/M7MC,O.V/.l 



;n.'i 



angular stones, rounded bowlders, and finer elays and sands. 

 These materials were evidently deposited as terminal moraines 

 in late Pliocene or early Quaternary times. 8uch dcpowits are 

 especially noticeable in all the larger valleys near the Cordilleras, 

 where they are frequently of great thickness, and, left as harriers 

 by the receding glaciers, they now aid in confining consideralde 

 hodies of fresh water, which as lakes extend in a more or less 

 continuous chain all along the base of the mountains. Among 

 the more imi)ortaiit of these are lakes Argentina, N'iedma, San 

 Martin, and Jkienos Aires. All these lakes extend far back into 



MOUNT leviathan: SOU I'H COAST OF TIKKRA DKI- FU EGO 



Ftom a Photograph by J. li. Hatcher 



the otherwise almost inaccessible recesses of tlie Cordilleras, 

 where they are fed by numerous glaciers. Xoue of the lakes 

 have been thoroughly ex{)lored and mapped, and their exact size 

 and sha])e are ns yet undetermined. 



There are no more rugged mountains anywhere in the \vt)rld 

 than are the Cordilleras ()f Patagonia. They rise directly from 

 the plains on the east and the sea on the west to a heiglit in 

 some places of more than 10,0()0 feet, and present myriaiis of in- 

 accessiljle peaks witliout so much as a single practicable pass, so 



