LATER TERTIARY (MIOCENE AND PLIOCENE). 



829 



The strata, thus described are tabulated by Merriam and Sinclair ^^^ as follows : 

 StratigrapJiic succession of the Cenozoic formations in the John Day Basin. 



Age. 



Quaternary. 



Pliocene. 



Miocene. 



Later 

 Miocene 



Earl i e r 

 Miocene 



Oligocene. 



ITnconfo'-mity- 



Eocene, 



TJnconf ormi ty 



Cretaceous (marine). 



Section in the John Day Basin. 



Terrace deposits with Equua and Elephas remains. 



Erosion interval (tilting of the Rattlesnake and 

 erosion of John Day Canyon) . 



Rattlesnake formation (tuffs, gravels, ashy soil, 

 and rhyolitic lavas). 



Unconformity (tilting and erosion of the Mascall). 



Mascall formation (tuffs, ashes, and possible grav- 

 els). 



Columbia lava (basalt and interstratified basaltic 

 tuffs). 



Unconformity. Slight folding of the John Day. 

 Interval of erosion. 



John Day 



series. 



Upper John Day (mainly buff-tinted 

 tuffs; sands and gravels near top). 



Middle John Day (drab and bluish- 

 green tuffs). 



Lower John Day (red, white, and green 

 tuffaceous shales). 



Correlatives. 



Later half of Quaternary. 



Sierran (?). 



Not determined. 



Pawnee Creek beds, Colorado; Deep 

 River beds, Montana; Ellensburg for- 

 mation, Washington ."I 



Yakima basalt, Ellensburg quadrangle, 



Washington. 

 Harrison formation. 

 Monroe Creek formation. 

 Rosebud formation. 



Clarno formation (shales, 

 tuffs, andesitic and rhyo- 

 litic lavas). The Clarno 

 has yielded an abundant 

 flora, but no vertebrate 

 remains have yet been 

 found. 



Upper Clarno beds 

 (upper Eocene). 



Lower Clarno beds 

 (lower Eocene). 



Chico formation (sandstones and conglomerates). 



Payette formation, Idaho. 6 

 Manastash formation, Washington.*: 



Basal Chico at Texas Springs and near 

 Horsetown, Cal.; Phoenix beds at '49 

 mines, Oregon.'* 



a Knowlton, F. H., Fossil flora of the John Day Basin: Bull. U. S. Geol. Survey No. 204, 1902, pp. 109-110. 



b Idem, pp. 110-111. 



c Smith, G. 0., Prof. Paper U. S. Geol. Survey No. 19, p. 16. 



<i Stanton, T.AV., note in Bull. Dept. Geology Univ. California, vol. 2, p. 294. 



Osborn ^^^' gives the following resume of the Oregon Tertiary as a whole : 



The known mammal fauna of Oregon, as determined partly by Cope and Wortman and 

 more precisely as to levels by Merriam and Sinclair, is found on five levels, partly separated by 

 volcanic overflows, as follows: 



=upper Miocene 



=middl8 Miocene 



=transition, upper Oligocene, 



lower Miocene 

 =upper Oligocene, second phase 



Rattlesnake 



Mascall 



Upper part of John Day 



=Procamelus zone. 

 =Merychippus zone. 

 =PromerycochQerus zone. 



Middle (fossils numerous) and (?) lower parts of 

 John Day. 



=Di8eratherium zone. 



