OF THE UPPER MISSOURI. 57 
teen miles of the mouth of the Big Blue river, were too isolated to determine in all cases 
the relations between outcrops seen at different places. Consequently, although we saw 
at several points along this part of the valley indications of a westward or northwestward 
inclination of the strata, we were left in some doubt whether or not there is a general in- 
clination of the rocks in that direction, between Wabounse and the Missouri. Above this 
point, however, our observations being more connected and the exposures more continuous, 
we were able to determine very satisfactorily that there is at least from near Wabounse, a 
uniform dip towards the west or northwest, so that in ascending the Kansas valley from 
this region we are constantly meeting with more and more modern rocks, as those we leave 
behind pass beneath the level of the Kansas. 
To illustrate this more clearly, we would, in the first place, remark that a bed of light 
grayish yellow granular magnesian limestone, occupying a horizon about 115 feet above 
the Kansas, two or three miles west of Zeandale, passes beneath the level of the Kansas 
before reaching the mouth of the Big Blue river, a distance of near seven miles; while 
another bed (No. 26 of the foregoing section) seen on the very summit of the hills two or 
three miles north of Zeandale, at an elevation of about 320 feet above the Kansas, was 
observed opposite Manhattan at the mouth of Big Blue river, only some 214 feet above 
the Kansas. Again, bed No. 12 of the foregoing general section, which was seen at a 
locality nearly opposite Ogden, at an elevation of about 363 feet above the Kansas, is at 
Fort Riley, eight or nine miles further west, elevated only some 215 feet above the 
Kansas. Above Fort Riley this bed forms a marked horizon, and can be followed by the 
eye without interruption for several miles along the hills on both sides of the river. We 
observed it gradually sinking as we ascended the Kansas valley, until at a point on 
Chapman’s creek, some fifteen miles a little south of west from Fort Riley, we saw it 
nearly down on a lével with the Kansas; beyond this it was not again met with on the 
north side of the Kansas, but we saw it at somewhat higher elevations on the south side 
of the river a little west of this. 
As the distance by an air-line, from the locality nearly opposite Ogden, where this rock 
occupies a horizon at an elevation of 363 feet above the Kansas, to the mouth of Chap- 
man’s creek, is about 23 miles, the dip would appear to be not far from 152 feet to the 
mile. It must be borne in mind, however, that the average fall of the Kansas,—at least 
below Fort Riley,—according to the barometrical observations of Col. Fremont and others, 
is near one and a half feet to the mile, and that if we assume the distance by the windings 
of the river between Chapman’s creek and Ogden, to be about thirty miles, it would make 
the elevation of the Kansas at the former locality some forty-five feet greater than at 
Ogden, which would reduce the dip to a fraction less than 14 feet to the mile. Still as 
the direction of the dip in this region is to the north of west, and the direction of the 
VOL. x11.—8 
