wiluams.1 CONCLUSIONS. 267 



nomenclature have been discarded because the facts did not support 

 the correlation when precision was applied. In the far West the auoin- 

 alies were so great that defenders of the traditional geology have stood 

 aghast. The Government geologists, who were chiefly concerned in 

 developing the facts, have gaiued the reputation of disregarding prece- 

 dent, European standards, and even the opinions of their brother geolo- 

 gists ; but after one of these doubters has climbed the Eockies, trailed 

 across the plateaus, and looked into the caiious, he has come back forced 

 to confess that "the half was not told him," and paleontologists and 

 geologists alike have been obliged to expand their systems to accom- 

 modate these bold geologists of the saddle. 



Such has been the result of seeking uniformity for a single continent. 

 Like results, we believe, will appear upon comparison of the formations 

 of different provinces on other continents. The experience of European 

 geologists who have not gone outside Europe has been mainly with the 

 details of a single geologic province; a certain degree of uniformity is 

 therefore practicable for them. It is no disrespect to the European 

 system that has led Americans to think lightly of conformity to any 

 uniform standard of geologic classification or nomenclature. The reason 

 for the failure on the part of American geologists to adopt and apply 

 the older standards of Europe to their formations is found in the fact 

 that the supposed uniformity does not actually exist. 



The literature of the first quarter of the century demonstrated that 

 classification can not be based upon uniformity of lithologic constitution. 

 The last twenty-five years has made it evident that uniformity of strati- 

 graphy cannot be relied on for correlations, and now the modern school of 

 paleontologists are demonstrating the fact that the divisional lines 

 marking the biologic or time scale do not correspond to those of the 

 structural or stratigraphic scale, but are determined by independent 

 factors. In the classification of rock formations the character of the 

 formations should receive chief consideration, but the particular geolo- 

 gic period in which sediments are deposited has practically no relation 

 to the nature of the sediments or their amount or their physical 

 arraugemeut as geologic deposits. It is, hence, a grave question 

 whether the development of our science does not demand that geo- 

 graphic factors should take precedence of time factors in all classifica- 

 tions of geologic formations. 



The correlations between form, density, and composition of minerals 

 are formulated in systematic mineralogy, the correlations between form 

 structure and age are formulated in systematic paleontology, and a sys- 

 tematic geology will be attained when the relations between the compo- 

 sition, the stratigraphic order, and the geographic position of rock 

 formation can be adequately formulated. 



The experience of geologists in the past shows conclusively that 

 composition and stratigraphic order of sequence are intimately asso- 

 ciated with geographic locality. Each geographic province has its own 



