MlRRI \M.] 



John Day Basin. 



29 1 



and not rarely the identification of some of these is more or less 

 doubtful, but as nearly as can be made out they should be of the 

 same age as Bridge Creek." 



It will be noticed that the determination of the plant remains, 

 both as regards tlie flora as a whole and with respect to its sub- 

 divisions, agrees with the statement relating to stratigraphic suc- 

 cession. The Bridge Creek beds, with the few specimens from the 

 shales one and one-half miles east of Clarno's Ferry, are considered 

 upper Eocene, while those from Cherry Creek are held to be an 

 earlier facies. 



JOHN DAY SERIES. 



Resting upon the Clarno formation and extending over the 

 greater portion of the John Day basin, is a thick series of sedi- 

 ments which Marsh* called the deposits of the "John Day Lake." 

 It has generally been referred to in geological and palajontological 

 literature as the John Day beds. Kingf correlates this series with 

 his Truckee beds as a part of the deposit of his Pah Ute Lake. In 

 the statement regarding this correlation, King has, however, recog- 

 nized Marsh's name, so that, if .1 correlation is attempted, Pah Ute 

 should be displaced by John Day. 



General Characters. — Nearly the whole of the John Day 

 formation consists of ashy or tufaceous materials. Only toward 

 the top of the section do we find typical products of ero- 

 sion. At Haystack, Spray, and in the lower end of Turtle Cove, 

 good exposures show the highest portion of the series to be com- 

 posed of one or two hundred feet of hard, blocky tuff, below which 

 is about the same thickness of sand and gravel. The gravels are 

 in some places quite coarse, containing pebbles four or five inches 

 in diameter. The sands sometimes show cross-bedding. Included 

 in these deposits are worn fragments of bones and teeth, which 

 probably represent forms similar to those in the beds immediately 

 below. 



Rhyolite flows are found toward the lower part of the Middle 

 John Day at Bridge Creek, near the top of this division in Turtle 



*C C. Marsh. Am. Jour. Sc., 1875, 2d Ser., Vol. 9, p. 52. 

 + C. King. Survey 40th Parallel, Vol. 1, p. 458. 



