Data for: Late Glacial to Holocene volcanism of the Jom-Bolok (Sayan Mountains, Siberia) recorded by microtephra layers of the Lake Kaskadnoe-1 sediments
This article presents first tephrochronological data on the volcanic activity in the valley of the Jom-Bolok River (East Sayan Mountains, Siberia), which is the largest manifestation of the Holocene eruptions in Central Asia. The data results from our study of the proglacial Kaskadnoe-1 Lake situated near the Jom-Bolok basalt field. The lake sediments include a series of tephra-rich layers. Radiocarbon dating of the lake sediments provided a robust age model which allowed us to build timing of eruptions formed the Jom-Bolok field. We recognize two large phases separated by almost 5 thousand years dormant phase. The first phase is traced back to ca. 14.3 cal ka BP and lasted until 6.3 ka BP. Ten clusters of microtephra layers in the sediments of the first phase show 300-800 years recurrence of the volcanic events weakening topward; the event of 14.3 - 13.3 cal ka BP probably represent the strongest eruptions of the Jom-Bolok. The second phase started ca. 1.6 cal ka BP and highly likely continues in our days. Its strongest eruptions occurred between 1.6 and 0.8 cal ka BP with periodicity of 200 years. This tephrostratigraphy shows a multiplicity of the Jom-Bolok volcanic events amplifying the earlier obtained scheme resulted from investigations of the stratified basalts, pyroclasts and lake damming events. Additionally, we indicate a possible influence of the Jom-Bolok volcanic activity on the regional and global climatic changes.