1220 



NEW YORK STATE MUSEUM 



Contorted beds at mouth of Glory Hole 



Before leaving the discussion of the Vlightberg, we wish to 

 call attention to the complex and highly interesting folding of 

 the rocks over the mouth of the Glory Hole incline [see pi. 8 

 to 11]. Of these plates, numbers 8, 10, 11 are adjoining views 

 all looking southwestwardly from the engine house. Plate 8 is 

 from the southeast corner of the engine house, looking along 

 the Glory Hole cut. Plate 10 is a view of the lower portion of 

 the cliff from the platform of the Glory Hole head-frame on 

 the west side of the engine house. Plate 11 shows the upper 

 portion of the cliff as seen from the western edge of the engine 

 house roof, and its lower portion duplicates the upper portion 

 of plate 10. The relations between plates 8 and 10 will be better 

 understood when it is recognized that the small wedge of ce- 

 ment rock in the top of the pillar in the right of plate 8 is the 

 same wedge that shows to the left of the center of plate 10. 

 It is shown also in the lower left hand corner of plate 11, where 

 it is marked " gray cement," and a view of its opposite side is 

 seen in plate 9, where it is marked "H?." 



Overhanging the Glory Hole incline is a long closed recum- 

 bent underfold of Leperditia limestone containing a core of 

 Prismatic cement. This fold can be traced along the foot of 

 the cliff toward the right for about 30 feet, till it is lost in the 

 vicinity of the Level incline. To the left of this fold, in the 

 top of the pillar which was left to support this very unstable 

 portion of the Glory Hole hanging wall, are wedges of cement 

 rock, the structure of which is best shown in plate 9. These 

 wedges are remnants of a faulted mass, produced by one of 

 those diagonal strike thrusts described on page 1212, by which 

 the Glory Hole vein was here duplicated to form what the 

 miners call a "double vein." 



Above the recumbent fold is seen the edge of a thrust plane 

 [thrust A, pi. 11], that appears to be the continuation of the 

 fault plane which produced the beautifully striated and scaly 

 surface on the hanging wall of the Glory Hole cut, shown in 

 plates 8 and 9. Next above is a series consisting of Leperditia, 

 Prismatic, Paving block, and lower Manlius (beds 12-14 of sec- 

 tion, p. 1183), which are terminated above by the almost hori 



