﻿THE HELDERBERG INVASION OF THE MANLIUS 



Introduction 



By glancing at Plate I it will be seen that several sections in 

 or across the Manlius stage have been studied extending from 

 "i, Union Springs" to "8, Helderberg Mts." The dotted line 

 at the top indicates the position of the Oriskany sandstone. 

 Measurements of the thickness of beds are expressed in feet to 

 the left of each columnar section, while to the right is a brief ref- 

 erence to faunal or stratigraphic features. 



Before beginning a detailed description of each section, it may 

 be stated that a similar study was undertaken by Prof. S. G. 

 Williams and his results were published in the American Journal 

 of Science, 1886, vol. 31, p. 139-145 Subsequent investigations 

 have shown that this author was scarcely warranted in his gen- 

 eral conclusions regarding the age and proper correlation of the 

 great masses of limestone between the gypsum beds and Oris- 

 kany in central New York, for he believed them to be locally 

 modified Helderbergian deposits, and hence above the Manlius 

 series. But this much must be said in his behalf, viz., that he 

 alone has seemed to grasp the true stratigraphic relations of the 

 various deposits about Union Springs, and he alone has empha- 

 sized the importance of the Oriskany Falls section in the eluci- 

 dation of Manlius and Helderbergian stratigraphy. As we pro- 

 ceed, we shall see that there is also a slight flavor of truth in 

 even his general conclusions as referred to above ; for the title 

 of the present article is such as to show that the relations of Man- 

 lius and Helderbergian faunas, are, so far as time goes, perhaps 

 not quite so distant as has generally been supposed. 



I. Union Springs 



Eurypterus Limestone. — The Eurypterus limestone of the 

 Salina is well shown at two localities near Union Springs: 1st 

 along the Lehigh Valley R. R. track from the Plaster Mills to 

 x /i mile east of Cayuga Junction; 2d, in the bed of the creek but 

 a few yards north of Cross Roads Station. At the former local- 

 ity there is a slight southerly or south-easterly dip so that by 

 following the stream bed just east of the Junction nearly to the 

 highway the section as given on PI. 3, No. 4 can be made up. 

 The upper portion of the section may also be seen in the outcrops 

 on the north side of the railroad track; in fact here is the plan 



