DAVIS. ROCKY MOUNTAIN TERTIARIES. 855 



therefore within what may be called the central area of the basin are 

 "coarse red sandstones, iuterbedded with more or less clays and arenace- 

 ous marls of pinkish and creamy colors" (361), "easily eroded red clay 

 and sandy beds " (361), " thin, reddish, flaggy sandstones . . . underlaid 

 by whitish clays" (364), "sandstones and calcareous shales, with slight 

 seams of lignite and several thin beds of a limestone " (365), "dark-drab 

 and gray gravelly sandstones" (367), " several bird-bones from a coarse, 

 gritty, buff sandstone" (367). Near the border of the basin, "con- 

 glomerates become more and more important, until directly north of the 

 upper canon of Weber river the mountain wall is composed of exces- 

 sively coarse conglomerate between 3,000 and 4,000 feet thick. It is 

 almost structureless, and lines of stratification can rarely be perceived. 

 The blocks of which the conglomerate is chiefly formed range from the 

 size of a pea to masses with a weight of several tons. . . . The rapidity 

 with which these conglomerates grow finer in advancing from the shore 

 along the Uinta is very conspicuous" (369). Sections here exposed in 

 certain canyons "display the graduation of the material from the coarse 

 conglomerate immediately in contact with the older rocks out toward 

 the north, until . . . they have become fine-grained, sandy beds, devoid 

 of pebbles " (370). Near Echo city are presented " 3,800 feet of strata, 

 chiefly of these Indian-red sandstones, containing toward the upper 

 limit gray shale-beds, with occasional sheets of fine conglomerate " 

 (371). "West of Concrete plateau there is an enormous development 

 of red sandstones and clays, with prominent belts of conglomerate, the 

 whole increasing in coarseness of sediment as it approaches the Uinta 

 on the south and the Wahsatch on the west. Here is an area about 

 sixty miles from north to south by fifty miles from east to west, which 

 is essentially a plateau of Vermillion creek beds, in general approxi- 

 mately horizontal, but in the vicinity of the Wahsatch rising to 14° 

 (37'2). "The thickest exposures of the Vermillion creek series are 

 in the immediate vicinity of the Wahsatch . . . where is exposed not less 

 than 4,000 feet. The most characteristic section ... is made up of a 

 heavy, gritty series at the base, . . .characterized by . . . red sandstones 

 and clays. . . . The middle members are of finer material and are more 

 intercalated with clays, while the upper part of the series ... is made 

 up of striped and banded sandstones " (375). "The entire Vermillion 

 creek series . . . was made up of sandstones and intercalated clays, with 

 more or less conglomerates near the old shores of the lake " (380). 



It seems perfectly clear from the context that all this formation was 

 regarded as having been deposited within the lake waters, on the lake 



