FEET. 



Hard, gray limestone 2 



Sandstone and clay shale 10 



Limestone, usually massive, arenaceous, and fria- 

 ble, but it varies to pure, tough limestone of 

 a gray color. Some bluish limestone, which 

 weathers to a white color, occurs near the 

 base of the bed 30 



137 



Below this section is about twenty feet of the Fayetteville 

 shale and its included stratum of blue limestone. The limestone 

 at this place is only about two feet thick. 



On the west side of Illinois river, about five miles east-southeast 

 from Greenleaf, the following section (Sec. c, PI. V) may be seen : 



FEET. 



Sandstones and grit (Coal Measures?) at top 



Massive, gray, brownish weathering limestone. . . 15 



Clay shale 20 



Massive gray limestone 4 



Blue limestone alternating with a little clay shale. 

 The limestone weathers to a rather smooth 

 but angular wavy surface and a whitish or 

 yellowish color ; the weathered cross sections 

 of fossils and wavy branching calcite seams 

 of a darker color than the mass of the rock 

 gives a streaked, wavy and mottled appear- 

 ance to its surface . , 30 



Rather massive but in part flaggy limestone which 

 in places contains abundant Pentremites. ... 50 



Clay shale 25 



Gray massive limestone 75 



215 

 The following section is exposed four miles southeast of Ft.. 

 Gibson on the south side of Bayou creek along the Ft. Gibson- 

 Braggs road : 



FEET. 



Sandstone (Coal Measures) at top 



Massive gray limestone 10 



PROC. AMER. PIIILOS. SOC. XXXVI. 150. Y. PRINTED DEC. 20, 1897. 



