1 88 EDWARD STEIDTMANN 



least partly of pre-Cambrian age. Most of the ores occur in a 

 residual clay derived from the decay of crystalline schists. The 

 minerals composing the ores are generally oxides, but silicates are 

 also represented, the latter being somewhat abundant in the 

 undecayed rocks. 



Woodman' states that the pre-Cambrian mountain protaxis of 

 Cape Breton, Nova Scotia, is not well known. Certain iron-bearing 

 dolomites called the George River limestone may be Upper pre- 

 Cambrian. 



'J. E. Woodman, "Report on the Iron Ore Deposits of Nova Scotia," Canada 

 DepL of Mines, igog. 



[To be continued] 



