|
Text Description: 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. References: ![]() |
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.