REVELATIONS OF THE YOSEMITE VALLEY 81 



U-shaped valley. As the glacier receded, torrential streams cut into 

 the glacial moraines, changing the vicinity of the upper reaches of the 

 Merced into more angular surfaces, with the ultimate purpose of 

 eliminating U and substituting V. 



After all the theories have been advanced, their truth or fallacy 

 will remain a matter of conjecture until the underlying facts are 

 brought to light. Buried far below the flowery meadows and boulder 

 overburden lies the unseen, pristine bed rock. Graven on tablets of 

 stone in indelible characters is the key to the cryptic cipher of this 

 Sierran Sphinx. The mining geologist is more practical than academic. 

 He would prospect the floor of the valley to unearth that hidden key. 

 Therefore, he would advise the sinking of shafts down through the 

 sediments, ascertaining their character and striking the sunken sill. 

 Following the rim of the latter for a short distance, the miner-geologist 

 would soon determine in finality the genesis of the Yosemite Valley. 

 If this deep basin was once shattered by a cataclysm, causing the fall- 

 ing away of an almost bottomless abyss, the zones of its marginal 

 fracturing could be definitely discovered. Or, if overdeepening of the 

 bed rock by the abrasive-shod plow of a glacier be the true cause of its 

 carving, the striated strata and the morainal drift will tell the tale. 

 Stream-erosion will also be revealed to its exact extent. Therefore, 

 it would seem that no appropriation for the researches of the Geological 

 Survey in this region can be expended to better advantage than by 

 prospecting in miner-like fashion for the hidden truth of the making 

 of this great natural wonder. That this practical idea meets with the 

 approval of the Geological Survey party is shown by a recent expression 

 by Mr. Francois E. Matthes in the Sierra Club Bulletin. " It is to be 

 hoped that some day such borings may be undertaken; they would not 

 merely serve to solve a problem of great local interest, but would con- 

 tribute much-desired data regarding the still-challenged eroding effi- 

 ciency of glaciers." 



The Yosemite at the Exposition 



One of the most interesting features of the federal government's par- 

 ticipation at the Panama-Pacific International Exposition will be the 

 presentation of a large relief model of the Yosemite National Park. 

 Cartographers of the United States Geological Survey are putting the 

 finishing touches on this miniature of the Yosemite Valley and its sur- 

 roundings. They will show its stupendous steeps and glaciated basins 

 as vividly as though viewed from an aeroplane. Every visitor to the 

 Exposition who may be interested in geological science will find this 

 replica replete with fascinating details carefully set forth. 



Buffalonians laid special stress upon the nearness of Niagara Falls 

 to the Pan-American Exposition. Likewise, Californians take great 



VOL. LXXXV. — 6. 



