36 NEW YORK STATE MUSEUM 



liill in the north central part of the Remsen quadrangle may pos- 

 sibly represent such an ancient hillock. This hill rises abruptly 

 almost 200 feet above the surrounding country and is separated 

 from a still higher hill to the northeast by a narrow depression. 

 This depression is difficult of explanation on the basis of the exist- 

 ing drainage, but it may be readily accounted for by the action of 

 a Precambric stream. 



Slope of the surface upon which the Trenton was being deposited 



Not far beyond the map limits to the southeast the Trenton 

 shows an increase in thickness, towards the southwest, of about 100 

 feet in 5 miles. This indicates that the slope of the surface on 

 which the Trenton was being deposited was about 20 feet per mile 

 southwestward . 



The thickness of the Trenton formation (including the Lowville) 

 at Trenton Falls is probably not far from 300 feet. In the Globe 

 Woolen Mills well at Utica it is 510 feet, which is an increase of 210 

 feet in the distance of 14 miles. Hence the slope of the floor here 

 upon which the limestone was laid down was about 15 feet per mile 

 ;southward. 



In the Rome well the Trenton is 375 feet thick and 20 miles to 

 the northeast it is from 200 to 250 feet or an increased thickness 

 northwestward of from 125 to 175 feet. This indicates that the 

 surface receiving limestone deposition sloped 6 or 8 feet per mile 

 .southwestward. 



Thus the general facts seem to be that the floor upon which the 

 Trenton was being laid down sloped 6 or 8 feet to 20 feet per mile 

 southwestward and that the slope was less in the northwestern part 

 of the region. 



Present Precambric slope beneath the Paleozoics 



At Northwood the Precambric lies at an elevation of 1220 feet, 

 while in the Campbell well near Utica it was struck at 1500 feet 

 below sea level. The distance between the points is 21 miles and 

 the difference in Precambric elevation is 2720 feet which shows a 

 present Precambric slope of 130 feet per mile southward. 



The Precambric at Forestport lies at 11 40 feet and in the Rome 

 well at 1 105 feet below sea level, thus showing a difference in ele- 

 ■vation of 2245 feet in a distance of 20 miles or a slope southwest- 

 ward of about no feet per mile. 



In the same way the difference in elevation between the Pre- 

 cambric at Forestport and at Vernon is found to be 2965 feet. 



