"Gary K. benson"

Abundant small black phenocrysts in a gray to brown matrix.

Cemented glacial gravel.

Small, rounded pebbles and tightly cemented granules.

Coarse-grained, with microcline, biotite and horblende phenocrysts.

Classic, very coarse-grained igneous texture.

Earthy, porous calcareous tufa.

Gray with line crinoid columnal fragments.

Light gray, earthy.

Light gray, with flow structure.

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

Brownish gray, kerogen-rich; commercial oil source.

Well-cemented, medium-grained orthoquartzite.

Gray andesite with phenocrysts of felspar and/or hornblende.

Soil