88 THE UNIVERSITY OF OKLAHOMA 



With the exception just noted in the Allen field no arkosic beds 

 have been found anywhere below the Pontotoc series in the entire 

 stratigraphic section l.ving along the northern flank of the Arbuckle 

 Mountains. 



Included in the Pontotoc series there are several limestone 

 conglomerates, and in these, pebbles have been found containing 

 fossils which clearly indicate that the conglomerate materials were 

 derived from the limestones of the Arbuckle Mountains which are 

 only a few miles distant. This evidence is taken to indicate that 

 the arkosic material of this series was likewise derived from the 

 Arbuckle Mountains. 



A collection of plant fossils obtained from the central part 

 of the series was sent to Dr. David White, who stated that the 

 assemblage indicated an upper Pennsylvanian age for the associated 

 strata. 



It is the writer's conclusion that the basal portion of the Pon- 

 totoc series represents the time equivalent of the period at which 

 the Arbuckle Mountains were first worn down to their igneous 

 core. 



XLI. A SILURO-DEVONIAN OIL HORIZON IN 



SOUTHERN OKLAHOMA 



Geo. D. Morgan 



From tlie Oklahoma Geological Survey. 

 Within the last few months a thick limestone formation lias 

 been rather unexpectedly encountered in four wells in southern 

 Oklahoma 



The locations of these wells and the depths at which the lime- 

 stone was found in each are as follows : 



Name arid location Depth at whicli 



of well limestone was found 



1. Nance Svndicate well 

 Sec. 4, T. 4N., R. 5E. 



Pontotoc County, Okla, 2.305 feet 



2. Transcontinental Well 

 Sec. 14, T. 5N., R. 4E. 



Pontotoc Countv, Okla. 2,660 feet 



3. Doan Well. 



Sec. 20, T. 5N., R. 4E. 



Pontotoc County, Okla. . 2,500 feet 



4. Maud Oil and Gas Co., No. 2. 

 Sec. 18, T. 7N., R. 5E. 



Pottowatomie County, Okla. 3,730 feet 



In the Nance and Maud wells the lime made a good showing 

 of light oil and on being shot made commercial yields. The initial 



