Stratigraphic Unit No. 5. Interpreted deposit type: tephra fall and paleosol complex. Thickness: 1.7 cm (6 mm of which is A-horizon of soil). Grain size: fine lapilli to medium ash. Bedding: massive. Sorting: well sorted. Juvenile clast type: white pumice (Hayes), black glass scoria (Crater Peak-reworked). Remarks: representative sample of base. Munsell color-wet: not provided. Munsell color-dry: 10YR 4/2 W/10YR 8/2 grains. Grain shape: subangular-angular. Age: >1630+/-60 yr. B.P.
Characterization and discrimination of Holocene tephra-fall deposits, Mount Spurr volcano, Alaska
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