44 History of Hingham,. 



dance over the hilly region between South and Elm streets, appear- 

 ing near the former in cliffs of considerable altitude, and it forms, 

 with the amygdaloidal melaphyr, a part of the shore rocks of 

 Rocky Neck that border Weir River, east of Planter's Hill. It 

 also occurs abundantly about and over the high lands contiguous 

 to Unit's Cove. 



Away from the coast and the islands in the harbor the most 

 imposing exhibition of this rock may be found in a narrow, pri- 

 vate road that runs from Real Street towards Weymouth River, 

 some distance north of the Hockley Lane. Soon after entering 

 this road it turns towards the north, winding about the base of 

 some exposures of the conglomerate which lie between it and 

 Beal Street. Following the passage through low ground and 

 through forest growth for the distance of about a quarter of a 

 mile, there suddenly appear high cliffs of the rock partially ob- 

 scured by trees, rising to the height of forty to fifty feet, and pre- 

 senting the appearance of having been torn asunder by some 

 convulsion of nature, large masses being found in the foreground. 

 The rocks extend along the road and near it six to seven hundred 

 feet. The exposure here is well worth visiting. 



The conglomerate rocks of Hingham were originally deposited 

 upon the more ancient rocks, perhaps much farther inland than 

 is now apparent, and were worn away by the erosion of the sur- 

 face in after ages. At some localities, however, a partial coating 

 of the conglomerate may be seen upon the granite, occupying 

 depressions in it, showing where it once rested probably in con- 

 siderable beds. 



CLAY SLATE, OR ARGILLITE, OF THE CONGLOM- 

 ERATE SERIES. 



The slate of the conglomerate series in Hingham occurs, as 

 may be seen by the maps, quite abundantly in the northern parts 

 of the town, alternating with the conglomerate. The color of 

 these slates varies considerably, a portion being of the ordinary 

 bluish shade, while other portions are red or reddish. Both 

 these colors are found quite near each other in the same exposure, 

 as in Hersey Street on the left side going from, and not far from, 

 South Street. 



The slate of the slate series will be mentioned after notice of 

 melaphyr, which is included in the conglomerate series. 



MELAPHYR. 



The name Amygdaloid commonly applied to this rock was given 

 because of the frequent occurrence in it of cavities filled with other 

 minerals than those constituting its mass, which are often approxi- 



