Development of a Down-hole Magnetic Susceptibility Logger and Soil Magnetic Laboratory for Archaeological and Soils Investigations

Minnesota State University Moorhead, Moorhead MN

Investigators

Abstract

With support from a National Science Foundation Major Research Instrumentation award, Dr. Rinita Dalan will collaborate with Bartington Instruments Ltd. to develop a down-hole magnetic susceptibility logger appropriate for archaeological and other near-surface applications. Surficial processes affect soil magnetic properties and in depositional contexts it is possible to use magnetic variation over depth both to identify individual buried surfaces and to gain insight into the factors responsible for their magnetic alteration. Based on preliminary data, Dr. Dalan believes that humanly modified surfaces can be distinguishable in this way. Thus, in principle, a magnetic susceptibility logger could be used as a prospection device to locate and to determine the extent of archaeological sites. Because the logger currently under development can measure sections up to 1.6 meters in depth and be inserted within a 1" diameter hole, it has the potential for widespread use. Working with Bartington Instruments Ltd. Dr Dalan will help to develop a stage two prototype. Both field and laboratory tests will be conducted and experiments will compare the performance of the second-generation prototype to the original and be used to provide advice on further improvements. Performance will be evaluated in terms of a number of variables including repeatability (noise), sensitivity, stability and resolution. In addition, speed and ease of field operation as well as flexibility of application will be evaluated. Field and laboratory tests, together with analysis and presentation will be conducted over a period of 1.5 years. The southern lake Agassiz Region, an archaeologically important area easily accessible to Dr. Dalan provides a set of diverse soil and sedimentary environments and thus offers an excellent test situation. Three/four sites, most archaeologically examined and pedologically described give a controlled context. In addition to down hole measurements, sediment samples will be collected for laboratory analysis. This project is important for several reasons. It will provide archaeologists and soil scientists with the ability to quickly and easily plot variation in magnetic susceptibility over depth and offer insight into the sediment characteristics responsible for this variation. It will also play a significant role in undergraduate student training. Dr. Dalan will actively involve Moorehead State University undergraduates in both laboratory and field aspects of the research. The project provides an excellent vehicle to teach principles of archaeology, geophysics and soil science and hopefully will provide an experience which encourages students to pursue careers in science.