Earthquake-induced deformation at archaeological sites in southeastern Gorny Altai (Siberia, Russia)

Abstract

Archaeoseismic studies in the Kurai Fault Zone in southeastern Gorny Altai (Siberia, Russia) reveal signatures of deformation caused by paleoearthquakes to burial and memorial sites (mound, khereksur, stone heap, stone enclosures), megaliths (steles), and irrigation ditch (suvak), which were located at the front of fault scarps or in their vicinity. The seismic motions left numerous traces of deformation: displaced of cairns of mound and khereksur; bending, displacement and rotation of parts of the khereksur's walls; bending stone structures at scarp crests; tilted and rotated enclosure's stone slabs; offset irrigation ditch; the displacement is most often directed. Dating of the archaeological site provides lower age bounds to the earthquakes. They all occurred for the past 3000 years, while the youngest events, ∼1.2 ka BP and no older than 1000 CE, were located in the northern Kurai and Kokorya basins, respectively. The deformation features in the mounds have bearing on the coseismic slip geometry.