302 J. F. Kemp — Buried Channels Beneath 



inferred elevation of the land which we had been led to assume 

 from the general phenomena of ice accumulation and from the 

 specific characters of the submarine valley of the Hudson, 

 whose recognition even before 1863 by the late Professor J. 

 D. Dana marks one of the many acute observations and infer- 

 ences regarding the local geology which we owe to his tireless 

 activity. Professor Dana, however, had but imperfect data 

 and consequently an inadequate idea of the depths involved.* 

 Mr. A. Lindenkohl of the IT. S. Coast and Geodetic Survey, 

 and with more extended soundings, took up the question 

 anew in 1885 and 1891. f A canyon was demonstrated in the 

 continental shelf which about 50 miles off Sandy Hook was 

 2400 ft. below the neighboring sea-bottom, there found at a 

 depth of 420 ft. Beyond this point and along the course of 

 the submerged channel, soundings of much less depth were 

 met, and for some years the inference was drawn that a bar, of 

 inexplicable character and apparently too far out to be a ter- 

 minal moraine, crossed the mouth of the canyon and filled it 

 up. Subsequently more numerous soundings proved this 

 apparent bar to be due to a sharp southerly bend in the canyon, 

 whose course had hitherto been southeast to east by south, and 

 that it extended with increasing depth to the edge of the con- 

 tinental shelf. These latter features have been especially brought 

 out and emphasized by J. W. Spencer in a valuable series of 

 papers discussing off-shore phenomena in the sea-bottom, and 

 best summarized in this connection in the reference given 

 below,;); in which will also be found a review of earlier work. 

 Dr. Spencer demonstrates the existence of the canyon down to 

 9000 ft. below the surface. This aspect of the subject will not 

 be pursued further in this paper, the object being merely to 

 remind a reader that these conditions exist off the mouth of 

 the Hudson and that they have an interesting connection with 

 the phenomena of its land-channel. The most obvious sugges- 

 tion in explanation is the elevation of the land, yet the amount 

 of elevation required is a bit staggering. We are reminded of 

 the alternative view, not without its advocates, that the land 

 may have remained stable while the ocean drew off to the 

 southern hemisphere and by lowering the sea-level established 

 equivalent drainage relations. § 



*See the Manual of Geology, 1st ed., 1863., p. 441, where the depth at 

 about 80 miles from Sandy Hook is given as only 720 ft. 



f Geology of the Sea-Bottom in the approaches to New York Bay, this 

 Journal, xxix, 475, 1885. Notes on the Submarine Channel of the Hudson 

 Biver, and other evidences of Bost-Glacial Subsidence of the Middle Atlantic 

 Coast Begion, this Journal, xli, 489, 1891. 



X The Submarine Great Canyon of the Hudson Biver, this Journal, Jan- 

 uary, 1905, 1-15. 



§ H. W. Bearson contributed a series of papers upon this point to the 

 supplement of the Scientific American, early in 1908. 



