1 10 APPENDIX 



of veins by molten matter from beneath, supports the same view, and in tins case we Bee 

 tin- hill of breccia and beneath the vein. It would be interesting, could we establish this 

 view <>f the origin of this peculiar rock. This is quite apparent, when we take into con- 

 sideration the multitude of these brecciated beds along the eastern limns of the Taconic 

 system. They range nearlj in a line running through Berkshire county, at the western 

 base oi the Green mountains, and northwardly into Vermont. The question will not fail 

 in sugge8l itself to every inquisitive mind, whether these beds are all connected with veins 

 beneath. The question of their origin then assumes s practical importance, and is worthy 

 of being followed verj carefully oul toils full solution. If such a result should be ob- 

 tained, it will open an inexhaustible source for this kind of ore, which is usually of an 

 excellent quality, and easy to smelt. It is, however, proper to state, thai the quartz rock 

 in which tins vein appears in Adams, is a hard rock to blast ; and it is possible that the 



expenses, from tins cause alone, of obtaining the ore, might be so great as to render these 

 wins useless. Much undoubtedly would depend on their width : if wide enough to he 

 quarried without rendering it necessary to blast the rock itself, then there would be no 

 difficulty in working these veins. The matter must remain undecided, until some of them 

 are opened and worked. 



The position of the \ eins of limonile adjacent to the primary of the Green mountains, is 

 analogous to those of Jefferson and St Lawrence counties, where the specular iron, both 

 in its earthy and crystalline state, appears in veins connected both with the primary below 

 and the potsdam sandstone above. In both cases the veins are found only in thin parts of 

 these sandstones, anil near or adjacent to primary rocks. It is curious to observe, how- 

 ever, that in one case, tin- iron is in a state of peroxide pretty uniformly, forming the 

 specular oxide, and I believe without, exception ; and in the other, it is the hydrous per- 

 oxide, constituting the mineral called limonite. The former docs not form a breccia with 

 tin potsdam Bandstone, and we find a different association of minerals also in each of these 

 cases. With the specular ore, we tind serpentine, barytes, crystals of quartz, cacoxenite, 

 etc; and with the latter, gibhsite, allophane, manganese, and white carbonate of iron. 

 The gibbaite and allophane are minerals of secondary formation, and, so far as observation 

 b Bfl extended. tbe\ are not found in the veins of limonite. Distinct and irregular veins, 

 however, of the latter mineral, are not new to mineralogists. Thus a few veins, a foot in 

 width, traverse the gneiss of Dekalb in St. Lawrence county. The same occurs near 

 Crow npoint, and indeed a thin vein has been found in the calciferous sandstone in Georgia 

 (Vermont). A practical remark is mi^i^ii 'd 1>\ the position of these veins, namely, that 

 their place is near or adjacent to primary or igneous rocks; or it is here that they are 

 accessible, and reach the surface, though it may not be at all improbable that they are 

 frequent in other situations, but concealed by a great thickness of sedimentary materials. 



1 take this opportunity to add a few additional remarks on the quartz rock itself. Some 

 geologists of eminence have maintained that this rock belongs strictly to the Primary sys- 

 tem ; that it is of the era and age of the gneiss, with which it is sometimes apparently 



