Anjuisky

Geological summary

The Anjuisky (Anyuy) volcano group consists of fissure vents and small pyroclastic cones, the largest of which is 120-m high and is capped by a 300-m-wide crater. The initial fissure eruptions produced trachybasaltic lava flows 15-17 km long that covered an area of 100 km2. The most recent eruptions were considered by the Catalog of Active Volcanoes of the World (Vlodavetz and Piip, 1959) to have occurred between about 1300 and 1700 CE from Aniusk (Monni) cone, based on morphological evidence. Later work (Ignatiev, 1994) showed that Monni was partially destroyed by glaciers and phreatic explosions produced by glacial meltwater flowing into the vent. Lava flows from Maly Anyuy volcano flowed onto glacial ice, and explosions induced by glacial meltwater destroyed the cone. The Monni lava flows dammed up drainages, forming lakes. During an early Holocene period of warming, large creeks overflowed from these lakes and deposited fluvial materials. The cone and lava flow are located between the Maly Anyuy and Bolshoy Anyuy rivers, about 75 km SSE of the community of Keperveyem.