RIPPLE-MARKS IN OHIO LIMESTONES 465 



SILURIAN RIPPLE-MARKS 



Beasleys Fork. — Ripple-marks in the upper part of the Brass- 

 field limestone (formerly called Clinton) were noted at several 

 localities in Adams County. One of these localities is in the bed 

 of the upper part of Beasleys Fork, some distance above the house 

 of Walter D. Grooms, which is about i\ miles south of West Union 

 on the Wrightsville Pike. This stream is crossed by three layers 

 of limestone in which ripple-marks are conspicuously shown. 



The lowest layer is a very crinoidal limestone, from 3 to 10 

 inches thick, which forms a small fall, and its top is about 8 feet 

 3 inches below the top of the Brassfield limestone. The ripple- 

 marks run about east and west, with the more gradual slope to the 

 north and the steeper toward the south. The top of the second or 

 middle ripple-marked layer is 4 feet 1 1 inches below the top of the 

 Brassfield formation, and the layer itself is 5 =*= inches thick, but^ 

 the ripple-marks are not so conspicuous as in the layer below and the 

 one above. These ripple-marks run north and south with the 

 steeper slope on the east side and the more gentle slope on the 

 west. Finally, there is the third or highest ripple-marked layer, 

 the top of which is 4 feet 5 inches below the top of the Brassfield, 

 and opposite the small house on the bank of the creek on the Joe 

 Morrison farm. The layer is a grayish, somewhat greenish- 

 spotted, crystalline limestone, 8=*= inches thick. The ripple- 

 marks run about north and south, with the steeper slope to the 

 east and the more gradual to the west. These ripple-marks are 

 heavy and the crests are 26, 31, 34, 35, and 38 inches apart. The 

 distance from the bottom of the trough to the top of the ridge 

 varies from 3 to 9 inches. 



These ripple-marks were noted by Dr. Foerste in his description 

 of the section "along the road to Beasley Fork." The following 

 is that part of this section in which the ripple-marks occur, as 

 described by Dr. Foerste: 1 



Ft. In. 



Limestone, wave-marked 3 



Clay 8 



Limestone 3 



Clay 3 



1 Kentucky Geol. Survey, Bull. No. 7, 1907, p. 42. 



