128 



BULLETIN OF THE ESSEX INSTITUTE. 



beat sharply down along the fault plane, which presum- 

 ably hades southwest 5° (from vertical) at this point. 



Crossing the next spur brings us to the valley of 

 Sutherland Creek (16), a living stream which] supplies 

 the reservoir near the limekiln. On the west of the 

 valley where it issues from the mountains, the Fountain 

 beds, as before, are tilted to a S. W. 85° dip. This out- 



a?, a 



\M . 



crop must be near the fault, for within a few yards south 

 of it the dike sandstone is seen also dipping S. W. 85°, 

 while higher up the dike sandstone dips S. W. only 5° to 

 10°. These outcrops are thus in perfect harmony with 

 those of the preceding gulch, and the accompanying 

 section (Fig. 3) may be regarded as expressing the 



