DAVIS: THE GRAND CANYON OF THE COLORADO. 147 
opportunity of attacking the strata here concerned ; for, as in the case 
of the Toroweap fault, until renewed uplift introduced the canyon cycle, 
it must be supposed that the strata in the Hurricane ledge of to-day 
were close to or even beneath baselevel, and hence out of reach of 
erosion. On the other hand, a branch of the main Hurricane fault cuts 
certain lava beds, — not the most recent ones (e, pp. 116, 117), — and 
this branch must be younger than the lavas, which in turn must at the 
oldest have been erupted late in the plateau cycle. 
The Hurricane fault seemed to me to fade away just north of Virgin 
river. The line of great cliffs that comes up from the south here gives 
place to a monoclinal flexure, dipping to the west in sympathy with the 
throw of the fault ; and a few miles further north the flexure loses im- 
portance, as far as we could interpret its structure in the view from the 
escarpment south of the river. A new displacement seemed to begin 
two or three miles to the west, rapidly increasing its throw northward 
and so continuing from Toquerville past Belleview, Kanarra, and beyond, 
where it sharply separates the Plateau province from the Basin range 
province. The southern termination of this displacement was not cer- 
tainly determined. As a fault, it ends just south of Toquerville, but it 
may turn southwest and find a continuation in the anticline at the 
eastern base of Pine valley mountain. In any case it seemed entirely 
independent of the Hurricane fault proper. The course of Virgin 
river hereabouts is perhaps consequent upon the overlap of these dis- 
placements, for it lies close to the sag between them. It may be added 
that, although we had a fine view northward into the valley of Le 
Verkin creek from the rim of Hurricane ledge, we did not detect the 
lapse of the Permian and the unconformable overlap of the Trias on the 
Carboniferous, as noted by Howell (p. 285); but to assert the non- 
occurrence of these features would be going too far. The neighborhood 
of Toquerville offers an unrivalled field for special study. The village 
serves as a good base of supplies, the surrounding district is traversed 
by many roads and trails, stratified rocks range from Carboniferous to 
Tertiary, igneous rocks are present in good variety, the structural 
features are of unusual interest, denudation has been enormous, and 
the half-desert scenery is superb in form and color. 
The Grand Wash Fault is said by Dutton to be no older than Pliocene 
(c, p- 191) ; yet the work of erosion after the fault had attained a strong 
measure of displacement would give it a much greater antiquity, for 
while a monoclinal slice of the Trias is preserved along its thrown (west- 
ern) side, there is no Trias on the heaved Shivwits block for fifty miles 
