70 
THIRTEENTH REPORT. 
Field Naturalist, who is appointed by the Director, with the approval of 
the Board of Geological Survey. Dr. Rutliven reported to you at the last 
meeting the progress of the biological survey and will report to you at 
this meeting the progress of the biological survey during the past year. 
The report upon the progress of the geological and topographic work 
which follow covers the period from my appointment, September 1, 1909, 
to date. 
GEOLOGY. 
Active field work has been prosecuted in the Northern Peninsula in 
both the copper bearing and iron bearing districts, and in parts of the 
Southern Peninsula. 
'Northern Pent nsnla. 
Copper Country : Report on the Geology of the Keweenawan or Cop- 
per Bearing Rocks. 
My predecessor. Dr. A. C. Lane, had, during his long period of services 
as State Geologist, become especially conversant with the geology of the 
Keweenawan or copper bearing rocks and at the time his resignation be- 
came effective had partially completed a monograph on the Keweenawan 
Series of Michigan designed to be an exhaustive treatise embodying all 
information of scientific and economic importance on the subjects treated. 
Dr. Lane was therefore requested to complete his work as soon as prac- 
ticable and money was appropriated for the purpose from our funds. 
The Survey has co-operated with Dr. Lane in bringing this work to suc- 
cessful completion. Mr. Karl S. Meuche was employed as assistant to 
Dr. Lane. The manuscript of Ibis report is now complete and ready for 
publication. 
Iron Region : Report on the Geology of the Iron River District. 
Prior to his appointment as State Geologist the writer had been en- 
gaged by the Board of Geological Survey to make a, survey and report 
upon the geology of the Iron River district. Field work was prosecuted 
during the summer of 1909 and also during a part of the summer of 
1910, which was followed by a report, published and distributed in 
February, 1911. 
Geologic Mapping West of the Iron River District. 
During the summer of 1910 a party of from 4 to 7 men were engaged 
in geologic mapping of 11 townships, viz.: T. 45 N., IL 35 W„ Tps. 42, 
43. 44 and 45, R. 36 W., Tps. 42, 43, 44 and 45, R. 37 W., and Tps. 43 
and 44, IL 38 W., lying west of the Iron River district. Blue prints of 
the field plats may be obtained at cost on application. The completion 
of The work on the Iron River district and the mapping of these town- 
ships forms a very good beginning on the general plan of mapping as 
rapidly as possible the unmapped Huronian areas of the Northern Penin- 
sula. A reward of careful magnetic work, which was carried on simul- 
taneously with the geologic mapping, was reaped in picking up a mag- 
netic belt in Section 16, T. 43 N., R. 37 W.. and carrying it thence west- 
ward over a deeply drift-covered area where there are no rock expos- 
ures. to the state boundary in Section 10, T. 43 N., R. 38 W., a distance 
of about 6 miles. This magnetic belt is doubtless underlain by iron 
bearing rocks which in the future will be explored by drilling, with the 
probable result that bodies of iron ore will be discovered and exploited. 
A map of the Surface formations and soils of the northern peninsula. 
