Thanks for all of the info so far. I am leaning toward cutting and jackhamering for a few hours to see it I can chanell it out. The house is a 20 x32 1.5 story spec house in the Southern Appalacians. One 32 foot side is on gently sloping bedrock that I would define as a mix of decomposed granite or Gniess, with some really hard sections. I will be pinning (yes it is hard enough) regardless of other factors due to backfill on one corner and the smoothness of the bedrock. One corner of the rock section protrudes up to the surface and is harder than the other rock. It appears to be a boulder at least 12 ft in diameter and 1 to 2 feet thick. ( I am sure it varies quite a bit.) I only need to chanell for about 36 inches. The rock in this area is stratafied so I think it will separate on a horizontal plane if I cut down, hammer and pry on it. It will cost a day of work but save me on form work, concrete, additional backfill. And I think it will be a better foundation.
I will update on the results when done. This group is awesome.
Thanks
HC