RIPPLE-MARKS IN OHIO LIMESTONES 457 



marks in the Trenton limestone near Hull, Quebec, 1 and given a 

 summary of previously described ripple-marks in American lime- 

 stones. 2 At an earlier date Dr. August Foerste had noted the 

 occurrence of wave-marks (ripple-marks) in the Ordovician and 

 Silurian limestones at a number of localities in Kentucky, Ohio, 

 and Indiana. 3 Recently Professor J. A. Udden has described 

 ripple-marks in the Burlington limestone of Iowa and in limestones 

 of Comanchean age in Texas. 4 



On account of the comparative infrequency of described observa- 

 tions of ripple-marks in limestone the writer has concluded to record 

 the most conspicuous of those which he has seen while engaged 

 in field work in Ohio. These will be grouped in the several geologic 

 systems in which they were observed, arranged in ascending order. 



ORDOVICIAN RIPPLE-MARKS 



Elk Run. — The best ripple-marks seen in the Ordovician are in 

 the upper part of the Richmond formation on Elk Run in the 

 northwestern part of Adams County. This locality is on the 

 Marion Dunlap farm, about 1 \ miles east of Winchester and 3 miles 

 west of Seaman, where the ripple-marked layer of limestone forms 

 the floor of the run for a considerable part of the distance between 

 the Norfolk & Western Railway trestle and the highway bridge. 

 An excellent view of these ripple-marks may be had from the 

 Norfolk & Western passenger trains while crossing the trestle 

 if one looks downstream to the north. 



The first series of ripple-marks is on a layer forming the bed of 

 the run a short distance below the trestle and continuing up a 

 branch from the west for about two rods. The direction of the 

 ripple-marks is about due north and south. The more gradual 

 slope (stoss) is to the east, and the steeper (lee) to the west. The 

 distance apart (amplitude) of the crests varies from 28 to 32 inches 



1 Jour. Geol., XXII (1014), 707-9. 



2 Ibid., pp. 709-11. 



3 Jour. Geol., Ill (1895), 50-60 and 169-97; 1-40 (reprint); Jour. Cincinnati Soc. 

 Nat. Hist., XVIII (1896), 167; Am. Geologist, XXXI (1903), 333-61. 



'•Jour. Geol., XXIV (March, 1916), 125, 126; illustrated by Fig. 3, p, 126, Fig. 

 4, p. 127, and Fig. 5, p. 128. 



