226 GEOLOGY OF THE SECOND DISTRICT. 



pyroxene or scapolitc ; and though phosphate of lime is very common in the primary hmestone, 

 it never occurs in this compound, and the same may be said of mica and feldspar. It is a 

 form of rock in which we should expect also to find some of the hard and rarer minerals, as 

 spinelle ; but in those localities where serpentine is largely mixed with the Hmestone, I have 

 not observed them. 



This belt of primitive limestone and serpentine is about eighty rods wide. It may be found 

 e.xtending to twice the width in some places in the range, though it has some interruptions. 



It is difficult to describe this rock in a few words, as it occurs near Port Henry. It is a 

 pure limestone near the furnace, quite coarse and crystalline, and not so subject to decomposi- 

 tion as in many other places. It is suitable for quicklime, unless more siliceous than appears 

 to the eye. The steep rock west of the public house is a mixture of yellowish serpentine 

 and primary limestone. It has a very good appearance when polished, though the color of 

 the serpentine is not sufficiently bright to produce the best effect. 



Near the dwelling of Mr. Foot is a mixture of the same materials ; the serpentine is darker, 

 and the contrast between the limestone and serpentine is greater. But this locality furnishes 

 an instance of apparent stratification. I say apparent; for after all, it is but the effect of a 

 jointed structure. The mass is divided in its bed by parallel joints, by which it separates into 

 ano-ular blocks. This locality appears the most favorable for quarrying the rock. It is not a 

 rock which looks fair upon the outside, but rather the contrary ; the limestone is acted upon 

 by the weather more rapidly than the serpentine, and hence the latter is left in irregular knobs, 

 imparting to the surface a warty appearance. Situated as this rock is, upon the shore of the 

 lake, it might be carried to market with little expense. 



In the same bed, in addition to the mixtures already mentioned, I found those of coccolite 

 and pyroxene in crystals, blood-red mica or mica which transmits a blood red light, hornblende 

 and limestone, etc. In the midst of the bed, half a mile from the lake, is an extensive one of 

 calcareous spar, which would probably furnish better lime than the bed at the furnace. I 

 mention this, as I understood that some fault was found with the lime at the latter place. It 

 contains a great abundance of graphite ; and it is possible that, in this vicinity, a vein of this 

 substance may be found. The full extent of this range of limestone southwest, I did not 

 determine. 



This rock appears again one and a half miles southwest from Moriah corners. It is an 

 extensive bed, but is not associated with serpentine. In none of the beds observed in this 

 neighborhood, do we find those wiiich are suitable for marble, when not associated with ser- 

 pentine. It is too coarse, with too great a tendency to friability ; or else, when firm and 

 sound, as it would be termed, it has many hard places, which interfere with the saw, and 

 prevent the reception of a good polish. 



This bed of limestone is well worth an examination, particularly at the fall above the fur- 

 nace. The small stream has cut the limestone, and discloses very clearly its relations to the 

 gneiss and hornblende which supports it on botli sides. The mode in which the limestone is 

 injected into these rocks, and the disturbances it appears to have produced upon them, are fully 



