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GEOLOGY: W. H. BUCHER 
1 . The crests of all large ripples are broadly rounded like the troughs. 
More than half of all seen in limestones of the Ordovician and Silurian 
of the Cincinnati Anticline were more or less symmetrical; the others 
are distinctly asymmetrical. 
2. Not one showed any sign of assortment. Shells of Rafinesquina, 
over 5 cm. long and wide, Bryozoans 8 to 10 cm. long and over 1 cm. 
thick, and, in the Richmond, calices of Streptelasma, over 10 cm. 
long and over 3 cm. wide are found scattered equally over crests, sides 
and troughs of the ripples, mixed in a most any proportion with finer 
shell fragments down to the finest matrix filling the interstices. The 
same broadly rounded, symmetrical crests with complete absence of 
assortment of any kind were observed in ripples measuring 145 cm. 
from crest to crest in the conglomeratic Berne member of the Black- 
hand formation. Here, pebbles of ±0.5 cm. diameter are uniformly 
mixed with coarse and fine sand. 
In the growth of oscillation ripples, the to and fro motion of the 
oscillating current produced by waves on the bottom of a water body 
involves a constant tossing of the grains. This results in a sifting 
and complete assorting of the grains. Its absence in the large ripples 
in question provqs that they have not formed by the action of waves, 
but of some current. Clues to its nature are found in the following 
observations. 
3. In Kentucky the Brassfield formation of the Silurian east of the 
Cincinnati Anticline shows one or two rippled layers within its 18 feet 
of thickness. West of it no traces of ripples were found according to 
Foerste.^ The ferruginous oolitic facies of the same formation is also 
limited to the east side of the anticline, extending over a distance of 
nearly 120 miles from Madison County, Kentucky, to Clinton County, 
Ohio, in a belt running roughly north-south (perhaps slightly east of 
north) . On the west side of the Anticline nothing but a salmon brown 
color of the limestone betrays the (relative) neighborhood of ferruginous 
deposits.® From this the inference appears justified that the shore- 
line of the Brassfield sea was somewhere to the east with a general north- 
south trend. 
Of the 13 measured exposures of rippled layers in the Brassfield, 
ranging over a distance of nearly 50 miles, 12 showed directions of strike 
between N 50 W and N 110 W, averaging N 76 W, i.e., at right angles 
to the direction of the assumed shore-line. The current, therefore, 
must have run parallel to this shore-line. This excludes the undertow 
and similar currents from discussion. 
4. Large current-ripples are found only on rocks of relatively coarse 
