12. PENN township. F 2 . 297 



dark, soft, sandy shale beds contained copper — a belief for 

 which there is of course not the slightest foundation. But 

 the excavation serves to make very plain the striking de- 

 velopment of the dyke at this point. From being a dyke 

 very much resembling the other three — perhaps rather 

 larger — it suddenly enlarges and becomes nearly 200 feet 

 from side to side. The bed of the Cove creek and the flat, 

 marshy ground alongside of it, overgrown with a thicket of 

 laurel, in some places impenetrable, is thickly bestrewn 

 with massive blocks of the dyke up to half a ton in weight. 

 How far this display continues through the wood I cannot 

 say nor to what height it rises on the north flank of Cove 

 mountain. 



The bearing of this dyke is S. 10° W. 



(2.) The Little Horse Shoe dyke. 



About a quarter of a mile east of the great Horse Shoe 

 dyke, another parallel line of fragments can be found high 

 up the south slope of Peters' mountain, in fact upon the 

 highest terrace. 



Its first appearance, so far as I am aware, is at an old 

 shaft sunk some years ago under the impression that the 

 trap dyke carried an ore vein. The shaft was sunk to a 

 depth of about 25 feet, and at the depth of about 22 feet 

 many blocks of the hard, tough, dolerite (trap rock) were 

 thrown out. 



This is the most northerly indication of this dyke that I 

 have seen in the cove. Hence, it may be followed at inter- 

 vals, southward down the slope of Peters' mountain, form- 

 ing an almost continuous line through the thickets to the 

 cleared land in the cove below, where it crosses first a field 

 and then the road leading west into the woods of the Horse 

 Shoe, and is lost to view at the creek, where a large meadow 

 is almost ruined by the number of blocks which lie scat- 

 tered about upon it. 



Beyond the creek no one, so far as I can learn, has suc- 

 ceeded in tracing it, so that it probably does not rise so 

 high on the Cove mountain as it does on Peters' mountain. 



I have no means of estimating the breadth of the dyke 



