Page:The Journal of geology (IA journalofgeology11893univers).pdf/261

This page has been proofread, but needs to be validated.
ORIGIN OF THE PENNSYLVANIA ANTHRACITE.
687

beyond which they advanced slowly, as shown by changing type of rocks, the chemical change should have been almost complete, especially in the eastern Middle and the eastern extremity of the Southern field, which occupy that part of the area in which the coal marsh, in almost every instance, appears to have thrust itself first upon the advancing delta.

It is quite possible that when detailed study of the anthracite areas in Arkansas and Russia have been made, the same explanation may be found applicable there also, and that the anthracite will be found near the old shore line, whence the marsh advanced as new land was formed.

John J. Stevenson.

This article is issued from Wikisource. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.