formation cherts. Both silicifations possess distinctive features allowing us to define strong differences from a macroscopic point of view (inclusions and micropaleontological content). The presence of these cherts in several archaeological sites located at more than 200 km away from the outcropping area is indicating a long distance exchange (e.g. Agua-Salenz cherts in Belvis Cave or Nankin cherts in Parco Cave) (Sánchez 2015). Consequently, these cherts of the Agua-Salenz Formation and the Nankin Formation can be interpreted as examples of long distance tracers for the Central-Eastern Pyrenees.To conclude, in this study are described the geological formations with chert documented in the Central-Eastern Pyrenees. This data corpus is a helpful tool for other researchers interested in lithic raw materials procurement.
