OF THE UNITED STATES. 419 



greenstone trap to a considerable distance, the hardness and so- 

 lidity of which had most probably survived the destruction of 

 their sandstone foundation ; may not similar derangements be 

 one of the causes of the broken and unconnected state of this 

 formation? 



Prehnite and zeolite are found in the trap of this formation ; 

 considerable deposits of magnetic iron ore at Grubb's mines are en- 

 veloped, and have their circular layers intersected by green- 

 stone trap, on a ridge of which this extensive cluster of iron 

 ore appears to be placed. 



Grey copper ore has been found in the red sandstone forma- 

 tion near Hartford and Washington in Connecticut; atScheuy- 

 ler's mines in Jersey, copper pyrites and native copper have been 

 found. The metallic veins on Perkiomen creek, containing 

 copper pyrites, blende, and galena, are in the same formation ; 

 running nearly north and south, across the east and west direc- 

 tion of the red sandstone; a small bed from an half to three 

 inches thick of brown or tile copper ore is interspersed and fol- 

 lows the circular form of the iron beds at Grubb's mines. 



Besides the sandstone formation, there is included within the 

 described limits of the primitive, a bed of transition rocks, run- 

 ning nearly S. W. from the Delaware, to the Yadkin river, 

 dipping generally to the south east 45 degrees or more trom 

 the horizon; its width is from two to fifteen miles, and runs 

 from the west of Morrisville, to the east of Nornstown, passes 

 Lancaster, York, Hanover, Fredencktown, Bull run mountain, 

 Milton, foot of Pig river, Martinsville, and finishes near Mount 

 Pilot, between the Delaware and Rappahannock; it is partially 

 covered by the red sandstone formation, and is in the shape of 

 a long wedge, the thick end, touching the Delaware, and the 

 sharp end, terminating at the Yadkin. 



This range consists of beds of blue, grey, red and white small 

 grained transition limestone, alternating with beds of grey iiacke 

 and grey icackc-state; with granular quartzose rocks, and a great 

 variety of transition rocks, not described or named in any trea- 

 tise yet published; much of this limestone is intimately mixed 

 with grey wacke-slate, other portions of it contain so g« at a 

 quantity of small grained sand, as to resemble Dolomite, and 



