Dolores Archaeological Program Technical Reports, DAP-078: Study of Correlation Between Magnetic Reconnaissance and Excavation in the Dolores Archaeological Program

Summary

In September of 1978, a magnetic reconnaissance program was initiated within the Bureau of Reclamation Dolores Project area of Colorado for the DAP (Dolores Archaeological Program). Themagnetic program was continued throughout the 1979 field season, by which time 26 grids, at 25 selected prehistoric sites, had been magnetically surveyed. The raw data obtained by these surveys was sent to NEBCAR (Nebraska Center for Archaeophysical Research) to be analyzed by Rob Huggins under the direction of Dr. John Weymouth.

The magnetic reconnaissance program was established to aid in archaeological investigations of the DAP. Magnetic surveying is an aid to locating subsurface features, and is, therefore, capable of indicating the presence of specific, buried archaeological features such as subterranean domiciles and hearths. The magnetic survey may also indicate site boundaries and outline the overall occupation pattern of a site, enabling a more accurate archaeological sampling procedure to be used.

Detecting the location of the subsurface archaeological features involved using a proton magnetometer to measure the earth's magnetic field over a grid of points on the surface of the site. Marked variations or "anomalies" in the earth's field, caused by differences in the concentration, composition, and orientation of iron oxides in the soil were plotted using a variety of graphical displays, primarily magnetic contour maps (SYMAP [Dougenik and Sheehan 1975]) and line contour maps. Because some cultural processes such as intense burning alter the iron oxides in the soil, an assessment could be made concerning the possible cultural origin of these anomalies and the location of a test area which was most likely to locate the archaeological source of the anomaly. Where possible, additional comments concerning the geometry of features were also noted (see Huggins and Weymouth 1978, 1981). Since anomalies in the earth's magnetic field can also be caused by geologic contributions or by recent and historic disturbances, and adjacent cultural features may produce ambiguous responses to the observer, a degree of uncertainty occurred in the assessment of each anomaly and in some cases no cultural features were located.

Originally the information in this record was migrated into tDAR from the National Archaeological Database Reports Module (NADB-R) and updated. In 2015, as part of its effort to improve tDAR content, the Center for Digital Antiquity uploaded a copy of the document and further improved the record metadata.

This Resource is Part of the Following Collections

• National Archeological Database (NADB)

Keywords

Spatial Coverage

Individual & Institutional Roles

Sponsor(s): USDI Bureau of Reclamation, Upper Colorado Regional Office

Prepared By(s): University of Colorado, Dolores Archaeological Program

Submitted To(s): USDI Bureau of Reclamation, Upper Colorado Regional Office

Record Identifiers

NADB document id number(s): 621518

NADB citation id number(s): 000000349658

Notes

General Note: As of April 2015, this and additional reports are hosted on the US Bureau of Land Management, Dolores Archaeological Program website; http://www.blm.gov/co/st/en/fo/ahc/dolores_archaeological/dap_technical_reports.html

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