Looking at that one photo, it takes a fair amount of imagination to see those impressions as a "frond". Since you had said that's what it was I was pre-conditioned to see it that way, but had I not been told what to expect, I would never have recognized it. Also, I see no perpendicular "laminae" and the "second fossil" is indistinguishable. If it really is a frond it looks like it had fallen onto one layer of rhythmite and the been covered by another, so that when the fossil was exposed the rock split along the plane of the rhythmite layers, with one layer below the fossil and the other "above" it on the piece of rock that was removed to see the fossil.
Kevin L. O'Brien