[Footnote 39: I have been informed by Mr. Peach that since the above was written additional light has been cast on this immense fault. It has been found, he says, that the fault consists of two sub-parallel branches, the more southerly of which has the effect of bringing the rocks of the Upper Silurian age against the Lower Silurian beds. The northern branch brings the upper division of the Lower Old Red Sandstones, in turn, against the Upper Silurian rocks. This, Mr. Peach remarks, does not in the least invalidate the reasoning as to the amount of material removed by denudation from this region in the time specified. In fact, it shows, he says, that a greater amount must have been removed than was at first suspected.] [Footnote 40: Jukes’s and Geikie’s _Manual of Geology_, p. 441.] Turning to the American continent, we find the amount of rock removed to be even still greater. In the Valley of Thessolon, to the north of Lake Huron, there is a dislocation of the strata to the extent of 9,000 feet.[41] In front of the Chilowee Mountains there is a vertical displacement of the strata of more than 10,000 feet.[42] Professor H. D. Rogers found in the Appalachian coal-fields faults ranging from 5,000 feet to more than 10,000 feet of displacement. In the Nova Scotia coal-fields one or two miles in thickness of strata have been removed in some places.[43] A great fracture runs along the axis of the Sierra Nevada for 300 miles, accompanied by a dislocation of 3,000 to 10,000 feet.[44] The anticlinal of the Park Range of the Rocky Mountains was cleft down the axis, and the eastern half depressed 10,000 feet. And Mr. J. P. Lesley gives an account of a fault in the Appalachians of not less than 20,000 feet, bringing the upper Devonian strata on the one side opposite to the lowest Cambrian on the other.[45] A fault with a vertical displacement of 20,000 feet was found in the Uinta Mountains.[46] In the Aqui range of mountains, Utah, there is a fault determined by Mr. S. F. Emmons to be at least 10,000 feet.[47] The Grand Cañon of Colorado, in some places 4,000, 5,000, and 6,000 feet in depth, is cut, says Professor A. Winchell, in a plateau which has itself been lowered by erosion to the extent of 10,000 feet; and this plateau occupies an area of 13,000 to 15,000 square miles.[48] The Grand “Wash Fault,” Colorado, has a downthrow to the west of 6,000 feet. The “Hurricane Fault,” close to it, has displaced the strata to the extent of over 12,000 feet.[49]