"Ward's Phenomena"

Light gray, earthy.

Brownish gray, kerogen-rich; commercial oil source.

Cemented glacial gravel.

Small, rounded pebbles and tightly cemented granules.

Gray to buff, with numerous ooliths and fossil fragments.

Typical green-gray, fissile, clay-rich.

Well-cemented, medium-grained orthoquartzite.

Black, soft; most widely mined.

Light gray, fine small clasts.

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