ArchaeoGeophysical methods in the Templo del Escalonado (Cahuachi, Nasca, Perù)

The application of geophysical prospection methods to detect earthen remains is one of the major challenging issues to be addressed in archaeological investigations. The subtle geophysical contrast between earthen buried remains and the surroundings makes the detection of archaeological features very difficult. In this paper, we address this challenge using a multi-technique approach. The integration of different geophysical methods has been used to identify archaeological remains in Cahuach, Peru, which is the largest adobe ceremonial centre in the world. The investigations herein presented are focused on two different geophysical campaigns carried out in 2008 in an area of the Templo del Escalonado, which is highly representative of the whole archaeological site. It is a desert environment where the archaeological features are covered by sand and alluvial material. The geophysical prospection, required by the archaeologists to guide excavation planning, was performed using both ground-penetrating radar (GPR) and geomagnetics with a gradiometer system. The first allowed the detection of significant anomalies, the latter confirmed the presence of these anomalies and also provided additional features not visible from GPR. Trial excavations were carried out in correspondence of some anomalies. The archaeologists unearthed a ceremonial offering in correspondence of an anomaly detected using both GPR and geomagnetic methods. Moreover, an altar and precious archaeological materials were discovered in the area characterized by a magnetic anomaly. From an archaeological perspective, these findings were very significant, because they enabled us to cast new light on the Templo del Escalonado. From a geophysical perspective, our results pointed out the high potentiality of magnetic and GPR techniques to detect, investigate and document adobe archaeological remains in a desert environmental setting