Febeuaby 7, 1902.] 



SCIENCE. 



203 



force for the promotion of science, ready to 

 cooperate witli other institutions which are 

 now or may be established in Washington 

 or elsewhere. By its very foundation it is 

 precluded from any thought of rivalry. If 

 the founder's hopes are realized his wise 

 and munificent bounty will benefit not only 

 oui' own country but the interests of man- 

 kind. 



D. C. G. 



THE WRECK OF UT. MAZAMA.* 

 INTRODUCTION. 



The geological record of this country 

 from the earliest epochs to the present time 

 is replete in volcanic phenomena, but the 

 cUmax in such matters appears to have 

 been reached in the earlier portion of the 

 Neocene, when one of the largest kuown 

 volcanic fields of the world was vigorously 

 active in our Northwestern States. It 

 stretches from the Rocky Mountains to the 

 Pacific, embracing a large part of Wyo- 

 ming, Montana, Idaho, Washington, Oregon 

 and California, and presents a great variety 

 of volcanic phenomena concerning which, 

 notwithstanding a copious literature, there 

 has been as yet but a small amount of de- 

 tailed investigation. The work of the Geo- 

 logical Survey has taken me across this 

 field in various directions and afforded an 

 extended opportunity at intervals during 

 nearly a score of summers upon the Pacific 

 coast to study the western portion of the 

 field. Instead of attempting a summary 

 of what has been done in this large field, 

 as perhaps might be expected upon this 

 occasion, I beg to call your attention more 

 particularly to a special feature in the 

 volcanology of the Cascade Range, which, 



* Abstract of Presidential address delivered be- 

 fore the Geological Society of Washington, Dee. 

 IS, 1901. The full address with geological map 

 and illustrations will probably appear as a bul- 

 letin of the U. S. Geological Survey. 



so far as I am aware, is not well represented 

 in any other portion of the field nor in fact 

 anywhere else Avithin the United States. 

 To set forth more clearly the wreck of Mt. 

 Mazama, which is the central theme, it is 

 necessary to consider briefly the general 

 relations of the whole range. 



LIMITS OF THE CASCADE RANGE. 



The western limit of the great volcanic 

 field is marked by the corresponding border 

 of the Cascade Range, which is made up at 

 least largely, if not wholly, of volcanic ma- 

 terial erupted from a belt of vents extend- 

 ing from northern California to central 

 Washington. Lassen Peak marks the 

 southern end of the Cascade Range and 

 Rainier is near the northern end. Beyond 

 these peaks the older rocks rise from be- 

 neath the Cascade Range and form promi- 

 nent mountains, the range itself occupying 

 a depression in these older terranes. 



FOUNDATION OP CASCADE RANGE. 



A clearer conception of the development 

 of the Cascade Range may be gained by 

 considering the geography of the region 

 during the later portion of the Cretaceous. 

 At that time the coast of northern Califor- 

 nia, Oregon and Washington subsided, 

 causing the sea to advance upon the land. 

 In California it reached the western base 

 of the Sierra Nevada and covered a large 

 part, if not the whole, of the Klamath Moun- 

 tains. In Washington it beat upon the 

 western base of the range near the coast 

 north of Mt. Rainier, but in Oregon it ex- 

 tended far into the interior. Marine de- 

 posits of this pei-iod occur along* the base 

 of the Blue Mountains in eastern Oregon. 

 The Cascade Range of Oregon did not then 

 exist to shut out the open sea from that 

 region. East of the Klamath Mountains, 

 as shown by the position and distribution 

 of the Cretaceous strata and their fossils 

 of marine origin, the open sea connected 

 directly with that of the Sacramento Val- 



