FORT RILEY LIMESTONE AND ITS CORRELATIVES. 49 



Meek and Ilayden accurately noted these beds — number 12 of their 

 section representing number 11 of Hay's — which they described as "a 

 light grayish yellow, rather granular, magnesian limestone; " mentioned 

 several fossils, and stated that it " forms a distinct horizon near summit of 

 hills in vicinity of Fort Riley ; also seen on Cottonwood creek."* Num- 

 ber 11 of Meek and Hayden represents number 12 of Hay, which they 

 described as a " light grayish and yellow magnesian limestone in layers 

 and beds, sometimes alternating with bluish and other colored clays," 

 containing Plenrophorns sabcaaeata, BakeuelUa parva, Euomphalus near 

 rugosas, Spirlgem \_Athijr'i>i], allied to subtilUa, but more gibbous ; Orthisina 

 umbraculam f, 0. shiunanUana and others, while the locality was given 

 as the ''summit of the hills near Fort Riley and above there; also seen 

 on Cottonwood creek " from 25 to 35 feet in thickness. Certain layers of 

 this bed contain abundant specimens of BakevelUn parva, M. and H., and 

 Plcurophnrus subcuiicatus^ M. and H., while Aviculopecten occidentalis (Shu- 

 mard), Meek and \\''orthen, Eaoniphalus sp. and other species are rare. 

 Number 11 of Hay's section is number 52 of Swallow's, which Swallow 

 called the " Fort Riley limestone," a name that seems very appropriate 

 for this horizon, and he characterized it as " a buff, porous magnesian rock 

 in thick beds," containing Prodactus calhounianus, Orthisina shumardiana, 

 ArchrTocidaris, Bakevellia^ etcetera, 8 to 10 feet thick, and exposed near 

 Fort Riley, Cottonwood and Fancy creek.f The limestones and shales 

 called number 12 by Hay and number 11 by Meek and Hayden were 

 subdivided by SwaHow into a number of beds. 



Rkview of the geologic Correlation of the Kansas River Section. 



The geologic correlation of the beds composing the Fort Riley section 

 is a very interesting question, which, considering the length of the pres- 

 ent i)aper, cannot now be taken up for general review, but which the 

 writer lioi)es to attemi)t at another time, together with the comparison 

 of this upper part of the Kansas section with tlie u])per Cottonwood 

 section. In closing it might be noted that Professor Hay divided the 

 section into tlie up})er and luwer Fort Riley beds, numl)er 11 (tlie Yovi 

 Riley limestone) forming the Inise of the u[)per l)eds. The Professor 



* Proc. Acad. Nat. Qo\., Phila.. vol. xi, p. 17. 



X Prelim. Rept. Geol. Surv. Kansas., p. 14. 



Dminj; the past snmmf!r, in conneftion with the preparation of the geologic maps of the Cotton- 

 wood Falls and Parkerville sheets, I determined that the " Fort Riley limestone " is the same lime- 

 stone as the one worked in the quarries near Florence in the Cottonwood vallej'. This limestone 

 may be followed, especially on the south side, for some distance along the bluft's of the Cottonwood 

 river.— C. S. P., November 17, 1894. 



