﻿Segregation in Ores and Mattes. 



18i 



A general tendency of copper to disperse to the rock 

 and to the vein walls, and of nickel to concentrate 

 towards the centre of the deposit, is thus shown to exist 

 in the ore-hody. Comparing Fig. 6 with Fig. 5, it will be 

 seen that in matte, as well as in ore, the travel of 

 the metals is the same, copper moving outward along a 

 horizontal line toward the cool outer surface, and nickel 

 moving inward to the centre. 



That copper-ore is attracted by the rock is readily seen 

 on examining the rock heaps at the various mines. This 





Horizontal Central Line of Ore-Body. 



rock occurs not only at the edges of the deposit, but also 

 in masses of every shape and size in the ore-body. If the 

 ratio of copper and nickel in the ore be taken as 1 to 1, 

 i.e., 100 pounds copper to every 100 pounds nickel, the 

 ratio in the sorted rock will be from 150 to 200 pounds 

 copper to every 100 pounds nickel. These metals are not 

 an essential constituent of the rock, but occur as shots and 

 veinlets of ore scattered through a dioritic matrix. 



We are justified, then, in stating that in the ore-body 

 the tendency of copper is outward along a horizontal line 

 toward the rock, while the motion of nickel is inward 

 toward the centre of the vein. 



It has been often said that the Sudbury ore-deposits 

 were originally worked for their copper contents, and that 

 the presence of nickel was noticed only after deeper 

 excavations had been made. This is in a certain sense 

 true. The surface workings of the Copper Cliff mine, for 

 €.\ ample, yielded nearly pure copper pyrites, while the 

 lower levels give nearly equal proportions of copper and 



