A history of explosive eruptions at Young Damavand volcano, Iran

Abstract

Young Damavand volcano is a steep isolated volcano in the Central Alborz Mountains, Iran, that is characterized by extensive lava flows and pyroclastic successions and is placed on the eroded remains of Old Damavand. Pyroclastic fall and density current deposits on all flanks of the volcano were sampled and studied. From a tephrostratigraphic and geochemical study of the proximal-medial sequences, 14 phases of explosive volcanic activity are identified, characterized by a combination of ash and pumice fall deposits, and/or dense and dilute pyroclastic density current deposits. Some explosive phases of Damavand are thought to have happened one after the other with only short time intervals, since almost no traces of paleosol can be identified between them. We also show that the intensity of the eruptions varied between different phases, confirmed by relative thickness and grain size of the different fall deposits and their distance from the crater. The evidence of numerous explosive eruptions, five of which with Volcanic Explosivity Index 4 in the history of the activity of Young Damavand volcano, shows the importance of assessing its potential volcanic hazards.