IOWA ACADEMY OP SCIENCES. 
55 
as seen at Le Claire'^, but be assumes that the inclination of the 
beds is due to folding and uplift subsequent to their deposition. 
On this assumption the Le Claire limestone would have a thick- 
ness of more than 600 feet, whereas the maximum thickness 
does not exceed 80 feet, and the average over the whole area is 
very much less. Prof. A. H. Worthenf studied this limestone 
at Port Byron, 111., and Le Claire, Iowa, and describes it as 
‘ ‘ presenting no regular lines of bedding or stratification, but 
showing lines of false bedding or cleavage at every conceivable 
angle to the horizon.” He assigns to these beds a thickness of 
* 
Figure 2. Inclined undulating beds o'^-tbe Le Claire stage near Newport, Iowa. 
fifty feet, but he offers no explanation of what he calls “false 
bedding or cleavage.” In White’s report on the geology of 
lowaj the oblique bedding seems to have been taken as evi- 
dence that a line of disturbance crossed the Mississippi river at 
Le Claire with a direction nearly parallel to the Wapsipinicon 
valley. This apparent disturbance was last recognized about 
three miles west of Anamosa. The angle of dip it is said has 
reached in some places twenty-eight degrees with the horizon. 
McGee in discussing the Regular Deformations of Northeastern 
Iowa% quotes Dr. White on the Wapsipinicon line of disturbance 
* Kept, on the Geol. Surv. ol the State of Iowa, Hall and Whitney, voL I, part I, pp. 
73-74. 1858. 
+ Geol. Surv. of 111., vol. I, p. 130. 1865. 
% Kept, on the Geol. Surv. of the State of Iowa, Charles A. White, vol. I, p. 133. 1870. 
§ Pleistocene history of Northeastern Iowa, p. 340. 1891. 
