orange fragmental deposit with patchy distribution around caldera rim; mantles Big Breccia deposit and the swales cut in the breccia; includes thoroughly hydrothermally altered blocks and agglutinated blocks of all sizes to decimeters-scale. Also includes 10-20% fresh grey lavas; matrix is orange due to comminuted hydrothermally altered material. Matrix is sandy with some clay component. Some agglutinated blocks are stratified. No pumice seen. Orange sediments atop ignimbrite near Y-3 include abundant orange-altered ferrocreted lake sediment clasts. Implies the orange hydrothermally altered deposit postdates the ignimbrite, too. Exposed thickness 5 to 8 m. MP typically decimeters; ML = 2+m.
Kaguyak dome field and its Holocene caldera, Alaska Peninsula
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.