Archaeomagnetism of burnt cherts and hearths from Middle Palaeolithic Amud Cave, Israel: Tools for reconstructing site formation processes and occupation history

摘要

Apart from magnetostratigraphy, archaeomagnetism is rarely used in Middle and Late Pleistocene sites. Here we present detailed palaeomagnetic analyses of cemented hearths and burnt chert items from Amud Cave, Israel (68-55 ka)-two types of materials common in Levantine Middle Palaeolithic cave sites. Both materials are shown to be recorders of the geomagnetic field and were used to reconstruct either the ancient field direction (for cemented hearths) or intensity (palaeointensity) (for chert) at the time of the last burning or shortly after. We test the utility of palaeomagnetic data to further our understanding of temporal aspects of occupations in the cave by comparing the dispersion of the palaeomagnetic data to the known characteristics of geomagnetic secular variation in the Holocene. We show that divergent palaeointensities can help identify diachronic burning events, suggesting different activity patterns in two areas of the cave. Additionally, we used palaeomagnetic directional vectors to distinguish between a well-preserved hearth and one that had been mixed prior to cementation. Using rock magnetic investigations, we demonstrate that magnetic methods can be used as a relatively fast and inexpensive method to identify burning of cherts in antiquity above 500 degrees C. The palaeomagnetic results are in agreement with results of previous studies at Amud Cave, obtained by other independent methods. This study shows that palaeomagnetic methods can serve as a powerful tool in the study of Palaeolithic sites.