286 TKENTON LIMESTONE. 



ters 



Range, Extent and Thickness. 



There are three ranges of Trenton limestone in Vermont. The principal one en 

 the State in West Haven, passes through Rutland and Addison Counties into Charlotte, 

 through the towns of Benson, Orwell, Shoreham, Bridport, Addison, Waltham, and 

 Ferrisburgh. It then loses itself in Lake Charnplain, re-appearing upon Grand Isle, 

 South Hero, and Isle La Motte. The second range is found upon the west flank of the 

 anticlinal in the Chazy limestone upon the lake shore, in Bridport, Addison, and Panton. 

 The third range is found in Vermont only in Highgate. 



Concerning the principal range we will speak first. A little less than a mile west of 

 West Haven Post Office, it appears as a light blue limestone, capping several small hills 

 with a very small easterly dip. It extends west to Codman's Creek. There is but little thick- 

 ness to it, while the calciferous sandrock beneath is enormously developed, as if nature 

 had exhausted herself by producing the latter, and during the Trenton and Chazy periods 

 was gradually recovering herself. In Benson, west of the village, this rock is developed 

 in an exceedingly inferior style. Rapacious metamorphic action has clutched it, and 

 left hardly any one of its peculiar characteristic forms and colors, by which it might be 

 recognized. The rock is gray, thick-bedded, with veins of calcite passing through it, and 

 it has a sort of neglected appearance. The same description applies to this rock as it 

 appears through most of Benson and Orwell. Occasionally a few obscure fossils appear, 

 which are the chief guide to the age of the rock, as for example, west of Z. Nearing's 

 house in the southwest corner of Orwell. 



The next observed exposure of this rock is near 0. H. Bascom's ho,use, in the west part 

 of Orwell, upon Section VII. We found no fossils, but relied mainly upon its position 

 for its place. Its lithological character is obscured by metamorphic action. We suppose 

 this to be the rock that Prof. Emmons in his work on American Geology, calls Trenton 

 limestone. 



At Larrabee's Point, in Shoreham, all doubt as to the age of this belt is put at an end, 

 by the fine development there of all its characteristic fossils. The rock is confined 

 mostly to the point, the back land being composed principally of Utica slate. A section 

 is given, in Fig. 178, of the relative position of the Chazy and Trenton limestones on this 

 point. This rock commences at Judd's quarry, and continues to some distance north, even 

 beyond the point. A large surface that has been striated by the drift agency, is finely 

 shown upon the shore, north of the United States Hotel. . The fossils may be found at any 

 exposure of the limestone upon the shore of the lake. Some of them, as CJicetetes lycoperdon, 

 have been washed out from their bed-rock, and are scattered about like pebbles. Other 

 specimens are from the walls of an old limekiln. The heat has calcined the shells with- 

 out injuring them, and thus they are rendered more distinct. Ripple marks were also 

 observed upon the Trenton at this locality. It is a finer locality for fossils than Highgate 

 Springs. 



Passing north we see but little of the Trenton, for, like the Chazy limestone, and other 

 rocks beneath, it sweeps westwardly across the lake to New York. A pinch of it, as it 

 were, is occasionally seen, as near Mr. C. Humsdon's house, near the lake shore, in the 

 northwesterly part of Shoreham. The principal range passes northeasterly from this 

 point into Bridport, east of the Chazy anticlinal. Near Bridport Center (both north and 



