210 



materially strengthened by the marked change in the strike, 

 tVoiu south of" east to north of east, as we cross it. 



In following tlie sedimentary rocks farther east we find an 

 outcrop of conglomerate in front of the school house on Elm 

 Street, nearly (jppositc; tiie end of Central Street, and directly 

 in the line of strike of the slate ; while several exposures of 

 the red slate are found in the field north of the school house. 

 These facts clearly suggest the third transverse fault shown 

 on tlie map. Tiie character of this fault is wholly uncertain. 

 No outcrops of slate or conglomerate have been observed 

 south of Elm Street ; and the map is iiere largely hypo- 

 thetical. Quite certainly the fault does not downthrow to the 

 west as the arrow indicates : but it is more probably a hori- 

 zontal thrust-faidt, the eastern extension of the strata having 

 been shoved bodily to the northward from 100 to 150 feet. 

 The rock showing in tlie field south of Elm Street and east of 

 Central Street is diorite and probably in situ. This indicates 

 a gradual narrowing of the sedimentary belt ; but beyond 

 this point tliere are no outcrops of any kind for more than 

 half a mile ; and where and how the sedimentary rocks termi- 

 nate we can only conjecture. As previously stated, the gen- 

 eral map is constructed in accordance with the view that they 

 ci'oss Main Street, pass beneath the sandplain occupied by 

 the cemetery, and end in the Home Meadows against the 

 ofreat boundary fault between the Hingham and Nantaskct 

 areas, supposed to coincide in position and direction with the 

 east shore of Hingham Harbor. 



Returning to Hersey Street and tracing this series of strata 

 westward, we find that all the beds which can be traced more 

 than 200 feet from the street are distinctly flexed to the north, 

 the flexure amounting to a horizontal shift of about 100 feet. 

 It is necessary to suppose, of course, that, as shown on the 

 map, the entire series is involved in the displacement ; and 

 there arc some indications that the beds are actually com- 

 pressed or pinched on the bend, as if they had experienced a 



