130 Kindle — Unconformity at the Base of the 



"In fact, the principle of diastrophism can rarely be used before 

 taking the fossil evidence into account, for it is the latter that 

 fixes and determines physical events. Diastrophism, however, is 

 of much value in paleontography, but it must follow, not precede, 

 the evidence furnished by the fossils." 



None of these authors has given us any faunal evidence for 

 transferring the Chattanooga shale to the Carboniferous from 

 the Devonian, where it had been generally placed and to which 

 it had previously been referred by one of them,* and separated 

 from the Carboniferous by an unconformity.^ Probably all 

 of the paleontologic evidence which the advocates of the 

 Carboniferous age of the Chattanooga shale might claim to 

 support their view has been presented by Dr. E. S. Bassler.;); 

 Although his paper does not eschew diastrophism, it proceeds 

 mainly on the paleontologic basis and consequently invites 

 our careful consideration and critical examination. The con- 

 tentions which Bassler makes in his paper are reducible to 

 three distinct theses, which may be stated thus : (1) The Chat- 

 tanooga shale of central Tennessee is a distinct formation 

 from the Chattanooga shale of the U. S. Geological Survey 

 folios of eastern Tennessee. (2) The Chattanooga shale should 

 be correlated with the Cleveland shale of Ohio. (3) The 

 Cleveland shale of Ohio is of Waverlyan age.§ Inasmuch as 

 Dr. Bassler admits the Devonian age of the east Tennessee 

 black shale, it is evident that the first proposition is of pri- 

 mary importance to his argument. It is stated by Bassler 

 as follows : " East and northeast of this Chattanooga band 

 of outcrop a similar black shale, but of undoubted Devonian 

 age, has been mapped as the Chattanooga shale."^f In support 

 of the distinctness of the eastern and central Tennessee Chatta- 

 nooga shale I find in Dr. Bassler's paper no evidence adduced 

 beyond the reference of the central Tennessee Chattanooga to 

 the Carboniferous. This reference rests primarily on evidence 

 submitted by Newberry nearly forty years ago, the validity 

 of which I am compelled to deny for reasons to be shown 

 presently. During the past summer the writer has discovered 

 in the most easterly outcrops of the Chattanooga shale in 



*Ulrich, E. 0., Prof. Paper, U. S. Geol. Survey, No. 36, p. 25, and Folio 

 U. S. G. S. No. 95. 



t Hayes, C. W.. and TJlrich, E. O., Folio TJ. S. Geol. Survey, No. 95, 1903. 



X The Waverlyan Period of Tennessee, Proc. U. S. Nat. Museum, vol. xli, 

 pp. 209-224, 1911. 



%Note. — In another paper|| the whole of the Ohio shale in Ohio has been 

 referred to the Mississippian by Dr. Bassler. This reference, however, was 

 evidently an oversight as regards the lower division of the Ohio shale, since 

 no evidence has ever been offered by Bassler or any one else tending to prove 

 that the lower portion of the Ohio shale is of later age than Devonian. So 

 we may confine our discussion of the proposed revision to the evidence rela- 

 ting to the position of the Cleveland and Chattanooga shales. 



I This Journal, vol. xxxi, p. 20, 1911. 



If Idem, p. 215. 



