276 LOCALITIES. 



uniform dip of this rock on the principal island opposite to Clowk Island, is 30 N.E. an unusually large 

 dip for the Chazy limestone. 



In the northwest part of Panton, at Adam's Ferry, there is another example of the conjunction of 

 chazy limestone and Utica slate. We are inclined to think that all the Utica slate on the shore of the 

 lake between Panton and Shoreham, is more or less disturbed by the same causes. North of Split Ilock in 

 New York, there is another case of the junction of slate and limestone, similar to the ones described here, 

 according to Prof. Emmons' Keport. * 



Bange, Extent and Thickness. 



There is one principal range of the chazy limestones in Vermont, interrupted only by 

 Lake Champlain. It has not been observed south of Benson, where Prof. Adams found 

 it in the northwest part of the town, upon the land of Orrin Benson. Next it is seen 

 upon Larrabee's Point in Shoreham, where there is a quarry of black marble. It is very 

 thin in these two towns, while the calciferous sandrock beneath is very largely developed. 

 Curving at Larrabee's Point, it crosses into New York, where it is abundantly seen at 

 Crown Point. Here it takes a northeasterly course, and crosses to Chimney Point, at the 

 southwest part of Addison, Vt. An anticlinal commences here, with the Trenton over- 

 lying it upon both sides. It was in this northeasterly direction through the whole of the 

 west part of Addison County. The anticlinal has been observed at both ends, but has 

 not been traced through the intervening space, because of the great difficulty experienced 

 in discovering any of the older rocks ; this whole region being completely covered up 

 with Champlain clay. We are almost inclined to believe that the so called calciferous 

 sandrock, at the foot of Snake Mountain, in Addison, is Chazy limestone. This might 

 relieve us of the necessity of supposing a fault to exist west of Snake Mountain ; for the 

 anticlinal in Chazy limestone is sufficient to account for the presence of Trenton limestone 

 on the lake shore, and the presence of an older rock at Snake Mountain dipping east. 



We will mention the localities at which we have found Chazy limestone between Bridport and Charlotte, 

 that any who choose may examine our data, and draw inferences from them for themselves, if they are not 

 pleased with ours. Madurea magna is found at Grosvenor's mill upon the west branch of Dead Creek, in 

 Bridport ; also south of E. S. Pettibone's house, in the northwest part of the same town. It is found at 

 Chimney Point, at the Ferry and near the house of Gen. J. Strong. At the west foot of Snake Mountain, 

 it is seen at several places, particularly south of Truman Smith's house. In the west part of Panton it 

 appears for two or three miles, and the house of Judge Shepherd is near a fine locality of its characteris- 

 tic fossil. In Waltham, near F. E. Benton's house, which is opposite to a school house, it is displayed in 

 great beauty. We regard the rock at Vergennes Center as Chazy, although no fossils were discovered in it. 

 The same kind of limestone occurs west and north of Vergennes in several places, but without characteris- 

 tic fossils. Along the coast of Ferrisburgh the Madurea is generally present, at every exposure of rock. 

 Prof. Adams found the same in the northwest part of Ferrisburgh, away from the shore. Prof. Emmons 

 says that it occurs east of the shore in Charlotte, with a westerly dip. These are the principal localities of 

 tHs rock in Addison County. 



At Charlotte the shore south of Me Neil's Point is mostly composed of bluffs of the Chazy limestone. 

 At this point it passes under the waters of Lake Champlain, to re-appear upon the New York side, in Val- 

 cour Island and upon South Hero, in Vermont. Providence Island, Straw Island and a lone rock near 

 Carlton's Prize, are mostly, composed of Chazy limestone. It enters South Hero at the west side of Mar- 

 tin's bay, embraces the rocks about Merriam's Bay, McBride's Bay, Sawyer's Bay, Sawyer's Island, and 



* Vide Geological Report, 2d District, New York, ]>. 278, and 1'late VI, Fig. 1. 



