434 TACONIC SYSTEM. 



If the contrary view is held, it will be necessary to regard this rock as belonging to 

 two different horizons one below and the other above the Eolian limestone. Upon 

 either theory the age of the schists is determined by that of the Eolian limestone. 



Both the Taconic and Silurian theories of the position of these schists, rank them as 

 superior to the Eolian limestone. If they are the magnesian slates, they certainly rest 

 upon the Stockbridge limestone; or if they be regarded as the Hudson lliver group, then 

 they must rest upon the lower Silurian limestones. 



THE TACONIC SYSTEM. 



We have referred so often to the Taconic System in Part II, that we deem it due to its 

 supporters to present a brief view of its history as a system, and to give an outline of its 

 method in explaining the intricacies of the stratigraphical structure of the rocks in West- 

 ern Vermont. We shall use the terms which are employed by Prof. Emmons, and shall 

 endeavor to represent his ideas, as they are published, as faithfully as though we were the 

 amanuensis of an advocate of the Taconic System. We think that Prof. Emmons would 

 modify some of the statements or terms, were he present ; e. g., would substitute the name 

 of talcoid schists for magnesian slate, etc., but we shall not venture to depart from his 

 published statements. 



We are not aware that any person except Prof. Emmons claims the credit of the 

 discovery that the belt of rocks along the Alleghany ranges, denominated Taconic, are 

 sub-Silurian. The first suggestion of the existence of the Taconic system was made in 

 the 2d Annual Eeport of the Geologists of New York in 1838. The question is asked, 

 whether the marbles, etc. of the Taconic series ought not to be removed from the primary 

 to the transition class. Subsequently these and associated rocks were grouped into the 

 Taconic system, and claimed to be distinct from and older than the Silurian system. 

 Professors H. P. and W. B. Rogers opposed these views in 1841, before the American 

 Philosophical Society. They drew a section across the different rocks in New York and 

 Massachusetts, exhibiting numerous close anticlinal and synclinal folds, and thus explain- 

 ed the apparent inversion of the dip, which other geologists have ascribed to one general 

 overturning of the whole series. They agreed with Prof. Mather in referring the granular 

 quartz to the Potsdam sandstone, the Stockbridge limestone to the lower Silurian lime- 

 stones, and the slates and schists to the Hudson River group, all in a metamorphic 

 condition. They had not examined Emmons' sections, which represented the calcifcrous 

 sandrock, and the Potsdam sandstone, as lying unconformably upon the Taconic slates, 

 but were satisfied in expressing their disbelief of the existence of any such unconformity, 

 because through the whole of the Middle States they had never met with any such 

 discordant stratification. Hence they reckoned the base of the palaeozoic series to be the 

 Potsdam sandstone. Similar views were developed by Prof W. W. Mather in his 

 Report upon the Geology of the First District of New York in 1843. 



Prof. Emmons developed his Taconic system more fully, in his Report upon the Geology 

 of the Second District of New York, in 1842. The rocks were not found within his dis- 

 trict, but were described in general terms, to illustrate some of the most interesting 

 relations of the Champlain group. Quite a full description is given of all the Taconic 



