Kaguyak Ignimbrite. thick light grey ignimbrite exposure with 3 good PCZ's and 2 weak ones. Mostly massive, except for 4 50-60-cm PCZ's in upper half. Most of the ignimbrite is clastrich with many 1-2-cm dacite pumice clasts and many small lithics. Ignimbrite base is especially rich in larger lithics. Top 1.5 m of exposure may be a secondary pyroclastic flow; it has a very fine 10-cmthick vitric silt layer between it and the main ignimbrite that trapped fumarolic alteration below it. This horizon includes lithics and is locally red-rusty altered. Exposed thickness ~10 m. 4-6 PCZs: 0.5 to 0.6 m. See text for MC and ML. Pumice clasts: mostly dacite, minor scoria, banded pumice present. Lithic clasts: mostly grey dacite lava.
Kaguyak dome field and its Holocene caldera, Alaska Peninsula