826 INDEX TO THE STEATIGKAPHY OF NOETH AMERICA. 



Astoria in this manner is regarded as objectionable, the name Empire beds might be taken for 

 the sandstones. 



DalP^^ has made an elaborate report on the fauna, with a discussion of the 

 stratigraphy and the history of investigation of the Empire formation, particularly 

 at Astoria. 



L 10. CASCADE RANGE AND YAKIMA VALLEY, WASHINGTON. 



The Miocene of the Cascade Range and Yakima Valley includes both sedi- 

 mentary and igneous rocks, but the sediments consist largely of volcanic material. 

 In order of age from older to younger the formations are the Taneum andesite, 

 Yakima basalt, Guye formation (probably contemporaneous with the basalts), 

 Keechelus andesitic series and EUensburg formation. The following notes are 

 condensed from the accounts by George Otis Smith: "^' ''^^ 



The Guye formation consists of dark shale and gray sandstone, with some chert and lime- 

 stone. It is interbedded with basalts and rhyolites. The formation is represented in a very 

 small area near Snoqualmie Pass, in the Cascade Range, where it is sharply folded and has been 

 intruded by granodiorite. The black shale contains Pladanus dissecta Lesq., Acer sequidentatum 

 Lesq., Ficus n. sp. cf. F. artocarpoides Lesq., and Cinnamomum n. sp., which are assigned by 

 Knowlton to the Miocene. 



The EUensburg formation occurs extensively in the Yakima Valley. It is composed largely 

 of volcanic sediments, occasionally but rarely containing pebbles of the underlying basalt. 

 The greater part of the conglomerate bed is composed of pebbles of light-gray and purple horn- 

 blende andesite and of white pumice of the same composition, while the sandstones and shales 

 consist of finely comminuted andesitic material. The composition of the conglomerate beds 

 and the prevalence of stream bedding indicate that the formation is of fluviatUe rather than 

 lacustrine origin. The original thickness can not be stated. Individual sections show 1,200 

 to 1,600 feet in localities where it is evident that the upper part has been removed. The EUens- 

 burg formation carries a flora in which 15 specimens have been identified. Of these 12 or 13 

 are reported by Knowlton as occurring also in the MascaU beds of the John Day Basin, which 

 are regarded as being upper Miocene. 



L 10-11. JOHN DAY BASIN, OREGON, AND COLTXMBIA PLATEAU. 



Merriam ^^"^ describes the strata of the John Day Basin as foUows: 



Resting upon the Clarno formation and extending over the greater portion of the John 

 Day Basin is a thick series of sediments which Marsh" caUed the deposits of the "John Day 

 Lake." It has generally been referred to in geological and paleontological literature as the 

 John Day beds. King ^ 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, recognized 

 Marsh's name, so that, if a correlation is attempted, Pah Ute should be displaced by John Day. 



Nearly the whole of the John Day formation consists of ashy or tuffaceous materials. Only 

 toward the top of the section do we find typical products of erosion. At Haystack, Spray, 

 and in the lower end of Turtle Cove, good exposures show the highest portion of the series to be 

 composed of 100 or 200 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 4 or 5 inches 

 in diameter. The sands sometimes show cross-bedding. Included in these deposits are worn 



a Marsh, 0. C, Am. Jour. Sci., 2d ser., vol. 9, 1875, p. 52. 

 * King, Clarence, U. S. Geol. Expl. 40tli Par., vol. 1, p. 458. 



