490 



Scientific Geology. 



(28) Granite Veins in Gneiss ; Palmer's Island ; N. Bedford Harbor. 



The surface sketched in No. 29 is nearly horizontal ; and the 

 strata of gneiss dip as in the last case. On one side the direction of 

 the strata is changed, and apparently through the influence of the 

 vein, as much as 10° or 15°. The vein is 15 inches wide. 



(29) Granite Vein in Gneiss : At the fort in Fairhaven. 



No. 30 exhibits also the basset edges of the gneiss strata where 

 they dip 35° northerly. A mass of granite, a, which is several feet 

 wide where it first appears above the soil, sends off a very crooked 

 vein of six or eight inches wide, which connects with another vein, 

 b ; which last vein also sends off a narrow branch. At d, the edges 

 of the strata are curved considerably, obviously in consequence of 

 the granite in their vicinity. 



