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Text Description: Kaguyak Ignimbrite. Rich in pale-grey pumice clasts and dacitic lava lithics in massive matrix, which is dark grey-brown when wet, dries pale grey. Includes as much as 30% clasts. Largely massive with no stratifications. Lower part is well indurated, almost sintered dark brown-grey zone of ignimbrite. Exposed thickness 15-18 m. Marked PCZ (30 cm to 1 m thick) near top of ignimbrite. See text for MP and ML. Pumice clasts: grey to white crystal-rich dacite pumices most common. Uncommon black scoria is present. All are coarsely vesicular and dense. Lithic clasts: mostly dark to medium-grey, large-pl-rich dacite lava. Some scattered orange altered lava clasts and widely scattered Jn clasts. 10-15 volume% lithics may account for matrix color. References:  Kaguyak dome field and its Holocene caldera, Alaska Peninsula |
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