64 



PROTOZOIC ROCKS 



The above instances abundantly prove that the Lower Magnesian Limestone, as 

 well as the Upper, is lead-bearing ; whether productively so, or not, cannot be fully 

 determined until the rock is scientifically mined. It is certain that, at many of 

 the above localities, the rock is exceedingly cherty, and is consequently hard, and 

 difficult and expensive to work, and near the surface the ore is much scattered and 

 disseminated through the rock, rather in horizontal openings than in vertical veins ; 

 still, if this surface ore should be connected with deeper-seated lodes, as there is 

 some reason to believe it may be, then these would be well worthy the attention 

 of the miner. 



Under present circumstances, however, and with the uncertainty attaching to 

 the last hypothesis, I have not considered it my duty to recommend lead mineral 

 reservations where this formation prevails. 



As to its copper ore, the Department will recollect that, on the 23d of November, 

 1848, I reported certain sections, and fractional sections, which were regarded as 

 mineral lands, but added, that, until the chemical analyses of the various samples 

 of ores taken from different crevices were completed, I could not decide upon their 

 productiveness. These examinations have now been made; and their results, 

 together with other considerations, do not, in my opinion, justify their designation 

 as productive mineral lands. Some of the richest portions of the copper ore have 

 yielded, it is true, as much as twelve per cent, of copper ; and, it is possible, by the 

 outlay of a large sum of money, veins might be followed, and finally yield a profit 

 to the miner ; but the average percentage of all the ore and copper-earth which I 

 have analyzed will not amount to more than four or five per cent., and a great deal 

 of it to only one per cent. In a new country, distant from a market, ores of this 

 description are not worth working. 



SECTION IV. 



ITS PHYSICAL FEATURES AND AGRICULTURAL CHARACTER. 



The constant theme of remark, whilst travelling in the region of the Upper 

 Mississippi, occupied by the Lower Magnesian Limestone, was the picturesque 

 character of the landscape, and, especially, the striking similarity which the rock- 

 exposure presents to that of ruined structures. 



The scenery on the Rhine, with its castellated heights, has furnished many of 

 the most favourite subjects for the artist's pencil, and been the admiration of 

 European travellers for centuries. Yet it is doubtful whether, in actual beauty 

 of landscape, it is not equalled by that of some of the streams that water this 

 region of the Far West. It is certain that, though the rock formations essentially 

 differ, Nature has here fashioned, on an extensive scale, and in advance of all civi- 

 lization, remarkable and curious counterparts to the artificial landscape which has 

 given celebrity to that part of the European Continent. 



The features of the scenery are not, indeed, of the loftiest and most impressive 

 character, — such as one might expect to witness on approaching the source of one 



