section of the devonian near marble city 669 



Chattanooga Shale 



The Sylamore sandstone is overlain unconformably by the "Chatta- 

 nooga black shale/' variable in thickness in the Tahlequah quadrangle up 

 to at least 40 feet, this variability being due to another erosion interval 

 following the deposition of the shale. The age of this formation is un- 

 known, since no fossils have been found in it in the Tahlequah quad- 

 rangle. It may be of late Devonian or early Mississippian (Kinderhook) 

 time. 



Sectiox of the Devonian near Marble City, Sequoyah County, 



Oklahoma 



The following section is made up in the main from the hillside (Quarry 

 Hill) due northwest of the marble quarry and the hillside to the northeast 

 of the quarry. The region is a little more than one mile to the north of 

 Marble City and on the northwest side of Sallisaw Creek : 



Lower Mississippian. 



Boone chert (= Keokuk). 



Marked break in deposition, no Saint Joe being present. • 



Upper Devonian or early Kinderhook. 



"Chattanooga black shale," 20 to 40 feet thick. 



As no fossils are known from this formation, its age is uncertain. 

 Break. North of the marble quarry in Walkingstick Hollow, Taff describes 

 the sequence as broken and the contact as sharp between the shale and 

 sandstone. 



Middle Devonian. 



Sylamore sandstone = Camden chert of western Tennessee. At least 5 

 feet thick, but from Taff' s description attains to 20 and even 30 feet 

 thick. The basal 5 feet are a white to brown, coarse quartz sandstone, 

 muddy, cemented with more or less of carbonate of lime, weathering a 

 rusty brown. From loose blocks scattered over this formation were ob- 

 tained Leptcena rhomboidalis ventricosa Hall, Schuchertella (new large 

 species), Spirif er worthenanus Schuchert, and Amphigcnia curt a (Meek 

 and Worthen). Taff reports the presence of the bones of Dinichthys 

 and small teeth of fishes. 

 Trobable break in deposition. 



Lower Devonian. 



Upper Oriskanian white limestone. From 5 to 8 feet of a fossil coquina 

 of fragmented and worn fossils cemented by a coarsely crystalline car- 

 bonate of lime. Fossils are common, but are hard to get because of the 

 massiveness of the limestone. Those marked with an asterisk also occur 

 in Missouri in a very similar limestone. Favosites shriveri, F. (large 

 ramose form), large crinoid stems, FcnestcUa two species, Trepostomata 



