Magnetometry for archaeological exploration of historical sites
- 4 Downloads
To investigate the advantages of magnetometry for archaeological exploration of historical sites, a magnetic survey was undertaken of Fort Ouiatenon (12T9, Tippecanoe County, Indiana). Comparison with excavation findings demonstrated that historical occupations are likely to be characterized by geomagnetic fields which contain a considerable amount of information regarding the subsurface distribution of artifacts. Archaeological remains which may readily be identified by the magnetic method include iron objects, hearth-type features, wells, pits, and structural trenches.
Iron artifacts are characterized by dipolar anomalies with large amplitudes and compact geometries. The strong remanent moments for a distribution of iron artifacts occur in a random fashion about the site. Areas of forging activity, however, may be characterized by slag iron dipoles with predictable declination and inclination attributes.
Undisturbed hearth-type features may also be characterized by well defined dipolar anomalies that reflect predictable characteristics of remanence . Well sites are affiliated with large wave length monopoles, whereas pits are characterized by weaker and smaller wave length monopoles and dipoles. Structural trenches yield the weakest magnetic signatures of all that may require, in general, a relatively dense survey grid and specialized archaeomagnetic data enhancement processing to resolve.
Broad scale disturbances of the geomagnetic field as well as large relative iron anomalies also may identify indirectly structural features within the site. Furthermore, the density distribution of anomalies that are affiliated with cultural alterations can be used to effectively delineate the general limits of the site.
Finally, the Fort Ouiatenon study demonstrated that magnetometry is capable of providing a rapid overview of the distribution of cultural remains which may prove useful to excavation design efforts. Furthermore, this information is made available without alteration or destruction of any feature of the site. In general, it is concluded that the application of the magnetic method for archaeological exploration of historic sites can help to optimize the time-consuming and expensive effort of excavation.
Unable to display preview. Download preview PDF.
- Aitken, M. J. 1974 Physics and Archaeology. Clarendon Press, Oxford.Google Scholar
- Kellar, J. H. 1970 Search for Ouiatenon, Indiana History Bulletin 47:123–33.Google Scholar
- Noble, V. E., Jr. 1978 Excavations at Fort Ouiatenon, 1977 Field Season: Preliminary Report. Report submitted to the Tippecanoe County Historical Association by The Museum, Michigan State University. Lafayette, Indiana and East Lansing, Michigan.Google Scholar
- Tite, M. S. 1972 Methods of Physical Examination in Archaeology. Seminar Press, New York.Google Scholar
- Tordoff, J. D. 1980 Excavations at Fort Ouiatenon, 1974–1976 Seasons: Preliminary Report. Report submitted to the Tippecanoe County Historical Association by The Museum, Michigan State University. Lafayette, Indiana and East Lansing, Michigan.Google Scholar
- von Frese, R. R. B. 1978 Magnetic Exploration of Historical Midwestern Archaeological Sites as Exemplified by a Survey of Ft. Ouiatenon (12-T-9), Unpubl. Masters Thesis, Purdue University.Google Scholar
- 1984 Archaeomagnetic Anomalies of Midcontinental North American Archaeological Sites. Historical Archaeology 18(2).Google Scholar