| Text Description: |
An orange-beige-pink, medium- to coarse-grained tephra layer is variable in thickness, between 1- and 5-cm thick, and 105-cm below the top of the 220-cm thick coal seam (U-seam of Barnes and Cobb, 1959). The contacts with the coal is sharp. There are three other < 1 cm-thick tephra layers in this coal bed (not sampled). Otherwise, the coal is clean and hard with some flexible pieces of wood near the base. The grain mount shows mostly poorly sorted sub-angular to sub-rounded, zoned and twinned plagioclase. Some grains are partly glass. The grains, which may not be totally disaggregated, form many agglomerated 5-6 mm ''lumps" of a clayey matrix, plagioclase, trace glass, hornblende, quartz, volcanic rock fragments, opaques, biotite, and possibly a few pollen and spores. The hornblende is needle-like to stubby with pale bluish-green to pale yellow-green pleochroism. The glass shards are unaltered to slightly altered and consist of delicate bubble-wall shards. |