TREIBWS 
The Age of the Second Terrace on the Ohio at Brilliant, near Steuben- 
ville.—The inquiry raised by Professor Chamberlin, in his comments 
(JouRNAL OF GEOLOGY, Vol. IV., pp. 107-112) upon the age of the 
gravel at Brilliant, Ohio, in which Mr. Huston’s discovery of an imple- 
ment was made, is both pertinent and important, and certainly calls 
for a more specific statement of my reasons for believing that its 
deposition was substantially synchronous with that of the 130-foot 
terrace at the mouth of the Beaver, about fifty miles above it, concern- 
ing whose age there is I believe, no question. Of course the only 
absolute certainty in the case is that at the time of the deposition of 
the gravel at Brilliant the floods in the Ohio River at that point reached 
a height something more than eighty feet above the present low-water 
mark. This the character of the cross-bedding actually demonstrates. 
The evidence connecting it with the 130-foot terrace at Beaver, while 
of a more general character, is still, I think, convincing. 
In the first place, Professor Chamberlin’s remark that there are 
terraces on the river above and below Brilliant that reach 120 and 
130 feet above low water, while the implement-bearing terrace reaches 
only 80 feet, though literally correct, conveys a false impression without 
a fuller statement of the facts. The nearest 130-foot terrace above 
Brilliant is that at Beaver, where a powerful glacial tributary came into 
the Ohio overloaded with terrace material. From that point down to 
Brilliant the terrace, though practically continuous on one side or 
other of the river, gradually diminishes both in height and in coarse- 
ness of material, and never rises more than 102 feet above low water 
until reaching Portsmouth, two or three hundred miles below, where 
the Muskingum River, the first glacial tributary below Brilliant, joins 
the Ohio. Here the terrace rises 110 feet, while at Cincinnati, below 
the junction of the Little Miami, the terrace for the first time jumps 
again to the 120-foot level. The smaller height of the terrace at Bril- 
liant, therefore, is readily explained without the theory of its having 
been worked over. 
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