Alaska Volcano Observatory
Aniakchak reported activity
EVENT SPECIFIC INFORMATION
Event Name : Aniakchak Post Pink and Brown Pumice Tephrafall
|Start: 380 (± 50 Years) || Years BP Tephrochronology || |
|Stop:|| 1931 ||Tephrochronology|
From Bacon and others (2014): "Atop the Pink and Brown Pumice layers on Half Cone itself are several more light and dark colored fall beds that have a total thickness of ~60 m. These vary from nonwelded pink-to-buff pumice fall to brick-red oxidized lithic-rich fall breccia and dark gray welded agglutinate. The variations in lithic content and welding are due to changes in eruption intensity at the vent. Although these layers have not been studied in detail, their thicknesses decrease substantially over short distances from Half Cone. Outcrops of this agglutinate are found as short, low ridge segments near the surface on the caldera floor northeast of Half Cone, as patches on Vent Mountain and West Dome, and in the wall of the 1931 Main carter. They are cut by the cliff face of Half Cone and are overlain by deposits of the 1931 eruption."
Page modified: March 30, 2017 14:36
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