THE OKLAHOMA FIELDS 697 



Loiver Cretaceous system (Comanche series). Feet 



S. BokcMto formation 140 



4. Caddo limestone 60 



5. KiamicM formation 150 



6. Goodland limestone 25 



7. Trinity sand, which includes the oil sand in the Madill 



field and gas sand at Woodville 200- 400 



18. (Unconformity.) 

 Permian series. 



Red sandstone, vari-colored shale, and beds of clay-iron 



conglomerate with thin lenses of limestone 400-1,500 



(Unconformity.) 

 Pcnnsylvanian series. 



1. Franks conglomerate. Limestone (Wapanucka) at top. 



Beds of chert, gravel, boulders, and sandstone; forma- 

 tion of local extent near mountains 500 



2. (Unconformity.) 



Glenn formation ; blue shale with lenticular beds of sand- 

 stone. Probable horizon of the main oil sand in the 



Healdton field (see under Ordovician system) 1,000-3,000 



(Unconformity.) 

 Mississippian series. 



1. Caney shale. Top is blue shale with sandy lentils and 



lower portion is black fissile shale with concretions of 



dark-blue fossilif erous limestone 1,500 



2. Sycamore limestone 0- 160 



Devonian system. 



Woodford chert 600 



Silurian system. 



1. Hunton limestone 0- 200 



2. Sylvan shale. Blue clay shale 50- 300 



Ordovician system. 



1. Viola limestone ; white and bluish 750 



2. Simpson formation; siliceous sandstone, bituminous sand- 



stone, fossiliferous limestone, calcareous sandstone and 

 shale (possibly contains deep oil sand at Healdton) ... 1,600 



Camhro-Ordovician systems. 



Arbuckle limestone; massive and thin bedded, white and 



light blue limestone with cherty concretions 4,000-6,000 



Camhrian system. 



Reagan sandstone; coarse dark brown sandstone with 



calcareous sandstone and shale at top 50- 150 



Precamhrian system. 



Tishomingo granite. 



The Pennsylvanian series in Oklahoma is made up of beds of sandstone 

 alternating with strata of gray, blue, and dark shale, with thin beds of 

 limestone at widely separated intervals. Coaldn commercial quantities 



