Name: Calcareous Shale

Geologic Name:  Windom shale

Reference:  Cooper, G.A., Stratigraphy of the Hamilton group of New York:
Am. Jour. Sci., 5th ser., vol. 19, p. 222-229, 1930.

Microscopic characters:  The slide is composed chiefly of small grains of calcite
which obscure the other constitutents.  In some places minerals with low
interference colors may be seen, among which chlorite may be identified.  Pyrite
is quite abundant in single grains and rod-like aggregates.