Geologi/, <$-c. of Malhay^ L, C. 221 



River Grand St. Anne, 24 miles below^ Quebec, three 

 strong seams of gray wacke form as many concentric arch- 

 es, in the face of a naked and perpendicular bank, the out- 

 er of which is about eight feet high, and twenty-two feet 

 span. The surrounding shale observes the same position* 



At t!ie bridge of the river Jaques Cartier, 30 miles 

 above Quebec, there is a beautiful natural arch of blue 

 llmesione of similar dimensions. 



The occurrence of comparatively uninjured organic re- 

 mains in a minute conglomerate is a remarkable circum- 

 stance, and shews that the shells, encrinites,* and orthoce- 

 ratiteshave not been subjected to the same attrition as the 

 quartzose nodules. 



These orlhoceratites shew in vvhat a qualified sense must 

 be taken the rule which determines the a^ra, and other re- 

 lations of rocks from their contents. Parkinson. Green- 

 hough, and Kidd, have expressed an accordance with this 

 opinion, without entering into proof. My own experience 

 in Noj'th America, leads to the same conclusion. The or- 

 thoceratitps are astonishingly numerous, large and varied 

 in the greenish grey and brown limestones of Lake Huron, 

 in the yellowish grey of Lalcc Erie, in the blackish blue of 

 the northern and southern shores of Lake Ontario, and of 

 the Falls of Montmorenci, in the brown aqd lead-coloured 

 beautifully crystalline variety of Point aux Trembles, and 

 Jacques Cartier. ten leagues aLove Quebec, and lastly in 

 the calcareous conglomerate of Malbay — substances of 

 marked dissimilarity under every aspect, geological and 



wineralogicah 



The alluvial depositions which have been noticed in the 

 romantic valley of St. Etienne, attract particular regard 

 only from their quantity and regularity of disposition. 

 They furnish a most gratifying and instructive lesson to the 

 young geologist, and seem to indicate four conditions of the 

 river Malbay, w^ith respect to size, each (it may be supposed) 

 being assumed, successively from the highest, as the barri- 

 er between the valley, and the St. Lawrence, has received 

 some great injury. 



* It is singular that no lily encrinites so numeroti? in England, have 

 been found in the vast secondary tracts of Xorth America. I know only of 

 one Echinite also— from Ononda£:a, New-York, I believe. It is in pos- 

 session of J, G.Bogert, Esq. New-York, 



29 



