GEOLOGICAL EXPLORATIONS AND LITERATURE. H 



between the Montreal river and lake Gogebic. In this work he was 

 occupied (hirinii' the months of July and August of 1884, retiirning with 

 a large collection and copious notes. His routes of trivvel are indicated 

 on tlie accompanying detailed maps. 



During the following fall months Prof. Van Hise carefully studied the 

 material collected, a large number of thin sections having been made; and 

 the locations of exposures, made always by pacings from section corners or 

 quarter-posts, were platted on a large scale map. This study served chiefly 

 to convince us that the whole belt, including the Wisconsin portion, was 

 worthy of still further research. Although Qjertain very interesting new 

 conclusions were reached, still more important lines of study were sug- 

 gested. The Wisconsin Survey work was done at a time when the micro- 

 scope was only just coming into use in this country as a petrograpliical 

 instrument, and consequently numerous important petrograpliical points 

 were missed by that survey; while its type collection liad meantime been 

 destroyed by fire. But what raoi-e particularly urged us on was the great 

 value of the iron-bearing series of this region as a type series. Accordingly, 

 it was decided that Prof. Van Hise should spend another season in the 

 region, not only in filling up g'aps in his own work of tlie previous season, 

 but in carefully revising the Wisconsin Survey work and extending it when 

 possible. On this woi'k he was engaged from June 26 to September 4, in 

 which time he succeeded in coverino- the entire distance from lake Gosrebic 

 to lake Numakagon. As has already been said, the writer joined this 

 party for a time during the summer, making a special study of the southern 

 contact. The routes followed and exposures located are all indicated on the 

 accompanying detailed maps. 



During the winter following this field season the material collected was 

 carefully studied, and it became -evident that additional field work was 

 needed, certain points having been overlooked, and certain others which 

 could not then be determined had become determinable by the great 

 activity in mining and prospecting Avhich during this winter and the follow- 

 ing season went on along the Penokee-Gogebic range. Accordingly, Prof, 

 Van Hise returned to this field June 16, 1887, and was there continuous]}' 

 occupied until July 25, taking advantage of all of tlic liglit whicli had been 



