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A geophysical approach to buried site detection using down‐hole susceptibility and soil magnetic techniques
Author(s) -
Dalan Rinita A.
Publication year - 2006
Publication title -
archaeological prospection
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.785
H-Index - 38
eISSN - 1099-0763
pISSN - 1075-2196
DOI - 10.1002/arp.278
Subject(s) - remanence , geology , soil water , magnitude (astronomy) , magnetic susceptibility , rock magnetism , environmental magnetism , magnetic anomaly , geophysics , mineralogy , soil science , archaeology , paleontology , sediment , magnetic field , magnetization , geography , chemistry , physics , quantum mechanics , astronomy , crystallography
Recently developed down‐hole magnetic capabilities and laboratory soil magnetic techniques are combined in a geophysical approach to identify buried archaeological sites. Down‐hole magnetic susceptibility measurements are used to locate palaeosols and soil magnetic studies are applied to evaluate whether an associated human occupation is likely. This geophysical approach has the potential to locate and explore buried archaeological deposits across varied environments in a cost‐effective, efficient, and relatively non‐invasive manner. This approach was developed and tested on sites in Minnesota and North Dakota, USA. Prototype Bartington Instruments MS2H down‐hole sensors allowed identification of major stratigraphical units, buried occupation layers and non‐cultural palaeosols at these sites. Buried soils correlated with enhanced susceptibilities. Buried cultural soils produced, in some cases, a signal over twice the magnitude of non‐archaeological palaeosols. Although this magnitude shift suggested a possible avenue for determining if ancient land surfaces had been occupied by humans, laboratory soil magnetic techniques, which allow an understanding of changes in composition, concentration and/or grain size of the magnetic carrier that produce this contrast in magnitude, were found to be much more effective in making this determination. These soil magnetic tests were applied to sediments collected from the down‐hole locations. An increase in magnetic remanence carried in the coarse soil fraction was found to consistently and reliably distinguish those soils associated with human occupation. Investigations into the origin of the magnetic signature have suggested this remanence resides in nodules of burnt clay found in the archaeological soils. As it is suspected that domestic fires produced these clay aggregations, this phenomenon may extend to a wide range of sites and thus provide a technique for buried site identification that is broadly applicable. Copyright © 2006 John Wiley & Sons, Ltd.