440 (M)PPER VEINS IN THE ROCKS 



junction; but here it is found not to be a hopeful sign. The trap is not of a uniform 

 structure, and is not soft and open in texture, but is close and tough. Theoretically, 

 therefore, we should not anticipate well-defined and regular veins. The sections I 

 have given, show that the trap-rocks are very changeable at all these points, which 

 is a discouraging circumstance. Occasionally, a band of amygdaloid trap may be 

 seen apparently as good as any on Point Keweenaw or the Ontanogon, which in a 

 few steps is replaced by black flinty rock, approaching to hornstone. Veins and 

 fissures passing from the amygdaloid to the flinty trap become compressed and 

 crooked, are pinched and obstructed altogether, or degenerate into mere fractures 

 or cracks. It is from this unpropitious irregularity, that seems to be everywhere 

 prevalent, both in veins and the embedding rock, that I infer that for extended 

 and profitable mining, the Bad River Range does not offer sufficient inducement. 



After crossing the East Fork, the rocks answering to the greenstone become 

 coarser in grain, more crystalline, and are augitic and hornblendic. The black trap 

 belt, however, continues, and on its northern face contains particles of copper and 

 of iron pyrites. In the augitic and hornblendic portions, there are, as represented 

 on the map, patches of syenite and even granite, containing red felspar and epidote. :!: 



This belt of black trap no doubt continues westerly, though not seen by us on 

 account of the drift and red clay, as far as the portage to Long Lake, and probably 

 protrudes into the drift, at intervals, to the Brule and the Aminekan. Mr. Thomas 

 B. Cumings, an active and close observer, saw it, in 1846, between the Maringouin 

 Fork and the Middle and Main Fork. But neither Mr. Beesly nor myself found 

 it in place, although there were signs of its being in the vicinity. Its breadth can- 

 not be here very great, for the granitic, syenitic, and hornblendic rocks between Lac 

 des Anglais and the Maringouin Fork occupy most of the space. The low uplifts 

 seen west of Tyler's Fork, have the same or nearly the same bearing as those east of 

 it, that is to say, northeast by east, northeast, and northeast by north. As they 

 are situated on Long Lake and the Brule, entirely out of the line of the eastern 

 ranges prolonged, it follows that they are the terminations of parallel ranges less 

 developed, their extremities only being seen. Probably there is an underground 

 connexion with the trap rocks of the St. Croix, Kettle, and Snake Rivers. So 

 far as I have examined, or could collect information, the prospect of regular and 

 profitable veins along the whole line of the black trap uplifts, from the Montreal to 

 the Aminekan, is no better than at the Montreal River, where a faithful trial was 

 made and abandoned. 



Copper doubtless exists in the quartz veins of the igneous rocks of the interior, 

 but as yet seen only in scattering specks. The veins themselves are without system, 

 and the rocks are almost everywhere inaccessible, on account of erratic deposits, so 

 that no encouragement is offered for mining operations.f 



The sections and their explanations will furnish an idea, in connexion with 

 the foregoing remarks, of the details of the beds in which copper was supposed to 

 exist in valuable quantities. 



* See specimens No. 16 to 20, inclusive, of my collection. 



f Specimens No. 95 and 96 of my collection contain carbonate of copper. 



