The Revision Of Geological Time -- By: Anonymous
BSac 60:239 (July 1903) p. 578
The Revision Of Geological Time
G. Frederick Wright
In the Bibliotheca Sacra for April, 1884, I published an article entitled “The Niagara Gorge as a Chronometer.” This was based upon personal investigations made the summer before, and included a brief discussion of previous opinions upon the subject. Desor had estimated that the rate of the recession of the falls was so slow that the formation of the gorge must have occupied 3,500,000 years. Sir Charles Lyell thought it might have been accomplished in 35,000, but that it probably required 100, 000 years,—a surmise which has taken almost complete possession of the popular literature upon the subject, and which even now seems almost impossible to displace. Other investigators—notably Mr. Bakewell in 1846, Dr. Pohlman in 1883, and about the same time Mr. Gardiner of the New York Survey, and Professor A. Winchell—maintained that the rate of recession was as much as three feet a year. My conclusion2 was that, “from the best light we now have, it seems altogether probable that the cataract is receding at a rate that would suffice to produce the whole chasm from Queenston up in less than 12, 000 years; and if, as is not unlikely, any considerable portion of the gorge above the whirlpool had been formed by preglacial agencies, even that relatively short period must be considerably abbreviated. This article was considered of so much importance by Professor James D. Dana, that he immediately requested the privilege of republishing it in the American Journal of Science’, where it appeared in the number for July, 1884.
Since that time the accumulation of facts bearing upon this subject has been continuously going on, taking a very wide range, and involving, among other things, the question of the permanence of the outlet through the present channel. These investigations (one of the most important of which was conducted by myself) led to the discovery that in early postglacial time the outlet of the Great Lakes was not over Niagara, but from Lake Huron through Lake Nipissnig and the Mattawa River into the Ottawa, which enters the St. Lawrence at Montreal.3 But many indications went to show that the continuance of this Ottawa out-
BSac 60:239 (July 1903) p. 579
let was probably not more than 2,000 or 3, 000 years; so that the extension of the postglacial chronology, from that cause, beyond that given by the Niagara gorge, would not be relatively great. Among the most important of these investigations were those conducted by me, under the direction of the New York Central Railroad, bearing upon the enlargement of the mouth of the gorge at ...
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