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of unconformity and bevelled edges there is perfect correspondence on either 

 side of the supposed fault, not in a single section only, but in all adjacent to 

 the limestone, both along and across the folds. A great fault can with diffi- 

 culty be imagined that would trim the bed so neatly ; certainly none has 

 been observed. 



Faulting an Assumption. — With all structural and stratigraphical facts 

 the reverse of those connected with faults, and with the lack of fossils to 

 demonstrate a fault, it is clear assumption to say that there is one. There 

 is nothing to indicate a fault; therefore we are obliged to return to the view 

 that the beds were sedimentary deposits in their present relations— limestone 

 under the shale and sandstone. 



Analogous Sections. — Region west of the Blue Ridge. — This view is the 

 first and natural one, and is supported by the existence toward the west 

 of a similar series in a similar attitude — i. e., the Shenandoah limestone, 

 the Martinsburg shale (equivalent to the Hudson river), and the Massa- 

 nutten sandstone (equivalent to the Medina). Comparison of these sections 

 makes the Blue ridge shale Hudson River and the sandstone Massanutten 

 or Medina.^ It is through a precisely similar comparison that these sand- 

 stones were called Potsdam, and the lithological correlation is in one case as 

 strong as in the other. 



Homology between Massanutten Mountain and the Blue Ridge. — Addi- 

 tional sections of the Blue ridge to support our view are readily found in 

 other places. Rogers frequently states that the sandstones of the Blue 

 ridge appear to be above the limestone. The same general relation holds 

 all along the Massanutten mountain and adjacent points in the Blue ridge. 

 The structure is an anticlinal valley of Shenandoah limestone between two 

 synclinal ridges. The Massanutten synclinal is accepted Silurian ; from its 

 structure the Blue ridge is the same, and no fossils have proved the opposite. 



Sections at Turk's Gap, Buchanan and Christiansburg. — Twenty-five miles 

 southwestward, at Turk's gap, two flat synclines of sandstone nearly cover 

 the Blue ridge. Sixty miles southwestward, at Buchanan, the Massanutten 

 section is duplicated — an anticlinal of limestone between a Silurian sand- 

 stone syncliue and the eastward-dipping Blue ridge sandstone. Forty miles 

 farther southwestward, near Christiansburg, the Blue ridge sandstone rests 

 on shale and that in turn on the Shenandoah limestone, the whole series 

 dipping southeastward 10 degrees. These are instances taken from numer- 

 ous occurrences, and their use here is merely to corroborate. None the less, 

 these facts, both in nature and closeness of correlation, are of the same grade 

 as those cited by Rogers to support his view. 



Contrasted Sectioris, as at Balcony Falls and Dublin. — It will seem strange 

 to most geologists that Rogers and others dealing with the question should 



*The names " Massanutten," " Martinsburg," and "Shenandoah" are derived from Massanutten 

 mountain, Martinsburg, and Shenandoah river, all in West Virginia. The mouatain, town and 

 river are characterized respectively by the sandstone, shale, and limestone. 



