256 INFERENCES. 



rocks as forming an inverted anticlinal ; while in Micldlebury they appear to be a true 

 synclinal. 



Several shorter anticlinals and synclinals can be traced upon our sections, but the pre- 

 ceding are all which we have been able to discover extending through a large part of the 

 State. Our sections were all traced out in the field and protracted on paper without the 

 slightest knowledge of their existence. So that although a re-examination of the sections 

 may produce some modifications in the clips, we are confident that the great features 

 will remain. Hence we may feel confident that the rocks of Vermont have been 

 thrown into a succession of folds while in a semi-plastic condition by a force from the 

 direction of the Atlantic, and that their crests have been subsequently denuded. 



One important inference from these statements is that only a part of the strata as we 

 cross the State can be regarded as lying in an inverted position. Certainly those with 

 westerly dips forming the western side of anticlinals must occupy a normal position. 

 And so must the eastern side of those anticlinals that have been inverted. Hence, though 

 we cross an uninterrupted succession of easterly dips in going eastward we cannot infer 

 that we are constantly meeting with older and older rocks. It may be so for a time ; but 

 if there have been successive folds, one side of the folds may be in a normal position. 

 If organic remains are wanting and we cannot discover other proofs of inversion, we 

 shall be unable to say where the change takes place from a normal to an abnormal 

 position, and the reverse. And this may be a chief reason for the discordant views that 

 have been advanced by geologists, respecting the age and position of the Vermont rocks. 

 In many cases the evidence necessary to settle these questions, may never have been or 

 never can be discovered. Yet we feel confident that careful and prolonged researches 

 will furnish data for the solution of some of them. 



Another inference is, that mere superposition will not justify us in deciding upon the 

 relative age of rocks. The questions we must previously settle are, whether the strata 

 at the line of junction' are in a normal or inverted position ; or if inverted, which side of 

 the anticlinal or synclinal is it, that we are examining ? And if, as often happens, we 

 cannot decide these questions, the main question as to relative age must be left undecided. 



Unfortunately this reasoning applies to many of the questions, as to the relative age of 

 the metamorphic schists of Vermont, whose details will be given under the different rocks. 

 We are sorry to be obliged to confess that there is so much uncertainty upon this point. 

 But it will at least justify our hesitancy and caution on this subject. 



Another important conclusion from our discussion is, that if the rocks of Vermont have 

 been thus folded up and deeply denuded subsequently, then it may be that some of the 

 oldest of the rocks may be brought to light at the centers or axes of the folds. Take, for 

 instance, the first anticlinal described above, extending from Shelburne Falls, in Massachu- 

 setts, nearly through the State of Vermont. At Shelburne some 10,000 feet of schist have 

 been worn away, bringing gneiss to light at the bottom, and this rock is brought to light 

 on the first five sections, north of which the mica schist is not denuded deep enough to 

 expose the gneiss. Why may not this gneiss be hypozoic ? Surely the strata above it 

 that are denuded, are thick enough to embrace the silurian rocks, and there is no evidence 

 of cambrian strata in Vermont east of the taconic schist. The same reasoning may ap- 

 ply to the gnoiss of the anticlinal running along the crest of the Green Mountains. In 



