BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



VOL. 13, PP. 267-292, PL. 44 AUGUST 6, 1902 



DEVONIAN INTERVAL IN MISSOURI 



BY CHARLES R. KEYES 



(Presented before the Society January 2,. 1902) 



CONTENTS 



Page 



Introductory 268 



Devonian problems presented 269 



General geological cross-section of the region 269 



Main features * 269 



Base of the Carboniferous 270 



Superior limit of the Silurian 270 



Lower Paleozoic formations 271 



Thickness of the Interval deposits , 271 



Formations represented by the Interval 27 L 



Iowa terranes 271 



North Missouri beds 272 



Hiatus of west-central Missouri 273 



Devono-Carboniferous of southwest Missouri 273 



Arkansas section 274 



Nature of Kinderhook formation and Chouteau fauna 274 



General statement 274 



Owen's section 275 



Hall's determinations 275 



Swallow's views 276 



Meek and Worthen's Kinderhook formation 277 



Chouteau stage 278 



Faunal relations of the Interval deposits 279 



Devonian faunas of the north .......' 279 



Chemung formation in eastern Iowa. 279 



Dual nature of original Kinderhook faunas 282 



Affinities of the lower Kinderhook fauna 284 



Role of certain faunal elements 286 



Interval faunas of the Ozark region . 287 



Character of the transition zone 288 



Peculiarities of the original Kinderhook 289 



Evidences of unconformities 290 



Comparative values of correlative methods 291 



Recapitulation 292 



XL— Bull. Geol. Soc. Am., Vol. 13, 1901 (267) 



