ON CLINTON CONGLOMERATES AND WAVE MARKS 
IN OHIOVAND KENTUCKY: 
WITH A RESUME OF OUR KNOWLEDGE OF SIMILAR OCCURRENCES 
IN OTHER SILURIAN STRATA OF THESE STATES, AND THEIR 
EVIDENCE UPON PROBABLE LAND CONDITIONS. 
CONTENTS. 
First record of the occurrence of pebbles in the Clinton of Ohio, by Professor Orton. 
Former observations by the writer, based upon Professor Orton’s material. 
Pebbles and wave marks in the Cincinnati group. 
Observations by the Kentucky Survey. 
Trenton. 
Utica, or “Lower Hudson” of Kentucky Survey. 
“ Middle” Hudson. 
“Upper” Hudson. 
Observations by Mr. E. O. Ulrich, in Kentucky. 
Lower Hudson; West Covington; Middle and Upper Hudson. 
Observations by Professor John Locke, in Ohio. 
Upper Hudson, near West Union. 
Observations by Professor E. Orton, in Ohio. 
Lower Hudson, near Cincinnati. 
Observations by the writer. 
Lower Hudson, at West Covington, Kentucky. 
Upper Hudson, near Winchester, Ohio. ; ; 
Observations by Nelson W. Perry and Joseph F. James, near Oxford, Ohio. 
first record of the occurrence of pebbles in the Clinton of Ohio, by 
Professor Orton.—It is almost twenty-five years since the dis- 
covery of pebbles in the Clinton of Ohio was announced. The 
value of the discovery for determining the physical conditions 
which must have attended the deposition of this group was at 
once recognized. The Cincinnati anticlinal axis was believed to 
have been in existence as a land area in Paleozoic times, and the 
occurrence of pebbles towards the eastern border of the axis, the 
supposed shore line of Paleozoic times, seemed strong cor- 
roborative evidence of this view, and was believed to fix the 
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