418 VARIETIES. 



Limestone with slaty .seams, 39 feet. 



White limestone, 6 feet. 



Limestone of the last three varieties probably, obscured by drift along the line of the section, 437 feet. 



White limestone, 292 feet. 



Bluish limestone, 98 feet. 



Silicious limestone, 90 feet. 



Marble, with occasional beds of limestone unfit for marble, 479 feet ; Nos. i J ,, , J 3 . 



Saccharoid limestone, 142 feet ; Nos. ,t* and i* s . 



Blue compact silicious limestone, 86 feet ; No. iJ 6 . 



Talcose schist, capping the limestone, 498 feet ; Nos. -fir to -rttr. 



Making a total of 2468 feet, or 1970 feet of limestone and marble. Upon the west side 

 of the mountain the limestone is mostly covered by drift ; but what is seen corresponds 

 with that upon the east side. 



Mineral Contents. 



Of course the purer varieties of this formation, the marbles, constitute a mineral by themselves, and 

 might strictly be enumerated among them. Of this there is an exhaustless store in Vermont. The same 

 is true of amorphous dolomite. 



The mineral calcite, or crystallized carbonate of lime, is found abundantly in the geodic and other cavities 

 of this rock. It is best seen at Hubbell's marble quarry on the north side of Mt. Anthony, in Bennington. 

 A vast amount of flesh-colored and red calcites are found there sufficiently perfect to illustrate the species 

 well in a Cabinet. (See No. -/ v , and 328 to 331 of the minerals in the State Cabinet.) We noticed it 

 particularly, also, in the towns of Middlebury, Orwell, Burlington and Colchester. 



Calcareous tufa is found in Middlebury, etc. Stalactites and stalagmites are found in Dorset, Danby, 

 Middlebury, Weybridge, etc. Agaric mineral is rare, though found occasionally. 



The limestone in Chittenden County frequently contains very fine limpid hexagonal crystals of quartz 

 disposed in the small cavities which frequently occur in it. In Dorset the crystals of quartz are very good 

 (See Nos. 134 to 137, and 141 to 143.) 



In Middlebury milky quartz is found, not in crystals. 



In Weybridge, earthy asbestus is found near Pepu Hill. The hornblende minerals are not found in the 

 limestone of Vermont, but are very finely developed in the same range in Massachusetts as the minerals 

 tremolite, white augite and sphene. 



In Middlebury, there is black mica and iron pyrites in the limestone. Also epidote on Chipman's Hill. 

 A few specimens of limestone are coated with a film of green talc. Elegant crystals of titanium, from on e 

 five-hundredth to one one-hundredth of an inch in diameter and mostly an inch long, are very abundantly 

 disseminated in a fragment of a transparent smoky quartz crystal from Bristol. 



Albite is said to occur in the Eolian limestone in Castleton. 



Bowlders containing the crystalline and metamorphic minerals are sometimes found extensively upon this 

 formation. In Middlebury in this way there are zircon, galena, copper pyrites, jasper, tourmalin, serpen- 

 tine, hypersthcne and hornblende. In Weybridge, hypersthene and Labradorite are found, similarly 

 transported. 



The minerals in the trap, etc., dikes in all these sedimentary rocks, are mentioned under igneous rocks ; 

 one of the most interesting is a dike of lithomarge in North Dorset. 



Organic Remains of the Eolian Limestone. 



Although the Eolian limestone is largely distributed in our country, no fossils have been found in it, 

 except the few which occur in Vermont. We have found the following genera, to which specific names 

 cannot yet be attached : Euomphalus, Zaplirentis, Stromatopora, Chcetctes and Slictoporn. Two kinds 

 of encrinal plates have also been discovered. These genera were determined by Prof. James Hall. 



