January 27, 1905.] 



SCIENCE. 



J. D. Dana first recognized the submarine 

 channel of the Hudson as evidence of late 

 continental elevation. Lindenkohl first 

 perceived the canon-like character of the 

 outer portion of the channel near the border 

 of the continental shelf, where the channel 

 suddenly becomes a gorge 2,400 feet deep in 

 the submerged plain. Lindenkohl thought 

 that the canon was terminated by a bar, 

 but Dr. Spencer has determined that no 

 bar exists and that the canon cuts through 

 the edge of the continental bench about 

 eight miles farther. It then widens to a 

 valley which can be readily recognized for 

 an additional twelve miles and to a depth 

 of 9,000 feet at a distance of 71 miles from 

 the head of the submarine channel near 

 Sandy Hook. The cafion is double, the 

 upper part being four miles wide while the 

 inner, lower, more sinuoi;s portion is less 

 than two miles across. The period of great 

 elevation, amounting to about 9,000 feet, 

 coincides with that of the early pleistocene. 

 Since that time there has been a subsidence 

 to somew^hat below the present level, fol- 

 lowed by a re-elevation of 250 feet as seen 

 by the shallow channels of the continental 

 shelf. The region is now sinking at the 

 rate of two feet a century and is under- 

 going other and less important changes. 



In a second paper on 'The Improbability 

 of Land in the Vicinity of the North Pole,' 

 Dr. Spencer said in part: 



When Dr. Nansen discovered the deep 

 Polar Basin, sharply defined by a conti- 

 nental shelf, 300-350 miles wide, north of 

 Siberia, with this continuing to Spitz- 

 bergen, situated in its very edge, it was 

 proof that no land was to be expected ris- 

 ing out of the basin until the continental 

 shelf on the American side should be 

 reached. The broad Siberian shelf con- 

 tinues even north of Bering Straits, and 

 there are soundings which suggest the loca- 

 tion of its approximate border. Alaska 

 encroaches upon this shelf apparently to 



near its border, thus reducing its breadth 

 to probably 50 miles. Beyond into Beau- 

 fort Sea, the Mackenzie River empties by 

 a fjord known to a depth of more than 

 1,140 feet and another from behind Bank's 

 Land of 1,836 feet, not far from its own 

 head far within the line of the islands. 

 Among the islands another of the discov- 

 ered fjords reaches to more than 2,400 feet. 

 All of these features prove that the archi- 

 pelago of high mountains is only a dissected 

 plateau, now sunken and with drowned 

 valleys between the islands, which valleys 

 incise the continental shelf in such manner 

 as to indicate that the shelf itself can not 

 extend faf beyond the outer line of the 

 known islands. A sounding about 30 miles 

 north of Grinnell Land, with a depth of 

 432 feet further suggests that the edge of 

 the shelf is being approached, for the outer 

 margin of this seems to be limited by a 

 depth of about 300 feet beneath sea level. 

 From these submarine topographic fea- 

 tures, which are the very best guide, the 

 author supposes that no important islailds 

 exist beyond the line of the known archi- 

 pelago, and that the deep polar basin 

 reaches for 300 or 350 miles from the pole, 

 aproaching the American continental shelf 

 north of Grinnell Land. 



The formal sessions of Section E closed 

 with the reading of the following papers 

 by title in the absence of their authors : 

 'The Structure of the Central Great 

 Plains,' by N. H. Darton; 'Typical Desert 

 Deposits of Eastern Persia,' by E. Hunt- 

 ington; 'Interpretation of certain Lami- 

 nated Glacial Clays, with Chronologic De- 

 ductions,' by C. P. Berkey; 'The Fossili- 

 ferous Beds of Sankaty Head, Nantucket, 

 and Their Age,' by ]\Iyron L. Puller; 'On 

 the Jagersfontein Tiffany (Excelsior) 

 Diamond, Weight 971J Carats,' by George 

 F. Kunz ; ' On Some Pegmatyte Veins of 

 California,' by T. C. Hopkins; 'The Petro- 

 graphy of Belvidere Mountain, Vermont,' 



