GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 255 



the direction, N. 23° W., S. 23° E., is the one that seems the most com- 

 mon in the measurement of dips. In the case of inversion, the force is 

 commonly conceived of as acting in a direction opposite to that of the 

 dip ; hence the course upon Mt. Washington would be S. 23"^ E. Along 

 the Atlantic border the direction is usually stated as proceeding invaria- 

 bly from the ocean, or at right angles to that indicated among the moun- 

 tains. The pressure of the older gneiss area of Randolph and Berlin 

 towards the ocean would therefore seem to have been greater than that 

 of the submerged formation in Carroll county, from Madison to Frye- 

 burg, towards the north-west. 



Much might be said respecting the date of this elevation that would 

 be profitless, since the facts indicating the epoch of disturbance are 

 meagre. After the conversion of the Montalban strata into schists, 

 whether by metamorphism or original chemical deposition, we have evi- 

 dence of powerful disturbances among them ; — in other words, this was 

 the time of the formation of the Franconia breccia, when ledges of moun- 

 tain size were first shivered into fragments, and then cemented by erup- 

 tions of fine-grained granite. As this same series occurs at Franconia 

 and the Notch, fourteen miles apart, and possibly in Essex county, Vt., 

 thirty-five miles away from Franconia, the action must have been wide- 

 spread, and therefore powerful. That this period of eruption is distinct 

 from that of the Pemigewasset granites, is shown by several considera- 

 tions: I. The Uthological character is different. The breccia cement is 

 the fine-grained rock described above (p. 169) as the "Breccia granite," 

 bearing some resemblance to the so-called Concord granite, and very 

 little to any of the Pemigewasset series. 2. The latter are of later origin 

 than the breccia, because none of it has been found either in the frag- 

 ments or cement of the formation. 3. The Pemigewasset granites are 

 usually developed in massive overflows, while the Franconia cement is 

 more limited in amount. 4. The coarser granites are found constituting 

 the cement of clay and andalusite slates, the fragments of which have 

 not undergone metamorphism. There is, therefore, a Franconia and a 

 Pequawket breccia, formed at widely different periods, the materials of 

 which are very different from each other. It should be remarked, how- 

 ever, that the numerous large veins of Breccia and other varieties of 

 granite usually occur quite near the later series, as upon Mts. Webster, 



