Analyzing the Past, Part 1: lithic technologies
During and after excavation various efforts are made to describe and interpret the material remains. As has already been mentioned, these will generally be focused toward the description of the form, and the use or function of artifacts, ecofacts, and features. From this will come the interpretation of cultural processes and meaning (derived through hypothesis testing).
Perhaps the most resilient of the artifact types are stone or lithic artifacts, which are least subject to transformational processes. Also, stone tools have the longest history of all recognized human artifacts, dating back to at least 2.6 million years in East Africa. Stone tools are any stone material that has been deliberately modified by human efforts, and as such they are the product of human thought and design.
Stone tools can be initially classified by their technology; that is, how they were manufactured. The two basic types of lithic technology are:
1. Ground-stone industry: involves pecking and grinding or polishing stone.
2. Chipped-stone industry: involves fracturing or flaking stone.
Both have been found co-existing within cultures, though chipped-stone industries have a much longer history, dating back to the earliest stone tools, and are generally associated with what is called the Paleolithic (or Old Stone) Age. Ground-stone industries are much more recent in origin and tend to be associated with the Neolithic (New Stone) Age and is frequently correlated with more sedentary lifestyles and agriculture.
Ground-Stone industry
Ground-stone industries use harder, more durable stone (more heterogeneous in structure) that is less likely to flake (and hence may also be useful as hammerstones). The idea being to shape the desired tool by pecking and grinding with abrasives like sandstone (the latter akin to sharpening a blade). The stone tools produced by these techniques include axes, adzes, querns or metates, all of which were specifically required for tougher tasks, with repeated usage in mind, be it chopping wood (axes), digging (hoes) or grinding grains (metates).
Chipped-stone industry
Chipped-stone industries use the natural properties of specific types of hard, nonresilient and homogeneous stones, such as obsidian (volcanic glass), flint or chert, basalt and quartz. When struck with a hammerstone or some other implement (e.g., antler or wood) the stone or core will produce fragments or flakes, either or both of which may become the desired stone tool (or the basis for more refined tools) (see Fig. 6.1). The shape and size of the flake will vary according to the properties of the stones used, and the techniques used by the maker. Through ethnographic studies, reconstruction of cores, and experimental archaeology, the different techniques can be identified. These techniques are:
a. direct percussion: using a hammer stone to directly strike a core. (Fig.6.2a)
b. indirect percussion: using a punch (e.g., made of wood or bone) as an intermediate between the hammer stone and the core.
c. pressure flaking: using steady pressure in a small area to detach flakes off the core. (Fig.6.2b)
d. retouching: finely controlled pressure flaking on a core or flake.
The outcome of using these techniques is sharp-edged cores or flakes, which come in many different shapes and sizes for a range of potential functions. Among the more recognized forms of flakes are blades, which are long, thin, parallel-sided flakes (see Fig. 6.1). Blades frequently are the basis for a range of other tool types through the use of pressure flaking and retouching, for example, spear points.
Areas where this type of activity occurred are easy to spot, as they tend to be accumulations of discarded cores and flakes (called debitage) left over from the process of tool manufacture. The debitage will be of various sizes and shapes, and in some cases may be pieced together to make the reconstructed core. Such reconstructions are important as they allow a deeper understanding of how tools were made and the thought processes used by the person making the tool.
Identifying the behavioral cycle for lithic technology
Aside from the simple description of the artifacts, more sophisticated approaches to lithic analysis are also used. An important step in the interpretation of lithics and the refining of classification systems involve the determination of the intended function and actual use of the lithic artifacts (called use-wear analysis). The use of the stone tools may be determined through analysis of the form (e.g., shape) and attributes of the observed wear on the surface (e.g., pitting and edge erosion). Form and wear are frequently assessed with reference to modern equivalents (i.e., using the concept of analogy) or by making experimental replicas and using them for various tasks (experimental archaeology), to assess the resultant wear pattern and then comparing this to the actual artifacts. Use may also be determined by the analysis of organic (or inorganic) residues that survive on the tools, such as those which are retained on the edge of a flake, or the grinding surface of a quern or mortar. Blood or organic fragments may survive on the tool (given the right preservation conditions), with microscopic study and chemical analyses being used to identify the preserved organic remains.
Also important for understanding other cultural elements of the stone tools behavioral cycle are studies of the possible sources or origins for the raw materials. This is the first phase of the behavioral cycle for artifacts; see Fig. 4.6). Identifying lithic sources can be done through microscopic (petrographic) or chemical analyses of the mineral composition of the lithic material, and comparing it with possible quarry sources (these are discussed in greater detail with pottery analysis). Where the structure or composition of the stones match there is a high probability that the source has been found. From this evidence it becomes possible to reconstruct parts of the exchange networks or resource usage patterns of the culture.
The goal of classifying, reconstructing manufacturing techniques, determining function or use, and identifying source location is the reconstruction of that cultures behaviors and what the artifacts meant to the people who made and/or used them.