LAND SCULPTURE BY MOUNTAIN GLACIERS 381 



have relatively slight irregularities compared to the dimensions of 

 the cap itself. Except in very high latitudes this base must be 

 somewhat elevated, for like mountain glaciers ice caps are nour- 

 ished by the surface air currents, and their snows are deposited 

 above the snow line. 



The Norwegian tind or beehive mountain. Within temperate 

 or tropical climes the snow line lies so high that only the loftier 

 mountains are able to support glaciers. It follows that those 

 which are formed flow upon relatively high grades with corre- 

 spondingly high rate of movement and increased cutting power. 

 Within high latitudes the snow is found nearer the sea level, and 

 glaciers are for the most part correspondingly sluggish in their 

 movements as well as less active denuding agents. 



To this condition characteristic of high latitude glaciers, there 

 is added in Norway another in the peculiar shape of the basement 

 beneath the recent and the still existing glaciers. The plateau of 

 Norway is intersected by a network of deep and steep walled fjords, 

 and the glaciers have developed as small ice caps perched upon 

 veritable pedestals of rock, over the margins of which their out- 

 let tongues of ice descend on steep slopes into the fjord. The tops 

 of the pedestals thus come to be shaped by the plucking and abrad- 

 ing processes into flat domes (Fig. 406), while the knobs of rock, 

 which as nunataks reach above the surface of the ice, divide the 

 outflowing ice tongues at the margin of the pedestal. These 

 tongues being much more active denuding agents, because of their 

 steep gradients, continually lower their beds, thus transforming 

 the earlier knobs of rock into high and steep mountains of more or 

 less circular base. Such " beehive " mountains upon the margins 

 of the fjords are the characteristic Norwegian tinds (Fig. 407). 



READING REFERENCES FOR CHAPTER XXVI 



I. C. RUSSELL. Quaternary History of Mono Valley, California, 8th 

 Ann. Rept. U. S. Geol. Surv., 1889, pp. 329-371, pis. 27-37. 



F. E. MATTHES. Glacial Sculpture of the Bighorn Mountains, Wy- 



oming, 21st Ann. Rept. U. S. Geol. Surv., 1900, Pt. ii, pp. 179-185, 

 pi. 23. 



W. D. JOHNSON. Maturity in Alpine Glacial Erosion, Jour. Geol., vol. 12, 

 1904, pp. 569-578. 



G. K. GILBERT. Systematic Asymmetry of Crest Lines in the High 

 Sierras of California, ibid., pp. 579-588. 



