This is the sod layer of a new operation. Removal of sod exposed rocks across nearly the entire operation. Suspected to be largely wall fall, but will not remove until further exposure and cleaning. Top elevation at center is .53 b.d. 1. Other elevations on p. 1 of my 2015 notebook. Bottom elevation is 62cm b.d. 1 at center (other elevations on p. 5).