180 D. D. CAIRKES SECTIOX ALONG YUKON-ALASKA BOUNDARY 



was performed on behalf of the Canadian Geological Survey, and was ex- 

 tended for 2 or 3 miles on each side of the boundary line, an agreement 

 haying been entered into between the Geological Surreys of the United 

 States and Canada whereby geological work was conducted on both sides 

 of the 141st meridian to the north of the Porcupine, by members of the 

 United States Suirey, in exchange for similar work by the Canadian 

 Geological Surrey, to the south of this riyer. 



The belt to the south of Porcupine Riyer proved to be of particular 

 interest and stratigraphic importance, as all the Paleozoic systems from 

 the Cambrian to the Carboniferous are represented, and nowhere else in 

 the entire Eocky Mountain region of Canada and the United States is so 

 complete a section of the Paleozoic known within so limited an area. A 

 considerable collection of fossils was obtained, which includes, in addition 

 to the Cambrian faunas, many other interesting varieties, including 

 graptolites, which are of rare occurrence in Alaska and Yukon. 



Preyious TTork 



No geological work has been performed along the 141st meridian be- 

 tween the Porcupine and the Yukon except in the immediate vicinity of 

 these rivers. McConnell came down Porcupine Eiver in 1888, making a 

 geological reconnaissance en route,^ and Kindle made a geological exami- 

 nation of the rock formations along the Porcupine below Xew Rampart 

 House for the United States Geological Survey during the summer of 

 1907.^ In addition a number of geologists, including McConnell,^ SpuiT,^ 

 Prindle,^ Brooks and Kindle," and others have reported on the geological 

 formations along Yukon River in the vicinity of the International Bound- 

 ary. With this exception, practically nothing was known geologically 

 concerning the area in which the writer was engaged during the summers 

 of 1911 and 1912, previous to the commencement of this work. 



Topography 



Topographically, the area or belt along the 141st meridian between 

 Yukon and Porcupine rivers lies for the greater part at least within the 



3 R. G. McConnell : Report on an exploration in the Yukon and Mackenzie basins. 

 Northwest Territory. Geol. and Nat Hist. Surv. of Canada., Ann. Rept.. vol. iv, 1888- 

 1889. part D. pp. 129-134. 



' E. M. Kindle : Geologic reconnaissance of the Porcupine Yalley. Alaska. Bull. Geol. 

 Soc. Am., vol. 19. 1908. pp. 310-338. 



4 Op. cit.. pp. 134D-143D. 



5 J. E. Spurr : Geology of the Yukon Gold district. Alaska. "T. S. Geological Survey, 

 18th Ann. Rept.. part iii, 1896-1897. pp. 89-382. 



8 L. M. Prindle : The gold placers of^the Forty-mile. Birch Creek, and Fairbanks re- 

 gions. Alaska. U. S. Geological Survey. Bull. No. 2.51. 1905. 



■^ Alfred H. Brooks and E. M, Kindle : Paleozoic and associated rocks of the Upper 

 Yukon, Alaska. Bull. Geol. Soc. Am., vol. 19, 1908, pp. 255-314. 



