THEORY. 375 



the same as that of the slates adjacent. A mile north of Aklis Hill the same rock clips 

 15 E. The quartz rock K, overlies the Georgia slate, and is connected with the coarse 

 conglomerates further east. 



Thus we have the whole relations of the Georgia slate represented in this figure. The 

 natural inference from these relations is that the red sandrock is of the age of the 

 Oneida conglomerate or Medina sandstone, and the Georgia slate is still newer, and 

 therefore Middle Silurian. All the members of the Lower Silurian, the Potsdam sand- 

 stone, the various limestones, the Utica and Hudson River slates, lie between the red 

 sandrock and the Laurentian nucleus in New York, and the whole apparently form a 

 successive series of newer and newer rocks, like the corresponding series in New York, 

 from the Potsdam sandstone to the carboniferous conglomerate south of the same nucleus. 

 If one wished to establish a palreontological system from the stratigraphical relations of 

 the rocks containing the fossils under consideration, there is hardly a place to which we 

 could refer with such confidence for the true order of strata as to these rocks in St. Albans. 

 Yet it becomes us to speak with caution, because true science forbids too great cer- 

 tainty. Nor have we examined every ledge with compass, clinometer, and hammer, as 

 ought to have been done in a thorough survey. The possibility of any foldings had 

 never occurred to us until after the close of our examinations in the field. 



Objections to this view arise from the possibility of foldings, perhaps connected with 

 faults, and from palseontological evidence. Two difficulties occur in the way of supposing 

 folds to exist : 1. The dip of the strata is much smaller than is usual in foldings of such 

 a character as this fold must have been. 2. If C and K were composed of precisely the 

 same material, also E and G, we could imagine either a beautiful anticlinal or synclinal 

 axis, according to pleasure. C is dolomitic of a red or gray color ; K is pure quartz, brown 

 or of a bluish cast ; E is a genuine pudding stone of limestone pebbles ; G is a gritty 

 quartz rock, sometimes brecciated, sometimes a trifle calcareous, and of a different color. 

 The fact that these different members will not coincide when we endeavor to pair them 

 off into folds, very seriously militates against the theory of plications. 



But there may be faults. The great difficulty arising in this view is, that one fault will 

 not satisfy the opponent of this view. The theorist's desire for faults in speculating upon 

 these rocks is no more readily satiated than the miser's desire for gold the more he ob- 

 tains the more he wants. One instinctively shrinks back from a theory involving 

 numerous faults. Still we will say that if any one will prove satisfactorily from strati- 

 graphical or palseontological evidence that a series of faults are indispensable, we will not 

 hesitate to accept his conclusions. 



The principal fault which is supposed to exist by the second theory of the age of the 

 Georgia slate must be in the vicinity of B, in Fig. 257. We have seen no evidence of it 

 among the strata, but we would not say that its existence is impossible. 



If any one is disposed to think, from the greater dip of the slates at St. Albans village 

 (45 E.) than the mottled limestones, etc., west of them (5-10 E.), that the slates under- 

 lie the limestones unconformably the junction being obscured we hope he will go to 

 Henry Robinson's house in the north part of Georgia, three miles south of the section in 

 Fig. 257, where he will find the union of the two rocks, as they are represented. The 

 limestones underlie the slates, and both are inclined from 15-20. The superposition 



