EPR dating and evolution of the Elbrus volcano

This study is devoted to the reconstruction of the Elbrus volcano evolution by electron paramagnetic resonance (EPR) dating. The following ages have been obtained for the Elbrus activity cycles: early caldera cycle was apparent between 340 and 250 ka ago and changed into the denudation of volcano. Resumption of volcanic activity (late stage of caldera cycle) resulted in accumulation of thick volcanic rock mass (up to 2 km) took place about 170 ka ago. The end of this stage came 70–60 ka ago soon after the intrusion of subvolcanic bodies 90–70 ka ago. After Late Pleistocene glaciation, volcanic activity resumed several times, however, we have dated with EPR only one eruption which occurred 6.7 ka ago. Comparison with the results of geomorphological,14C, K−Ar and U-Th sensitive high-resolution ion microprobe dating show that EPR dating of quartz from volcanic rocks may be used for the reconstruction of the Late Neo-Pleistocene and Holocene history of the Elbrus. For older rocks, EPR ages are younger than those obtained with conventional methods. The causes of this disagreement are discussed.