CHAPTER TT. 



By W. S. liAYLEY. 



THE HASKMEN^r COMPLEX. 



P)e]()\v tIic .Vlyoukiau deposits of the Manjuette area are scliistose and 

 massive pliases of crystalline and pvroclastic roeks, so different from the 

 Algoukian sediments tliat there is rarely any diffii-uhA' in disting-uishiiiy 

 between them and the clastic rocks above them. These inferior rocks are 

 unconformabh' l)elo\v the lowest members of the Marquette series. It is 

 probable that the^' embrace members of widely different ages, but up to 

 the present time no separation of the schists into sharply defined subgroups 

 upon the basis <tf age has been attempted, because of the complexity of the 

 relations existing between the various r<:)ck types, due largely to the many 

 vicissitudes through which they have passed and the consequent alterations 

 to which they have been subjected. 



Divisions corresponding to the Laurentian and Greuville series of 

 Canada, as defined by Adaras,^ and even the lithological ones, Laurentian 

 and Mareniscan, proposed l)y X'dii Hise," are not clearh' distinguishable in 

 all of the district that has been studied. Jiut the work on the pre-C-ambrian 

 areas is as \'et far from complete. A more careful investigation of large 

 areas will jjrobablv show that, in a general sense, such broad distinctions 

 as those recognized in the terms "Laurentian" and "Mareniscan" do exist 

 in the Michigan "Archean." The present study of the Marquette district 

 was primarily directed to the Algonkian series. In the jjre-Algonkian 



'Afurtber pontribiitioii to our knowledge of the Laurentian, l)y F. 1>. Adams: Am. Jonr. Sci. 

 3d series, Vol. L, 1895, p. 58. 



^Correlation papers — Archean and Algonkian : Hull. U. S. Geol. Survey No. 86, 1892, pp. 488— tiO. 



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