REPORT OF THE STATE PALEONTOLOGIST 1902 



1217 



We have here the only direct evidence seen in this vicinity of 

 the existence of a compressing force acting from the northeast, 

 and even this force may be indirectly due to the same torsion 

 stresses that produced the buckling of the anticlinal arch. 



It seems appropriate to cite here other phenomena which we 

 consider to have been caused by torsion forces acting after the 

 formation of the main features of the region. Among them 

 are: the virgation of the Glory Hole vein at its southern end; 

 the small diagonal strike thrusts that intersect the hanging 

 wall of the Glory Hole vein, and several similar thrusts seen in 

 the Becraft limestone at the White lime quarry; the diverging 

 minor thrusts of the Becraft limestone in the Vertical cut; and 

 possibly also the small overthrust mass that caps the northern 

 top of the Vlightberg. 



3 The western anticline 



W r hen passing over the Vlightberg along the line of section 1 

 [pi. 2 and 3] the Coeymans limestone is found faulted on itself 

 over the hanging wall of the Glory Hole vein. This condition 

 is best seen at the Hill quarry where the lower mass of Coey- 

 mans limestone has fallen away from the overthrust plane into 

 the quarry, leaving the deeply striated under surface of the 

 thrust mass finely exposed to view. This thrust mass of Coey- 

 mans, which dips at a high angle (almost 80°) toward the north- 

 west, curves upward toward the top of the hill and becomes in- 

 verted toward the northwest, and finally is lost just below the 

 crest of the cliff along an approximately horizontal crushed zone 

 that marks the presence here of a dispersed fault. Above this 

 crushed zone the Coeymans limestone appears in its normal at- 

 titude exposed in low ledges of northeasterly trend just east 

 of the tenant house on the hilltop. These ledges of Coeymans 

 extend along the entire eastern edge of the hilltop, with an 

 exposure about 50 feet wide, and at a point about midway be- 

 tween the tenant house and the edge of the Middle quarry their 

 strike is n. 50° e., dip 60° n. w. 



At the southern end of the Vlightberg the strike of the Coey- 

 mans and New Scotland beds veers to the west around the 

 spooning-up end of the small synclinal trough that occupies the 

 northward-opening swale on the top of the Vlightberg. 



