30 R. T. CHAMBERLIN AND W. Z. MILLER 
evidence and from Cadell’s experiments, that the order of events 
was first slice faulting of the ordinary 45° angle type, and that, after 
a mass of slices had piled up in this manner, a low-angle thrust 
plane broke through the mass of slices and the whole mass above 
rode bodily forward on this plane as a ‘“‘sole.’” 
Similarly it will be observed that the well-defined Rome over- 
thrust in the southern Appalachians occurred in the midst of a 
Fic. 11.—Slice faulting, developing an imbricate structure. The bottom layer 
was composed of pure clay; the next above of mixed sand and clay; the third was a 
thin layer of sand; and the heavy competent layer at the top was made of plaster 
two parts, sand one part and clay one part. The brittle top layer arched up and frac- 
tured as the first slice fault developed. Each successive slice fault broke out below 
and in front of its predecessor. 
series of ordinary reverse faults. Directly south of the town of 
Rome, Georgia, there are mapped six large reverse faults just to the 
east of the line of the great overthrust. They are thus in the mass 
which traveled westward with the overthrust.? Similar slice faults 
in series, though they cannot be traced continuously into the par- 
«J. Horne, ‘‘The Geological Structure of the Northwest Highlands of Scotland,” 
Mem. Geol. Surv. of Great Britain, 1907, pp. 471-76; H. M. Cadell, of. cit., pp. 347-48. 
2C. W. Hayes, U.S. Geol. Surv. Geol. Atlas, Rome, Ga., Folio 78, 1902. Structure 
Section Sheet. 
