Pre-Excavation Identification and Dating of Iron Age Destruction Events

ABSTRACT To maximize extracted data while minimizing excavated areas, archaeologists increasingly use archaeological surveys, geophysical surveys and remote sensing to gain comprehensive regional pictures and decide if and where to excavate. The goal of this effort is to leave sufficient unexcavated areas for future generations and save time and resources required for fieldwork. Standard pre-excavation methods can neither securely identify nor date destruction layers, which are particularly important for determining the stratigraphy and chronology of archaeological finds. Here, we present a combination of pre-excavation archaeomagnetic research and magnetic surveys which enabled identification and dating of burnt destruction layers at two sites in the Beth-Shean Valley, Israel. We show that sun-dried mudbricks had collapsed during conflagration, resulting in a hard matrix, still partially exposed on the surface. It is characterized by a strong and unified magnetic signal, generating total-field magnetic anomalies and enabling determination of the scope of the fire. Using Fourier Transform Infrared Spectroscopy, we estimated firing temperatures. Archaeomagnetic dating suggests that the observed destructions occurred in the late 10th or early 9th century bce, potentially during the military campaign of Pharaoh Shoshenq I, mentioned in Egyptian historical sources and the Hebrew Bible.