The Acton Copper Mines. 355 



more or less abundance, with, strings and spots of calc spar. 

 The serpentine-like rock sometimes appears to surround these cal- 

 careous masses. 



" The copper ore appears to occupy a position immediately near 

 the isolated masses of limestone, and very little of it to penetrate 

 into the serpentine-like rock or the slate. Indications of it occur 

 on both sides of the calcareous masses and in some places can be 

 traced as if surrounding them ; but the chief part appears to be be- 

 neath them and intermediate between them and the slates and ser- 

 pentine-like rock. The ore consists of the pyritous, variegated and 

 vitreous sulphurets of copper, the second species being the most 

 abundant and the third more abundant than the first. The 

 green carbonate also occurs, but it must be regarded as a second- 

 dary product formed at the surface and in cracks. The chief ex- 

 cavation has been made in a cross-cut running S. 45 E., which is 

 at right angles to the strike. The depth excavated is from four 

 to eight feet, and the following is the succession of masses met 

 with in the cross-cut, given in a descending order and reduced to 

 vertical thickness for horizontal measurement. 



Feet. 



1. Limestone ; this may be a boulder deeply sunk in the 



soil but it is supposed to be in place and to belong to 



one of the isolated masses of the stratification 3 



Concealed & 



Limestone in place, belonging to one of the isolated mas- 

 ses ; small irregular spots of the pyritous sulphuret of 

 copper occur in the rock ; this is probably part of the 

 same mass as the first three feet and the concealed three 

 feet would also be a part, making the whole 8 feet. ... 2" 



2. Variegated sulphuret of copper enclosing numerous angu- 



lar fragments of limestone in irregular aggregations ; 

 this mass dipped with the stratification, but thinned out 

 and terminated downwards 2 



3. Limestone broken in various sized angular fragments by a 



number of reticulating cracks of from one quarter of an 

 inch to three inches in width, and filled with variegated 

 sulphuret of copper, with spots of white crystalline calc 

 spar and occasional crystals of transparent quartz IS' 



4. Breccia or conglomerate with a paste composed of variegat- 



ed and vitrious sulphurets of copper mingled with fine 

 grained silicious matter, enclosing fragments of lime- 



