OEOLOaiCAL "NOTES IN THE GREAT EXHIBITION. 



Portneuf — a distance of more than a hnndrod miles. In this area the ore 

 seems to be concentrated in the neigliboiirhood of the St. Maurice and 

 Batescan rivers; and iron has been smelted in the neighbourhood of tliese 

 three rivers for u])wards of a century. The ore with winch the Jxadnor 

 furnaces are sui)plied is derived from the soi^nories of Cap de la Made- 

 laine and Champlain, where it occurs close to tlie surface in a multitude of 

 patches of from 3 to 24 inches in thickness. It is brouf^lit to the funiacea 

 partly by the workmen of the Fori^e Company and partly by the various 

 farmers on whose lands the ore occurs. The ore is washed at the smelting- 

 works to free it from soil, and it then contains from 40 to 50 per cent, 

 of iron. Other specimens of bog ore are exhibited, from Vaudreuil, where 

 the bed is from 4 to 8 feet thick, and there lies beneath it in some parts a 

 thin stratum of blue phosphate of iron. At St. Vallier in Bellechasse 

 there is an interrupted becl of from 12 to 20 miles thick and over 10 or 

 15 square miles, near the iunction of the two branches of the Eiviere du 

 Sud. ^ 



Of red hematite, or oli^^ist ore, there is a fine sample from an unworked 

 bed of 30 feet thick, restinpf upon crystalline Laurentian limestone, and 

 limited at top by the magnesian limestone of the calciferous group. Ana- 

 lysis gives 58 per cent, of iron. 



Of magnetic ore there are highly interesting samples. From Sutton we 

 have it from a bed 12 feet thick, consisting of dolomite abounding in 

 small crystals of the magnetic oxide of iron. From the " big iron-ore 

 bed of Marmora," which is not however a single bed, but a succession — 

 over 100 feet thick — interstratified between gneiss or crystalline limestone. 

 From Hadborough and Crosley, from a bed 200 feet thick in gneiss ; 

 samples of numerous other beds in Laurentian gneiss are also displayed ; 

 and there is a specimen of ilmenite with rutile from St. Urbain, Bay of 

 St. Paul. The hitter bed is 90 feet thick, and interstratified in anorthorite 

 rock, also of Laurentian age. Samples of lead ores are shown from the 

 Lower Ilelderberg group, Quebec group, Calciferous formation, and the 

 Laurentian rocks — in the latter case cutting crystalline limestone ; — of 

 copper from Laurentian gneiss, and from the w^ell-known Bruce Mines, 

 where a group of lodes intersect a thick mass of greenstone trap in the 

 Huronian formation ; from Acton, in dolomite, at the base of the Quebec 

 group ; and from many other mines in that formation : native from a lode 

 in St. Igiuice Island, Lake Superior, where the vein cuts a thick mass of 

 amygdaloidal diorite conformable with the strata, — the vein is about 



5 inches thick, and many of the masses of native copper weigh upwards of 

 100 lbs., accompanied by native silver, in a gangue of calcspar. Copper- 

 ore is shown from other places, all in the Quebec group ; amongst them 

 Mamainse, on Lake Superior, from whence is 450 lbs. in a single sheet 

 from a vein. The promontory of Mamainse consists of various layers 

 of coarse conglomerate and of amygdaloidal greenstone, in one of 

 the bands of the latter bay intersected by a narrow^ fissure running 

 N. and S., nearly in the strike of the beds ; its greatest w-idth is 



6 inches, and in some places it is found to be nearly filled with native 

 copper ; other veins intersect the same rock. In ancient shallow holes 

 sunk at intervals along the course of some of these veins of metallic co]-)per 

 there are occasionally found the remains of Indian hammers, consisting 

 of small boulders usually of trap, having shallow grooves worked round 

 them to receive the withes or thongs attaching the handles— evidence of 

 the rude aboriginal attempts at mining many centuries since. From the 

 Quebec group we have also sulphuret of nickel (Millerite) and native 

 silver. 



