GEOLOGY OF CHILHOWEE MOUNTAIN, IN TENNESSEE. 83 
of red shale alone is enough to cover the time for the sand¬ 
stone deposit. Thus the hypothesis of simultaneous depo¬ 
sition must harmonize the following unique conditions : 
Accumulation of 2,500 feet of slowly forming limestone and 
shallow-water shale contemporaneously with 1,200 feet of 
quickly forming sandstone, in sharply defined and contigu¬ 
ous areas. 
(8) To sum up, the limestone lies here higher and there 
lower than the upper quartzite. It is thicker than the 
quartzite it seems to replace, although of slower accumu¬ 
lation. It is discordant with the Chilhowee group in strike 
and dip. It is lithologically distinct from Chilhowee and 
only twice shows traces of a transition bed, which may also 
be regarded as a basal sandstone. These apparent transitions 
take place between different horizons in both limestone and 
quartzite. The limestone series has no possible equivalent 
in Chilhowee for its red shales. Lastly, at one contact the 
limestone series contains fragments of quartzite. On these 
grounds it seems necessary to exclude the first hypothesis, 
contemporaneous deposition, and test the second and third. 
VI. ( b) The second hypothesis, that of discordance pro¬ 
duced by a thrust fault, is next in consideration. The con¬ 
tact of dolomite and Chilhowee resembles a fault plane as 
far as variety of beds in contact is concerned, but the changes 
are even more abrupt than is common with faults. Section 
B, before described, is an instance of this; the filling of a 
narrow ravine by limestone without change of strike and 
dip on either side would be a very unusual feature in a fault. 
(1) In one important point the plane of discordance differs 
from a fault plane. It is folded in with the formations as if 
it were a bedding plane, and has endured the full extent of 
deformation that they have, even to overturning. Ordinary 
types of fault are displayed in the two bounding the Chil¬ 
howee area, and their connection with the synclines is ob¬ 
vious. They are a later stage of deformation, and, rising 
out of well developed anticlines, ride over the synclines and 
in places cover them completely. Few fault planes in the 
