ИСТИНА

The Russian Altai is one of the world's regions where evidence has been recognized of past catastrophic events – megafloods and large paleoearthquakes. The giant current ripples interpreted now as footprints of floods that resulted from water flowing from big lakes formed due to the intramontane basins glaciers blockage. The rapid outbursts of glacial lakes and formation of megafloods that passed down river valleys and produced thick bars composed of specific megaflood deposits (cf. Carling, 2013) - parallel layers of small to medium gravel with inclusions of large blocks of rock. Here we present the results of ground-penetrating radar (GPR) investigations of deposits in the Altai Mountains that related to past catastrophic events. We carried out GPR survey on the high (up to 180 m) bars composed of megaflood deposits and the obtained data allowed us to understand the sedimentation mechanism and to choose the best locations for the sampling for absolute age dating. The giant current ripples were to be the next subject of GPR study, where we obtained high-resolution data on internal structure and stratigraphy. We also collected a set of GPR profiles close to the several trenches opened across a fault scarp affecting Quaternary deposits, specific wave patterns on them showed the difference between initial and disturbed sediments. The results of our study is necessary step to reconstruct the history of the glaciation and seismicity of the Russian Altai.