134 ^'EW YORK STATE MUSEUM 



the stream flows and which constitutes essentially an luilimited 

 storage reser^'oir to feed underground circulation. This is all the 

 more true if crush zones are extensively developed as accompani- 

 ments of the faulting. 



In general as to perviousness the indications are somewhat ob- 

 scure. But the data now obtained seem to prove that all the for- 

 mations except the Binnewater sandstone and the High Falls shale 

 are compact and fairly impenaous along the bedding lines. Only 

 where crevices have formed or where crushing occurs is there 

 likely to be heavy circulation. This is all the more important since 

 so many of the beds are limestones known to be readily soluble in 

 circulating water. One of these limestones, the ]\Ianlius, exhibits 

 occasional large open solution joints at the surface — so large that 

 a surface stream disappears entirely at the so called '* Pompey's 

 cave" and joins the subterranean circulation. But such caves are 

 probably limited to the surface. 



It is near tliis point, however, that one of the earlier borings at 

 one side of the present line discovered xtry soft ground at a depth 

 of about sea level, i. e. over 200 feet below the present surface, 

 which shows that similar conditions prevail at certain points to 

 great depth. 



Pumping tests made on hole no. 32 in an attempt to establish 

 some data on the inflow of water gave very interesting results. 

 These tests were vers* thorough. It was proven that the water was 

 supplied in apparently inexhaustible quantity at maximum pumping 

 capacity, which was ninety gallons per minute. Futhermore, the 

 chief inflow seemed to be from the Binnewater and High Falls 

 formations as was to be expected. \Miether a crush zone allowing 

 free circulation is furnishing a portion of this supply or whether 

 the whole inflow represents the normal porosity condition of these 

 formations is not yet proven.^ 



Other porosity tests have been made in such way as to locate 

 and measure this factor [see later discussion]. Hole no. 10 shows 

 an artesian overflow that comes from the Binnewater sandstone. 

 A working shaft has been put down also in the vicinity of hole 

 no. 32 and at the same depth found an enormous inflow of water 

 which drow-ned out operations for a time. The lateral supply in 

 this case has been reduced by introducing a thin cement grouting 

 through holes bored in the surrounding rock from the surface. 



Holes no. 12 and no. 14 also show an artesian flow, but both are 



1 In construction the Binnewater sandstone has been found ver\- wet. 



