GEOLOGICAL EXPLORATIONS AND LITEKATUKE— isr)(l. 21 



The autlidv coiichKles his remarks on the general geohio-y of tlie re<'ion 

 by inentionini;- the h)eations of fourteen exposures of iron ore met with ak)no- 

 the traversed lines. He infers from his observations that the reoion is an 

 exceedingly rich one, far excelling- any other portion of the United States 

 in the abundance and good quality of its ores (p. 852). It is to lUnl's 

 energy and to his disco^'ery of ore that later developments of the iron dis- 

 trict are due, although, as we have seen, Locke's report referred to t-he ores 

 of the region two years before that of their discoverer was given to the 

 public. 



Lists of specimens collected along the township lines are appended 

 to the reports, and it is these that have afforded such great aid to later 

 geologists. 



Jackson, Charles T. Report on tlie geological and mineralogical survey of 

 the mineral lands of the United States in the State of Michigan, etc. Dated 

 ]S!^ovember 10, 184ii. 31st Congress, 1st session, 1849-50. Senate Documents, Vol. 

 Ill, No. 1, pages 371-502. With maps. Also House Documents, Vol. Ill, No. 5, 

 pages 371-502. 



Reference has ah-eady been made to the appointment of Dr. Jackson, 

 in 1847, as geologist for tlie survey of the mineral lands of the State of 

 Michigan. The reports of Locke and Channing, wdiich appeared in 1848, 

 Avere the first fruits of the survey. Li 1850 the reports of Jackson himself 

 and of several of his assistants were submitted to the Secretary of the 

 Interior, concluding the survey under Jackson's charge. 



In his own rejjort Jackson gives a miiuite and detailed account of his 

 explorations and their results. Most of Jackson's personal observations 

 were made m the copper region. In the report, however, he notes that in 

 1846 Mr. Joseph Stacy explored the region "between the mouth of Dead 

 River and Lake Michigan, and established the fact that there was an 

 inexhaustible amount of compact and micaceous specular iron ore in that 

 district." Its analysis gave: Silica, 3.88; lime, 0.17; peroxide of iron, 

 96.11. A small portion of the ore is in the state of magnetic oxide. The 

 localities were examined more carefully in 1847 by Assistant Geologist 

 Locke and Subagent Channing, whose report is referred to below. In 1 848 



