J 074 



NEW YORK STATE MUSEUM 



South of this fault, the structure becomes more complicated. 

 The eastern sharper and more closely crowded folds now appear, 

 and with them a number of thrust as well as gravity faults. 

 The structure of this area, as far as section 20, is shown on a 

 larger scale on the section map, and will now be described 

 in detail. 



Just south of the point where Claverack creek strikes the 

 eastern road, i. e. at fault no. 9, we meet with one of the numer- 

 ous, more or less overgrown wood roads which lead up the 

 mountain. Following this road, which leads off westward from 

 the main road, we find, on turning at a bend, that we are follow- 

 ing a depression along the strike of the strata. This depression 

 marks the location of fault no. 10, a strike fault. To the west 

 of this fault the strata dip 20° to 25° westward, while on the 

 other side they dip as much or more to the east. The strike of 

 the Manlius and the overlying Coeymans, east of the wood road, 

 is at first nearly east and west, the dip being as high as 30° or 

 35° to the south. This is caused by fault no. 11, a short diagonal 

 fault between 10 and 12. Between this shorter fault and the 

 main strike fault (no. 10) a triangular surfaced block has been 

 tilted to the degree indicated by the dip. As this block stands 

 now, only the Coeymans and Manlius compose it. East of fault 

 11 the strata dip steeply to the southeast, the angle ranging 

 from 50° to 75°, while the strike is n. 30° e. Nearly the entire 

 thickness of the Coeymans is exposed three times in the region 

 of these faults, as shown by section no. 7. The Manlius forms 

 the eastern portion of the section, dipping, as far as exposed, 

 about 60° to the southeast, thus showing a complete overturn 

 of the strata, the Manlius resting on the Coeymans. 



South of the triangular fault block the structure is somewhut 

 simpler, being affected only by two longitudinal strike faults. 

 The first (no. 10) brings the steeply eastward dipping New 

 Scotland (70°, s. 60° e.) against the gently inclined westward 

 dipping Coeymans (20°, n f 00° w.), as shown in sections 8, 

 and 10. To the west of the fault the beds from the Coeymans 

 up are shown, while on the cast of this fault, the New Scotland, 

 Coeymans and Manlius are found in the reverse order, owing 



