I 
BULLETIN OF THE LABORATORIES 
Fig. I. SECTION FROM MOOT’S RUN TO FLINT RIDGE, LICKING CO., OHIO. 
There is nothing to indicate any great disturbance in position in 
the strata since their deposition. Although there is no obvious uncon- 
formity between any of the strata exposed, yet the fact that so many 
•of them are shore deposits and the fact that farther south and east 
Tands of limestone are interpolated, indicates that here and there there 
must have been intervals of considerable duration when the process 
-of accumulation was interrupted and the days ran round unrecorded. 
Any attempt to estimate the time represented must include ample al- 
lowance for such breaks in the continuity of the series. Within the 
limits of our study about 400 feet in vertical thickness can be assumed, 
of which 200 feet consists of the coal measure rocks, and the remain- 
der of shales and freestones of sub-carboniferous age. It is probable 
that 100 feet should be added below the rocks exposed in this part of 
the county to touch the dividing line between the Devonian and car- 
boniferous. We have then some 500 feet of material, representing at 
least, say 500,000 years, without allowance for the intervals. 
Much of the material, undoubtedly, accumulated much more rap- 
idly than a foot a century; while the shales and coals no doubt repre- 
sent periods of slower deposition. Highly carbonated waters and at- 
mosphere no doubt facilitated subaerial erosion, while the profusion of 
vegetation must have greatly increased the deposit of organic matter. 
