36 PROCEEDINGS OF THE ASSOCIATION OF 



ferons limestones and shales, resting upon sandstones, the whole dip- 

 ping a lew degrees east of south. The limestones appear only on 

 the southerly portion of the peninsula, while the underlying sand- 

 rocks form the immediate coast of Lake Su])erior. 



At a point very nearly one hundred and fifty miles west from the 

 easterly extremity of the peninsula, and near to the immediate coast 

 of Lake Superior, several low ranges of granitic hills make their 

 appearance, which hills are flanked on the south, by quartz rock, 

 alternating Avith mica, talcose, and clay slates. These liills have a 

 general easterly and westerly direction. 



Northerly from these, other ranges of hills occur, having a similar 

 direction, but in the several ranges as we proceed north, the gi'ariitic 

 character ])ccomesless and less perfectly defined, being first sienitic, 

 after this, altered sienite, and finally the outer or northern range is 

 made up of well defined trap. This range of trap hills continues 

 very nearly unbroken for a distance of one hundred and thirty-five 

 miles within the limits of Michigan. 



The trap rock, which chiefly appears as a compact greenstone, is 

 nevertheless, quite uniformly iDOunded on the north by an amygda- 

 loid, against or u}ion which rests a veiy coarse conglomerate, and 

 upon this a series of alternating strata of conglomerate and sand- 

 stone, the whole being capped by an extensive formation of red 

 sandstone. 



The group of stratified rocks referred to, which have an entire 

 thickness of several thousand feet, dip very regularly, and usually at 

 a high angle, into the basin of Lake Superior ; and since the same 

 is the fact in regard to the rocks upon the north coast, that lake may 

 be said to occupy a synclinal basin. 



After some remarks upon the successive elevation of the several 

 ranges of hills referred to, together with the long intervals of time 

 that would appear to have elapsed between the several uplifts. Dr. 

 H. proceeded to say, that with our present imperfect maps, it would 

 be nearly impossible to convey a clear conception of its geographi- 

 cal geology, and that in fact he had made these references, only to 

 render more intelligible what he wished to say upon the subject of 

 the metalliferous veins of the district. 



It is a fact well known, that south from the district referred to, 

 transported masses of native copper are occasionally met with, in 

 the diluvial deposits which are so abundantly spread over the 

 country ; and these loose masses are distributed over an area of 

 many thousand miles, including southern INIichigan, Wisconsin, Illi- 

 nois and Indiana. In northern Michigan they are still more fre- 

 quently met with. 



The great transported mass of native copper on the Ontonagan 

 river, so frequently alluded to by travellers, and which he, Dr. H., 

 estimated to contain about four tons of native metal, was stated to 

 have all the characters of the other loose masses referred to. 



The source of these transported masses has, heretofore, been 



