METAMORPniC ROCKS. 275 



sand feet soutli of the Reed miue. To the west of the mine, and again to 

 the east of it, are hirge areas of serpentinoid rocks, which are connected by 

 a neck a few hundred feet in width, cut by the ci"eek near the mine. Tlie 

 strike of the unaltered strata in both areas is northwesterly, coinciding in 

 general direction with the creek, and a large portion of these strata are 

 inclined at high angles, most of those in the creek bed and a large part of 

 those in the southern area being vertical or nearly so. Had the crystalline 

 rock, including serpentine, been deposited before or after the ordinary sand- 

 stones and shales, and conformably with them, the two unaltered areas 

 would be continuous, instead of being divided by an isthmus of crystalline 

 rock. If the cr^'stalline rocks had been first deposited, but disturbed prior to 

 the deposition of the sandstones, so that the latter were unconformably de- 

 posited and afterwards folded up, it is difficult, but perhaps not impossible, 

 to imagine relations such as those thus far described; but this hypothesis 

 is entirely inconsistent with another structural feature. The north branch 

 of Davis Creek, from below the Reed mine to the northwestern edge of the 

 map, follows the axis of an anticlinal fold, so that the strata on each side dip 

 into the hills. The same structure is traceable to the south also, jjarticu- 

 larly on Eticuera Creek below the Redington mine. If, therefore, there is 

 any difference in age, the crystalline rocks are younger than the sandstones 

 and overlie them. But this is also impossible ; for, while the sandstones are 

 comparatively little broken, the cr3'stalline rocks show most abundant evi- 

 dence of extremely violent disturbance, and evidently the upper portion of 

 a series cannot be crushed while the lower portion remains intact. 



Section on Davis Creek. — Thc following soctiou ou the north branch of Davis 

 Creek was carefully worked out from numerous measured dips (Fig. 7). Tlie 

 evidence of anticlinal structure is clear, and, in view of the foregoing, it is cer- 

 tain that the southwestern side of the anticlinal fold consists of a crystalline 

 mass, while the northeastern side is composed of fossiliferous sandstones, 

 shales, and impure limestones. Nearer the Reed mine both sides of the an- 

 ticlinal are crystalline and only the highly compressed poi'tion close to the 

 axis is arenaceous. 



Transitions from ordinary sediments to crystalline rocks are not lack- 

 ins' at Knoxville. Some of these are much more striking under the micro- 



