314 THE POPULAR SCIENCE MONTHLY. 



its sediments the Humboldt Group. In the middle province was a 

 smaller body of water called the North Park Lake, of which the area 

 is underlain by beds to which the same name has been given by Hague 

 and Hayden, while in the region of the Great Plains the Niobrara Group 

 of Marsh was laid down in what King terms the Cheyenne Lake. 



The details of the description of these Tertiary lakes, and of the 

 history of their formation and disappearance, are among the many 

 things which Mr. King's volume contains, that for want of space must 

 be passed without notice. 



Quaternary. One of the most interesting chapters in Mr. King's 

 volume is that which describes the records of the Quaternary age in 

 the region which he surveyed. The salient points in this history are 

 briefly as follows : Along the fortieth parallel in the far West during 

 the glacial period there was no general glaciation, no continental ice- 

 sheet, but glaciers formed on all the more important mountain-ranges, 

 extending down from their summits to the level of from 6,000 to 9,000 

 feet above the sea. Traces of these ancient glaciers are seen in exca- 

 vated lake-basins, glaciated valleys, and terminal and lateral moraines. 

 The glaciers of the Uintah Mountains were by far the most important 

 in all this region. Snow and ice crowned the Park and Medicine Bow 

 Ranges, and extended down all the valleys which radiated from them ; 

 but the ice-covered area was small as compared with the great breadth 

 of the country. The Uintah Mountains, however, according to Mr. King, 

 then formed a broad-topped table-land 17,000 or 18,000 feet above the 

 sea, all of which was one great ice-field, with local glaciers descending 

 the valleys both toward the north and south. The whole length of the 

 range was thus covered, and the ice-field had a north and south width 

 of some fifty miles. Thus it formed a glacial area considerably larger 

 than that of the Alps at present. West of the Great Basin, as we know 

 from the reports of King and Le Conte, the Sierra Nevada was the 

 theatre of glacial action on a still grander scale. 



The topographical changes in the far West during the Quaternary 

 age seem to have been numerous, but not consequent upon great dis- 

 turbances, although this unquiet region has shown more or less of its 

 instability to the present day. The changes which would most strike 

 an observer were variations in the water-surface ; for Mr. King, join- 

 ing his observations to those of G. K. Gilbert, has shown that even as 

 late as the Quaternary the Great Basin was a well-watered country, 

 and contained two lakes, which in magnitude were scarcely exceeded 

 by any of those now existing on the continent. Of these, one called 

 by Gilbert Lake Bonneville, occupied the Great Salt Lake Valley, with 

 a vast extension toward the south and west. Great Salt Lake occupies 

 the deepest portion of its basin, and, with Utah and Sevier Lakes, rep- 

 resents the residue of its water after a long period of dryness, during 

 which the evaporation exceeded the precipitation. The other great 

 Quaternary lake of this region has been named by Mr. King La Hon- 



