1881.] 
255 
[Wadsworth. 
Geological Survey of Scotland, who also remarked regarding one of 
the geological sections : “ The section, I submit, involves a series of 
physical impossibilities, or at least of such glaring improbabilities as 
to demand full and incontrovertible proof in its support. For, in 
the first place, it requires us to believe that the cliff against which 
the Paleozoic sediments were deposited, must have been at least 
twelve miles high! * * * In the next place it necessitates the 
admission that this stupendous precipice was subsequently turned 
over on its back carrying with it the adhering later rocks.” 
(Amer. Journ. Sci. 1880, (3) XIX, 363-367.) The granite of the 
Wachoe Mountains was held to be Jurassic in 1876 (YI, p. 49), 
but Azoic in 1878 (I, pp. 59-60). 
The granite at Agate Pass was regarded by Zirkel as an excel- 
lent example of the titanite granites (Jurassic ?) (VI, p. 48), but 
King is inclined to object to this determination and prefers “to 
consider it rather as a diorite than as a granite ; ” that is a grani- 
toid modification of the surrounding “ diorite ” (I, p. 72). When 
the writer studied these rocks in the summer of 1878 he saw no 
reason to dissent from Professor Zirkel’s determination of the 
above granite as granite, but he did see reasons for objecting to 
the assignment of the Agate Pass “ diorite V to the “ diorites ”. 
He then held that this u typical diorite ” was a granite holding 
abundant quartz and biotite, as well as hornblende, plagioclase, 
and orthoclase (YI, p. 91, No. 184, Col. No. 1858). 
He would explain the resemblance of the above granite and 
“ diorite ” in the reverse way from Mr. King, that is : the diorite 
is a modification of the granite. In like manner the “ diorite ” 
from Mill Creek Canon, which Zirkel says “ is very peculiar,” and 
which Mr. Emmons thinks may be best classed as a diorite, 
although it presents many features of a fine grained granite, Mr. 
King holds is an intermediate link between granite and diorite 
(YI, p. 91, No. 183, Col. No. 1823 ; II, p. 571 ; I, p. 74). 
The writer regards this as a fine grained granite, the same as 
the fine grained modifications of granite which can be seen at 
Rockport, Mass. These modified fine grained portions of the 
Rockport granite are continuous with the main granite (coarse 
grained) mass. 
