HURON I AN UNCONFORMITY IN MICHIGAN 581 



strengthens the evidence of the importance of the erosion interval 

 which intervened between the deposition of the Princeton and 

 Gwinn series. Incidentally it has a practical bearing on the possi- 

 bilities for success attendant on drilling for iron ore in the immediate 

 vicinity of the Little Lake Hills. Some drilling, of which the 

 writers have no records, has already been done and we understand 

 that additional drilling is contemplated by parties who are likewise 

 ignorant of the results of the former explorations. 



