"gel box"

Buff, coarse, crystalline “Austin Marble” with shell casts and molds.

Gray to brown mudstone with abundant silt.

Well-cemented, medium-grained orthoquartzite.

Gray with line crinoid columnal fragments.

Gray, fine to medium-grained “Berea grit”.

Typical green-gray, fissile, clay-rich.

Black, fissile; commonly with carbonized fossil plant impressions.