Geophysical prospection of a bronze foundry on the southern slope of the acropolis at athens, Greece

The sanctuary of the Acropolis of Athens in Greece provided one of the first monumental bronze statues some 2500 years ago, which was dedicated to the goddess Athena. During recent decades, important understanding of the statue's manufacturing processes has been achieved by archaeological studies, and the former production site has been identified on the southern slope of the Acropolis. Two major bronze production pits have been detected and one was excavated in 2001 and 2006 and was found in an unexpected location. Therefore, in 2010 a geophysical survey of the whole production site was carried out for the first time in order to either reveal or to exclude any further sites of the bronze foundry complex. A combination of different geophysical methods was applied to survey the subsurface; magnetometry (MAG), two- and three-dimensional electrical resistivity tomography (ERT), as well as two- and three-dimensional ground-penetrating radar (GPR). Two major anomalies have been identified in the processed data, which provide evidence for additional production sites. One was a known site identified in a test trench in 2001, and our survey has outlined the extent of the former pit. The other anomaly, which was detected by ERT and GPR, was 8-10m in length and 2-3m in width and is oval-shaped and about 2.5m deep. Steep vertical walls, together with two narrow points at the ends of the pit, which could reflect former entrances, were identified. Virtual ERT and GPR models generated from cross-sections of a ground-based LiDAR scan of the 2001 and 2006 excavated pit helped to interpret and understand the geophysical data of anomaly 2. This anomaly was finally interpreted as a newly detected production pit of the bronze foundry complex, and based on these findings new excavations are planned.