XXX.—On the Laws of Structure of the more Disturbed Zones of the Earth's Crust
Having, several years ago, in the course of a prolonged investigation of the geological structure of the Appalachian chain of the United States, conducted partly in co-operation with my brother, Professor W. B, Rogers, as a purely scientific inquiry, partly by myself, in connection with a Government Survey of the State of Pennsylvania, discovered what we deemed important laws, applicable generally to all corrugated tracts of strata; and being prepared, by observations since made in the United States and in Europe, to extend their application, and give them a more general expression, I have thought that I could not select a more suitable subject for my first communication to the Royal Society of Edinburgh, than this portion of descriptive and dynamic geology, which has engaged much of my attention, theoretically and practically, for these many years. In presenting an outline of the views already arrived at, and published by us as a necessary part of the further generalizations since reached, I will refrain from repeating, in historical detail, what we have already written, but will give our conclusions in the form and with the brevity most compatible with clearness, referring to the printed papers and communications where the special topics included in this more general summary may be seen.