TACONIC QUESTION IN GEOLOGY. 137 



valley, and confounded them with the Second Graywacke. This error it was which 

 completely misled the Geological Survey of Canada up to 1860, and continues to obscure 

 the subject in the minds of many American geologists to the present time. 



§ 165. It should be remembered that, as already pointed out in Chapters II and III, 

 the overlying Graywacke or Upper Taconic does not include the schistose rocks immedi- 

 ately above the Lower Taconic limestone, but that a considerable amoiint of crystalline 

 schists and argillites occxirs, both interstratified with and overlying this limestone, and 

 forming an integral part of the Lower Taconic series. "We have, moreover, set forth in 

 Chapter V, evidences of the distinction between the Upper and the Lower Taconic, and 

 have shown that the latter is not limited to the great Appalachian valley, which confines 

 the former, but is met with in more or less interrupted belts lying upon the crystalline 

 rocks of the Atlantic region, south and east of the great valley, from New Brunswick to 

 Georgia. Thus, in North Carolina, not less than four distinct and separate parallel bands of 

 the Lower Taconic are met with between that of the great valley and the overlying terti- 

 ary strata of the coast, whil(^ similar narrow bands of the same rocks are found in southern 

 New York and New Jersey, lying upon the ancient gneisses. AVith none of these Lower 

 Taconic belts outside of the great valley, so far as is known, is the Upper Taconic to be 

 found, its absence being due either to erosion, or more probably, as suggested by Emmons, 

 to the elevation of these areas above the sea during Cambrian time. 



§ 166. On the other hand, it has been shown in Chapter VI, that what Mather re- 

 garded as a continuation of the great Gray wacke series from the east of the Hudson, ex- 

 tends south-westward across Orange County and, according to Horton, there rests, with a 

 high eastern dip, on the north-west side of the gneissic belt of the Highlands. From cen- 

 tral Vermont, north-eastward along the great valley, to the St. Lawrence below Quebec, 

 the Lower Taconic is not known, and the Upper Taconic or Graywacke series rests di- 

 rectly upon older crystalline schists, as in Orange County, New York. The same condi- 

 tion of things is again seen in Newfoundland. These facts, already given in detail, serve 

 to show the distinctness and independence of the crystalline Lower Taconic from the un- 

 crystalline Upper Taconic or Cambrian series, which two were probably separated by a 

 considerable interval of time, corresponding to the stratigraphical break, long since pointed 

 out by Eaton, at the base of the First or Transition Graywacke. 



§ 16Y. The student who refers to Dana's paper of 1882, already noticed, on " The Age 

 of the Taconic System," will obtain no light on the question of the Graywacke series, nor 

 indeed any evidence that the author has ever seriously studied the literature of the ques- 

 tion, or comprehended its relation to the complex question before us. He will get no 

 notion of the two opposing views as to this series of rocks, or its position as above or be- 

 low the Trenton limestone, or even of its existence as a great succession of uncrystalline 

 sediments, many thousand feet in thickness and distinct from the Lower Taconic lime- 

 stones, as maintained alike by Eaton, by Emmons, by Mather, and by Logan, and as set 

 forth in the preceding chapters. We leave it to the reader to seek for an explanation of 

 this incompetent and partial statement of the great geological problem under discussion 

 by one who assumes to be alike an investigator, a teacher, and a critic, and forbear to fol- 

 low him into the details of his criticisms. 



§ 168. The hypothesis of Mather and H. D. Rogers as to the Lower Taconic rocks was 



Sec. IV., 1884. IS. 



