126 



Scientific Geology. 



it is difficult to see why the same reasoning will not apply to the 

 whole of Massachusetts Bay; and when we see with what tremen- 

 dous force the ocean must, for ages, have battered the hard sienitic 

 rocks of Cape Ann, and what an immense accumulation of sand, 

 gravel, and bowlders, has been made along the south shore of this 

 bay, we feel almost prepared to adopt this theory. And yet, we are 

 staggered in our belief when we reflect on the immense period of 

 time requisite for such a work ; and doubt whether other geological 

 facts do not indicate a later commencement to the present order of 

 things on the globe. 



The proper place for learning the dynamical effect of northeast 

 storms upon our coast, is on the north east side of Cape Ann. Rocks 

 of many tons weight have been in this manner moved from their beds, 

 and driven inward a considerable distance. I regret that I cannot be 

 more definite in this statement. But one has only to visit this coast 

 to be astonished at the marks every where exhibited of the powerful 

 agency of a stormy ocean, and to be satisfied that nothing but the ex- 

 treme hardness and unstratified structure of the rocks has enabled 

 them to resist its violence. And when we learn that the rocks of 

 Boston Harbour are softer and shistose, we see a sufficient reason 

 why they have given way before the breakers, while Cape Ann, and 

 the shores of Cohasset and Scituate, maintain their position. 



Several cliffs of clay and sand along the coast exhibit the combined 

 effects of the ocean, rains, frost, &c. in wearing away the land. In 

 Chilmark, on Martha's Vineyard, is one of these facing the southeast, 

 and at least a mile in length. It is now rare that the breakers rise 

 high enough to impinge directly against the cliff : but they wash 

 away whatever materials have been brought down by the rains. Gay 

 Head, which is the western extremity of the same island, presents a 

 cliff of variegated clays, sands, &c, not less than 150 feet high; and 

 which, standing exposed to the bufferings of wind and waves from the 

 sea, and to the wastes of storms from above, exhibits perhaps the most 

 instructive example along the shore, of the effects of these agents. 

 In the second part of my Report, I described this cliff as a most pic- 

 turesque object of scenery ; but there is not likewise a more interes- 

 ting spot in the State, to the geologist. And among other things he 

 cannot but notice the numerous fantastic forms into which the lofty 

 masses of clay have been worn, while the numerous bowlders and 

 pebbles along the beach attest the violent action of the sea. The fol- 



