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TABLE OF CONTENTS. 



IX 



pebbles had been squeezed or pulled, shown to be only the result of his mis- 

 takirig the enclosing matrix lor the pebbles, 438. Dodge, in ISSl, gives 

 details of his observations near L^oston, nofcieing the oecurreuee of felsite dikes in 

 the granite, as had been before shown by Wadswortli and Diller, 439. Wads- 

 WORTli, in 1881, calls attention to more of Crosby s errors of observation, 439. 

 Wadswoiitji, in 1883, points out the relations of tho Roxbnry conglomerate to 

 the argillite, 439. DoDUR, in 1883, claims that tlierc are two granites in the 

 Quincy district, but olf(!rs no evidence in supjiort of this view, 439, 440. 

 Errors of SuALioji, Uugeuh, and Jaokhon, in regard to the argillite and granite 

 pointed out by Wadsworth, 440. 



VERMONT AND WESTERN MASSACIIITSETTS. 



Small progress made by the eai-lier invcsligaiors tow;ird 'unravelling the intricate 

 problems presented in tliis region, 440 ; a specimen from Hitcikmick's Final Re- 

 port, 440, H. D. Ro(JEn.s'K division of the rocks b(dow the " Cambrian or Older 

 Silurian " into azoic and liypozoic, 440, 441 ; this elassiiication has no basis of 

 fact, 441 ; he says that it is absolutely impossible to determine " the true base of 

 the RaliEozoie system," 441. Importance to New England that the work of the 

 Canada Survey shonhl be well done, 4.11. First publisljcd statement of the bear- 

 ing of the results of that survey on the solution of problems in New England 

 geology, by Hunt, in 1849, 441, 442 ; the whole of the Green Mountain rocks 

 said by him, to belong to the Hudson River group, 441, 442. " Witli such a key 

 to the structure of tho metamorphic rocks of New England, and of the n-,-cat 

 Appalachian chain," Hunt thinks that "the diffiimlties that have long environed 

 tho subject are in a great degree removed, 442; similar views expressed by 

 Hunt, in 1850, and EmM(>ns> views of the age of the Tacouic entirely rejected, 

 442 ; again, in 1854, Hunt refers the crystalline limestones of New England and 

 their continuation southwest to the Lower Silurian, 412, 413; in 18()1 and 

 again in 1863, similar views were expressed, 413 ; ui ISCiO, Hunt said that the 

 Quebec group '' constiiuted the groat metalUrerous r(\giou of Eastern Canada, 

 Vermont, and Newfoundhunl " ; he also refers the (niprifcrous rocks of Lake 

 Superior to the same group, 443 ; in 18()7, ho repeated the same statement, eon- 

 sideri]ig the Quebec group as being the equivalent o\' the Landeilo, and furilier 

 remarking that this group formed the Notre Dame and Civcn Mountains, and 

 that it " played a very important r6ie throughout tho Aitpalachiau chain," 443 ; 

 this all repeat(Hl agahi later in the same y<'ar, 444 ; the statement also repeated 

 that the White Mountains Avero of Devonian age, 444; again, in 1808, it is 

 asserted that there is no proof of the existence in Vermont of any strata older 

 than Potsdam, the gneiss of the Green J\Iountains being referred to the uin>er 

 portion of the Quebec group, 444; oneo more, in 1870, HrNT assorts the lower 

 Silurian a<j;e of tho Green ]\rountains, 445. 

 In 1870, Hunt's views undergo nnaamorphism, and he claims that the theories 

 which he liad hv.cn ad vo('ating since 1803 were only liis ofiicial ones, and that 

 his own views wore quite diiT^-rent, 445 ; the rocks of the Green Mountains 

 begin to be eabcd Iluronian, tho idea of the Devonian ago of the Wliite Ab)un- 

 tains being abandoned, and tho provisional name of Terranovan introduced for 

 thorn, 440, 447 ; Dana objects to Ihose views for various reasons, and especially 

 on the gi'ound thai minerals are not fossils, and that thoro is no reason for 



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