219 



roui^li cliaracter of tlic melaphyr, points to the conclusion that 

 it sutt'ercd but little erosion before the conglomerate was spread 

 over it, and hence that it is probably a submarine flow. 



The conglomerate dips south or away from the melaphyr at 

 the normal angle ; and these eastern ledges overlap and supple- 

 ment the extensive and [)rominent outcrops farther west, in the 

 vicinity of the small pond, the entire breadth of the bed being 

 thus satisfactorily exposed. This bed is throughout a normal, 

 massive, well-indurated puddingstone, embracing very little 

 arenaceous material. The pebbles are mainly from one to two 

 or three inches in diameter : but in certain layers the maxinunn 

 rises to six inches or even a foot. The southerly dis[)lacement 

 of the conglomerate in passing from the eastern to the western 

 ledges is very noticeable, and evidently related to the increased 

 breadth of the melaphyr in that direction. Two explanations 

 have been suggested for the latter : first, a diminished dip, 

 which would cause a curvature of the overlying strata, as shown 

 on the map, even though they retain throughout their normal 

 high inclination ; secondly, a strike-fault, as indicated by the 

 conglomerate enclosed in the melaphyr, which might have the 

 same result as regards the overlying beds, or, ending against 

 transverse faults, might involve an actual dislocation of the 

 sedimentary series. Unfortunately, the entire absence of out- 

 cro[)s along this north-south line makes it impossible to choose 

 between these explanations ; and it may well be that both of 

 them are true. 



With this introduction, we can pass rapidly over the entire 

 section from the granite southward, since it is, in a large 

 measure, a repetition of the Village section. The strike ranges 

 from S. 65° to S. 80° E. ; and the dip, except perhaps with 

 the niela[)hyr, varies but little from S. 80°. The thicknesses 

 are chiefly approximations, the beds, either on account of not 

 being sharply deHned or from lack of continuity in the outcrops, 

 rarely admitting of exact measurement. The numbers refer to 

 the "eneral table of Hinj^ham strata and also indicate the corre- 



