B horizons are commonly referred to as the subsoil are a zone of accumulation where rain water percolating through the soil has leached material from above and it has precipitated within the B horizons or the material may have weathered in place. Well drained soils typically have the brightest color development within the B horizons.
And c horizon?
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.