24 TIIK :\IAUQUKTTE lUOX-BEAEINd DISTRICT. 



both localities are the same. Other Ijeds ot" tlie same ore were observed 

 farther south along tlie Menominee River. Foster writes (p. TTG): 



These bed.s, .'^o far as I have observed, present a marked siiuilaritj' in niineralogical 

 characters, and derive their origin from common causes, and these were aqueous. 

 The jointed structure and waved strati tication of some of the beds prove that ujneous 

 causes have opoi'ated, since their deposit, to modify and cliange their character. 



WmTNKV, J. 1). Verbal communication to the Boston Society of Natural 

 History. Deceiid)er 1!», 1849. Proc. Boston Soc. Nat. Hist., Vol. Ill, pages 210-213. 



J. D. Wliitney, who was also associated with Jackson, gave the main 

 results of his work in an address to the Boston Society of Natural History, 

 delivered in December, 1849, anticipating, to some extent, his official 

 reports. As in the case of most other accounts of Lake Superior geologv, 

 this one is devoted principally to the copper region. Reference, however, 

 is made to innnense deposits of iron ore, existing- maiuh'- as a fine-grained, 

 almost chemically pure peroxide of iron. "It occupies about eighty quarter 

 sections of the mineral country, and, at the nearest point, is about 12 miles 

 from the lake." The quantity of the ore is re|3orted to be beyond calcu- 

 lation. "It api)ears in the form of solid ridges and knobs, evidently of 

 igneous origin, the highest being about 1,100 feet above the level of the 

 lake, and some of them being half a mile long." The speaker exhibited 

 to the society a specimen of banded jasper and ore. In rejilvto questions, 

 Whitney declared that no New Red sandstone occurs in any of the region 

 examined by him. Since he had examined the coast of the lake near the 

 Carp and Chocolate rivers, it is evident that he disagreed with Rogers as to 

 the age of the Lake Superior sandstones and conglomerates. 



Foster, J. W., and Whitney, J. D. Synopsis of the explorations of the 

 geological corps in the Lake Superior land district in the Northern Peninsula of 

 Michigan, under the direction of J. W. Foster and J. D. Whitney, U. S. Geologists. 

 Dated November r>, ISIO. 31st Congress, 1st session, 1849-50. Seuate Documents, 

 Vol. Ill, No. 1, pages 605-625. With map.s. 



After the resignation of Dr. Jackson from the position he held on the 

 Lake Superior Survey, J. W. Foster and J. D. "\Miitney, his priucii)al assist- 

 ants, were ai)pointed to succeed him. They were furnished with copies ot' 



