844 E. O. ULRICH CORRELATIONS OF CHESTER FORMATIONS 



oolitic limestone in which the characteristic fossils of the Upper Ohara 

 member either failed to exist, except locally, or, as seems the more prob- 

 able, they were broken into unrecognizable fragments by wave action. 

 Accordingly, the more eastern and southern facies of the formation do 

 not represent merely the Fredonia member of the Sainte Genevieve lime- 

 stone, but rather the whole of the formation. It is, therefore, inaccurate 

 to employ the term Fredonia to the formation as developed in Kentucky 

 east of Christian County, and in Tennessee, Virginia, and Alabama, in 

 all of which areas the Rosiclare sandstone that separates the Fredonia 

 member from the Ohara member is wanting. Instead of Fredonia we 

 should use the name Sainte Genevieve limestone. 



The section near Huntsville, Alabama — Details of the section. — Re- 

 garding the section in the vicinity of Huntsville, Alabama, which in all 

 essential features is surprisingly like the Somerset section, the features 

 that I shall mainly emphasize concern (1) the position of the most pro- 

 lific of the Platycrinus huntsvillo? beds and (2) the other fossils that 

 occur associated in the same bed with it. The details of the Sainte 

 Genevieve and Gasper parts of the section, which is continued upward in 

 Montesana to well into the overlying Lower Pennsylvanian sandstone, 

 are as follows : 



Detailed Section of the Montesana Limestone Group in Hills 8 Miles south of 



Huntsville, Alabama 



Feet 

 Hartselle sandstone, about 12 feet, succeeded by a small thickness of 

 sparingly fossiliferous shale thought to represent the Golconda. 

 Montesana group. 



Gasper limestone. 



Calcareous shale full of fossils ; Archimedes very abundant ; also 

 other Bryozoa, Pentremites, and among the Brachiopoda Chon- 



etes chesterensis in typical form 15 



Limestone, rather massive, some ledges fine grained, others either 



subcrystalline or oolitic, all more or less sparingly fossiliferous 35 

 Shaly and highly siliceous layer ; under the weather liberates 

 great numbers of well preserved silicified Pentremites and 



crinoids of characteristic Gasper species 1 



Limestones of usual Gasper types, fossiliferous but giving few 



good specimens 19 



Limestone mostly in heavy ledges, some of them oolitic, with a 

 thin layer at top full of the dismembered plates of a low-based 

 species of Agassizocrinus, a cherty coral-bearing ledge, with 

 Lithostrotion sp. and Cijathophyllum sp. in the lower half, and 

 beneath this a thick basal layer containing Pentremites pyr- 

 iformis and large erinoid columns 30 



Total thickness of Gasper limestone 100 



