THE KEl'UBLIO T1U)UG11. 533 



(juartzite is a rid^c^ niimiuij;- luirtlicast, iiiadci up niainlv <>t' <iTanite. Near 

 the soutliwest end and ou the northwest side of this rid<>-e, which has a 

 steep northwest shtpe, is found, lying- upon the granite, a northwesterly 

 dipping fringe of conglomerate which extends some 50 feet along- the strike 

 as a continuous rock mass, and occurs besides in occasional disconnected 

 patches farther north on the sloping face of the hill. TIk; granite is of the 

 usual gray variet)^, and carries large orthoclase crystals up to 2 inches in 

 length. 



The conglomerate consists of pebbles of granite, (piartz, and black 

 hornblende-schist end)edded hi a matrix of quartz and mica-schist. The 

 cement is distinctl}- color-banded, the bands being parallel to the contact 

 surface. They are thrown into small folds about axes which pitch north- 

 westerly in the direction of the di}) of the rock. The pitch is closely 

 parallel both with the axis of the main Republic fold and with a pronounced 

 parallel cleavage which affects the overlying griiuerite-magnetite-schists, 

 the conglomerate cement, and also the imderlying granite for a considera- 

 ble distance back from the contact. The granite pebbles vary in size from 

 a fraction of an inch up to 5 feet in diameter, and are unmistakably water- 

 rounded. The larger are comparatively thin slabs, lying with their flat 

 sides in the bedding of the matrix which often follows around the inclu- 

 sions. The granite of the pebbles is lithologically identical with that of the 

 main mass on wdiich the conglomerate rests. 



The contact itself is very definite. Between the undoubted conglom- 

 erate above and the undoubted granite l)elow is a narrow zone, a few inches 

 wide, of schistose material, which probabh' i-epresents a shear zone affecting 

 both rocks, due to movement along the contact during- the folding. At the 

 north end of the main outcrop a large mass of granite is traversed by thin 

 seams of the conglomerate, one of wdiich tapers to a point at one end and 

 connects with the main body of conglomerate at the other. It is impossible 

 to avoid the conclusion that this represents an original crack in the some- 

 what irregular surface upon which the conglomerate was laid down, into 

 w hich the liner sand and ])ebbles were washed. 



The facts at this contact can only be interpreted as signifying that the 

 gra}' granite upon which the conglomerate now rests existed in its present 



