The long-term dynamic influence of human activity on topsoil magnetic susceptibility
Magnetic survey has become increasingly important in locating and characterising sites of archaeological potential. Magnetometry and topsoil magnetic susceptibility are the principal methods employed. In recent years advances in the design of magnetometers have made their use almost universal, somewhat to the detriment of magnetic susceptibility survey. This is especially true when the efficacy of various geophysical methods in locating sites of archaeological potential is compared. Such direct comparisons are, however, open to serious question. When sealed below the soil archaeological features acquire a degree of permanence, and their relatively static nature allows them to be identified by magnetometer survey on morphological grounds. By contrast, soil is continuously exposed, and over a period of 'deep time' is subject to the vagaries of human activity. The soil itsc1fbecomcs an artefact and the information it contains at any given time need not be site - specific but extensive. The problem addressed here is that of the interpretation of such topsoil magnetic data. Through occupation, industry, and agriculture, communities have historically affected the nature and proportion of the iron minerals (mostly
Johnson, Anthony
The long-term dynamic influence of human activity on topsoil magnetic susceptibility. Magnetic survey has become increasingly important in locating and characterising sites of archaeological potential. Magnetometry and topsoil magnetic susceptibility are the principal methods employed. In recent years advances in the design of magnetometers have made their use almost universal, somewhat to the detriment of magnetic susceptibility survey. This is especially true when the efficacy of various geophysical methods in locating sites of archaeological potential is compared. Such direct comparisons are, however, open to serious question. When sealed below the soil archaeological features acquire a degree of permanence, and their relatively static nature allows them to be identified by magnetometer survey on morphological grounds. By contrast, soil is continuously exposed, and over a period of 'deep time' is subject to the vagaries of human activity. The soil itsc1fbecomcs an artefact and the information it contains at any given time need not be site - specific but extensive. The problem addressed here is that of the interpretation of such topsoil magnetic data. Through occupation, industry, and agriculture, communities have historically affected the nature and proportion of the iron minerals (mostly
long_term dynamic influence human_activity magnetic_susceptibility magnetic survey become_increasingly important locate characterise site archaeological potential magnetic_susceptibility principal method_employ advance design make_use almost universal somewhat detriment magnetic_susceptibility survey especially true efficacy various geophysical method locate site archaeological potential compare direct comparison however open serious question seal soil archaeological_feature acquire degree permanence relatively static nature allow identify survey morphological ground contrast soil continuously expose period deep time subject human_activity soil artefact information contains give time need site_specific extensive problem address interpretation magnetic data occupation industry agriculture community historically affected nature proportion iron mineral mostly