CAMPBELL AND SYRACUSE WELLS AND SECTIONS. 101 



Campbell Well and Section. — Very interesting for comparison with this 

 well is the record of the Campbell well, three miles west of Utica, which 

 was drilled to a depth of 2,250 feet. This well was described by Mr 

 Charles D. Walcott in August, 1887,* and through his courtesy the 

 writer has had the pleasure of studying the set of samples saved from 

 it. The record of this well as reported by Mr Walcott may be briefly 

 summarized as follows : 



SECTION OF THE CAMPBELL WELL NEAR UTICA, NEW YORK. 



Formation. 



Lorraine shale of the Hudson group.. 



Utica shale. 



Trenton limestone. 



( rap of 180 feet between the Trenton and Calciferous, 100 feet of 

 which probably belongs»to the Calciferous, which would make 

 the top of the Calciferous at about 1,230 feet. 



Calciferous and arenaceous strata, 260 feet ; Calciferous in all about 

 360 feet in thickness. 



Potsdam. 

 100 -f- Pre-Cambrian and Archean. 



The careful study of the Campbell well record and specimens has fur- 

 nished much assistance in interpreting the record of the Utica well. The 

 top of the Trenton limestone is reached at a depth of 570 feet in the 

 Utica well and at 800 feet in the Campbell well, a difference of 230 feet. 

 Supposing the formations to have about the same thickness, then the 

 top of the Calciferous might be expected at a depth of about 1,000 feet, 

 and the light gray, strongly calcareous rock, which is considered as rep- 

 resenting the Calciferous, occurred at 1,080 feet. In the same manner 

 the top of the. Potsdam would be reached at about 1,360 feet, while the 

 sample which is regarded as probably coming from near the top of the 

 Potsdam was reached at a depth of 1,400 feet, and the bottom of the well, 

 at a depth of 1,720 feet, is still in this formation, the Archean not having 

 been reached. 



The line of separation between the Trenton limestone and the Cal- 

 ciferous is somewhat difficult to determine, and it is especially so between 

 the Calciferous and Potsdam. The point at 1,400 feet, indicated as the 

 beginning of the Potsdam, can only be taken as probably near the line 

 of separation between these two formations. 



Syracuse (State) Well and Section. — In 1884 the "state well" was drilled 

 at the southern end of Onondaga lake, near Syracuse, about fifteen miles 



*Proe. Am. Assoc. Adv. Sci., vol. xxxvi, pp. 211, 212. 



