CLASSIFICATION OF UPPER PALZOZOIC ROCKS. 783 
tain localities as the conspicuous massive ledge. It is important 
to bear the above statement in mind in stratigraphic work in 
regard to this horizon, for a greater uniformity of appearance in 
outcrop has been assigned to this limestone than actually exists. 
Above the Fort Riley limestone Swallow also reported vari- 
ously colored shales and marls sixty-four and a half feet in 
thickness before reaching the base of the ‘‘second cherty lime- 
stone’’—bed No. 44—which he described as “hard, bluish drab 
and very cherty, four feet. Productus, Myalina and Spirifer’” 
exposed on the ‘Cottonwood and Carey Creek.’’* This bed 1s 
probably the Marion flint of the Chase formation which answers. 
quite well to the above description. The base of the Florence 
flint is a clearly marked stratigraphic line, and Swallow assigned 
a thickness of from 118% to 120% feet to the beds between the 
bases of his third and second cherty limestones, while in the 
Chase formation, from the base of the Florence flint to that of 
the Marion, it is given as 126 feet. From sixteen to twenty- 
four feet above the top of the second cherty limestone is bed 
No. 40 of Swallow which he called the “first cherty limestone” 
and characterized it as ‘‘a brownish-buff magnesian limestone 
with cherty concretions, four feet. Productus Calhountanus, semt- 
retculatus (?), Athyris subtilita ?, Archeocidaris,” exposed on ‘‘ Cot- 
tonwood and Carey Creek.” 
It is inferred that this ‘“‘first cherty limestone” of Swallow is 
the Marion concretionary limestone of the Chase formation, and it 
d 
will be noticed that Swallow mentions “cherty concretions”’ 
instead of simply ‘‘chert’’ as in his description of the other 
cherty limestones, although he does not refer to the prominent 
stratigraphic feature of this bed. 
Finally, Swallow gave the total thickness of the beds from 
the base of his fifth cherty liimestone— No. 62—to the top of 
the first cherty limestone— No. 40—as ranging from 223% to 
279% feet.2 These beds include all the cherty limestones of 
tPrel. Rep. Geol. Sury., Kansas, p. 13. The Carey Creek frequently mentioned 
by Swallow is supposed to be the creek of that name in the eastern part of Dickinson 
county. 
2 Tn the section there are a few beds to which no thickness was assigned by Swal- 
low, but it is supposed those were regarded as local and simply a modification of the 
other beds so that their thickness was considered in those beds. 
