THE MISSISSIPPIAN PERIOD. 



509 



Pennsylvania, 1 West Virginia, 2 Maryland, 3 and Tennessee, 4 and the 

 tendency of recent studies is to greatly extend it. (See also sections 



Fig. 231. — Diagrams showing unconformity between the Mississippian and Penn- 

 sylvanian systems in Indiana, A, at Little Pine Creek; B, at Turkey Run (Hop- 

 kins: Ind. Geol. Surv.) 



pp. 557 et seq.) In Indian Territory there was disturbance (perhaps 

 orogenic) in the Arbuckle mountains at the close of the Mississippian 

 period. 5 



Fig. 232. — Coal in a trough excavated in Mississippian limestone. Cooper Co.. Mo 

 (Winslow, Missouri Geol. Surv.) 



This wide-spread emergence, erosion, and submergence, with the 

 accompanying unconformity of the overlying series, is just the sort 



duller, Gaines (Pa.-N. Y.) folio, U. S. Geol. Surv.; Campbell, Brownsville-Con- 

 nellsville (p. 7), Masontown-Uniontown (p. 7), and Elkland-Tioga (p. 3) folios. 



2 West Virginia Geol. Surv., Vol. II, p. 610 (I. C. White); Campbell, Charleston 

 (W. Va.) folio, U. S. Geol. Surv. 



3 White (David), 20th Ann. Rept., U. S. Geol. Surv., Pt. II, and Martin, Md. Geol. 

 Surv., Report on Garrett Co., p. 110. 



4 Maynardville, Tenn., folio, U. S. Geol. Surv. (Keith). 

 6 Colgate, I. T., folio, U. S. Geol. Surv. (Taff.) 



