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MUSEUM OF COMPARATIVE ZOOLOGY. 



11 



the Copper Mines of Lake Superior, and Observations on the Geology 

 of the Lake Basins and the Summit of the Mississippi; together with 

 all the Official Reports and Scientific Papers of both Expeditions." As 

 giving us an insight into the early knowledge of the geology of tlio 

 southern shore of Lake Superior, this woi'k naturally should be of great 

 value, especially as it purports to contain the original scientific repoi'ts. 

 In the Preface we Icaru that he brings the subject down to the date 

 of publication in some respects, and by comparing the work with the 

 original, published in 1821, we find that he gives discoveries as if made 

 by himself in 1820 wliich were not made until at least nearly twenty-five 

 years later. Tliis insertion in the body of the text may perhaps be par- 

 doned, in the light of the Preface ; but when it comes to pubhshing offi- 

 cial documents with their original date and official signature, but with 

 a " tinkered " body, we object. We cannot therefore credit Mr. School- 

 craft with the discovery of the iron ore of the Marquette district in 

 1820, although any one reading this work would suppose that ho dis- 

 covered it. It repi-esents to us simply what he wished, in 1854, others 

 shoidd think he had known and written in 1820. This also applies in 

 part to his reports on the Copper district, and we shall not mention the 

 book further. 



In 1854 was also published a description of this and the Copper region 

 by Fr. C. L. Koch,* The trap and granite were regarded as, eruptive, 

 and it was thought that the quartz rock (quartzite) may probably be so. 

 The schists are supposed to have been metamorphosed through the 

 agency of igneous masses. The iron rocks he would consider as 

 upheaved from great depths, or else to have suffered great motamor- 

 phism by the influence of igneous masses. That they (the iron rocks) 

 maybe simply the quartz rock impregnated with oxide of iron is thought 



probable. 



In 1855 and 185G two papers on this and the Copper district were 

 published by Prof. L, E. Rivot.t As wo understand his work, it would 

 seem that he regarded all the rocks from Sault St. Marie to the Onto- 

 nagon Piver as of sedimentary origin, and of the same geological age, 

 whose differences were entirely owing to peculiar metamorphism, or its 

 absence, as the case might bo. The sandstones were in general, in the 

 Marquette district, of prior deposition to the other rocks in the places 

 in which they are now to be found. The traps and their associated 

 schists, which originally formed the base of the sandstone, had been 



* Studion des Gott. Vorcins Bcrgni. Frennde, VI. 1 - 248. 

 t Aimales des Minos, (5,) Vll. 173-323, X. 3G5-474. 



