Lithic analysis

In archaeology, lithic analysis is the analysis of stone tools and other chipped stone artifacts using basic scientific techniques. At its most basic level, lithic analyses involve an analysis of the artifact’s morphology, the measurement of various physical attributes, and examining other visible features (such as noting the presence or absence of cortex, for example).

The term 'lithic analysis' can technically refer to the study of any anthropogenic (human-created) stone, but in its usual sense it is applied to archaeological material that was produced through lithic reduction (knapping) or ground stone. A thorough understanding of the lithic reduction and ground stone processes, in combination with the use of statistics, can allow the analyst to draw conclusions concerning the type of lithic manufacturing techniques used at a prehistoric archaeological site. These data can then be used to draw an understanding of socioeconomic and cultural organization.

The term "knapped" is synonymous with "chipped" or "struck", but is preferred by some analysts because it signifies intentionality and process. Ground stone generally refers to any tool made by a combination of flaking, pecking, pounding, grinding, drilling, and incising, and includes things such as mortars/metates, pestles (or manos), grinding slabs, hammerstones, grooved and perforated stones, axes, etc., which appear in all human cultures in some form. Among the tool types analyzed are projectile points, bifaces, unifaces, ground stone artifacts, and lithic reduction by-products (debitage) such as flakes and cores.

Materials

Stone is the one category of material which is used by (virtually) all human cultures and, for the vast majority of the human past, is the only record of human behaviour. The end of prehistory does not signify the end of stone working; stones were knapped in Medieval Europe, well into the 19th century in many parts of Europe and the Americas. Contemporary stone tool manufacturers often work stone for experimentation with past techniques or for replication.

Flint and chert are the most commonly knapped materials and are compact cryptocrystalline quartz. The difference between the two terms is colloquial, as they are geologically the same type of material. In common usage, flint may refer more often to high quality material from chalky matrix (i.e. "chalk flint" as found in Britain) and chert refers to material from limestone matrices. To avoid this, the term "silicate" may be used to describe the family of quartzes that are suitable for knapping.Fact|date=February 2007

In North America, Central America, and other places around the world, such as Turkey and New Zealand, obsidian, or volcanic glass, was also a highly sought-after material for knapping and was widely traded. This is due to the quality of the stone, the razor sharpness of edges that can be created, and the fact that it fractures in highly predictable ways.

Soapstone, or steatite, has been a popular rock for grinding and carving among many cultures worldwide. It has been used for production of such disparate items as vessels/bowls, pipes, cooking slabs, and sculptures.

Areas of study

Conventional approaches to the analysis of knapped stone can be grouped into three elementary, yet ultimately interconnected, areas of study: typological analysis, functional analysis, and technological analysis. Additional areas of study, such as geochemical analysis, have been developed in recent decades.

Typological classification

In reference to lithic analyses, typological classification is the act of artifact classification based on morphological similarities. Resultant classes include those artifacts subsumed by tool, production, and debitage categories.

The best known lithic typology is the series established by Francois Bordes (1950) for the Lower and Middle Palaeolithic of France, where sixty three types of stone tools were defined on the basis of manufacturing techniques and morphological characteristics. According to Bordes, the presence or absence of tool types, or differences in the frequency of types between assemblages, were manifestations of cultural differences between ethnic groups. Notwithstanding that there have been several re-evaluations of Bordes’ interpretation of the "ethnicity" of variations in assemblage type composition, the basic assumption that there is explanatory value in the construction of morphologically defined types of artifacts has remained. For instance, the use of typologies as indicators of chronological and/or cultural affiliations is rarely disputed and is acknowledged as an invaluable analytical tool for this purpose.

Function

Functional analysis of stone tools – a term given to a variety of approaches designed with the aim of identifying the use of a stone tool – is based on the argument that the uses to which tools were put in antiquity leave diagnostic damage and/or polish on their working edges. This type of analysis is also known as use-wear analysis

Although there are debates concerning the physics of both edge polishes and edge damage which draw on the science of tribology, modern microwear analysis usually depends on the comparisons of the edge wear of modern experimentally produced samples with archaeological and/or ethnographic tools. The ability of a microwear analyst has been tested in the past using sets of experimentally utilised tools. The mode in which these tools have been applied is unknown to the analyst before analysis. After analysis, comparison can be made between the actual use and the analyst's interpretation (this is known as "blind-testing"). The overall purpose is to provide an accurate, and precise, analytical instrument for the identification of stone tool function. It is worth noting that the precision of functional identifications may range considerably, from "scraping soft material" to "scraping fresh hide for 10 minutes" with a corresponding drop in accuracy as precision increases.

Technology

Technological analysis is concerned with the examination of the production of knapped-stone artifacts. The study of the attributes of waste products (debitage) and tools are the most important methods for the study of knapped-stone technology, backed up with experimental production. A very wide range of attributes may be used to characterize and compare assemblages to isolate (and interpret) differences across time and space in the production of stone tools.

Petrological and geochemical analysis

Petrological and geochemical analysis can be useful in identifying the sources of lithics and assist in establishing trade and migration routes. Methods used are typical of those used in geologic research, such as petrographic thin section analysis, neutron activation analysis, stable isotope analysis, and X-ray fluorescence.