OE()I.O(4I0AL NOTES. 11 



is greatest and the new-formed mountains are highest, and, fol- 

 lowing the course of these fissures, the molten material reaches 

 the surface, to carry death and destruction to the surrounding 

 country. Other and smaller rents may be the receptacles for 

 precious metals and ores, and will then be sources of wealth for 

 future ages. 



In studying the great geological formations, the jjrocess des- 

 cril)ed above seems to have very generally occurred, hut it must 

 he remembered tliat an area of settlement may embrace such a 

 large tract of country as New Brunswick. Quebec. Northern 

 Ontario, and Northern Manitoba, taken together. 



The Laurentian formation — tlie oldest sti-atitied body of rocks 

 Avhich is known — occu|)ies ■his large area and is of great thick- 

 ness. 



After deposit, upheaval took [)!ace. and it is pi'obable that in 

 Eastern Canada mountains existed as high as the present Rock- 

 ies, but ages of wear and dissolution have reduced them to the 

 comparatively low Laiu'entian range of (Quebec and the liigh- 

 lands of Manitol)a and Ontario. 



That volcanic action took [ilace also is shown clearly near St. 

 John, at (jreen's limestone (jnarry. where a black mass of igneous 

 rock, called by geologists a trap dyke, rises through and in 

 strong contrast with the surrounding limestone, which has been 

 altered almost into marble by [tressure and heat. 



The great formations of the Palffiozoic Age. especially the 

 Silurian and Carhoriiferous. so strongly developed on the Atlan- 

 tic seaboard of Nortii x\merica, resulted in the formation of the 

 Alleghany range of mountains, and culminated in the great 

 volcanic action which formed the ])a]isades of New York and 

 produced the immense lava tield which, beginning in t'uujlier- 

 land County. Nova Scotia, forms the headlands of Hlomidon and 

 the entrance to r)igl)y Gut. and extends the whole distance to 

 Briar Island in the Atlantic. 



A small example of about this period may be seen atCaraquet 

 in Gloucester County. N. B.. where a trap dyke ascends through 

 beds of carboniferous sandstone. The sandstones near the black 

 itrneous rock are hard and burnt almost to tiles and clinkers. 



