356 A. W. GRABAU — SILURQ-DEVONTC CONTACT IX NEW YORK 



In figure 2 a channeling in tin; same rock is shown from another part 

 of the quarry. In this channel rests a lens of the Onondaga limestone, 

 followed by regular beds of the same rock. 



Figure 1. — Sagging and Truncation <ij Manlius Limestone. 



In figure 3 a number of small channelings in the Manlius limestone 

 are shown, none of which are over a foot in depth. These are filled by 

 lenses of the Onondaga limestone, the whole being overlaid by regular 

 beds of the same rock. 



Figure 2. — Channeling of Manlius Limestone. Figure '■>. — Channeling of Manlius Limestone. 



In figure 4 a more pronounced case of erosion is shown. This is 

 probably a portion of a broad channel, the other side of which is not 

 exposed. The depth of the excavation is from 3 to 4 feet. The beds of 

 Manlius limestone are horizontal and are cut off obliquel} T on the left, the 

 depression being filled by thickened lenses of the Onondaga limestone. 



T 



Figure 4. — Erosion of Manlius Limestone. 



In all these cases the contact between the two limestones is either 

 direct or a thin sheet of decomposed shale, the representative of the 

 Oriskany, lies between them. 



