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Veins are frequently thickened by local disturbances, 

 such as a bend, a crumple or a faulting of the strata. 



Although leads show a great similarity and are very 

 numerous, yet many of them possess a certain individuality, 

 some peculiarity of colour, structure, lamination, distri- 

 bution of sulphides, quantity or form of gold, serving to 

 distinguish them from others of the same district. 



Cross or Fissure Veins. 



A few important veins cut across the strata for a 

 considerable distance, and in some districts they form the 

 principal auriferous deposits. These cross veins, often 

 spoken of as fissures, sometimes curve and branch, contain 

 inclusions of country rock, and have a gouge on the walls. 

 All the most important are found on domes, generally 

 cutting the main anticline at various angles. They occur 

 chiefly in the Golden ville formation, but also in the Halifax 

 formation, especially at the base. Seldom does a cross 

 vein lie in the fault plane. In the case of the Cope lode 

 of Central Rawdon and the Baker vein of Oldham, which 

 are exceptions to this rule, the faults are probably younger 

 than the veins. 



The thickness of the cross veins is less regular than that 

 of the interbedded veins, probably because they generally 

 intersect alternating beds of different hardness. They do 

 not attain great thickness, except sometimes at their inter- 

 section with interstratified leads, flexures or rolls. The 

 mineral content is generally the same as that of the inter- 

 bedded veins, but the laminated structure is wanting. 

 In many cases the value of the gold extracted is much 

 reduced by the presence of silver. At West Gore enough 

 stibnite was found to form gold-antimony ore deposits of 

 considerable value and extent. 



Bull Veins. 



There is another kind of vein differing much from those 

 already described. It may cross the strata or roughly lie 

 in a stratification plane. It shows little or no trace of 

 lamination, carries few metallic minerals and is composed 

 of white crystalline quartz in which geodes with quartz 

 crystals are sometimes found. These veins are usually 

 thicker than the others, varying from one to several feet. 

 They are not auriferous and are known as bull veins. 

 35063—12 



