GEOLOGY OF THE REMSEX QUADRANGLE 37 



The distance between the places is 30 miles and hence the slope 

 southwestward is about 100 feet per mile. 



Slope of the surface where no Paleozoics now cover 



At Forestport the Precambric outcrops at 11 40 feet and 6 miles 

 northeastward at 1500 feet. The difference in elevation is 360 feet 

 or the southwestward slope is 60 feet per mile. 



At the mouth of Little Black creek the Precambric lies at 11 8a 

 feet and ij miles north of Reeds Mill it lies at 1900 feet. The dis- 

 tance is 10 miles and the difference in elevation is 720 feet. Hence 

 the Precambric slope is here 72 feet per mile southwestward. 



At Northwood the Precambric is exposed at 1220 feet and to 

 miles northeastward at 2210 feet, showing a difference in eleva- 

 tion of 990 feet. The slope southwestward is thus nearly 100 feet 

 per mile. 



From these considerations it is evident that the general Pre- 

 cambric slope where not now covered by the Paleozoics is much 

 less steep than where covered. This marked dift'erence is readily 

 accounted for b}' erosion and gives us some idea of the amount 

 of erosion in the Precambric surface since the Paleozoics were 

 removed. The original dip of the Paleozoics was found to be 50 

 to 100 feet per mile which is considerably less then the slope of 

 the Precambric beneath them. Also the dip of the Paleozoics is 

 very nearly the same as the present slope of the Precambric where 

 no Paleozoics cover. 



ABSENCE OF THE DOLGEVILLE (UPPER TRENTON) 



SHALES 



The Dolgeville shales, formerly called the Trenton-Utica passage 

 series, and described by Gushing are always present between the 

 Trenton proper and the Utica shale in the Little Falls district.* 

 The rocks of the series are rather thin bedded, alternating lime- 

 stones and shales and are distinctly transitional in character. A 

 maximum thickness of about 100 feet is shown in the Little Falls 

 district. Over the entire Remsen quadrangle such transitional 

 beds are nowhere exposed, although the Trenton limestone covers 

 a wide area and in a number of places the Utica and Trenton may 

 be seen in close proximity if not in actual contact. A small area 

 in the southeast corner of the quadrangle especially that portic^n 

 known as Sand hill, is probably occupied by the Dolgeville shales 

 which here represent the northwestward extension of the sanie 



* op. cit. p. 31-32. See also p. 20 of this report. 



