AND MANHATTAN STONK. 87 



building stone. The layers vary from about 6 inches to 1 foot in thick- 

 ness. This is probably number 3 of Professor Kroadliead's jNlanhattan 

 section, wliicli he described as a ''rather uniforndy fine-grained lime- 

 stone " o2 feet in thickness,'^ and it is also ^leek and Hayden's bed 26, a 

 light gray, argillaceous limestone showing on weathered surfaces a some- 

 what laminated structure ; contains large spines oi Archcwcldaris,'f exiposed 

 near Ogden Ferry and Manhattan, and 9 feet in thickness. Professor 

 Swallow stated that these three beds, numbers 82 to 84, " are sometimes 

 represented by a bluish gray and buff, porous magnesian limestone," 

 which is exposed on the Cottonwood. This stratum is well shown on 

 the north side of the Cottonwood river east of Strong City and S-l miles 

 west of the city or on the soutli side of the river toward Elmdale. In a 

 paper by Professor Erasmus Haworth and Mr M. Z. Kirk on the Cotton- 

 wood River section this limestone stratum was called number 12 of their 

 section.;]: 



Above the thin limestones are shales and marls, with thin limestone 

 layers, which Swallow described as '* blue, brown, purple and green " in 

 color, 31 feet in thickness, while Meek and liayden assign a thickness of 

 about 36 feet to this bed. 



THE MANHATTAN STONE. 



Its Thickness and general Characteristics. — Capping the shales just re- 

 ferred to is a massive limestone stratum, number 5 of my section, the 

 base of which Professor Swallow gave as 37 feet above the " dry bone '' 

 or irregular limestone, ]Meek and Hay den as 45 feet, and tlie writer about 

 40 feet on mount Prospect. This stratum is a massive yellowish to light 

 gray limestone, 5 feet thick, containing a considerable amount of chert 

 and in the upper part large numbers of Ficsnlina. culindrica, Fischer, and 

 is known as the Manhattan stone, being the most important economic as 

 well as stratigrai)hic horizon in the Manhattan section. The rock, which 

 is very valualjlefor building and abutment stone, is quarried extensively 

 in the vicinity of Manhattan and forms a well marked stratum, wliich, 

 when taken in connection with the yellowish, fossiliferous shale on top, 

 is the most distinctive and readily traced formation yet seen in the u])per 

 Paleozoic rocks of Kansas. In another unpublished paper I dwell upon 

 this fact in connection with the Cottonwood River section, and here I wish 

 to call attention to the same fact in reference to the Manhattan limestone 

 and shale in order to show that these formations are one and the same. 



Bed 2Jf of Meek and Hayden. — The Manhattan limestone is bed 24 of 

 Meek and Hayden's section, which was described as a " hard, very light 



*Triins. St. Louis Acad. Science, vol. iv, p, 491. 



tProc. Acsul. Niit. Sci., Philu., vol. xi, p. 17. 



t Kansiis Univ. Quarterly, vol. ii, p. ll'J, and pi. iv, fig. :j, 



VI— Bull. Geoi,. Soc. Am., Voi,. G, 1804. 



