THE MINING AND QUARRY INDUSTRY I913 45 



In form the deposit is a long shoot, with its principal axis follow- 

 ing the northeasterly trend of the country rocks but inclined down- 

 ward at an angle of 19°. The inclination or pitch holds very uni- 

 form throughout the entire distance, although the shaft which gen- 

 erally follows the bottom of the ore has a slightly steeper pitch at 

 the start. In cross-section it is heart-shaped, having two lobes 

 which converge below and are separated above by a horse of gran- 

 ite. On the outcrop the deposit appeared to be a double vein, as 

 shown in a section included in Mather's report already mentioned. 

 The lobes are somewhat unequally developed, the southerly one be- 

 ing the higher. The whole mass has a steep dip toward the southeast 

 conformity with the lamination of the country gneiss. In structure 

 the deposit may be compared to a narrow synclinal fold slightly 

 overturned, the wings of which terminate abruptly a short distance 

 above the arch. That the body has actually been folded, however, 

 is not at all certain from any evidences so far presented; the rela- 

 tion of the ore t9 the country gneisses is also in doubt. 



The gneiss is a laminated biotite-feldspar-quartz rock which 

 shows banding in lighter and darker layers. It belongs to a very 

 common type of the gneissic rocks exposed in the Precambric belt 

 of southeastern New York and northern New Jersey. Its deriva- 

 tion is not known, as in fact the Precambric rocks of this section 

 of the State have been studied only in a preliminary way. The 

 banding which seems at first suggestive of sedimentary affinities, on 

 closer study is seen to be due in part to the injection of lighter gran- 

 itic material along the planes of lamination. In the vicinity of the 

 ore body the gneiss has been so permeated with granitic material 

 that the latter predominates over the gneiss itself. The horse of 

 granite which apparently follows the ore all the way from the sur- 

 face is a solid mass of this intrusive of a somewhat coarser type 

 than the average. It is composed of pink and green feldspars and 

 quartz, with magnetite as the only dark mineral of importance. 

 The granite is also seen in places along the two walls and occasional 

 stringers and bodies of it are found within the ore itself. The de- 

 posit has been a locus of igneous activity, a feature that has been 

 noted by the writer to be frequent in many of the other deposits 

 of Orange county. Its significance with respect to the origin of the 

 ore body in question can not now be stated, if there is indeed any 

 connection between the intrusive and the formation of the deposit. 

 The possibility that the magnetite has been introduced in its pres- 

 ent place as a result of igneous action, however, may be consid- 



