46 



APPENDIX TO THOJIPSON'S VERMONT. 



TACONIC BOCKS. 



EOOFING SLATE. 



STOCKBRIDGE LIMESTONE. 



The portion represented in the cut, is about 

 30 feet broad at the base. 



The general strike of the Red Sandrock 

 formation is about N. 20 E. , and the dij) 

 varies from 4-" to So*- or more. Its width, 

 from east to west, is very variable, but will 

 average, perhaps, five miles. 



This rock is very barren in fossils, and 

 those found are very obscure, consisting of 

 fucoidal layers, and fragments of crinoidea 

 and trilobites. Marks of rain-drops, and 

 vrave and ripple marks are very common, 

 and well defined. The fragments of trilo- 

 bites have been found most abundant in 

 this rock in Highgate, but they are there 

 so much decayed, and so obscure, that it is 

 veiy difficult to determine the species. 



Tacoxic Hocks. 



Under this name have been embraced the 

 rocks in the southern half of the state, 

 which lie to the eastward of the Champlain 

 group, aud to the westward of the main 

 ridge of the Green Mountains. They occu- 

 py a large part of the counties of Benning- 

 ton, Rutland and Addison. They derive 

 their name from a range of high lauds, 

 which extend from the western part of 

 Massachusetts into Vermont, and which 

 are called the Taconic Mountains. The 

 true geological position and character- of 

 these rocks is not yet well settled. While 

 some regard them as primary, and others 

 as metamorphic silurian rocks. Prof. Em- 

 mons, and some others, have maintained 

 that they are a distinct group of palaiozoic 

 rocks, which are older than the Potsdam 

 Sandstone, which is the oldest member of 

 the Champlain group. 



The Taconic group of rocks consists of 

 Roofing Slates, Sparry Limestone, Magne- 

 sian Slates, Stockbridge Limestone and 

 Granular Quartz. 



Roofing Slate. — The roofing slate of this 

 formation is found principally in the west- 

 ern part of Rutland county, particulai'ly 

 in the towns of Castleton, Poultney and 

 Fairhaven. Some sixteen or eighteen slate 

 quarries have already been opened in these 

 towns, many of which yield slate of a very 

 superior quality. There are two principal 

 varieties of the slate, one of which is of 

 greenish color, and the other reddish brown. 

 Several of the quai-ries have been opened 

 very recently, and have not yet yielded a 

 large amount. The yield of all the quai'ries 

 above mentioned, in 1852, was estimated 

 to exceed 10,000 squares, and the annual 

 yield will doubtless go on increasing, from 

 year to year, indefinitely. It already finds 

 its way, not only to Boston and New York, 

 but to Buffalo, Cleveland, and other cities 

 at the west. 



Sparry Limestove. — This rock stretches 

 through the western parts of the counties 

 of Addison and Rutland. It is divided and 

 checked by numerous beds of calcarious 

 spar. Its color is bluish, or gray of differ- 

 ent shades. 



Magnesian Slates. — These slates lie to 

 the eastward of the roofing slates and sparry 

 limestone, and to the westward of the 

 Stockbridge limestone. They sometimes 

 alternate with the latter, as the two former 

 do with eacli other. They are most fully 

 developed in the northwestern part of Ben- 

 nington county, and southwestern part of 

 Rutland county. 



The magnesian slates are usually of a 

 light grayish color, and. often of a greenisli 

 hue. They, in many places, are easily 

 split into broad fiat masses, the surfaces 

 of which often have a pearly lustre, and an 

 oily feel. But for the most part, these 

 slates are largely filled and checked with 

 veins and seams of white quartz. 



Stockbridge Limestone. — In an economi- 

 cal view, the Taconic group probably fur- 

 nishes the two most valuable rocks in the 

 state, excepting only the Isle la ]\!otte Lime- 

 stone; and these two are, the roofing slate, 

 already mentioned, and the Stockbridge 

 Limestone. 



Commencing at the south line of the 

 state, in Pownal, the Stockbridge Limestone 

 forms a belt, which extends northward 

 through the counties of Bennington, Rut- 

 land and Addison, as far as tlie town of 

 Monkton. This belt is, on an average, 

 nearly five miles wide, having the Magne- 

 sian slate on the west, and a range of 

 Granular Quartz on the east. To the north- 

 ward of Bennington county this rock occu- 

 pies, for the most part, the valley of Otter 

 Creek. 



This range of limestone furnishes, through 

 almost its entire extent, ah abundance of 

 excellent marble. Its color is generally 

 light, varying from dove color to the purest 

 white. Some portions of it are of a light 

 flesh-color, and others r,re beautifully vari- 

 egated ; aud at several places a very good 

 statuary marble is found. Stephenson's 

 statue of the wounded Indian, which was 

 exhibited at the World's Fair, in London, 

 v;as made from Vermont marble, obtained, 

 I think, from a quarry in Rutland. 



Marble quarries, at various places in the 

 Stockbridge Limestone, have been more or 

 less worked for many years. The principal 

 of these are in the towns of Dorset, Rutland, 

 Pittsford, Brandon and Middlebury. The 

 great expense of transportation, for a long 

 time prevented these quarries from being 

 extensively worked, but the construction of 

 railroads, along the whole line of this for- 

 mation in Vermont, has opened easy out- 



