GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 265 



from the Laiirentian to the Carboniferous ; hence, as we have both these 

 formations at the same distance apart — a few hundred miles along the 

 Hne of strike — the intermediate strata in New England must be the 

 same with those in the British provinces, or the Paleozoic in a metamor- 

 phic condition. There may be other considerations ; but these are the 

 most important, and are the ones which have carried conviction to many- 

 minds. As the process of metamorphism is supposed to be capable of 

 modifying the mineral character of rocks, whether by abstracting, alter- 

 ing, or adding constituents, it has afforded a very convenient method of 

 explaining why there should be little or no chemical resemblance betvv^een 

 the original and derived strata. 



I would answer the arguments as follows, in the same order: — i. We 

 accept the difference between the Atlantic parts of the White Mountain 

 series and the Laurentian, while insisting that the latter is represented 

 in our two oldest groups. The Atlantic and later rocks are not repre- 

 sented at all in Laurentian regions. 2. We have presented the results 

 of special explorations in north-western Maine (pp. 204-209), which en- 

 tirely disprove the assertion of the passage of the Gaspe into the White 

 Mountain rocks. 3. The dips, in proceeding south-easterly from the 

 Adirondacks, are uniform to the east in many sections. Where this is 

 the case, it simply proves inversion. If the strata have been inverted, 

 then we descend the scale of formations instead of rising ; and therefore 

 the Green and White Mountain rocks are older than those of the Cham- 

 plain valley. Furthermore, many sections display a number of axes in 

 pursuing this course, as is illustrated upon Plates II, III, and IV. In the 

 Vermont report there are fourteen sections crossing the Green Moun- 

 tains. Eight of these show distinctly an anticlinal structure for the 

 Green Mountains, the most clear cases being in the Winooski and La- 

 moille valleys, where rivers have cut through them to their base. Two 

 others possess the same structure, as learned by careful reexamination of 

 their routes since the printing of the report. Of the four others, all are 

 monoclinal, — that is, have an inverted dip. 4. If the argument held good, 

 we should not find the Paradoxidcs in a slate adjacent to the Carbonifer- 

 ous in Massachusetts, since the formation containing the trilobite is older 

 than anything in the Champlain valley. 



The following considerations are strong arguments in favor of the 

 VOL. II. 34 



