6 THE PBNOKEB IRON-BEARING SERIES. 



1848 under the joint charge of Messrs. J. W. Foster and J. I). Whitney. 

 Mr. Barnes appears to have been the first geologist to enter any portion of 

 our district.^ In the summer of 1847 he accompanied the township hind 

 surveyors, noting and locating all rock exposures met with oii the lines 

 surveyed, from a point on the Ontonagon river where it crosses the east line 

 of T. 49 N., R. 41 W., Michigan, southward for 28 miles; then westward 12 

 miles, north 12 miles, west 6 miles, north G miles, and east 6 mile*s to the' 

 northeast corner of T. 47 N., R. 43 W., Michigan; and thence northward 

 to Gogebic lake. Mr. Barnes's exploration was thus chiefly in the granitic 

 and gneissic region in the southern part of the southern end of our district. 

 One of his lines, however, crossed the iron-bearing slates, but without 

 affording him any indication of their existence.^ 



Whitney and Barnes (1847).— Later in the Same scason Mr. Barnes accom- 

 panied Mr. J. D. Whitne}', then one of tlie chief assistants under Jackson, 

 in a second trij) into the country between Gogebic lake and the Montreal 

 river.^ Tlieir course was from the mouth of Black river to the northwest 

 corner of T. 48 N., R. 46 W., Michigan ; thence along the range and town- 

 ship lines (then the only surveyed lines in the region), soutli 12 miles, east 

 6 miles, north 12 miles, and west 5 miles to the Black river, on the north 

 line of T. 48 N., R. 46 W., Michigan. This route, as also that previously 

 traversed by Mr. Barnes, is indicated on Fig. 1. Thus Messrs. Barnes and 

 Whitney made in 1847, in all, three traverses of our district, the easternmost 

 one lying 6 miles west of lake Gogebic, and tlie westernmost 2 to 5 miles 

 east of the Montreal river. Whitney also saw nothing on his trip to sug- 

 gest to him the existence in the region of any other formation than the 

 granites to the sonth and the eruptive greenstones of the coppei--l)earing 

 series to the north. Accordingly this portion of tlieir district was mapped 

 by Messrs. Foster and Whitney with the granites to the south and the erup- 

 tive greenstones to the north coming directly into contact with one aiiotlier, 

 without any intervening slates. This mapping was reproduced on nil Inter 



' Diary of field work for the summer of 1847, iu Report on the Geological anil Mineralogical Sur- 

 vey of the Mineral Lauils of the United States iu the State of Michinan; by C. T. .lacksiiu, I'nited 

 States Geologist. Senate Uocs., 1st sess. 31st Cong., 1849-50, vol. iil, No. 1, jit. 3, pp. 371-0115, also 

 627-801. 



2 See p. 34. 



^ Whitney's diary, iu same report as that of Mr. Harues just referred to, pp. 33, 34. 



