Methodology

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Archaeologists, regardless of the period being studied, use a multidisciplinary approach to study the different kinds of data that may be recovered from an archaeological site. These data are diverse: stone artifacts, ceramics, animal bones, mollusks; human remains;, sediment; organic remains such as pollen and charred material; walls, pits, houses... Each category of information offers complementary data to the study of prehistoric hominids. Working in collaboration with various specialists, it is thus possible to attempt to reconstruct past human activities and ways of life.

 

Here we present a range of techniques available to the archaeologist to study the different kinds of data. Depending on the data available at Trou Al'Wesse, and the research questions being addressed, we are using (or will use) such techniques to analyze the context of human occupations, from the scale of the site to regional and continental scales.

 

Geology

 

The geologist analyzes the stratigraphic sequence of a site in order to determine the formation processes of the geological layers present. These layers may contain material from human occupations, but also information about the processes affecting this material after abandon of the site (deposition of sediment, erosion, displacement by water, bioturbation, etc.). Such information is crucial in determining the context and integrity the artifact assemblages left by humans. In addition, geological data are used to study changes in climate and environment through time (see also separate Geology page).

 

Zooarchaeology

 

The zooarchaeologist studies faunal remains recovered from archaeological context. Identification of species, taphonomic analysis, and study of human modification of bone, among others, represent important sources of information on the history of the site, which includes occupations by both animals and humans. Geological and climatic phenomena recorded in the deposits, and the local environment, are evidenced by bone alteration (weathering, fossilization) and the kinds of fauna present. Cutmarks on bones indicate butchery activity while other bones were shaped into various tools, such as awls, harpoons and needles. Faunal analysis addresses a series of behavioral aspects, including subsistence strategies employed, seasonality, and, for more recent periods, the domestication of certain species.

 

Dating

 

The succession of geological layers (strata) reflects a relative chronology, which can be placed in an absolute framework via radiometric dating. Several techniques are available:

 

Radiocarbon dating (14C and AMS) is based on measurement of the amounts of radioactive isotope (carbon-14) and stable isotope (carbon-12) in an organic sample. Material that can be dated must be organic, and includes charcoal, seeds and bone. Range: to around 40 ka.

 

Mass spectrometric U-series dating  is a similar process, measuring the decay of uranium into thorium. It can be used to date, for example, speleothems, calcites and travertine. Range: 1000 to 400 ka.

 

Electron spin resonance (ESR) measures the rate of accumulation of radiation in a sample, using its resonance in magnetic fields. This technique can be applied to tooth enamel on fossil teeth. Range: 40 ka to 2 mya.

 

Thermoluminescence (TL) measures the rate of radiation accumulation using the luminosity produced during the heating of a sample. Material that can be dated includes burned flint, ceramics, stalagmitic calcite, sediment. Range: 10 to 800 ka.

 

Paléomagnetism measures variations in the earth's magnetic field recorded in minerals.

 

These techniques can be applied to date artifacts and geological strata. Ideally, a date is obtained for more than one category at the same time, for example, a geological stratum, a human activity, an artifact and a species (hypothetical case: horse metacarpal bone tool used for scraping, found in stratigraphic context).

 

The validity of a sample depends on its state of preservation. Its direct association with a human occupation should be clearly established; its precise stratigraphic position is thus crucial.

 

Archeobotany

 

Vegetal remains are rarely preserved in Paleolithic contexts, but have been found. They can be used to reconstruct the local environment and, in some cases, prehistoric diet. Analyses of such organic remains are compared with the faunal record.

 

Palynology is the study of fossil pollen grains. While plant remains decompose, the envelope surrounding the reproductive cell, called the exine, is preserved and fossilized. Via systematic sampling and species determination, it is possible to reconstruct a pollen sequence that shows changes in environment through time in the area around the site.

 

Plant macro-analysis is the study of seeds, wood, nutshell and other macroscopic plant remains, charred or otherwise.

 

Lithic analyses

 

A lithic assemblage is the most durable element in the archaeological record. Tool morphology can be compared to toolkits from other sites, using a typological approach. Technological analyses include analysis of the morphology of reduction products (cores, core preparation by-products, blanks), and refitting, which is a sort of 3-D puzzle reconstructing the technical processes that took place during knapping. Technological and typological analyses are complementary.

 

Characteristics and sources of lithic raw materials inform on strategies employed by prehistoric groups to obtain the material necessary to make tools. Local or long-distance procurement also indicate the range of the territory exploited, as well as possible contacts between groups. Technological analysis of a lithic assemblage, taking into account raw material variability, also addresses such issues as intensity of reduction, preferential selection of blanks by size, form and raw material properties for different kinds of tools.

 

Use-wear analysis studies the microscopic traces left on tools during use, such as abrasion, polishes, microflaking and striations, that have been experimentally associated with different gestures and materials.

 

Spatial analysis

 

Analysis of the spatial context of an archaeological assemblage, using three-dimensional measurements of objects and stratigraphic context, makes it possible to evaluate the integrity of an assemblage, the degree of movement (in place or displaced), identify concentration or activity zones, and can associate different classes of artifacts.

 

It is thus possible to delimit occupation zones in which different activities occurred, such as butchery and knapping, and to describe the spatial organization of a site (e.g., location of hearths, huts, activity zones).

 

At Trou Al'Wesse, the superposition of measured artifacts onto a profile clearly indicates the differences between the Early Neolithic stratum 4a and the Mesolithic facies of stratum 4b. Stratum 4a contains ceramic sherds and bone fragments, as well as Mesolithic material displaced by slope processes on the terrace. The Mesolithic facies contain a dense concentration of lithics, as well as bone fragments and traces of ochre.