Archaeogeophysical Exploration

Abstract

Geophysical techniques are a commonplace tool in today's archaeology as a result of an extensive collaboration between scientists and archaeologists on both sides of the Atlantic. This "cross-fertilization" has produced growing subdisciplines, of which archaeological geophysics is one example. As may be recalled from our introductory chapter, K. Butzer defined geoarchaeology as archaeology done using a geological methodology. G. Rapp and J. A. Gifford describe archaeological geology as the use of geological techniques to solve archaeological problems. Fagan has called geoarchaeology a "far wider enterprise than geology," involving (1) geochemical and geophysical techniques to locate sites and features; (2) studies of site formation and spatial context; (3) geomorphology, palynology, paleobotany; (4) absolute and relative dating procedures; and (5) taphonomic studies. Archaeological geophysics is a major aspect of archaeological geology. The application of geophysical exploration techniques in archaeology is also known as archaeogeophysics. Geophysical methods of potential usefulness to archaeological geology fall within the following classes: 1. seismic: reflection/refraction 2. electrical & electromagnetic: resistivity and conductivity 3. magnetic 4. radar 5. microgravity 6. thermography All have been used on a variety of archaeological problems. The application of geophysical techniques has grown as (1) the access to the instruments and (2) the methodological understanding of the users have increased. Access to geophysical instrumentation has been made easier by the steady development in solid-state design and computerization, which has reduced size and costs as it has in almost every technical field. The beneficiaries are the geologists and archaeologists. The first to recognize the applicability of geophysical methods to archaeology were the geologists—more specifically, the geophysicists. Working in association with their archaeological colleagues, the earth scientists translated the objectives of the archaeologists into practice. Such cooperation was very productive but suffered from the same kinds of problems that dogged the early usage and acceptance of radiocarbon dating. The archaeologists' untutored enthusiasm, coupled with their lack of a true understanding of the physics and atmospheric chemistry inherent in that technique, led to a backlash of skepticism when dates reported by the first radiocarbon researchers were found to be in error.