Investigation of magnetic surveying data of buried grave jars in Harmanoren Necropolis (Turkey) using linear transformations and analytic signal

Abstract

Harmanoren Necropolis is the third biggest excavated necropolis in southwest Anatolia, dating back to 2500 B.C. The individual burials are composed of ceramic jars. The dead bodies were placed in the fetal position in buried grave jars which were elongated eastwards. Buried burnt ceramics can be located by their own magnetic field directions. Thus, magnetic surveying was used in the Harmanoren Necropolis in three different areas to locate buried grave jars ahead of archaeological excavation. Magnetic anomalies present some results, but to identify these as buried grave jars, advanced spectral methods were applied to the magnetic anomalies. Polarity orientations of magnetic anomalies are different from a north-south direction due to remnant magnetization. 'Reduction to the pole' transformation could not entirely remove disoriented polarities arising from the effect of remnant magnetization. 'Analytic signal' transformation minimizes the disorientation caused by the effect of remanence. Magnetic susceptibility measurements of samples from the excavated jars indicate that the observed magnetic anomalies could be caused by them. A good correlation was observed between the processed magnetic anomalies and excavation results. (c) 2005 Elsevier Ltd. All rights reserved.