63 JOURNAL OF THE 



ate is sericite schist. The true talc schists are very rare. 



The chloritic schists are probably more truly crystalline 

 schists, and are richer in accessory metamorphic minerals, 

 such as garnet and epidote. 



The argillaceous slates and sericite schists are fre- 

 quen^:ly siliciiied; the chlorite schists are not as a rule. 

 This siliciiication exists in varying- deg'rees up to a com- 

 pleteness which renders the rock so hard that it resists 

 scratching- with a knife. 



The strike of the formation as a whole is g-enerall}^ 

 northeast, and the dip steeply to the northwest. These 

 strikes and dips refer to the schistosity of the rocks, and 

 not to the bedding- planes. 



In g-eneral the force producing- schistosity and slaty 

 cleavag-e appears to have acted downward from the north- 

 west, producing- normal faulting with but little deform- 

 ation. No instance of reverse faulting was recorded. 



Now, as to the origin of these schistose and slaty 

 rocks; in part it seems that they must be sedimentaries 

 altered by dynamo- and hydro-metamorphism. The evi- 

 dence of this is offered by several observations of bedding 

 and banding extending across the schistosity, generally 

 at low angles, although in most instances this original 

 structure has been obliterated. Bmmons' supposition 

 that the gold in the slates and schists is of sedimentary 

 origin (page 55) is altogether untenable. 



The lamination or schistosity, however, is wholly the 

 effect of shearing, produced by dynamo-metamorphism. 

 It has no connection with bedding planes of stratigraphic 

 structure, as both Emmons and Kerr supposed. The 

 original bedding planes may correspond to certain of the 

 present cleavage planes, i. e. lie parallel to them, but in 

 that case the bedding structure has been obliterated. 

 Schistosity must not be confounded with bedding. 



It does not seem probable, at the present stage of in- 

 vestigation, that these slates have been derived from the 

 granitic and other more basic ig*neous masses lying on 



