LOWER SILURIAN OF CAPE BRETON — GILPIN. 173 



from the rocks they rest on. It is possible that further investi- 

 gations may result in the separation of the lower members of 

 of this series into a sub-horizon. The present facies of the rocks 

 of this formation and their fossils show their accumulation in 

 comparatively shallow border waters, having a comparatively 

 mild temperature. Presumably the outline of Cape Breton was 

 then as now indicated most strikingly by the comparatively ele- 

 vated lands of the precambrian, which, together with the older 

 rocks of Newfoundland, protected the Gulf of St. Lawrence and 

 gave sheltered waters for the accumulation of the Silurian slates 

 and marls, some of whicli we now find comparatively unaffected 

 by metamorphic action. 



This set of rocks in Cape Breton has not yet been found to 

 carry any important mineral deposits. Mr. Fletcher speaks of 

 the abundant presence of iron oxide in the rocks between the 

 Barasois and McSween's Brook on St. Andrew's Channel. In 

 one or two places it impregnates the rocks so strongly as to form 

 beds of iron ore which, however, on being traced, proved to be- 

 come of inferior quality. At one place near McLean's point an 

 opening has been made into a bed of red hematite of excellent 

 quality, and a few tons extracted. Although irregular at the sur- 

 face the bed appeared to become more defined in depth. On 

 analysis it proved to contain — 



Metallic iron, per cent 62.50 



Silica, " 7.82 



Phosphorus, " 0.9 



Sulphur, " trace. 



Magnesia, " 88 



Lime, " 67 



Water, " 1.10 



I am not aware of any other deposits of iron ore in rocks of 

 this age which promise to be of value. No mineral is more 

 deceptive than iron ore. Its oxide spread in a thin film over 

 boulders in a conglomerate and forming the cement of the mass 

 has often led to the waste of large sums of money. A bed may 

 be met giving the characteristic streak, color, &c., of an excellent 



