io8 /. G. ANDERSSON 



that the sohfluction here works with less intensity than in the 

 tracts studied by me. 



Detritus terraces of the type mentioned have been noted by 

 De Geer on the Ovik Mountains in Jamtland, and by Svenonius 

 at Sitasjaure and Vassijaure in Swedish Lappland.^ 



All these observations are made in the high mountain regions, 

 but Professor Hogbom has, in a very interesting paper, called atten- 

 tion to the fact that under favorable conditions solifluction can 

 work on a rather large" scale also in the woody lowlands of Norr- 

 land, and in some rare cases also in more southern parts of Scandi- 

 navia. Hogbom describes from Lule River how forest trees grow- 

 ing on slowly moving ground are deformed, and he clearly dem- 

 onstrated that in the fine fluviatile sediments, filling the lower parts 

 of the large river valleys in Norrland, soil- flowing in some places 

 is a very important transporting agent. ^ 



Tibet. — In the vast Tibetan highlands Dr. S. Hedin during his 

 last expedition underwent most trying experiences of solifluction. 

 For days and weeks his caravan struggled through a terrible quag- 

 mire of water-saturated detritus. Many a time the animals were 

 brought out of the treacherous soil only with the utmost difficulty, 

 and once a camel got lost in such a morass. "The poor beast was 

 literally swallowed up in the mud, and all attempts to get him out 

 failed."^ ■ 



The descriptions by Hedin clearly show that the saturated soil 

 actually moves down-hill, and that the solifluction in those far- 

 extended highlands works on a very large scale, lowering the moun- 

 tains and filling the valleys: 



I could not help thinking that the whole bunch of hills would, like a viscous 

 fluid or thick porridge, gradually flatten themselves out to a uniform level. This 

 conformation was caused by the incessant precipitation searching into the 

 ground and making it like a sponge; for only a very small quantity trickled 

 into the superficial brooks and rivulets, and so flowed away. The absence of 

 vegetation with its interlacing roots also contributed to the same result. In 

 two or three places the shales stuck up edgewise and cut the camel's feet.^ 



^Geol. Foren. i Stockholm Fork., 1904, p. 466. 

 'Ibid., 1905, pp. 19-36. 



3S. Hedin, Central Asia and Tibet, Vol. II, p. 288. 

 4lbid., Vol. I, p.' 519. Italics are mine. 



