Sorry, no winners so it is time to reveal the answer.  A few of you were
HALF right, but you needed both answers to win fair and square.

I wish I could talk all scientist-like, but alas, in the words of Prof.
Pratt of Elmira College:

The bedrock taken from the quarry [at Quarry Farm] is not slate, which is a
metamorphic rock formed when shale is heated under pressure deep within the
earth. Such conditions have not existed in the Southern Tier. Rather all the
stone in the quarry that I have found to date falls into two categories of
sedimentary rock: 1. *siltstones *characterized by a slightly gritty texture
and 2. *fine-grained sandstones* with a somewhat more granular/gritty feel.


Harold K. Bush, Ph.D
Saint Louis University