698 THE JOURNAL OF GEOLOGY. 



ery of small amounts of gold in the schists at Vermilion Lake, 

 and a genuine "boom" (so-called in later years) centred on that 

 region. Much prospecting was done and much money squan- 

 dered, but little geology resulted from these two years of the 

 administration of Mr. Eames. The state survey collapsed inglori- 

 ously, and was not revived till the commencement of the present 

 survey in 1872. 



From other sources, however, the geology of Minnesota was 

 kept in a state of progress. Professor James Hall visited the 

 state in 1865, and examined the St. Croix valley with reference 

 to its prospects for copper in the vicinity of Taylor's Falls. This 

 visit was prolonged for the purpose of examining the reputed 

 coal beds of southwestern Minnesota which he found to belong 

 to the Cretaceous system. The next year a report of the trip to 

 the southwestern part of the state was made by Professor Hall. 

 It is published in the Transactions of the Philosophical Society of 

 Philadelphia. This paper embraces the first geological observa- 

 tions ever made on a very large area in the region southwest 

 from the Minnesota River, and may be said to have supplemented 

 and extended the observations of Keating and of Featherston- 

 haugh. In 1866 also were published the field observations of 

 Colonel Charles Whittlesey made in northern Minnesota in the 

 years 1859 and 1864. These also embodied some more detailed 

 descriptions of the region north of Pokegama Falls, resulting 

 from the survey of D. D. Owen whose assistant Whittlesey was. 

 The papers of James Hall and of Charles Whittlesey constitute 

 the most valuable contributions to the geology of the state dur- 

 ing the period following the territorial exploration, and preceding 

 the present survey. There were, however, some later surveys. 

 One was a topographical survey of the Minnesota valley by 

 General G. K. Warren, under the United States government. 

 His reports are to be seen in the Report of the Chief of Engineers 

 for 1867, 1868, and 1874. He first published, with full demon- 

 stration, the idea that the valley of the Red River of the 

 North was formerly covered by a freshwater lake which 

 embraced the region of Lake Winnipeg. Professor Henry Youle 



