Quantitative interpretation of magnetic anomalies produced by thick and quasi-thick beds in archaeological and environmental geophysics

Magnetic prospecting is one of the most widely used methods for archaeological and environmental investigations in the world. Noise both of natural (main factors are inclined magnetization, Complex geological (archaeological) structure of investigated sites, and uneven terrain relief and artificial origin strongly obscure interpretation of observed magnetic anomalies. For quantitative analysis of magnetic anomalies under aforementioned conditions a non-conventional interpreting system has been developed (Khesin et al., 1996; Eppelbaum et al., 2001, 2010). This system includes eight different components most important from which is quantitative analysis of magnetic anomalies in conditions of oblique magnetization, rugged relief and unknown level of the total magnetic field by the use of improved versions of characteristic point and tangent methods. These methods were developed for analysis of magnetic anomalies produced by three interpreting models: (1) thin bed, (2) horizontal circular cylinder (sphere), and (3) thick bed. However, on the practice many archaeological and geological bodies occupy an intermediate geometrical form between the thick bed and thin horizontal plate. In this paper is shown that quantitative analysis of magnetic anomalies due to such intermediate beds could be successfully carried out by the use of methodology developed for thick bed model. The reliability of the interpretation methods was tested on several models as well as on real archaeological target.