10 REPORT OF THE SECRETARY. 



EXPLORATIONS AND RESEARCHES. 



STUDY OF OLDER SEDIMENTARY ROCKS. 



During the past twenty years I have been studying the older sedi- 

 mentary rocks of the North American Continent from Newfoundland 

 to Alabama on the eastern side and from southeastern California to 

 northern Montana on the western. In the interior, east of the Rocky 

 Mountains, studies were carried on in Texas, South Dakota, Minne- 

 sota, and Wisconsin. 



Three important sections remained to be examined — one of the 

 Lower Cambrian in western Nevada, one in northern Montana, and 

 another of the lower Paleozoic Rocks of the main range of the Rocky 

 Mountains in the vicinity of the Canadian Pacific Railroad. 



The latter was selected for examination during the field season of 

 1907, and although the work did not begin until after the close of the 

 fiscal year I will here briefly recount some of its results. Early in 

 July, a camp outfit was secured at Field, British Columbia, and work 

 begun on Mount Stephen. Subsequently sections were studied and 

 measured at Castle Mountain, west of Banff, Alberta ; at Lake Louise, 

 south of Laggan, Alberta, and on Mount Bosworth on the Conti- 

 nental Divide near Hector, British Columbia. 



Upwards of 20,000 feet of strata were carefully examined and 

 measured, and collections of fossils and rocks made from many locali- 

 ties. It was found that the Cambrian section included over 12,000 

 feet of sandstones, shales, and limestones, and that the three great- 

 divisions of the Cambrian — the Lower, Middle, and Upper — were 

 represented in the section of Bow River series and the Castle Moun- 

 tain group. Characteristic fossils were found in each division. 



ALASKAN EXPEDITION. 



In continuation of work already satisfactorily begun, the Secretary 

 authorized, in April of the present year, an expedition for the col- 

 lection of the remains of large extinct vertebrates, particularly mam- 

 mals, in Alaska. Although fragmentary materials have been se- 

 cured there from time to time by various exploring parties and 

 mining expeditions, the country is still, to a considerable extent, a 

 virgin field, and the recent great development of the mining industry 

 makes the present time particularly favorable for the work proposed, 

 especially on account of the facilities for transportation thus rendered 

 available. 



The expedition has been placed in charge of Mr. C. W, Gilmore, a 

 member of the staff of the National Museum, who will have the serv- 

 ices of a guide trained in the methods of the work to be accomplished 

 and thoroughly familiar with the regions to be explored. 



