IG J. J. STEVENSON — LOWER CARBONIFEROUS, APPALACHIAN BASIN 



Intkoduction 



It is the writer's purpose in this work to describe in detail the Car- 

 boniferous deposits of the Appalachian basin, to correlate them, to ascer- 

 tain as far as possible the conditions existing during the deposition of 

 the various rock masses, and finally to apply the facts in a discussion of 

 the origin of coal and coal beds. 



Appalachian basin, as here used, refers to the area bounded at the east 

 b}^ the old Appalachian land, at the west by the Cincinnati uplift to 

 central Kentucky, and thence southward to Alabama by the area whence 

 erosion has removed the newer rocks and thereby separated the eastern 

 from the western Carboniferous region. In a general wa}^ it includes 

 Pennsylvania, Maryland, and Virginia west from the Blue ridge, the 

 whole of West Virginia, eastern Ohio and Kentucky, east-central Ten- 

 nessee and northern Alabama. In Alabama the Appalachian and Mis- 

 sissippi areas are continuous ; in Tennessee they are separated by the 

 Great Central valley, while in Kentucky the dividing strip is but a few 

 miles wide. The basin, as thus rudely defined and with an extent of 

 probably 150,000 square miles, was almost w^holl}^ covered with Carbon- 

 iferous rocks of one period or another ; but the beds have been removed 

 from nearly one-half of it, so that in some portions, especially at the 

 east, there remain only outlying strips, preserved in synclinals or along 

 the borders of great overthrust faults. 



A general description of the deposits is possible now because of the 

 detailed work done by the geologists of Pennsylvania, Ohio, Maryland, 

 and West Virginia at the north, as well as by those of Tennessee and 

 Alabama at the south, supplemented by the studies of the United States 

 geologists and others in Kentucky, Virginia, and Tennessee. The de- 

 tailed work of the United States geologists for the most part is still unpub- 

 lished, and one has within reach only the synopses given in connection 

 with the individual folios. Acknowledgment of the waiter's indebted- 

 ness to these observers is made in the proper connection. It is more 

 than probable that there are omissions or errors in the references, and 

 that there are misinterpretations in statements of other's opinions. As 

 such defects not only do injustice to fellow-students in the same field, 

 but also detract from the usefulness of the work, the writer urges those 

 who detect them to inform him, that the corrections may be published 

 with the succeeding chapter. 



In the descriptive portions the names applied to formations will be, 

 as far as possible, those employed by the geologists whose work is quoted 

 for a locality, but questions of nomenclature will be considered in the 

 discussion closing each chapter. The names employed by the second 



