RfiSUME OF LITERATURE. 97 



in the Keewatin formation; (5) the magnetites of the crystalline schists of 

 the Vermilion formation. It is maintained that the upper iron deposits 

 of the Mesabi and those of the Penokee-Gogebic are the equivalents of the 

 Taconic ores of western New England. 



Irving, R. D., and Van Hisb, C. R. The Penokee iron-bearing series of Michi- 

 gan and Wisconsin: Mon. U. S. Geol. Survey Vol. XIX, 1892, pp. 534, with pis. 

 and maps. See also Tenth Ann. Rept. U. S. Geol. Survey, 1890, pp. 3il-507, with 

 23 pis. and maps. 



Irving and Van Hise in 1890 and 1892 give a detailed description of 

 the Penokee series of Michigan and Wisconsin, and of the complex of rocks 

 south of this series. They discuss the relations whicli the Penokee rocks bear 

 to the underlying and overlying series, as well as to the Eastern sandstone. 

 The Marquette and Felch Mountain series of Michigan, the Menominee 

 series of Michigan and Wisconsin, and the Auimikie and Vermilion Lake 

 series of northeastern Minnesota and Ontario are alluded to, since they con- 

 tain large developments of rocks which are almost exact reproductions of the 

 iron formation rocks in the Penokee series. The Animikie is considered in 

 more detail than the rest, since a comparison of its iron-bearing formation 

 shows that it consists of the same kinds of rocks which have been derived 

 from an iron carbonate in the same manner as those of the iron formation 

 of the Penokee series. 



A further comparison of the Penokee series proper and the Animikie 

 series shows that they also occupy the same relative positions with refer- 

 ence to overlying and underlying rocks, one dipping northward under the 

 basin of Lake Superior and the other dipping southward under the same 

 body of water. They are therefore regarded as equivalent. The rocks in 

 various other areas in the Lake Superior basin refei'red to the Upper 

 Huronian are regarded as probably equivalent with the Penokee series 



Van Hise, C. R. An attempt to harmonize some apparently conflicting views 

 of Lake Superior stratigraphy: Am. Jour. Sci., 3d series, Vol. XLI, 1891, pp. 

 117-137. 



In the above paper Van Hise describes the physical break between a 

 Lower and an Upper Huronian series. That the two series are separated 

 MON XLV — 03 7 



