EAST CANON CEEEK. 381 



miles south of Weber Station, that the canon narrows very much. Around 

 Morgan Valley, the Vermillion Creek series consists almost entirely of red- 

 dish-gray and brick-red sandstones, having a gentle dip toward East Canon 

 Creek from the west, and again toward it from the east. In the upper part, 

 these beds consist of heavy conglomerates, containing pebbles of limestone, 

 quartzite, and Archaean schist, which seem to be quite horizontal. There 

 appears to be no unconformity, however, throughout the series, but a slight 

 undulation, which reaches its maximum dip west of Morgan Valley. 



Near the little village of Richville, about 4 miles south of Weber 

 Station, the valley-bottom is occupied by a narrow area of gray trachyte, 

 consisting of sanidin and biotite, in a very rough, gray, crystalline ground- 

 mass. This trachyte is little more than a tufa, and seems to have been 

 deposited for the most part under water ; it represents probably an eruption 

 that has taken place after the greater part of the present topography had 

 been marked out by erosion, and when Morgan Valley was occupied by a 

 lake. Other evidence that Morgan Valley was a Pliocene lake is to be found 

 in the friable white sand beds and argillaceous strata which occur on the 

 immediate foot-hills on either side of the valley, outcropping indistinctly 

 through the Quaternary. Their range is uncertain and their occurrence 

 obscure, but they have been laid down on the map, since there is enough to 

 warrant the belief that Morgan Valley, like Ogden Valley, was well cov- 

 ered with lacustrine Pliocene, which must have rested unconformably in a 

 basin eroded out of the Eocene beds. Up East Canon, above the trachyte 

 outcrop, there is an exposure of olive-gray and cream-colored sandstones, 

 having a considerable dip southeast or up the canon, and apparently un- 

 conformable with the Tertiary beds which appear on the flanks of the hills 

 higher up ; these beds probably represent the edges of upturned Cretaceous 

 strata, but, as they contain no fossils, their position is so uncertain that they 

 are not indicated on the map. About half-way between Morgan Valley 

 and Parley's Park, a broad open valley extends from East Canon Creek 

 in a northeasterly direction, quite through to the Weber Valley. The 

 western half of this valley is undoubtedly formed of the Vermillion Creek 

 Eocene, whose beds rise to the north and south of it in high mountains, 



