GENERAL GEOLOGY 



NOTES ON THE STRATIGRAPHY AND IGNEOUS 



ROCKS 



BY BENJAMIN KENDALL EMERSON 

 WITH PETROGRAPHIC NOTES BY CHARLES PALACHB 

 INTRODUCTION 



Stratigraphical geology and petrography form the sub- 

 ject of this chapter. The plan of the expedition, giving 

 only rare opportunities for long stops or inland excur- 

 sions, was not so favorable for studies in this field as for 

 work in many other departments of science. It was 

 rather our fortune to enjoy the geology with the scenery 

 of the remarkable regions we were visiting, and to contri- 

 bute through our geological enthusiasm to the pleasure 

 and interest of the party as a whole, than to bring away 

 much that was new to our science. 



It was greatly to our advantage that we had with us 

 Dr. Dall, who knew more of the paleontology, zoology, 

 geology and hydrography of the coastwise regions of 

 Alaska and Bering Sea than any other person, and Mr. 

 Gilbert, whose knowledge of the geology of the western 

 half of the continent is so especially full. Mr. Palache 



