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The Sant Genís Formation is located in the NE of the Iberian Peninsula (Catalonia, Spain) and is dated to the Priabonian (upper Eocene), being part of the evaporitic formations of the margin of the Ebro Basin. It is formed by a succession of sandy lutites, occasional limestone layers, marls, and local stratified gypsum and cherts, including the Sant Martí de Tous chert. The Sant Martí de Tous chert type is confirmed by its abundance at specific locations within the territory (NE Iberian Peninsula). This is an important raw material procurement area, as evidenced by the presence of this chert in the main prehistoric sites of the region (e.g., Abric Romaní) and the constant discovery of new sites in the area around the Sant Genís Formation, especially from the Neolithic period onwards (e.g., Cal Sitjo, La Guinardera Nord workshop). All these features, together with the great heterogeneity of the Cenozoic evaporitic cherts, prompted us to carry out a multi-proxy characterization for obtaining a valid criterion by which to identify this chert in the archaeological record. This very heterogeneity hampers the macroscopic characterization of archaeological cherts (e.g., at Abric Romaní), but through petrographic analysis we have been able to identify their origins and, albeit to a lesser extent, their lithostratigraphic unit of provenance within the formation. The complementary mineralogical and geochemical techniques applied in this study show that, although it is difficult to establish an exact origin, through intensive sampling and criteria such as the differential presence of Fe and Ca, some differences among the siliceous varieties within a formation can be detected. [ABSTRACT FROM AUTHOR]

Ancient dental calculus research currently relies on destructive techniques whereby archeological specimens are broken down to determine their contents. Two strategies that could partly remediate a permanent loss of the original sample and enhance future analysis and reproducibility include (1) structural surface characterization through spectroscopy along with crystallographic and spectroscopic analysis of its molecular structure, and (2) surface decontamination protocols in which the efficacy of cleaning dental calculus prior to extraction is demonstrated. Dental calculus provides ancient starch research a niche where granules may be adsorbed to minerals, coated, overgrown, entrapped, and/or protected from chemical degradation. While encapsulation offers protection from degradation, it does not shield the sample's surface from contamination. The most common approach to retrieving microbotanical particles from archeological calculus has been the direct decalcification of the sample, after a cleaning stage variously consisting of immersion in water, acids, and mechanical dislodgment via gas, sonication, and/or toothbrushes. Little is known about the efficiency of these methods for a complete removal of sediment/soil and unrelated microbotanical matter. In this paper, controlled laboratory experimentation leads to chemical structural characterization and a decontamination protocol to eradicate starch granules. Several concentrations of acids, bases, and enzymes were tested at intervals to understand their potential to gelatinize and fully destroy starch granules; arriving at a procedure that effectively eradicates modern starch prior to dissolution without damaging the matrix or entrapped starch microremains. This is the first attempt at creating synthetic calculus to understand and systematically test effective decontamination protocols for ancient starch research. [ABSTRACT FROM AUTHOR]

Raw material provenance and procurement studies are an essential research line to infer landscape exploitation, mobility dynamics and territorial management among prehistoric hunter-gatherer groups. This paper proposes an original and intuitive method, the chert abundance ratio, aimed at quantifying lithic resource occurrence in the landscape while considering the geological natural factors of an area (chert-bearing formation extent, thickness, occurrence index, size and chert content). The resource availability can be statistically compared to any archaeological assemblage distribution to define the procurement strategies, whether generalist or selective, and the mobility patterns. The study area, the north-east of the Iberian Peninsula, focused in the Prades Mountains, represents a regional scenario with high chert disposal shared by several Late Upper Palaeolithic occupations. The discrimination of the procurement areas is used as a parameter for outlining the foraging radius and the territorial range, contributing to an understanding of several aspects of the settlement, such as site functions, occupation length or intensity and group size. [ABSTRACT FROM AUTHOR]

The Montmaneu Formation is located at the NE margin of the Ebro Basin (Catalonia, Spain), and is dated to the Rupelian (Lower Oligocene). It is formed by 120 m of light grey stratified limestones with bedded-nodular chert, the Panadella chert, associated with the La Segarra lacustrine system. This chert is macroscopically characterized by very fine-grained, homogeneous, opaque greenish black colors, containing bioclasts that generate mudstone-wackestone textures. Thin-sections show a micro-cryptocrystalline quartz matrix with micritic calcite, abundant charophytes, and scattered detrital quartz. These features confer excellent qualities for knapping, as attested by its suitability for manufacturing stone-tools throughout the Abric Romaní sequence (Capellades, Barcelona). The Abric Romaní rock shelter has approximately 50 m of sedimentary infilling ranging from 110 to 40 ka BP. The archaeological assemblages recovered in several levels from 50 to 55 ka BP present this chert as lithic manuports. The Panadella lithotype is scarcely exploited in most of the levels, although differential management strategies are observed. At an intra-assemblage level, there are no differences in the technical strategies for the exploitation of the Panadella chert when compared with other chert lithotypes. Diachronically, however, the Abric Romaní sequence shows a tendency of the Panadella chert to increase when complex reduction methods based on predetermination (e.g., Levallois) are dominant. As we have demonstrated by means of geoarcheological surveys, the Panadella chert was procured in primary formations, confirming the increase in the procurement radius of the Neanderthals who occupied the Abric Romaní site to about 24 km. [ABSTRACT FROM AUTHOR]