GRANITIC PHENOMENA, 379 



of the Silurian schists, the porphyries, and the red CHAPTER 

 grits." * '^;^"- 



The Altaic Mountains are not a chain forming the 

 boundary of a country like the Himalaya, which limit Elevation of 

 the elevated plain of Thibet, and have a rapid slope only ^ "'"^ 

 on the side next to India, which is lower. The plains ic 

 the neighbourhood of the lake Balkachi have not an 

 elevation of more than 1920 feet aI)ove the sea. 



Between the meridians of Oust-Kamenogorsk and Prolonpation 

 Seniipolatinsk the Altaic system is prolonged, from east "vstem '""^ 

 to west, under the parallels of 49 and 50 degrees by a 

 chain of low mountains over an extent of 736 miles, as 

 far as the steppe of the Kirghiz. This ridge has been 

 elevated through a fissure which forms the line of sepa- 

 ration of the streams of the Sara-sou and Irtisch, and 

 which regularly follows the same direction over an ex- 

 tent of 16 degrees of longitude. It consists of stratified 

 granites not intermixed with gneiss, and of greenstone, 

 porphyry, jasper, and transition-limestone, in which there 

 occur various metallic substances. Humboldt observes 

 when referring to the granitic phenomena cf this regian : 

 — " In no part of the two hemispheres have I seen rocks Granitic 

 which have more the character of eruption or effusion, i' ^'-"""i^°^- 

 than the granites which surround the mass of the Altai. 

 These insulated I'ocks rise in the steppe at the foot of the 

 Alpine Mountains, in the most picturesque forms. In 

 descending from the steppe of Platovsk to the rocky 

 banks of Lake Kolyvan, we are surprised by the granitic 

 eruptions which, over several square leagues, rise from a 

 perfectly smooth soil. The rocks are sometimes in a row, 

 sometimes dispersed over the plains, affecting the most 

 bizarre forms of narrow walls and little towers or poly- 

 gons. The smallest masses resemble tribunes, chairs, or 

 funereal monuments. But what gives so singular an as- 

 pect to this country, is the contrast in the height and 

 volume of these granitic elevations. Some of them, such 

 as the Vyssohaya Gora, attain a lieight of 400 or 500 

 feet, while others are only seven or eight feet high, and 



