284 Field and Forest Rambles. 



in thickness. Gypsum, salt, albertite, bitumen, and petro- 

 leum are found in remunerative quantities. Iron and lead 

 sparsely, but manganese in quantity. 



Devonian Periods. 



Iron abundant in form of hematite. Copper in forms of 

 copper glance, peacock ore, yellow sulphuret, green carbonate, 

 and copper pyrites are thinly dispersed, but not as yet re- 

 munerative. 



Silurian Periods. 



Iron mines of Woodstock : superior ore, and abundant. 

 Iron pyrites sparsely distributed. Antimony mines of Prince 

 William very remunerative. 



Cambrian and Silurian Periods. 



Limestone and graphite of superior qualities, and abundant. 

 Copper sparsely distributed. 



