The Stone Quarry. 13 



the explanations that these different groups 

 of rock may be the petrified beaches of three 

 different beach periods, and in this explana- 

 tion the quarryman and the scientist are at 

 one. This new thought becomes important. 

 Let us see what it implies. If we designate 

 the first, the Rogue River group, because of 

 its association with the Rogue River valley; 

 the second the Umpqua group, because of its 

 association with the Umpqua valley; and the 

 third the Willamette, because of its associa- 

 tion with the Willamette region, and these 

 three groups are held to represent the sea 

 beaches in their relation to each other in the 

 order of their occurrence, this order must be 

 universal. This, also, is found- to be true, that 

 whenever these groups are found in contact, 

 the lower one is always the Rogue River 

 group, the Umpqua next, and the Willamette 

 the uppermost. Not only is this true on the 

 Pacific coast. The world over, the group of 

 rocks we have associated with the Rogue 

 River valley, geologists have called the Cre- 

 taceous; the group we have associated with 



