678 SCHUCHERT AND TWENHOFEL ORDOVICIC-SILURIC SECTION 



Page 



Siluric system. Niagaran ( Anticostian) series 704 



General discussion of the series 704 



Becsie River formation (Richardson's C12 to C14 and DJ 705 



Correlation 706 



Gun River formation (Richardson's Division D, excepting DJ . . 708 



Correlation 711 



Jupiter River formation ( Richardson's Division E ) 713 



Correlation 714 



Chicotte formation (Richardson's Division F) 715 



Correlation 715 



Introduction 



In 1856 James Eichardson, of the Geological Survey of Canada, spent 

 the months of July, August, and September studying the geology of 

 Anticosti and the Mingan Islands to the north, adjacent to the south 

 shore of Labrador, now Quebec. His collection was a large one, consist- 

 ing of forty boxes and barrels of fossils. The result of this study was 

 the determination of a section beginning early in Ordovicic time, having 

 a thickness of 540 feet, followed by 19 miles of sea, when the section 

 again begins high in the Ordovicic and continues well up into the Siluric 

 through 2,300 feet of limestones and shales.^ 



Eichardson's sections are in all essentials still correct and the strati- 

 graphic foundation upon which all subsequent work for this region must 

 be based. 



The fossils of Anticosti were studied by Billings, and he states that 

 during his preliminary work "an opportunity was afforded me of examin- 

 ing these in connection with Professor Hall, the eminent Palaeontologist 

 of the State of New York, who was then on a visit to this city [Mon- 

 treal]." This joint examination made it all the more possible for 

 Billings to make the correlations that have since stood unchallenged.^ 

 His conclusions are as follows : 



"All the facts tend to show that these strata were accumulated in a quiet 

 sea in uninterrupted succession during that period in which the upper part of 

 the Hudson River group, the Oneida conglomerate, the Medina sandstone, and 

 the Clinton group were in the course of being deposited in that part of the 

 Palaeozoic ocean now constituting the State of New York, and some of the 

 countries adjacent. If this view be correct, then the Anticosti rocks become 

 highly interesting, because they give us in great perfection, a fauna hitherto 

 unknown to the Palaeontology of North America. When the great thickness of 



a Richardson : Geological Survey of Canada, Report of Progress, 1857, pp. 191-245. 

 3 Billings: Ibidem, 1857, pp. 247-255. 



