At this quarry, there is a seam of rock that they mined - just like a coal seam.  At one place it looks like it is almost 10 feet thick and it tapers down to about 4 feet thick. As the seam is getting thicker, it is diving down and there is more overbear or unusable rock above it.  They reached a point where it was not economical to get to the seam of good stone, and they quit mining.

At another outcropping, the slope of the rock strata was very noticeable - about a 10 to 15 degree slope.

I just had to shoot the photo on your right; the sun and shadows are just right making the rock look like something from Easter Island.  It is 3:00 PM.

In the stream, several hundred feet upstream from the quarry area, there is this rock in the middle of the stream with some marks on it plus the marks of the drills used to separate the stone in the quarry.

On the way back to the car, I saw this stone just lying there with the hills in the background and thought that it kind of typifies the quarry as it exists today; (Photo on your left) there are rocks and boulders all over the place and it is just quiet; you can hear a jet going over and you can see the Potomac River and the canal - really still.  The only thing moving are a couple of trees in the wind as I followed the paths of deer and people on the berm side of the turning basin of the canal.  It makes you wonder what this was like when they were shipping 850,000 tons of rock in a year.

Seneca Stone Mill 2-27-04 Cont.