DISCERNING PREHISTORIC ACTIVITY AREAS IN FLOODPLAIN SETTINGS: THE MINERALOGY BEHIND THE MAGNETICS

In order to advance geoarchaeological theory and method, the interpretation of near-surface geophysical survey data must extend beyond simple archaeological ground-truthing. This poster identifies the parent mineralogy, magnetic domains/grain sizes of iron oxide phases, and depositional processes responsible for spatial variability in the environmental magnetism of several archaeological sites in North Carolina. Powder Xray diffraction techniques, complementing results from stepped sediment-firing experiments, discern significant anthropogenic processes including thermal transformation of goethite through dehydroxylation and the non-pedogenic oxidation of ferrimagnetic minerals. These data are an example of middle range research necessary for refining magnetics-based geophysical survey methods and enhancing the interpretive value of such studies for anthropological archaeology.