452 E. B. BRANSON A MISSISSIPPIAN DELTA 



thickness. The variegated shales would be emphasized to a much larger 

 extent in describing the formation in the Narrows area. During the 

 early part of the work in this region the writer believed that these were 

 the Pulaski shales^ basing his belief on the published descriptions, to- 

 gether with the rather deceptive fact that some of the Mississippian 

 strata are reversed, owing to an overturned fold. Marine conditions 

 seem to have given place to nonmarine at the opening of Hinton time, 

 but recurred for short periods several times before the close of the age. 

 Evidences of subaerial origin are amphibian footprints preserved in the 

 lower part, variegated colors of the sediments, presence of partly decayed 

 tree trunks, and absence of marine fossils excepting at a few horizons. 



BLUE FIELD FORMATION 



It was found impossible to obtain a complete description of the Blue- 

 field in the Narrows region, but at Peterstown, 2 miles to the east, the 

 entire section is present. The Bluefield grades gradually into the Hinton. 



Feet 

 15. Dark bituminous shales, with occasional 1 to 2 inch beds of very 



fossiliferous limestone 170 



14. Dark limestone and shale alternating. Limestone beds thin above 



and thick below 235 



13. Dark shaly limestone appearing to be in thick beds 148 



12. Light-green shale 11 



11. Bluish to greenish shaly limestone and sandy shale 7 



10. Reddish to purple sandy shale grading to light green above 31 



0. Greenish to brownish compact thin-bedded sandstone 01 



8. Blue limestone 15 



7. Shaly limestone, blue to yellow 115 



6. Light-blue shaly limestone 51 



5'. Thick-bedded coarse blue limestone 37 



4. Green calcareous shale to shaly limestone ^ ]00 



3. Green thin-bedded shale 102 



2. Alternating black and yellow shale 15 



1. Soft yellow shale 15 



Total thickness of Bluefield formation 1,213 



GREENBRIER LIMESTONE 



The Greenbrier consists of limestone witli inore or less chert below 

 and alternating limestones and shaly limestones above. It is not sharply 

 differentiated from the Bluefield above. 



Feet 

 41. Alternating greenish gray to blue limestones and calcareous shales. . 24 



40. Blue limestone 100 



30. Thick-bedded gray limestone 9 



