the Hudson and its Tributaries. 



309 



The High Falls Crossing of the Rondout Valley. — As 

 shown in fig. 4, the aqueduct reaches the Kondout valley on 

 the northwest side at 500 ft. grade. Beyond this point for 

 over four miles it must utilize a pressure tunnel known as the 

 Rondout Siphon. The borings reveal a buried channel on 

 the northwestern part of the valley sunk in the bed-rock to 

 80 + , or 270 ft. below the present surface. As this is near 

 the hamlet of Kripplebush we have called it the Kripplebush 

 channel. The cores prove that we have a fault, probably a 



Fig. 4. 



MANLIUS |rt_ 1&INHE.-1 HIGH I5HAWANOCNK GRIT IHUDSON RIVER SUATE. 



,u WATER. FALLS 



SHAW A 



7V K~~ G K I ~T I HUDSON KiV. Sl. 



Fig. 4. The Kondotit Crossing near High Falls. B. Becraft limestone; 

 N.S. New Scotland limestone; C. Coeymans limestone; H.F. High Falls 

 shale ; H.E.S. Hudson Eiver slate. The sections are continuous. 



normal one, upon which the stream was located at the time it 

 was overwhelmed. It had worked down the Onondaga lime- 

 stone against the basset edges of the Hamilton just as had the 

 old-time stream at the Hurley crossing, and then it had been 

 arrested and obliterated by' the drift. We have no further 

 records of this stream, but along the line of the siphon and 

 after leaving the valley of the Kripplebush there is only 

 a thin cover of drift, with frequent outcrops before the next 

 depression is reached. Then about two miles farther east- 



