540 



REPORT OF NATIONAL MUSEUM, 1904. 



Subsequently (1881) Rominger, still acting as a State geologist 

 (18T8-1880), issued a report on the Upper Peninsula, which dealt 

 almost entirely with the economic problems of the iron region. 



He regarded the region about Marquette as — 



a synclinal trough of granite which, by the upheaval of its northern and southern 

 margins, caused the inclpsure of the incumbent sedimentary strata between its walls 

 and their simultaneous uplift and corrugations into parallel folds by the lateral 

 pressure from its rising and approaching edges. 



Concerning the origin of the iron ores of the Upper Peninsula, he 

 wrote: 



These ore deposits are not regular sedimentary layers originally formed of iron 

 oxide in a state of purity, but are evidently the product of decomposition of the 

 impurer mixed ferruginous ledges by percolating water, leaching out the siliceous 

 matter and replacing it by the deposition of oxide of iron held in solution. 



This view is not greatly different from the conclusion reached b} T 



Brooks, as already noted, and subsequently 

 by Van Hise. 



His views as to the origin of serpentinous 

 rocks were not at all (dear. Writing with 

 particular reference to those of Presque 

 Isle, he remarked that they occur — 



generally in bulky, nonstratified masses which, if 

 they ever originated from mechanical sedimentary 

 deposits, are by chemical action so completely trans- 

 formed as to efface all traces of their former detrital 

 structure. They resemble volcanic eruptive rocks 

 forced to the surface in a soft, plastic condition, and 

 most likely heat was one of the prime agents in their 

 formation, or else transformation, in combination 

 Pig. si.— Carl Rominger. with aqueous vapors. 



Rominger, in his first report, that on the Paleozoic rocks of the 

 copper district, took the ground that the Silurian age of the Lake 

 Superior sandstone was unequivocally proved by its stratigraphical 

 position. This is the view now generally held, though the Potsdam 

 period, to which the beds are referred, is now considered as the upper 

 part of the Cambrian instead of the Lower Silurian, as at that date. 



Rominger's career, like that of Lesquereux and others that might 



be mentioned, offers an interesting illustration of the 



sketch of Rominger. difficulties with which the early naturalists had to 



contend, particularly when foreigners and but little 



acquainted with the language of their adopted country. 



Born in Wurtemberg, he came to America in 1848 on account of revo- 

 lutionary disturbances, and without previous preparation. Though 

 trained as a physician and geologist, yet his poor command of Eng- 

 lish he felt excluded him from associating with scientific men, and, 

 being without financial resources, he established himself as a physi- 



