Veerle Rots

Wear Traces and the Interpretation of Stone Tools

Abstract Hafting traces integrated within a larger functional analysis can be used to improve our understanding of the dynamic life cycle of a stone tool. Based on the analysis of hide scrapers from the Magdalenian site of Verberie, France, the potential of research that considers macroscopic and microscopic traces from different causes (e.g., production, use, manual grasping, and hafting) is demonstrated. Hafting traces can throw light on a tool’s use and hafting mode, but also on its morphology and reasons for discard, among other things. Most importantly, the principles necessary to analyze experimental hafting traces are shown to be useful for interpreting archaeological hafting modes.

Making Sense of Residues on Flaked Stone Artefacts: Learning from Blind Tests

Residue analysis has become a frequently applied method for identifying prehistoric stone tool use. Residues adhering to the stone tool with varying frequencies are interpreted as being the result of an intentional contact with the worked material during use. Yet, other processes during the life cycle of a stone tool or after deposition may leave residues and these residues may potentially lead to misinterpretations. We present a blind test that was designed to examine this issue. Results confirm that production, retouch, prehension, hafting, various incidental contacts during use and deposition may lead to residue depositions that significantly affect the accurateness of identifications of tool-use. All currently applied residue approaches are concerned. We therefore argue for a closer interaction with independent wear studies and a step-wise procedure in which a low magnification of wear traces is used as a first step for selecting potentially used flakes in archaeological contexts. In addition, residue concentrations on a tool’s edge should be sufficiently dense before linking them with use.

Residue and microwear analyses of the stone artifacts from Schöningen.

Stone artifacts from Schöningen 12 and 13 were examined microscopically to identify residues, wear, and manufacturing traces in order to clarify their possible anthropogenic origins and their function. We present evidence showing that the stone tools were used for working wood and hide and for cutting meat. The results from the use-wear and residue analyses proved complementary in several instances. Suggestive evidence of hafting was observed on a few pieces, which is particularly interesting given the identification of wooden hafts at the site. The positive results of this analysis demonstrate the efficacy and potential of these techniques for Lower Paleolithic sites such as Schöningen.

Pressure flaking to serrate bifacial points for the hunt during the MIS5 at Sibudu Cave (South Africa)

Projectile technology is considered to appear early in the southern African Middle Stone Age (MSA) and the rich and high resolution MSA sequence of Sibudu Cave in KwaZulu-Natal has provided many new insights about the use and hafting of various projectile forms. We present the results of a functional and technological analysis on a series of unpublished serrated bifacial points recently recovered from the basal deposits of Sibudu Cave. These serrated tools, which only find equivalents in the neighbouring site of Umhlatuzana, precede the Still Bay techno-complex and are older than 77 ka BP. Independent residue and use-wear analyses were performed in a phased procedure involving two separate analysts, which allowed the engagement between two separate lines of functional evidence. Thanks to the excellent preservation at Sibudu Cave, a wide range of animal, plant and mineral residues were observed in direct relation with diagnostic wear patterns. The combination of technological, wear and residue evidence allowed us to confirm that the serration was manufactured with bone compressors and that the serrated points were mounted with a composite adhesive as the tips of projectiles used in hunting activities. The suite of technological and functional data pushes back the evidence for the use of pressure flaking during the MSA and highlights the diversity of the technical innovations adopted by southern African MSA populations. We suggest the serrated points from the stratigraphic units Adam to Darya of Sibudu illustrate one important technological adaptation of the southern African MSA and provide another example of the variability of MSA bifacial technologies.

Projectiles and Hafting Technology

Stone tool hafting has always been considered important, but its interpretative potential has not yet been sufficiently recognized. While wear studies have recently demonstrated the possibility of deriving hafting data from the stone tools themselves, it is essential that these kinds of data are now also integrated with regard to armature identifications. New experiments with spears and arrows show that armature identifications are complex and that no single feature on its own is diagnostic of projectile impact. Also the distinction between different projecting modes is still seriously hampered by the lack of a reliable reference. It is argued that hafting wear is essential for more adequate identifications of armatures and their projecting mode. The analysis of a number of archaeological Middle Palaeolithic and Late Palaeolithic assemblages in North West Europe allowed identifying the existence of hafted spear points for the Middle Palaeolithic sites and arrows armed with tips and barbs for the Late Palaeolithic sites.

The Middle Holocene Shell Mound of el Gouna on the Red Sea (Egypt)

Abstract In the El Gouna (Hurghada) area on the Red Sea of Egypt, a Middle Holocene shell mound from around 5800 B.P. (uncalibrated radiocarbon years before A.D. 1950) has been tested by a restricted excavation. Collection of shellfish on the Red Sea shore provided subsistence opportunities for Middle Holocene groups coeval with the Early Predynastic Tasian of the Nile Valley. The El Gouna site demonstrates for the first time that prehistoric shell mounds exist near the Egyptian Red Sea shore.

Extracting residues from stone tools for optical analysis: towards an experiment-based protocol

The identification of residues is traditionally based on the distinctive morphologies of the residue fragments by means of light microscopy. Most residue fragments are amorphous, in the sense that they lack distinguishing shapes or easily visible structures under reflected light microscopy. Amorphous residues can only be identified by using transmitted light microscopy, which requires the extraction of residues from the tool’s surface. Residues are usually extracted with a pipette or an ultrasonic bath in combination with distilled water. However, a number of researchers avoid residue extraction because it is unclear whether current extraction techniques are representative for the use-related residue that adheres to a flaked stone tool. In this paper, we aim at resolving these methodological uncertainties by critically evaluating current extraction methodologies. Attention is focused on the variation in residue types, their causes of deposition and their adhesion and on the most successful technique for extracting a range of residue types from the stone tool surface. Based on an experimental reference sample in flint, we argue that a stepwise extraction protocol is most successful in providing representative residue extractions and in preventing damage, destruction or loss of residue.

Alla ricerca di una metodologia comune: analisi delle tracce d’impatto dei manufatti litici provenienti da Riparo Villabruna (Belluno – Italia)

Looking for a standard method: impact fractures analysis of the lithic materials from Riparo Villabruna (Belluno – Italy) We present here a macro fractures analysis of the lithic material from Riparo Villabruna (Belluno - Italy) with a new methodology, making use of a large reference collection, in order to find projectile points.

Breakage, scarring, scratches and explosions: understanding impact trace formation on quartz

Quartz projectiles have received attention in the recent years due to, for instance, their discovery at prominent South African Middle Stone Age sites. However, very few methodological studies have been dedicated to quartz armatures and the ones published so far are not built on an understanding of the particular behaviour of quartz under mechanical stress. Here, we investigate impact damage formation on automorphic and xenomorphic quartz (crystal quartz and vein quartz) through the microscopic analysis of 91 experimental armatures using a combination of low and high magnifications and SEM. Our results show that the structural properties of quartz affect the attributes of impact breaks and other damage. We also examine wear patterns on three different types of projectiles and offer preliminary guidelines for identifying them in archaeological assemblages. We argue that while quartz assemblages withhold significant potential for understanding past hunting technologies, the methods used for identifying and interpreting quartz projectiles need to be adjusted so that they take into account the notable differences between the macrocrystalline and cryptocrystalline varieties of this raw material.

Correction: Making Sense of Residues on Flaked Stone Artefacts: Learning from Blind Tests

[This corrects the article DOI: 10.1371/journal.pone.0150437.].