8 4 



Coming, finally, to the Temiskaming mine it is found 

 that the diabase has been encountered on the fourth and 

 fifth levels, and at a depth of 575 feet in the main shaft. 

 The surveys show that the sill dips at angles varying from 

 17 to 30 or 40 degrees in different parts of the mine, but it 

 is probable that faulting may have caused some of the 

 steeper inclinations, because a vertical fault between the 

 diabase and Keewatin is known to occur on the fourth level. 

 There are, however, no data at present to determine the 

 throw of this fault. 



Quartz-diabase, Cobalt, showing- labradorite, P, embedded in a micro- 

 graphic intergrowth of quartz and feldspar. 



Facies of the Diabase. 



While, as will be seen from the preceding descriptions, 

 the diabase in the productive part of the Cobalt area is fairly 

 uniform in character, differentiation is found in the outlying 

 areas. Thus, a few miles to the west and also to the south 

 of Cobalt pink spots, areas of micropegmatite, appear in the 

 diabase. In certain localities these oink spots increase 

 until the rock becomes pink or reddish, and is then more 

 correctly described as granophyre than as diabase. A 

 similar, but more complete, change, from a basic, darker 

 rock to a lighter colored, more acidic variety, is found in 

 the norite of Sudbury. 



