OF COMMON SALT. 



139 



that I am aware of, of the formation of rock salt in 

 Post-Tertiary times — a long interval, which includes the 

 Pre-Glacial, and perhaps the Pliocenic, the Glacial, Post- 

 Glacial, Pre-Historic, and Historic— the last, or Historic 

 division of which, is known to occupy about 6,000 years. 



I purposely exclude from this consideration the salt of 

 the Eunn of Kutch, and other similar superficial deposits of 

 clearly marine origin, which do not possess the characters of 

 rock salt. 



Let us now see the geographical distribution and extent of 

 rock salt formations. As might be expected, rock salt has 

 very wide geographical limits. It is found in all the older 

 continents of the world, and its discovery in the newer, as 

 Australia and New Zealand, is probably a question of time. 

 It will be sufficient here to mention the principal countries in 

 which it is found. In Europe, it is found in Austria, Poland, 

 Germany, France, Switzerland, Hungary, Spain, England, 

 and Ireland. A vast chain of salt mines extends along each 

 side of the Carpathian mountain range, comprehending the 

 salt mines of "Wallachia, Transylvania, Galicia, Upper 

 Hungary, Upper Austria, Styria, Salzberg, and Tyrol. In 

 Asia, it is found in India, Afghanistan, Persia, the Kirghis, 

 and Asiatic steppes of Eussia, Burmah, and China. In 

 Africa, it is found in the northern Highlands, in Morocco, 

 Algeria, and also in Madagascar. In North and South 

 America it is found in Washington Co., Nevada, the Andes, 

 the Alleghanies, the Oregon Mountains, Bolivia and Peru, 

 and in an island in the Gulf of Mexico. 



As regards its present level in the earth's crust, rock salt is 

 found at the surface, and at various elevations, above and 

 below it. It is also found above and below the level of the sea. 

 The Wieliczka mines are 1,000 feet below the level of the 

 soil, and 400 or more below that of the sea ; their lower 

 limits are undiscovered. At Middlesborough-on-Tees, rock 



