PEEVIOUS WORK, 19 



He also gives his analysis (No. 68, p. 302 of Brooks's report) of an ore 

 sample from the district, and calls attention to its abnormally high water 

 content, freedom from silica, and richness in iron as compared to those of 

 the more eastern mines in the Menominee region. 



isso. 

 Brooks, T. B. Geology of the Menominee region. Geol. Survey of Wisconsin, 

 Vol. Ill, Part V, 1880, pp. 430-6.55, Atlas folio. Pis. XXVIII and XXIX, and PI. 

 XXX, by C. E, Wright. 



In an article on the geology of the Menominee region, which was 

 written for the geological survey of Wisconsin, the same author briefly 

 touched on that part of the adjoining Michigan territory which is included 

 in the district under consideration. His observations were thus confined to 

 a few exposures in a limited portion of the area. He attempts to correlate 

 'certain beds by means of their lithological character with those with which 

 he was familiar in the Marquette district and refers them uniformly to the 

 higher members of the Huronian. 



They are also so referred on the map which accompanies the report, 

 thoug'h this is dated a year earlier than the date of publication of the re2:)ort. 

 That portion of the map covering a small part of the Crystal Falls region 

 is reproduced on PI. IV. The present survey enables us to add very little 

 ^o this, and these additions are chiefly of a petroldgical character. 



1881. 



RoMiNG-BE, Carl. Geology of the Menominee iron region. Geol. Survey of 

 Michigan, Vol. IV, 1881. 



In 1880 Dr. Carl Rominger, at that time State geologist of Michigan, 

 spent a season in the Menominee district, and in his report gives detailed 

 descriptions of a few occurrences in the Crystal Falls district, to which I 

 shall refer later on. He considers the rocks in general to belong to the 

 Huronian, and distributes the beds among his diorite group, iron-ore group, 

 and arenaceous-slate group, as given and defined in the previous report on 

 the Marquette district No attempt at more definite correlation was made. 



1S90. 



Van Hise, G. E. An attempt to harmonize some appai-ently conflicting views 

 of Lake Superior stratigraphy. Am. Jour, of Sci., 3d series, vol. 41, 1891, p. 133, 



On December 30, 1890, Prof C. R. Van Hise read a paper on Lake 

 Superior stratigraphy before the Wisconsin Academy of Sciences, Arts, and 



