272 THE JOURNAL OF GEOLOGY. 



traversed by a rude cleavage, which has a general northwesterly 

 direction, and so makes a large angle with the line of contact. 

 The direction of cleavage varies between the limits of N. 40° W. 

 and N. 60° W., and is usually represented by a multitude of 

 planes, in which the micas only are foliated. This cleavage is 

 more strongly developed on the western side of the exposure, 

 near the contact, than elsewhere ; and as the cleavage becomes 

 more perfect, the large orthoclase crystals disappear, 



IV. Conglomerate. 



The matrix of the conglomerate varies between a somewhat 

 micaceous quartzite and a fine grained mica-schist, and shows 

 very distinct bands differing in color, texture, and composition. 

 These bands are thrown into little folds, about northwesterly 

 plunging axes ; in strike they conform to the direction of the 

 line of division between the conglomerate and the granite. In 

 this quartzitic matrix are imbedded clearly water-rounded peb- 

 bles of quartz, granite, and of a black crystalline schist. The 

 quartz pebbles are as a rule small, few exceeding six inches in 

 diameter. They are of different varieties, clear, milky, brown, 

 and blue gray quartz all being represented. All are more or less 

 thoroughly granulated. They are of very different shapes, and 

 within the planes of bedding, their longer axes lie in different 

 directions. All agree in being smoothly worn and are unmistak- 

 ably water-rounded. 



The granite fragments vary in size from pebbles a fraction of 

 an inch up to bowlders five feet in diameter. The larger are 

 usually thin slabs lying with their flat sides parallel to the bed- 

 ding. The foliation of the matrix often follows round the inclu- 

 sions. The contacts between pebbles and matrix are exceedingly 

 sharp ; sometimes, however, where several pebbles lie close 

 together, it is a matter of some difficulty to trace the boundary 

 of each on the weathered surface. The distribution of pebbles 

 is very irregular. Near the south end of the exposure they are 

 closely packed, while the northern part of the main exposure 

 has comparatively few. The granite of the pebbles and bowl- 



