REPORT OF THE STATE PALEONTOLOGIST 1902 1211 



Structure of the Vlightberg 



The principal structural features seen in the Vlightberg are 

 a monocline and two anticlines, all of northeasterly trend, and 

 a small overthrust block. 



1 The Glory Hole vein along the east slope of the hill, is at 

 present a monocline of steep northwesterly dip, though it may 

 have originated as the eastern limb of a compressed or faulted 

 synclinal trough. 



2 An eastern anticlinal arch, just northwest of the Glory Hole 

 vein, is seen at the surface at the Delaware avenue quarry at the 

 northeast, in the underground workings of the Spring, Level, 

 and Middle quarries, and again is exposed at the surface in the 

 small arch just east of the Taylor's corner workings at the 

 south end of the Vlightberg. 



3 A second, western, anticlinal arch forms the north- 

 western half of the Vlightberg. The axis of this arch passes 

 through the point J, and just west of the point K on the map 

 [pi. 2], and its western limb is exposed in the steeply dipping 

 Vertical cut along the outcrop of the Becraft limestone [see 

 V-V, map, pi. 2]. 



4 An overthrust block of small extent and uncertain relation- 

 ships, cut off by the fault 2-2 at the north end of the Vlightberg. 



1 Glory Hole vein 

 The most important feature of the eastern side of the Vlight- 

 berg is the long deep cut made in the Glory Hole vein of the 

 cement rocks, which extends with a general strike of n. 60° to 

 70° e. from the engine house (E) south westward for about 600 

 yards to beyond the Middle quarry (M), where it loses its 

 identity. 



* This "vein" of cement rock has an outcrop at least 20 feet 

 wide that appears on the hillside at altitudes varying from 100 

 feet at the engine house to about 175 feet between the Hill and 

 the Middle quarries. The vein dips into the hill at the steep 

 angle of 75° to the northwest, and at the northeast end, be- 

 tween the engine house and the Hill quarry, it has been exca- 

 vated in the Glory Hole workings to a depth greater than 150 

 feet below tide level. In these deeper workings, and also in 



