Quantitative Interpretation of Magnetic Anomalies from Thick Bed, Horizontal Plate and Intermediate Models Under Complex Physical-Geological Environments in Archaeological Prospection

Magnetic prospecting is one of the most widely used methods for archaeological prospection 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 (different iron-containing targets, electric power lines, etc.) strongly obscure interpretation of observed magnetic anomalies. For quantitative analysis of magnetic anomalies produced by archaeological targets under aforementioned conditions a non-conventional interpreting system has been developed. Methodology of magnetic anomalies interpretation from models of thin bed and horizontal circular cylinder (sphere) 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 tangents has been earlier suggested. However, many archaeological targets have geometrical form of thick bed, thin horizontal plate and intermediate between these two models. In this paper methodology of magnetic anomalies produced by thick bed models in complex environments is explicitly described. It is shown that quantitative analysis of magnetic anomalies due to intermediate (between the thick bed and thin horizontal plate) targets could be successfully carried out by the use of methodology developed for the thick bed model. In the case of thin horizontal plate with a large horizontal extent, the two measured anomalies may be interpreted as anomalies from thin beds. The interpretation methodology was successfully tested both on typical models and on real archaeological targets with some success.