INTERCISION TYPE OF STREAM PIRACY 



441 



has found its way through the divide along joint and bedding planes, so 

 that the two streams are now connected by a subterranean passage. This 

 channel has been enlarged by solution, so that now a sufficient volume of 

 water passes through it from Cook's Creek to North River to cause alarm 

 on the part of the o'UTiers of a mill located a short distance below, who 

 depend on the water of Cook's Creek for power. Several attempts have 

 been made to stop the underground passage but without success. The 

 amount of water which flows through the underground channel varies 

 with the stage of water in the two streams, but especially with that in 

 Cook's Creek. 



The point where the water emerges on the face of the bluff on the 

 North River side of the divide is about 2 or 3 feet above low water in 

 North River, but at high water the opening is frequently submerged. 



10 25 



50 



100 FEET. 



Fig. 3. Cross Section of Divide Between North River and Cook's Creek. 



The source of the water flowing from the underground channel is deter- 

 mined readily, since the water of Cook's Creek is usually stained very 

 (lark bj'- the refuse from a tannery at Harrisonburg. A cross section of 

 the divide between North River and Cook's Creek is shown in figure 3. 



Case III. Reference to the map (fig. 4) of Bridgewater and vicinity 

 will show that North River flows in a meandering course through a ridge 

 about 1 mile northwest of the town. This ridge is typical of nmnerous 

 low linear cherty ridges which characterize the Great Valley in western 

 Virginia. Round Hill is one of the common conical-shaped monadnocks 

 which occur at intervals in these chertj^ ridges throughout the Vallej' 

 pro%dnce. The rocks composing this ridge are for the most part massive- 

 bedded cherty limestones, the most resistant members of the Shenandoah 

 group. The ridge is monoclinal in structure, the beds dipping toward the 

 southeast. 



