return to: [Alaska Peninsula Tephra top page]
[tephra site map]
[previous site]
[AVO main page]
Chemical data are in weight percent. One standard deviation as a percent of the reported value is in parentheses
for each oxide except TiO2 and MnO. The number of analytical points that make up each analysis is in
parentheses after the total. Totals do not sum to 100% because gases like CO2 and hydration water
are not analyzed, and because microvesicles in the glass may have been inadvertently included.
Sample labels ending in a number indicate multiple glass components in the same sample. "c/o/h" is
proportions of clinopyroxene, orthopyroxene, and hornblende phenocrysts. "(c/o/h)" are estimated
proportions, "n.d." is not determined, and "---" is a minor glass component that has the same proportions
as the major component. "o", "a", or "b" after the hornblende number indicates accessory olivine,
apatite, or biotite.