Stratigraphic Unit No. 9. Interpreted deposit type: tephra fall, locally reworked. Thickness: 63 cm. Grain size: coarse to fine ash. Bedding: massive; AT-227, AT-228 are mottled with pods of brown lapilli pumice (AT-228) possibly reworked. Sorting: AT-211 to AT-213, well-sorted; AT-227 to AT-228, moderately to poorly sorted. Juvenile clast type: white pumice (AT-211 to AT-213); white pumice (Hayes) and black glass scoria (re-worked Crater Peak) (AT-227, AT-228). Remarks: Hayes tephra-set middle. Munsell color-wet: 5Y 6/1. Munsell color-dry: 5Y 6/1. Grain shape: angular-subround. Age: ~3650+/-150 yr. B.P.
Characterization and discrimination of Holocene tephra-fall deposits, Mount Spurr volcano, Alaska
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G19AC00060 and G19AC00171.
Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.