C. W. Honess — Stanley Shale of Oklahoma. 65 



Many of the details of the lithology, distribution and 

 structure of the sediments have been worked out and facts 

 regarding the origin and source of the beds and evidences 

 of their age have accumulated, until it is believed a close 

 approximation to the truth with respect to these matters 

 is at hand. That the Stanley is either upper Mississip- 

 pian or Lower Pottsvillian (lowermost Pennsylvanian) 

 in age has for sometime been the opinion of David Wliite^ 

 and most stratigraphers are in accord with this view. 



During the four years just past it has been the privilege 

 of the writer to pursue his own bent and his interests have 

 led him into a field which involves the Stanley series. The 

 area covered lies in southeastern Oklahoma (see index 

 map) in the south-central part of the Massern Ranges 

 ('^Ouachita Mountains" of most writers), and the sur- 

 face exposures range in age from doubtful Cambrian to 

 Pennsylvanian. The succession of geological formations 

 in this region is essentially the same as that in west-cen- 

 tral Arkansas, where the same formations are exposed 

 and where identically the same dynamic forces have oper- 

 ated. This succession has been worked out and briefly 

 described by H. D. Miser^ after years of painstaking 

 study and labor in the DeQueen and Caddo Gap Quad- 

 rangles. In brief the complete section is as follows : 



Generalized section of Paleozoic rocks in the Ouachita Mountain 

 region of west-central Arkansas. 



[From U. S. Geol. Survey, Bull. 691, p. 272; by H. D. Miser.] 



Carboniferous : Feet. 



Pennsylvanian : 



Atoka formation 6,000 



Upper Mississippian : 



Jackf ork sandstone 5,000-6,600 



Stanley shale 6,000 



Hot Springs sandstone 0-200 



Unconformity. 



Devonian (upper part may possibly be Carboniferous) : 



Arkansas novaculite 0-950 



Unconformity . ( ? ) 

 Silurian : 



Missouri Mountain slate 50-300 



Unconformity ( ? ) 



Blaylock sandstone 0-1,500 



« Quotation in Fauna of Canej Shale, p. 8, U. S. Geol. Survey Bull. 377. 

 ^ Miser, n. D. : loc. cit. 



Am. Jour. Sci.— Fifth Series, Vol. I, No. 1.— January, 1921. 

 5 



