VERMONT CONGLOMERATE. 



satisfy any one that no mechanical agency is sufficient to explain these phenomena. We 

 have been driven to the supposition of some polarizing force acting upon soft ma- 

 terials. If, as Sir John Herschell supposes, cleavage may have resulted from a sort of 

 crystallization in plastic materials, why may not joints come into the same category? 

 Why should the conclusions drawn from the experiments of Mr. Fox upon the lamina- 

 tion of plastic clay by galvanism, be limited to cleavage ? 



5. The Newport conglomerate is probably only a modified variety of that extensive 

 deposit of highly silicious pudding stone found so abundantly between Boston and Rhode 

 Island. Both have the same geological position we believe, and were the Roxbury con- 

 glomerate to be brought into a plastic state and the pebbles elongated and flattened by 

 pressure, we think the Newport conglomerate would be the result. 



Thus far we think we are legitimately conducted by the Rhode Island rock. We are 

 carried farther by the Vermont conglomerate, which we now proceed to describe. We 

 select two localities, although doubtless many others might be found, equally instructive. 

 The rock occurs on both faces of the Green Mountains, and we can hardly doubt that it 

 once formed a fold over the mountain, which denudation has swept away. 



We have found this rock in connection with quartz rock, mica and talc schists and 

 gneiss ; sometimes merely in juxtaposition, as in the case of the quartz rock, but some- 

 times interstratified. The conglomerates at the different localities may not be identical as 

 to geological age ; yet we incline rather to the opinion that quartz rock, micaceous and 

 talcose schist and gneiss, may be varieties of the same original rock, which metamorphism 

 has sometimes converted into one, and sometimes into others, of the series. Quartz rock 

 may be the residuum of certain silicates ; the schists and gneiss are those silicates modifi- 

 ed. Any of these rocks we think might be formed out of the conglomerate under 

 consideration, as we shall now endeavor to show. If so, we might perhaps find it in con- 

 nection with them all, without implying a difference of age. 



In the northeast part of Wallingford, on the western slope of the Green Mountains, on 

 the hill north of David Hager's, is an interesting exhibition of the conglomerate. 



East. 



Fio. 8. 





f"-,-o- fo^S,",? *3F&<ii 



&* <gg..;Sr> s .-f -S 



/ 7 / - / " - ~ 



o:g><3 =>> ^ 



Surface of Wallingford Conglomerate. 



