PRE-CAMBRIAN LITERATURE OF NORTH AMERICA 561 



Allen' finds a series of magnetic belts in a region covered by 

 Paleozoic rocks and glacial drift extending east of Waucedah 

 on the Menominee range to Escanaba, a distance of about twenty- 

 eight miles. From Waucedah, the buried eastward extensions of 

 two productive iron formations have been traced for six miles by 

 magnetic survey. The detached magnetic belts east of this limit 

 may or may not be equivalent to the iron ranges at Waucedah. 

 They undoubtedly represent belts of folded sedimentary rocks 

 which may include iron formation. 



Allen and Barrett^ describe the Conover district of northern 

 Michigan, about forty-five miles southeast of the Gogebic range, as 

 a drift-covered area showing several magnetic belts. Drilling 

 has shown that the underlying rocks are slates intruded by granites. 

 The authors believe that the slates are the equivalent of the iron- 

 bearing slates of the Iron River district. 



Allen and Barrett^ state that the existence of the Manitowish 

 range is indicated by a series of strong, parallel linear magnetic 

 belts about twenty-five miles southeast and parallel to the Gogebic 

 range. Drilling has shown that the underlying drift-covered rocks 

 are mica schists intruded by granites. 



Allen and Barrett* report that the Vieux Desert district of 

 Wisconsin and Michigan lying about forty miles southeast of the 

 Gogebic range is a deeply drift-covered area showing several faint 

 magnetic belts. As shown by drilHng, the underlying rocks are 

 acid gneisses and schists. 



Allen and Barrett^ correlate the strongly magnetic iron forma- 

 tion of the Marenisco range with the Ironwood formation of the 



^ R. C. Allen, "Relative to an Extension of the Menominee Iron Range Eastward 

 from Waucedah to Escanaba, Michigan," £c(?w. Geo^., Vol. IX, No. 3(1914), pp. 236-38, 

 I map; also in Mick. Geol. Surv. Pub. 18 (1915), Geol. Ser. 15. 



^ R. C. Allen and L. P. Barrett, "Geology of the Conover District," Mick. Geol. 

 Surv. Pub. 18 (1915), Geol. Ser. 15, pp. 123-29. 



3 R. C. Allen and L. P. Barrett, "Geology of the Manitowish Range," Mick. Geol. 

 Surv. Pub. 18 (1915), Geol. Ser. 15, pp. 111-17. 



4 R. C. AUen and L. P. Barrett, "Geology of the Vieux Desert District," Mick. 

 Geol. Surv. Pub. 18 (1915), Geol. Ser. 15, pp. 119-21. 



s R. C. Allen and L. P. Barrett, "Geology of the Marenisco Range," Mich. Geol. 

 Surv. Pub. 18 (1915), Geol. Ser. 15, pp. 65-86. 



