Thickness of 1.5 to 17 cm (with an average of 10-12 cm). Consists of gray silt-size particles, inequigranular sand, and pumice lapilli up to 5 cm (mainly 1 cm) in size. Thickness varies considerably from section to section. Ash particle size generally grows larger westward. In some section, the ash was intercalated with a layer of humus sandy loam. Could be two ash layers that were ejected from the same vent during different eruptions within a small time frame. Characteristic features include high glass content (76%), absence of green hornblende, and low percentage of pyroxenes (3%) and brown hornblende (2%).
Volcanic ashes of Adak Island, Aleutian Islands, Alaska [Vulkanicheskiye peply na o-ve Adak (Aleutskiye o-va, SShA)]
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