Fossil footprint
If the fossil footprint was found on the surface of the shale labelled B then the rocks are nearly upsidedown. To restore original horizontal we would have to rotate the rocks in the direction of the red arrows. this would make the sandstone the youngest rock.
Suppose the fossil footprint (left) was found on the surface of the shale at point A. To restore the rocks to their original horizontal, we must rotate them in the direction of the green arrow. In this case, the chert is the youngest rock
