Text Description: |
4- to 16-cm thick tephra; white with black mafics. Highly vesicular pumice with an average grain size of 250 microns. Collected from within the top 1 meter of Unit 6, which consists of organic-rich, black-gray silt. Within the silt are 1- to 3-cm-thick, organic-rich bands and fine laminations of silt and tephra. This tephra is the thickest and most coarse-grained tephra in the section; it occurs as 4- to 16-cm-thick lenses within organic-rich silt up to 30 cm below tephra 96TOK1-12. Salt-and-pepper in color. Thickest, cleanest sample of this lower, coarse, pumiceous, hornblende-rich tephra was collected for Ar/Ar analysis. |