Stratigraphic Unit No. PIT 1, unit b. Interpreted deposit type: tephra fall, paleosol complex. Thickness: 12 cm (4 cm of which is poorly developed A-horizon of soil). Grain size: 1.3 cm (average 5 mm) lapilli to coarse sand size. Bedding: massive. Sorting: moderately sorted. Juvenile clast type: tan (pumice-like clasts, yet still poorly vesiculated) and black (dense, scoria-like clasts). Remarks: representative sample. Munsell color-wet: 5YR 3/2. Munsell color-dry: 5YR 4/2. Grain shape: angular. Age: <3650+/-150 yr. B.P.
Characterization and discrimination of Holocene tephra-fall deposits, Mount Spurr volcano, Alaska
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