225 



the granite axis can he ohserveci. It is very plain that these 

 beds curve regularly around the granite, following its north- 

 western as faithfully as its southern margin. The broadening 

 of each bed as it rounds the angle is due to the natural dim- 

 inution of the dip at this point. North of Beal Street the belt 

 of melaphyr is, at first, a[)parently, scarcely 100 feet wide, but 

 it gradually broadens northward, possibly as the result of a 

 diminished dip. It is seen in contact with the basal conglom- 

 erate at several points. The most northerly and most satisfactory 

 exposure of the contact is in a small excavation on the soutli- 

 west side of Hawke's Lane, where the conglomerate is not 

 marked on the map ; l)ut in every case the appearances are 

 best explained by regarding the melaphyr as contemporaneous 

 rather than intrusive. It fills the inequalities in the surface 

 of the conglomerate ; but does not properly penetrate that i-ock. 

 AlthoTigh the great bed of conglomerate (3) overlying the 

 melaphyr is well exposed for the entire distance betvveen Beal 

 Street and Lincoln Street, not a single good contact could be 

 found. 



Scattered through the woods and swamp, stratigraphically 

 above this conglomei-ate, are numerous outcrops of conglom- 

 erate, sandstone, and slate which it is difficult to connect 

 satisfactorily in continuous belts. These are somewhat 

 generalized on the map, and the correlation indicated there is 

 probably not entirely correct. It can hardly be doubted, 

 however, that we have here, in normal sequence, the red 

 slate (4), conglomerate and sandstone (5), and red slate (<^)) ; 

 and then follow in succession conglomerate, slate, conglomerate, 

 melapliyr, and conglomerate, as shown on the map. South of 

 Real Street, however, and disregarding this melaphyr, it would 

 not be difficult to divide the nearly continuous line of outcrops 

 so as to identify or represent every bed in the Beal's Cove 

 section up to the highest conglomerate (13). The interpreta- 

 tion of this part of the Beal's Cove area is one of the puzzles 

 of Hingham geology. The general structure appears to be 



OCCAS. PAPERS v.. S. N. II. IV. 15 



