Name:  Argillaceous sandstone

Geologic Name:  Nunda Sandstone

Reference:  Clarke, J.M., and Luther, D.D., Geologic map and descriptions of
the Portage and Nunda quadrangles: New York State Mus. Bull. 118, p. 61-63, 1908.

Microscopic characters:  Angular pebbles and grains of quartz, microcline,
microcline-perthite and acid plagioclase are predominant.  The feldspar is
sometimes fresh and sometimes more or less altered to sericite.  Muscovite
flakes and magnetite grains are common.  The cement is both siliceous and
ferruginous.  Some chlorite and secondary calcite are present.