C-horizons are glacial or post-glacial material in the Northeast.
C layers: are commonly referred to as the substratum. These are layers, excluding bedrock, that are little affected by soil forming processes and have changed very little if any since the time they were deposited. C - horizons can have redoximorphic features within them.
Little affected by soil forming processes.
Lack color development, color is that of the unweathered geologic material.
Geologic layering or strata is often present.
Most soil in the Northeast have a “cap” or mantle of eolian material over the geologic C horizon, the 2C designation would be used for soils with an eolian cap.