conflicting Views of Lake Superior Stratigraphy. 135 



series in these districts, but the Lower Marquette, Lower Ver- 

 milion, Hunter's Island and Lower Kaministiqua series. It is, 

 however, by no means clear that the Keewatin will not prove 

 to be a complex series just as have the Marquette and Vermil- 

 ion Lake rocks. One other term has been proposed for this 

 place, Marquettian,* but this term is objectionable because as 

 used it included both Upper and Lower Marquette. Dr. 

 Selwyn very strongly maintains that Huronian as used by the 

 Canadian Survey includes not only the rocks designated in 

 this paper under the term Original Huronian, but also all such 

 series as the Keewatin, Lower Marquette, and Lower Vermilion 

 Lake. This also accords with what has been done on the 

 United States side of the boundary in the past, so that for the 

 position in the general column below the Original Huronian is 

 used Lower Huronian. 



Mr. Lawsonf has proposed Ontarian to cover the Keewatin 

 and Coutchiching. It appears to us that this term is unneces- 

 sary, and that the purposes of geology are better subserved by 

 using the term Algonkian to cover all the clastic series between 

 the Fundamental Complex and the Cambrian, and to retain 

 Archean as a term of coordinate value with this for the under- 

 lying complex. 



Dr. Selwyn and Professor N. H. Winchell maintain J that 

 the Keweenawan and , Animikie are properly Cambrian. 

 Whether the term Cambrian shall be so extended downward 

 as to cover two great unconformities and two additional rock 

 series of very great thickness is purely a matter of policy and 

 of nomenclature. While it is of primary importance that an 

 agreement shall be reached as to the actual rock successions in 

 the Lake Superior region and their equivalence, it is but a sec- 

 ondary matter as to the names which shall be applied to them. 

 That fossils are found in the Huronian is not sufficient evidence 

 that the Cambrian shall be extended downward indefinitely. 

 That the evidences of abundant life are here found has been 

 long known. Many of the slates heretofore called Huronian 

 on the south shore of Lake Superior not only contain graphitic 

 material, but a considerable percentage of hydrocarbons. In 

 the Animikie, on the north shore of Lake Superior, it is said 

 that in certain mines and openings rock gas forms in consider- 



*Geol. and Nat. Hist. Survey of Minn., 16th Ann. Kept., 1887, pp. 365, 366. 



f The Internal Relations and Taxonomy of the Archean of Central Canada, 

 Andrew C. Lavvson, Bull. Geol. Soc. of America, vol. i, pp.. 175-193, 1890. 



IT. S. G-eol. Survey, 10th Ann. Rept, Report of the Director. 



The Pre-Cambrian Rocks of the Black Hills, C. R. Yan Hise, Bull. Geol. Soc. 

 of America, vol. i, foot-note p. 238. 1890. 



X Tracks of organic origin in rocks of the Animikie group, A. R. C. Selwyn : 

 this Journal, III, xxxix, 145-147, 1890, with Geol. and Nat. Hist. Survey of Minn. , 

 17th Annual Report, 1888, p. 68. 



