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DON VALLEY BRICK WORKS. 



The most interesting - clay and shale deposits at Toronto 

 belong to the Don Valley Brick Works, where the follow- 

 ing section is seen in descending order : 



1-3 feet boulder drift clay. 



80 feet glacial stratified clay A. 



1 foot boulder drift clay. 



21 feet interglacial cool water beds. ) -p 



12 feet interglacial warm water beds J 

 of clay and sand. 



12 feet reddish sand, often carbonacious C. 



3 feet boulder drift. 



60 feet Hudson River shales, with interbanded lime- 

 stone D. 



It is not the writer's intention to describe these clays 

 geologically, as this has been already done by Dr. Coleman 

 in the guide-book to excursion B 2, but the object of this 

 excursion is to study the industrial side of these clays. 



The upper glacial clay A has been collected rapidly, and 

 is of the character already described in the introduction 

 above. It has not lost its calcium carbonate, and therefore 

 burns to buff-colored products. This clay is dug by itself 

 and manufactured into sand-stock brick, and hollow-spaced 

 block. 



The interglacial banded clays B were slowly-collected 

 weathered clays, which had lost their calcium carbonate 

 before or during the gathering process, they therefore burn, 

 as was described in the introduction, into red ferric pro- 

 ducts. These two banks, thirty-three feet in all, are there- 

 fore dug with a steam shovel and manufactured by them- 

 selves into red sand-stock brick and red wire-cut brick. The 

 underlying twelve feet of reddish sand is dug and mixed at 

 times with these interglacial clays B when they, of them- 

 selves, are too " fat " or strong for the purpose in hand. 

 The addition of this sand diminishes the shrinkage and 

 cracking on drying or burning. 



At the base of these clays there is a three-foot layer 

 of boulder clay, which has to be removed and discarded, 

 when the underlying Lorraine shale comes to view. 

 This shale is blasted out, picked free from limestone beds, 



