PHYSICAL HISTORY OF NEW HAMPSHIRE. 525 



of mountains, as well as to the formation holding them, occupying the region of the 

 primitive rocks of Maclure. The mountains specified are the Blue Ridge, Alleghany 

 mountain, Iron mountain, Unaka, etc., and the name proposed is that of Atlantic 

 Primary Chain* From further remarks by Mr. Featherstonhaugh, 1836, in his report 

 of a geological reconnoissance by way of " Green Bay and the Wisconsin Territory to 

 Coteau de Prairie," it appears that he intended to have the name Atlantic applied to 

 these primary rocks in the same sense that Cambrian and Silurian were applied to 

 formations in England by Sedgwick and Murchison. He says, p. 38, "the terms 

 primary and primordial are, undoubtedly, always very properly applied to the lower 

 rocks, to which an igneous origin has been attributed ; but may fairly be extended to 

 any series of rocks constituting a great geographical boundary, to which they give a 

 predominating character, especially at a period when the term transition is passing into 

 disuse, and leaves the term primary freed from theoretical views, to class all the rocks 

 in below the secondary order." In his "secondary," he expressly includes the Cam- 

 brian of Sedgwick, so that his application of the term Atlantic is free from ambiguity. 

 It includes the geographical area of crystalline rocks from Maine to Alabama, which 

 are supposed to be pre-Cambrian. This proposition was objected to by Prof. W. B. 

 Rogers, state geologist of Virginia, in his Geological Reconnoissance, published in 

 1836, on the ground of "superficial and precipitate generalization." It was at this 

 time that Messrs. H. D. and W. B. Rogers, and other eminent geologists, began to 

 entertain the notion that the New England portion of the Atlantic crystalline area 

 consisted of metamorphic paleozoic strata. If this were a theory, confirmed by 

 explorations, then the adoption of Featherstonhaugh's suggestion would have led 

 the world astray. Inasmuch as the metamorphic theory blinded the eyes of geol- 

 ogists for thirty years, the proposed use of the word Atlantic was lost sight of; 

 and those of us who now find that the older theories best explain the phenomena 

 discovered by exploration had forgotten Featherstonhaugh's proposal, and had 

 made use of the term White Mountain series in its place. But now, finding that 

 the proposal proves to be correct, we cannot do better than accept it, to the 

 exclusion of the term Montalban, for application to the entire system. Meanwhile, 

 the necessity for the use of a geographical term for the oldest rocks led Sir 

 W. E. Logan to apply the terms Laurentian and Huronian to the primitive formations 

 in Canada, expressly to the exclusion of the Atlantic rocks, as this author believed, in 

 the Paleozoic age of the New England crystalline schists ; and these terms have been 

 generally adopted. Featherstonhaugh did not know that the "primary" group was 

 susceptible of subdivisions ; but the study of the eastern belt of crystalline schists by 

 Dr. Hunt led him, in his address at Indianapolis, to refer them to the White Mountain 



* The original proposition is couched in the following language : " It will be apparent, I think, to every 

 geologist, that as this primary chain is the true boundary of the sedimentary rocks lying west of it, and forms so 

 important a feature in the mineral structure of the country, it should receive a clear geological designation ; and 

 as it looks upon the Atlantic coast in its whole course, I shall propose the name of the ATLANTIC PRIMARY 

 CHAIN." Featherstonhaugh's Report, 1835, p. 33, second edition,*!* the one printed with the reports of 

 congress does not contain this paragraph. 



