Introduction

Geoarchaeology explores the natural context of archaeological sites in order to investigate research problems related to archaeology. All sites have context. Whether sites deeply buried, lying on the surface, or underwater, each lies within a natural landscape and environmental context. Since many sites are buried or partially buried, the physical context of sites includes the landscape surface surrounding the site and the three-dimensional regional stratigraphy which lies below the landscape surface. Each archaeological site occupies a specific location within this complex context or matrix of sediments, soils, and landforms. Sediments, soils, and landforms are dynamic and can change dramatically during and after a landscape is occupied by humans. Therefore, each of these landscape components may have an impact on the preservation of archaeological sites lying within this context and/or human activities of the past.

As its name implies, geoarchaeology involves interdisciplinary investigation between archaeology and the geosciences. In other words, geoarchaeology is geoscience for the purpose of archaeology. For example, geoarchaeological investigations may include studying the stratigraphy of an archaeological site, site formation processes, landscape position of a site, the local geology, and palaeoenvironmental history of a region. Sometimes geoarchaeology is used to establish which features at an archaeological site are natural and which are cultural. An archaeologist may wonder if a particular feature in profile is the remains of a fire hearth or an odd-looking root burrow. As with mainstream archaeology, the ultimate goal of geoarchaeology is to reconstruct past human behavior.

Methodology

Although geoarchaeology is considered a subdiscipline of archaeology, it maintains its own methodology and theoretical orientation. The methodology of geoarchaeology is most commonly defined as the application of methods from the earth sciences for solving archaeological research problems. Such methods include those from geology, geography, sedimen-tology, pedology, stratigraphy, and geomorphology. In this sense, geoarchaeology has been conducted nearly since the origin of archaeological investigation in the eighteenth century and its development is closely tied to the development of the field as a whole. During the earliest periods, archaeologists and geoscientists investigated archaeological sites together and this evolved into close collaboration in later years. However, the theoretical orientation of modern geoarchaeology was not formalized until the 1976 publication of Geoarchaeology: Earth Science and the Past by Davidson and Shackley and with Colin Renfrew’s famous quote in the Preface which states that: ‘‘...every problem in archaeology starts as a problem in geoarchaeology’’.

Research Questions

As Renfrew pointed out 30 years ago, geoarchaeology has its own theoretical orientation and own research problems. Geoarchaeology is much more than simply describing the stratigraphy of an archaeological site, conducting sedimentological analyses, or drilling sediment cores. For example, geoarchaeology can help evaluate research questions such as: what was the landscape like when this site was settled? Did the inhabitants have easy access to water? Has this site been disturbed by plants, animals, insects, groundwater, or artifact hunters? Was there one occupation at a site or multiple occupation phases? Is this piece of charcoal that the author would like to radiocarbon date associated with these artifacts? Why is there no charcoal at this site? Geoarchaeology is not a mere descriptive tool or singular type of methodology. Modern geoarchaeology is as scientific and holistic as its roots which were established in processual archaeology. Geoarchaeology has its own set of research questions which bridge the geosciences and archaeology (see Archaeometry; Bioarchaeology).

So, what does this mean? By investigating the natural context of the archaeological record, geoarchaeology can help determine the chronological context of the archaeological record through analysis of stratigraphy and dating, evaluate the preservation of the archaeological record (i. e., by studying formation processes of a site or a landscape), and interpret whether this natural context may or may not have had any impact on past human behavior. Geoarchaeology can suggest how complete or disturbed an archaeological record of a region or single site is. It can also analyze whether or not a landscape had an impact on a human population or whether humans had an impact on the landscape. The more a landscape or site is altered, the less potential information can be gathered to interpret past human behavior.