REPORT OF THE SECRETARY. 11 



RESEARCHES AND EXPLORATIONS. 



An important phase of the Institution's work in the " increase and 

 diffusion of knowledge among men " is the scientific exploration of 

 little-known parts of the earth, as well as the extending of existing 

 knowledge concerning better-known regions through field-work. 

 Although the Institution's funds for this purpose are extremely 

 limited, it is often able to cooperate advantageously with other 

 establishments in putting expeditions in the field. The results of 

 these numerous explorations in every quarter of the globe have not 

 only advanced scientific knowledge, but have greatly enriched the 

 collections in the United States National Museum in biology, geology, 

 and anthropology. 



A number of the expeditions sent out during the past year are 

 described in the appendices to this report, and others are here re- 

 viewed briefly to indicate the character of the Institution's work in 

 this direction. 



GEOLOGICAL EXPLORATIONS IN THE CANADIAN ROCKIES. 



Your secretary continued his geological field-work in the Cana- 

 dian Rockies with two main objects in view, (1) the determination 

 of the character and extent of the great interval of nondeposition 

 «»f sedimentary rock-forming material along the Front Range of 

 the Rocky Mountains west of Calgary, Alberta; (2) the clearing up 

 of the relations of the summit and base of the great Glacier Lake 

 section of 1919 to the geological formation above and below. Work 

 was begun early in July along the Ghost River northeast of Banff, 

 Alberta. 



The solution of the two problems attacked may be briefly described 

 as follows : 



The Rocky Mountain front is formed of masses of evenly bedded 

 limestone that have been pushed eastward over the softer rocks of 

 the Cr.etaceous plains- forming rocks. This overthrust is many miles 

 in extent and occurred long before the Devils Gap, Ghost River Gap, 

 and other openings were cut through the cliffs by running water and 

 rivers of ice. Great headlands and high buttes have been formed 

 by the silent forces of water and frost, many of which stand out 

 against the western sky as seen from the distant foothills and plains. 



It was among these cliffs that we found that the first great cliff 

 was of lower Middle Cambrian age, and that resting on its upper 

 surface there were 285 feet (86 meters) of a yellowish weathering 

 magnesian limestone, named the Ghost River formation, which 

 represents the great interval between the Cambrian below and the 

 Devonian above. Sixty miles to the west, over 4 miles in thickness 



