Welded tuff. Black cinders(highly vesicular) large dense clasts, lithics. Largest lithics are ~4 cm. Base is uncertain, but ~ 6m wall exposed. Exposures are on both sides of creek, opposite wall downstream shows ~ 10 m thick section. Deposit is poorly welded. Some banded pumice seen, but rare. Large, dense blocks have oxidation rinds up to 2 cm thick and have lithics within, some up to ~1.5 cm. Single black scoria bomb, broken up. Highly vesicular. Very few xtals, nearly aphyric.
Volcanism on Unimak Island, Alaska, USA: a special focus on Shishaldin and Fisher volcanoes
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G22AC00137
Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.