Prof James B Gill | University of California, Santa Cruz, USA
Abstract: At about 1000 AD, the Changbaishan shield volcano, on the border between China and North Korea, produced one of Earth’s few recent VEI=7 eruptions. It was 95% peralkaline rhyolite (comendite), ending with trachyte to basalt. Similar trachyte has erupted at least twice since, and volcanic unrest in 2002-2005 caused wide concern in East Asia. The talk will summarize the volcano’s tectonic setting, the multinational efforts to study the volcano’s Holocene history, the petrology and geochemistry of the Millennium Eruption, evidence of rapid fractional crystallization near a ternary eutectic, and challenges of 14C, Ar-Ar, and U-series dating of recent eruptions.