Area in Louisiana and Eastern Texas. 83 



Buried Pemisylvanian hills in northern Texas and southern 



Oklahoma. 



Sidney Powers^^ says : 



''Information concerning the extent of this former land area 

 [Pennsylvanian land area in east-central Texas] * * * is being 

 secured by the subsurface discoveries at Healdton, Oklahoma, 

 and at Electra, Burkburnett, and Petrolia, Texas, and in the 

 area south and east of these fields. Granite of pre-Cambrian age 

 has been found beneath the Petrolia field, in Clay County, at a 

 depth of 4,240 feet in the Texas Company Byers No. 41 and in a 

 well 7 miles north of St. Jo, Montague County, at 3,007 feet. 

 Limestone, which has been identified as probably of Ordovician 

 age, occurs above the granite in the Byers well below 3,750 feet 

 and in Ball No. 1, 5 miles north of Myra, Cooke County, below 

 2,195 feet (identified by Dr. J. A. Udden). However, most of 

 the massive limestone found in the deep wells in the Red River 

 section is supposed to be of Pennsylvanian age, unconformable 

 with the overlying Cisco beds [of Pennsylvanian age]. These 

 buried hills are interpreted as outliers of the main land area to 

 the southeast. ' ' 



The buried hills just mentioned lie not far south of the 

 Arbuckle and Wichita mountains and doubtless stood 

 above sea level during much of the time in the Pennsyl- 

 vanian epoch that these two regions were land. The 

 occurrence of limestone of supposed Pennsylvanian age 

 beneath the unconformity in the buried hills region and 

 the occurrence of the Cisco [Pennsylvanian] beds above 

 it indicate that the folding and uplift in this region, 

 which has been described by Powers and others,^^ took 

 place during the Pennsylanian epoch. 



Trans-Mississippian extension of Appalachian land area. 



J. C. Branner has presented much evidence in support 

 of the theory that the ^^old Appalachian land area crossed 



^^ Powers, Sidney, The Butler salt dome, Freestone County, Texas, this 

 Journal, (4), vol. 49, p. 142, Feb., 1920. 



'"'^ Powers, Sidney, Idem. 



Ordovician. strata beneath the Healdton oil field, Oklahoma (Ab- 

 stract), Geol. Soc. America, Bull., vol. 28, p. 159, 1917. 



The Healdton oil field, Oklahoma, Econ. Geology, vol 12, pp. 594-606, 



1917. 



Hager, Lee, Eed Kiver uplift has another angle, Oil and Gas Jour., pp. 

 64-65, Oct. 17, 1919. 



Merritt, J. W., Pennsylvanian sedimentation around Healdton Island, 

 Amer. Assoc. Petroleum Geologists, Bull., vol. 4, No. 1, pp. 47-52, 1920. 



