and on the Age of the Cascade Mountains, 173 
Creek, from the south. As these streams run at right angles 
to the course of the main river, they give actual sections some- 
what similar to the ideal section, fig. 3. oreover, as the 
stream-beds rise rapidly as we go up stream, I ho to find 
in the stream-beds the actual contact of the basalt with the 
conglomerate. As we shall see, my hopes were completely 
diameter, five to six feet long and many tons weight. A little 
farther up the gorge the stream falls perpendicularly about 150 
feet, over the upper and more firmly cemented portion of the 
conglomerate, upon the softer portion of the same beneath. On 
one side of the ravine, just below the fall, is exposed an admir- 
able section, showing the basalt resting directly on the conglome- 
rate. In fig, 5 J give a rough sketch of this section, made on 
oe spot. The perpendicular height of the section is about 200 
eet. 
OTH 
ATH « 
cieet th a 
oe 
¢ 
y : « tl ET ea 
dL genes 
: gissbnO-ce= 
Fig. 5. Cliff on Rock Creek a | su taining silicified 
j .—a a, pebble-conglomerate containing 
Wood ; 5 6, tified sands and clays; ¢c, irregularly columnar basal 
0 0, stra’ 
Superficial uncemented drift. 
