336 Notice of a Scientific Expedition. 



mitted that this bay was once narrower than it is now, the inference 

 would follow that its tides must have risen much higher ; when it 

 therefore received into a narrow channel the great tidal wave of the 

 Atlantic, it must have swept with a force inconceivable, and have 

 carried on its undermining operations, with a fearful rapidity. The 

 comminuted fragments too, would be borne to a greater distance, and 

 be spread out upon a far greater surface. The tendency, however, 

 of all this would be to erect finally, barriers against its own powers, 

 and to create a limit to its own destructive agencies ; so that probably, 

 the real width of the bay does not now increase, what is lost on one 

 side being gained on the other, with the exception of what may yet 

 be spread out on the bottom of a wide ocean. 



Stratification. — Trap rocks are rarely if ever stratified. If, how- 

 ever, we are not deceived, there are places where these rocks assume 

 such an appearance, or are in fact stratified. The only place to 

 which we can safely refer the observer is Cape Split. The stratifi- 

 cation is, on what may be termed a large scale ; the strata are thick 

 and heavy, but the parallel lines* separating the strata, may be seen 

 one fourth of a mile. See Fig. 3. 



Junction of the trap with sandstone. — We are not satisfied with 

 what we saw at those places of junction, which came under our ob- 

 servation. There is a sort of blending of the two rocks, and they 

 form a species of breccia, but did not present marks of a partial fu- 

 sion, by exhibiting vesicles or cavities. The effects of trap on the 

 adjacent rock, are not uniform. They seem to depend on circum- 

 stances, which we can only conjecture. 



Contortion of strata. — Remarkable instances of the contortion of 

 strata, may be seen between Partridge Island and Cape Sharp. 

 Here, for the distance of six miles, the shale and sandstone appear 

 in alternating layers. At many places, the strata are nearly vertical, 

 but there is no regularity in the dip of the rocks, or in the arrange- 

 ment of the strata among themselves. Fig. 2, is a representation of 

 one instance among many, of the contortions occurring between P. 

 Island and Cape Sharp. This disorder among the strata of shale 

 and sandstone, is supposed to be produced by its proximity to the 

 trap, by dykes which have been forced between the layers of those 

 rocks, and of course have acted very unequally on different points. 



Scenery. — The scenery is peculiar and characteristic. Its char- 

 acters arise from two causes ; the nature of the rocks themselves, 



* Are these lines any thing more than fissures produced by cracking ? 



