"We may even demonstrate that in some mountainous ground, the strata have been turned completely upside down, _if_ we can show that the fossils in what are now the uppermost layers =ought properly= to lie underneath those in the beds below them."[26] Some day, I fancy, a statement like this will be regarded as a literary curiosity. There are plenty of examples under this head, though two or three ought to be as good as a dozen. In the part of Alberta east of the Rockies already referred to, is a section of country of about fourteen square miles at least--and we know not how much more--where Cambrian fossils are found =above= Cretaceous, and the inevitable "thrust fault" is thus described by one of the officers of the Canadian Geological Survey. He has just been speaking of "a series" of these "gigantic thrust faults":-- "One of the largest and most important of these occurs along the eastern base of the chain, and brings the Cambrian limestones of the Castle Mountain group over the Cretaceous of the foot hills. This fault has a vertical displacement of more than 15,000 feet (? three miles), and an estimated horizontal displacement of the Cambrian beds of about seven miles in an easterly section. The actually observed overlap amounts to nearly two miles. The angle of inclination of its plane to the horizon is =very low=, and in consequence of this its outcrop follows a very sinuous line along the base of the mountains, =and acts exactly like the line of contact of two nearly horizontal formations=. "The best places for examining this fault are at the gaps of the Bow and of the south fork of the Ghost River. At the former place the Cretaceous shales form the floor of the bay which the Bow has cut in the eastern wall of the range, and rise to a considerable height in the surrounding slopes. Their line of contact with the massive gray limestones of the overlying Castle Mountain group is well seen near the entrance of the gap in the hills to the north. The fault plane here is nearly horizontal, and the two formations, viewed from the valley, =appear to succeed one another conformably=."[27]