HUNTINGTON AND GOLDTHWAIT: THE HURRICANE FAULT. 209 
“The lower Aubrey group corresponding to the coal measures is a series 
of sandstones of exceedingly fine texture and often gypsiferous. There 
is a notable absence in these beds of signs of very shallow water... . 
On the other hand there is no reason to suppose that the depth was at 
all profound” (c, p. 210). ‘In the upper Aubrey series we come upon 
some indications of shallow water, and from the base of the Permian 
upwards these are ever present. In the Permian, Trias, and Jura we 
find instances of . . . peculiar unconformities by erosion without any 
unconformity of dip in the beds. Perhaps the most widely spread 
occurrence of this kind is the contact of the summit of the Permian 
with the Shinarump conglomerate, which forms the base of the Trias. 
Wherever this horizon is exposed this unconformity is generally mani- 
fest. Between the base of the Permian and the summit of the Car- 
boniferous a similar relation has been observed in numerous localities, 
and there is a similar instance in the lower Trias. It has also been 
detected between the Trias and Jura, and between the Jura and 
Cretaceous” (c, p. 211). ‘During the entire [Mesozoic] age the sur- 
face of deposition was always very near the sea-level. The proof of this 
is abundant and clear. Throughout the Plateau province the strata are 
all shallow water deposits. Fossil forests, ripple-marked shales, frequent 
unconformities by erosion without discrepancy of dip, cross-bedded sand- 
stones, occasional retirements of the waters, all mark very shallow water 
in the Permian, Trias, and Jura; while coal, carbonaceous shales, abun- 
dant remains of land plants indicate the same for the Cretaceous. And 
finally, the absence of all traces of appreciable displacement except along 
the coasts combines to prove that the Mesozoic beds were deposited with 
almost rigorous horizontality, and very nearly at sea-level, throughout 
the entire Mesozoic” (c, p. 69). ‘‘ Now and then the waters retreated 
from [the surface of deposition], but only for very brief periods. On the 
whole deposition proceeded almost continuously” (c, p. 211). 
“ From six thousand to fifteen thousand feet of strata were deposited 
over an area of more than one hundred thousand square miles with com- 
paratively few unconformities and contemporary disturbances, while the 
level of the uppermost stratum remained at sensibly the same geographi- 
cal horizon. . . . The case is analogous to that of the Appalachians dur- 
ing Paleozoic time,” and the conditions during the western Cretaceous 
are especially like those of the eastern Carboniferous. ‘The more we 
reflect upon the similarity the stronger does it become. It fails, how- 
ever, when we come to reflect upon the phenomena presented in the two 
regions in the period subsequent to the deposition ; the Appalachian 
