BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 6, pp. 333-342, PL. 17 MARCH 30, 1895 



TEPEE BUTTES 



BY G. K. GILBERT AND F. P. GULLIVER 



(Read before the Society December 27, 1S94) 



CONTENTS Page 



Introduction 833 



Descrii>tion of the cores 333 



Geologic relations 333 



Distribution 334 



General features 335 



The tepee rock 336 



Fossils 337 



Allied phenomena in Canada 338 



Theories for the orij^in of the cores 338 



Concretion theory 338 



Spring theory 339 



Colony theory 839 



Poison theory 340 



Conclusion 340 



The Buttes 340 



Conditions affecting distribution 340 



Conditions affecting form and size 341 



Comparison v.ith buttes of other origin 342 



Acknowledgments 342 



Introduction. 



In the Pierre shales of Colorado are limestone masses of peculiar 

 character. Their height is greater than their width and all dimensions 

 are of a size to be measured by feet or yards. Resisting erosion much 

 better than the shales, they stand above the general surface. Their fallen 

 fragments protect sloping pedestals of shale, and their positions are 

 marked in the landscape hy conical knolls or ])uttes. The formal re- 

 semblance of these buttes to the conical lodges, or te[)ees, of the Sioux 

 and other Indians has led us to call them distinctivel}' tepee buttes. It 

 will be convenient also to call the masses of limestone tepee cores and 

 their material tcpce rock. 



Df:scRiPTiox OF THE Cores. 



OEOLOGI C R EL A TI O XS. 



The Pierre group, as developed in the Arkansas basin outside the 

 Rocky mountains, (.-omprises about o,(J(XJ feet of shales, and they hold 



XLVI I-HuiJ.. Or.01,. Sor. Am., Vol. C, 1894. (333) 



