Frozen mounds in Gorny Altai: geophysical and geochemical studies

The importance of pre-excavation permafrost detection within ancient burial mounds in the Altai by geophysical methods is hard to overestimate. There was no way of detecting small quantities of frozen ground or ice under stone mounds, and this is a topical issue in Russian archeology. Frozen mounds, which retain organic matter owing to natural processes, are an exceptional source of information about historical and cultural processes in the Early Iron Age. Pre-excavation geophysical prospecting is especially important in the context of global warming, which might destroy a whole layer of cultural and historical information.The integrated geophysical studies conducted in recent years focused on a group of archeological sites of the Pazyryk culture whose burial constructions are very likely to contain frozen artifacts. As a rule, such burial mounds are located at a considerable altitude and contain permafrost, which creates unique conditions for the preservation of artifacts. Such localities include the Ukok high plateau (southern Altai) and the northwestern part of Mongolian Altay. Systematic field studies were conducted on the Ukok Plateau in 2003 and 2007 and in the adjacent territory of Mongolian Altay in 2005 and 2006. The following geophysical methods were used: vertical electrical sounding (VES), electrical tomography (ET), shallow frequency scanning, georadiolocation, magnetic susceptibility measurements, gamma-ray spectrometry, and chromatography. The field works were planned with a heavy reliance on the 3D mathematical simulation of electric and EM fields, which is meant for a realistic estimate of the possibilities of geoelectrics and the best ways of its application to burial-mound studies and data interpretation.The excavations conducted in 2006 in northwestern Mongolia within the Altai Mts. confirmed the geophysical prediction of permafrost at all the sites identified by the geophysical studies in 2005. In one of the mounds, they yielded a unique intact tomb of a Scythian warrior.