248 
obscure and their study difficult. Illustrations of such faults are given in 
figures 11 to 13. In figure 18 the lower of two beds twenty feet apart has 
been forced an unknown distance over the upper bed. Some of the accom- 
panying phenomena consist of oblique jointing, induced in the strata, and 
in the vertical thickening of coal beds, as illustrated in figure 10. 
DESCRIPTION OF PLATES. 
Plate I—Typical normal faults: 
Lehited sal 
Type of monoclinal fault. See figures 5 to 10 inclusive. 
Broken arch type of fault. See figures 11 to 13, inclusive. 
Type of fault shown in figure 14. 
Type of fault shown in figure 2 of plate II. 
fault in Fairview Mine, Clay county. 3 
Fault in B. B. C..Co.’s No. 10 Shaft. Map and sections. 
Fault on Otter Creek, 8 miles north of Brazil. From photo. 
Double fault in Peerless Mine, Vigo county. 
Double fault on Big Vermillion River, near Hanging Rock. 
Fault on north fork Otter Creek, near Coal Bluff, Vigo county. 
One of series of faults in Fairview Mine. 
Fault crossing shaft in Jackson Mine, Clay county. 
Plate Il—Irregularities due to faulting; clay, sandstone and coal veins; 
overthrust faults and crushed structure: 
Hig. 1 
5 
=] 
11-12. 
9 
we 
, 
Combined fault and “roll,” Monarch Mine, Clay county. 
Fault of type 4, Dugger Mine, Sullivan county. 
Clay veins resulting from faults. P. Co. C. Co.’s No. 6 Shaft, 
Parke county. 
Clay in old fault plane, Winsett Mine, Vermillion county. 
Clay vein, Dugger Mine, 10 feet from and running parallel to 
large fault. 
Sandstone vein, Ray Mine, Vigo County. Shows displace- 
ment in another entry. 
Sandstone vein, Mecca No. 1 Mine, Parke county. 
Sandstone vein, B. B. C. Co.’s No. 8 Mine, Clay county. 
Showing structure of coal bed thickened to nearly four times 
normal thickness by lateral pressure, in region of overthrust 
faults, Columbia No. 38 Mine, Clay county. 
Coal bed greatly disturbed, Lee’s Mine, Vermillion county. 
Overthrust fault, Columbia No. 4 Mine, Clay county. 
