210 J. J. STEVENSON — CARBONIFEROUS OF APPALACHIAN BASIN 



Doctor White's sections are too far apart to make close identification 

 more than conjectural.* 



The Anthracite Fields of Pennsylvania 



The stratigraphical study shows that the Rockcastle or Lower Potts- 

 ville is thickest in the Southern field, that much of the lower por- 

 tion is wanting in the Middle field, and that practically the whole of the 

 section is absent from the Northern field. The study of plant remains 

 tells the same story ; for twenty years ago Doctor White, making use of 

 Mr Lacoe's studies, found in them the proof for his conclusion that the 

 Campbells Ledge coal bed of the Northern field belongs near the base of 

 his Pottsville. Mr David White's study of plants from many horizons 

 in the Southern field leaves no room for doubting the general statement. 

 In this work Mr White offered tentative correlations with horizons at 

 localities in the Virginias and farther southward, tentative because they 

 were based upon limited collections from the southern localities. These 

 do not coincide in all cases with the conclusions reached in this paper 

 from study of the stratigraphy ; but in several instances the study of 

 extensive collections has enabled Mr White to reach final conclusions, 

 which, in so far as the localities studied are concerned, are in practical 

 agreement with those suggested by the stratigraphy.f 



The Anthracite fields are separated by hundreds of miles from the 

 nearest localities at which the Lower Pottsville is shown in great thick- 

 ness. The conditions in the Anthracite area were very different from 

 those of any southern area except eastern Alabama, so that any attempt 

 at correlation on the basis of stratigraphy would be deserving only 

 of ridicule. The question as to whether the whole of the Rock- 

 castle section and Lower Pottsville section is to be looked for in the An- 

 thracite area or in the southern areas must remain without answer until 

 study of the fossil plants has been completed. 



A similar condition exists with respect to the Alabama coal fields, 

 where a great mass of measures is found, separated by at least 100 miles 

 from the nearest locality in Tennessee, where the upper beds have es- 

 caped erosion. The probabilities seem to be that the Pottsville, above 

 the Bonair sandstone, is enormously expanded; but the determination 

 of this matter also must be left for the paleobotanist, as there is nothing 

 on which the stratigrapher may build securely. 



* That this remark be not construed as a reflection on Doctor White, it is well to state that the 

 material published in the bulky volume ii of the West Virginia Survey is a gift from the author 

 to his state, the work having been performed prior to his appointment as state geologist. 



f I. C. White : Geology of the Susquehanna Region (G 7), pp. 41-43. 

 D. White : Fossil floras of the Pottsville formation ; Twentieth Ann. Rept. U. S. Geol. Survey, 

 pp. 755 et seq. 



