LETTER OE TRANSMITTAL. 



Department of the Interior, 



United States Geological Survey, 



WasJiinyton, D. C, Jajiuari/ 31, 1896. 



Sir: I transmit herewith the inanuscript and iUustrations of a memoir 

 and the plates for an accompanying athis upon the Marquette Iron-bearing 

 District of Michigan, by W. S. Bayley and myself 



The field work upon which the present report is based began more 

 than five years ago. This work was by W. N. Merriam, W. S. Bayley, 

 H. L. Smyth, J. Morgan Clements, James R. Tliompson, and C. R. Van 

 Hise, although Mr. Bayley mapped a larger area than anyone else. 

 Several others have rendered subordinate assistance. The mapping of the 

 area from west of the center of R. 28 W. to Michigamme was mainly 

 the work of Mr. Merriam. He also studied the Republic tongue, but his 

 work in this part of the area was supplemented by a much more detailed 

 study by Mr. Smyth. From the center of R. 28 W. to the center of 

 R. 27 W., the mapping was partly the work of Mr. Merriam and partly 

 that of Mr. Bayley. East of the center of R. 27 W. to Lake Superior 

 the mapping was mainly by Mr. Bayley, although i\Ir. Clements assisted 

 one field season. Mr. Smyth mapped the Republic tongue and the area 

 to the west. All the underground work in connection with the mines 

 was done by Mr. Thompson. My own part of the task was tlie structural 

 study of the whole district, to which I gave one entire field season and 

 large parts of several others. 



The field work on the western part of the district l)y ]\Ir. Merriam 

 and. Mr. Smyth was for private parties. The original specimens, notes, and 

 maps were placed at our disposal for the joreparation of this report. To 



