Essay on the Transition Rocks of the Caiaraqui. 79 



leave farther investigation of these fairy forms of architecture, and 

 of animals left to our admiring eyes from the wrecks of ancient for- 

 mations, to continue our tour, in which we stopped on the summit of 

 Point Henry, and which, in proceeding eastward, brings us once 

 more to the shores of Lake Ontario. 



Directly opposite to the south west end of Cedar island on the 

 main shore, a quarry was opened some years ago. This is called 

 the soft limestone quarry, because the stone, when first exposed, cuts 

 with much ease. 



Amidst the wonderful variety of transition aggregates with which 

 the singular locality we are describing abounds, this appears to be a 

 mere bed or mass, and to rest upon the granite ; but it is every 

 where, as far as it is visible, surrounded by the usual dark transition 

 limestone of the Caiaraqui. It has been opened to some extent, and 

 presents a continuous face for a considerable length, and at its base 

 on one side, the hard layers appear as if conjoining with it, whilst 

 here, on careful examination, may be seen the feet, that it also par- 

 tially reposes on those beds, and that the passage of one into the 

 other most probably takes place generally at this line of contact, not- 

 withstanding instances occur where the soft stone appears, at it were, 

 cemented to the dark blue limestone. 



Near the junction of the two substances, a kind of variolous as- 

 pect is given to the soft stone by little sprigs or buttons of carbonate 

 of lime of a dull white color, jutting from its surfaces. 



This soft stone, so totally different from the other limestones of 

 the Cataraqui, consists of silica, lime and alumina, and somewhat 

 resembles, in its appearance and properties, the gres blanc of the 

 French geologists, a building formed of it looking like those of the 

 finest white freestone of Bath or Edinburgh. But, although it hard- 

 ens a good deal by exposure, yet from the alumina being in quantity, 

 it can neither resist the dripping of rain, nor the severe frosts and 

 sudden thaws of the Canadian climate where it is exposed in thin 

 portions. Its mean specific gravity is 2.6. 



I believe that no fossil remains have been seen in this rock, which 

 is regularly stratified and divided into Dands or zones, assuming dif- 

 ferent colors as they becom.e weathered. The two lower beds are 

 of a lighter blue (approaching to grey,) than the hard rock on which 

 they rest, and next to these, comes a band of an iron brown color, 

 which, from the quantity of silica in its composition, disintegrates to 

 a mere sand. Tiiis band is eaten outwardly into numerous holes in 



