M. jBT. Howorth — Elevation of American Cordillera. 447 



solitudes no rivulet flows, and no water spring gushes forth ; only- 

 after journeying for many a long hour the traveller sometimes 

 comes upon some field of crystallized salt, a white expanse on 

 which the clouds and bhie sky are reflected as on the surface of 



a lake The solitudes of the Andes most resembling the desert 



regions of the old world and of the United States are the elongated 

 plateaux, which rise one above another between the sea and the 

 principal chain of the Andes, in southern Peru, and on the frontiers 

 of Bolivia and Chili ; such as the Pampas of Islay and Tamarugal, 

 and the desert of Atacama. The Pampa of Tamarugal has a mean 

 altitude of from 2900 to 3900 feet. It is a plain nearly covered 

 with beds of salt, or salares, which are worked like rock-quarries. 

 The strata of salt are so thick, and rain is so rare upon the plateau, 

 that the houses of the village of Noria, which are inhabited by the 

 workmen, are entirely constructed of blocks of salt. Some deserts 

 situated to the east of the Tamarugal, on more elevated plateaux, 

 contain a still larger quantity of salt. 



The Pampa of Sal, which is overlooked by the volcano of Isluga, 

 has a mean altitude of not less than 13.800 feet, and its whole 

 extent, which is 125 miles long, and from 9 to 24 miles wide, is 

 perfectly white. The depth of salt deposited upon this plateau 

 varies from 5 to 16 inches, according to the undulations of the 

 ground." 



" Whence do these enormous masses of salt proceed ? Doubtless 

 from the sea or ancient lakes which formerly covered these countries, 

 and have been gradually emptied by the rising of the soil " (Reclus, 

 "The Earth," pp. 107-108, and 110-111). 



We can hardly separate the drainage of these seas from the 

 upheaval which uplifted great collections of bones of the Mastodon 

 to a level close to the snow-line, and quite outside the range of the 

 soft- wooded trees on which they fed. The Salt-licks of Ohio actually 

 contain great masses of Mastodon and other bones. 



If we cross the Cordillera, both in North and South America, from 

 west to east, we have another and equally difficult problem to solve, 

 namely, to account for the vast and continuous beds of unstratified. 

 loam which, whether we call it Loess or Pampas mud, has the same 

 structure, and which no ingenuity can mistake for a deiDosit which 

 has been thrown down by water in a gradual way, or been accumu- 

 lated at all in a gradual way, since it not only has no signs of 

 stratification, except in very local circumstances, but overspreads 

 whole continents with its mantle, irrespective of the drainage or the 

 contour of the country, and which seems unmistakeably to prove the 

 operation of some rapid and cataclysmic cause. 



In regard to South America some of the most distinguished 

 geologists, such as D'Orbigny, Brongniart, Elie de Beaumont, etc., 

 have not scrupled to explain it as a consequence of the sudden or 

 very rapid upheaval of the Andes. D'Orbigny, who is much the 

 most distinguished geologist who has written on South America, 

 which he explored so diligently, and upon which he published a 

 most magnificent work, is very emphatic on the subject, and I must 

 quote some passages from his too little consulted masterpiece. 



