﻿144 NEW YORK STATE MUSEUM 



of the great sponge of sand plain, on which is located the military 

 camp, is not into the Black river but north into the Indian river. 1 

 Along the north side of the sand plain huge springs gush out along 

 the contact with the impervious drift, while such are entirely want- 

 ing on the Black river side. It is certain, therefore, that if the 

 delta at Felts Mills and Black River were not there the river would 

 plunge northward. It is equally certain that before the ice invasion, 

 and the deposition of the delta and moraine barrier, the river did 

 flow northward. The only condition which could produce south- 

 ward flow would be a northward uplift 20 or 30 feet per mile 

 greater than we have today, which is extremely unlikely for this 

 district. As long as any of the St Lawrence valley drainage passed 

 north the Black river went with it. 



The westward course of the Black river from Great Bend is due 

 to glacial diversion. The river is on rock and with no proper valley. 

 It is in a postglacial channel. Moreover, there, is no south leading 

 valley in the Watertown district sufficient for a large river. If 

 there were the Black would be in it today as there is no heavy drift 

 barrier to block drainage in .the district south of Watertown. 



The later history is quite clear. During not only the advance and 

 retreat of the latest ice sheet but probably that of earlier ice sheets 

 the Black valley high-level waters were forced westward and south- 

 ward around the Rutland promontory. High on the slopes at Copen- 



1 Extracted from report of Frank A. Hinds to the Water Board of the 

 City of Watertown, June 29, 1908. 



. . the entire country slopes toward the north and west and away 

 from the bank of the river which is the highest part. 



The Pine Plains is a sheet of very clean sand from. 50 to 75 feet thick 

 and covering an area of from 25 to 40 square miles. The sand is so porous 

 that all the rainfall sinks directly into it and forms a natural reservoir at 

 the bottom. This ground water has a slow movement in the direction of the 

 slope but does not become exhausted during the dry season as the constant 

 character of the springs at its edge proves. 



While the water of the river opposite the (U. S. military) camp is 100 

 feet below the surface of the plains, there is an impervious bed of day 

 and rock underlying the sand which is from 30 to 50 feet above the river. 

 This clay may be seen in many places along the bank, though in others the 

 sand has run down and covered it over. Five miles to the west the sand 

 plateau stops and the clay substratum continues as the surface soil of the 

 country; but here it is 100 feet lower than where it commences at the 

 river brink under the camp. 



This northwesterly slope of the subsoil determines the direction or flow 

 of the underground water and accounts for the fact that there are but few 

 and comparatively small springs flowing into the Black river from under 

 the plains, while those along the western border of the sand are more 

 copious and gather into several creeks or brooks of noticeable magnitude 

 which flow westerly into the Indian river. The few springs along the 

 Black river bank are where the underground water spills over the easterly 

 upper edge of the clay stratum, but they are comparatively few and small 

 . . . the water which emanates from under the Pine Plains" does not 

 get into the Black river to any extent worthy of attention. 





