Electromagnetic conductivity mapping for site prediction in meandering river floodplains

Abstract

Spatial mapping using electromagnetic (EM) conductivity can quickly define past sedimentary environments within meandering river floodplain settings and, most important, those most likely to include archaeological materials. Natural levee and uplifted fluvial terrace environments would have been the most likely areas for people to place permanent settlements, as these topographically high areas would have remained dry during most annual floods.The spatial patterning of high and low electrical conductivity regions, when combined with geological core and auger information, can define a number of depositional environments in floodplains including channels, point bars, natural levees and oxbow lakes. Conductivity maps can then be used to predict the locations of prehistoric floodplain environments, and therefore the most likely locations for archaeological remains. Suitable areas can then be further tested for archaeological features using detailed geophysical surveys and other archaeological survey methods. Case studies are presented from California, Texas and Mississippi that integrate these methods for depositional environment mapping as a way of accessing the archaeological potential in meandering river floodplains. Copyright © 2008 John Wiley & Sons, Ltd.