50 Smithsonian Exploration in Alaska in 1904 



" In the case of the Beresowka the supposition of Bunge is un- 

 tenable. The ice wall there presents a concavity of great radius, 

 corresponding to the curvature of the bank of the river, i. e., to 

 the direction of the washing away by the Beresowka, but not of a 

 crevasse. Neither can his supposition explain how the ice is to 

 be found at the upper edge of the terrace. 



" The presence of ice on a terrace gives us an occasion to say 

 a few words about the supposition accepted by many American 

 scientists about the formation of land ice from lakes. We can very 

 well imagine such a way of formation of the ice and accept it for 

 certain cases, but then the ice must have the structure of water ice, 

 and this is not the case with the Beresowka ice." 



As will be discussed later the classification of ice by its gas content 

 presents a very wide range of possibilities, for in nature many 

 extraneous conditions must be considered that do not present them- 

 selves in laboratory examinations. Apparently nothing is to be 

 gained toward demonstrating the snow origin of ice-beds by a 

 microscopic study of its crystalline structure, for the ice no matter 

 of what origin, but especially if from water, may undergo such 

 modifications in crystalline form by recrystallization and regelation, 

 especially near exposed surfaces, as to obscure all tracing of its 

 original structure or origin. The presence of air or gas bubbles of 

 various shapes and in varying quantity to the cubic unit of ice lead to 

 nothing upon which to base even conjectures, for this phenomenon 

 of enclosed gas is a variable occurrence in both snow and water 

 ice, especially in nature. 



" According to Toll's observations of * stone ice ' in the islands 

 of New Siberia there is not any stratification to be found.''* In 

 other cases, as for instance in the ice deposits of the Ljachow Island, 

 and also in quite new ice exposures on the Siberian continent on 

 the lower Yana, he saw the stratification quite distinctly. When 

 Bunge speaks of the ground ice of northern Siberia, he says ex- 

 plicitly : ' if the mass of ice were stratified, w^e should consider it as 

 coming from accumulated masses of snow. These, of course, 

 would have shown horizontal stratification, similar to those that 

 we find in new deposits of snow ; but nowhere are horizontal stripes 

 to be found.' 



" We must therefore admit that this ice is really not stratified^ 

 for it is not possible to admit that the stratification has been over- 

 looked by the observers." 



^* Die fossilien Eislager, p. 72. 



