COERELATIOX OF DEVOisIAX STRATA 377 



region, there probably occurred a great expansion of the sea in the In- 

 terior Continental province. During Manitoban time the Arctic Sea ad- 

 vanced as far south as Iowa, northwest Illinois, and northern Missouri 

 and spread eastward as far as the James Bay and Abitibi Eiver region 

 about as shown in figure i. This great expansion prevailed also in the 

 late Devonian during the time of deposition of the Spoj-angites-heSiTmg, 

 Long Eapids shale. 



Long Eapids shale. — The only fossils found in the Long Eapids shale 

 are the spores of a species of a pteridoph3^te plant known as Sporangites 

 huronense, which occur in great abundance throughout the black shale. 

 Numerous spores of this species are also characteristic of the Sweetland 

 Creek shale (usually referred to the Upper Devonian) of Iowa and Illi- 

 nois, which is known to extend as far north as Chicago and Milwaukee. 

 It may be that the Long Eapids shale is to be correlated with the Sweet- 

 land Creek shale farther south, the latter then being a representative of 

 the Long Eapids deposit. 



Professor Parks has reported several species of Devonian fossils from 

 Kwataboahegan Eiver and Little xlbitibi Eiver that do not appear in the 

 foregoing lists and that seem to indicate a fauna older than that found 

 along Abitibi Eiver. There seems no doubt that other fossiliferous De- 

 vonian horizons are present in the James Bay region than those found 

 along the Abitibi and Moose rivers. It is possible that a part or all the 

 older Devonian strata indicated by the fossils reported by Parks from 

 Kwataboahegan and Little Abitibi rivers may be represented in the 

 Abitibi Eiver section by the unfossiliferous sandstone and shale of the 

 Sextant formation, which is older than the Abitibi Eiver limestone. It 

 is also recognized that in other places in the James Bay region a fossilif- 

 erous limestone, not represented in the Abitibi Eiver section, may be 

 present at a horizon lower than that of the sandstone and conglomerate 

 occurring in the basal part of the Devonian along Abitibi. The detailed 

 description of the relation and correlation of the Devonian rocks in this 

 region older than the Abitibi Eiver limestone must be postponed until a 

 more detailed study of the rocks ex])osed along the Kwataboahegan and 

 otlier rivers tributary to the Moose and Albany rivers can be made. 



