1883. 155 Trans. N. V. Ac. Set. 



several tunnels through the trap ridge of Bergen Hill, and other 

 species from North Carolina. 



Dr. J. S. Newberry then read the following paper : 



THE EVIDENCES OF ANCIENT GLACIATION IN NORTH AMERICA, 

 AND THEIR BEARING ON THE THEORY OF AN ICE PERIOD. 



(Abstract). 



Prof. Newberry exhibited a map of North America, on which he had 

 represented all the known glaciated areas, and described, chiefly from 

 his own observations, such as lie within the limits of the United 

 States. He showed from the facts given, first, that glaciers once cov- 

 ered most of the elevated portions of the mountain belts in the Far 

 West, as far south as the 36th and, in the east'ern half of the Continent, 

 the 40th parallels ; second, that the ancient glaciers were not pheno- 

 mena produced by local causes, but were evidences of a general 

 climatic condition ; third, that they could not have been produced by a 

 warm climate and an abundant precipitation of moisture ; fourth, that 

 they were the products of a general depression of temperature, and 

 therefore were proofs of the truth of the glacial theory. The facts pre- 

 sented may be briefly summarized as follows. 



The glaciation of the Sierra Nevada is general and very striking ; it 

 has been described by Whitney, King, Le Conte, and others, who have 

 given abundant proof that all the highest portion of the range was once 

 covered with snow-fields, and that glaciers descended from these down 

 the valleys on either side. 



Mt. Shasta once bore many great glaciers, of which miniature repre- 

 sentatives still remain. 



The Cascade Mountains exhibit perhaps the most stupendous record 

 of ice-action known. All the higher portions of the range are planed 

 down and furrowed by glaciers, which descended into the valley of the 

 Des Chutes on the east, and that of the Willamette on the west, as 

 shown by the observations of the speaker in 1855, at least 2,500 feet 

 below the present snow-line. Mt. Ranier still carries glaciers of con- 

 siderable size ; and all the country around, as well as about Puget's 

 Sound and on Vancouver's Island, shows evidence of former glaciation 

 In British Columbia the signs of ancient glacial action, as shown by 

 George M. Dawson, Dr. Hector, Richardson, etc., are conspicuous in 

 all the high country explored. The valleys of the Wasatch range were 

 once filled with masses of ice as far south as central Utah. A type of 

 these was the Little Cottonwood glacier of which the record has been 

 carefully studied by Dr. Newberry. It formed in a cirque at Alta, 

 10,000 to 11,000 feet above the sea, had a length of about ten miles, a 

 thickness — as shown by the line of granitic blocks left along its sides — 



