312 TJie American Geologist. May, l^9y 
anticline, with Plattsmouth at its crest. The slope from the 
south end of the section is the general inclination produced by 
the uprising of the Ozark dome. 
The shales appear to become thinner northward; while the 
limestones seem to vary little in thickness. There is one note- 
worthy exception in the lola limestone. This bed which is 
one of the most important in the series in Kansas rapidly be- 
comes thinner north of Leavenworth. At Atchison and St. 
Joseph it is not more than a dozen feet in thickness, and dis- 
appears eritirely before Forest City is reached. The Bethany 
formation retains its usual thickness so far as the limestones 
are concerned, but they appear to separate somewhat in the 
south. With the fading out of the lola limestone, the Thayer 
and Parkville shales merge, forming an uninterrupted shale 
bed 125 feet in thickness. To the northward it becomes re- 
duced to one-third of this measurement. The Plattsburg re- 
tains its full development from one end of the section to the 
other. The Lawrence shales also diminish in thickness to- 
wards the north; and the subordinate latan limestone appears 
to merge wnth the Plattsburg below. The Platsmouth 
limestone shows no appreciable difference in thickness 
in the south and north limbs of the syncline. The 
Platte shales form a lenticular bed, the thickness of 
which is nearly 200 in the middle of the Brown- 
ville syncline, though thinning on each side to 50 feet. The 
Forbes limestone retains about the same thickness throughout. 
Only for a short distance in the center of the syncline does this 
layer disappear below the water-level of the Missouri river. 
The Atchison shales are about 325 feet thick along the line 
of the section. This brings the horizon of the Cottonwood 
limestone, the upper member of the Missourian series, not 
m.ore than 300 feet above the Missouri river at the lowest 
point of the syncline. 
The Plattsmouth anticline has a gentle slope on the north, 
but a rather steep slant southward. This fact, which was not 
recognized until very recently, was no doubt the main cause 
of much of the confusion that existed regarding the strati- 
graphy of this part of the section, in the early days of its ex- 
ploration. 
