REPORT OF THE STATE PALEONTOLOGIST 1902 1221 



zontal thrust plane of the Vlightberg overthrust, 2-2. Above 

 this 2-2 thrust is more Manlius and, at the top of the view, the 

 Coeymans limestone. 



The middle block, between thrusts A and 2, shows a very fine 

 example of beds dragged beneath a thrust plane. The over- 

 thrust mass above plane 2 moved in a direction n. 40° w. The 

 broken edges of the under segment were caught by the moving 

 mass, curled up, as shown at the left of the center of plate 11, 

 again broken off, and a small intermediate thrust plane (thrust 

 B) about 50 feet wide was formed. Along this latter plane the 

 small broken off segments of the beds involved were carried 

 along and actually jammed farther into the face of the cliff. 

 Thrust B has a true overthrust plane at the edge of the cliff at 

 the left of the picture which diminishes to a mere sliding plane 

 between normally superimposed layers of the Manlius limestone 

 at the right side of the view. 



The North hill and the White lime quarry thrust 



Sections 3, 4 and 5 of plates 3, 4 and 5, illustrate the structure 

 of the North hill, which is very much simpler than that of the 

 Vlightberg. With the exception of the extreme southeastern 

 corner, the entire area north of Delaware avenue depicted on 

 the map [pi. 2], exhibits a shallow synclinal structure with the 

 beds at the eastern edge of the trough dipping steeply west- 

 ward. The anticlinal arch seien in the Spring and Delaware 

 avenue quarries does not constitute one of the structural feat- 

 ures of the North hill, as its axis has an east-northeast trend 

 that diverges from the almost northerly direction of the base of 

 the hill slope. 



The strike of the formations on the North hill is generally 

 about n. 20° e., excepting near Delaware avenue, where, in the 

 vicinity of the Gross quarry and Gross residence, the strike 

 veers to the southwest and west with a corresponding change 

 in the dip to northwest and north. Farther west at the first 

 intersection of the railroad with the avenue the southwest 

 strike is again resumed in the Oriskany pebble bed. 



Along the line of section 3, which is about on the line of Dela- 

 ware avenue, the various formations succeed each other in nor- 

 mal sequence of Manlius, Coeymans, New Scotland, Becraft,. 

 Port Ewen and Oriskany. There is evidence of diagonal strike 



