THE ALTERNATING SERIES. 1 1 1 



the following beds: first, a series of thinly bedded sandstones and impure 

 limestones, the latter somewhat magnesian, varying in color— pink, white, 

 yellow, and gray; the limestones containing only traces of fossil remains. 

 These have "altogether a thickness of 150 to 200 feet, and pass gradually 

 into (second) a sandstone somewhat argillaceous and calcareous, of a deep 

 red color, but often streaked or variegated with yellow or pink Fre- 

 quently on fracture the sandstone has a somewhat lighter color or is almost 

 white ; and while much of the predominating deep coloration is derived 

 from the oxidation of iron in the rock itself, a considerable portion is also 

 produced through staining by a downward infiltration from the red clay 

 above. It generally shows little or no stratification and is massive, but it 

 weathers in a brecciated or broken manner, with twisted or bent lines of 

 decomposition parallel with the general stratification of the rocks. It has 

 a thickness of 100 to 150 feet, making the entire thickness of the upper 

 or fourth member of the Carboniferous 250 to 350 feet. Detailed and 

 accurate sections of these rocks are given on another page. 



Within the area of the plateau no good exposures of the upper beds 

 were seen, but along its western edge they appear in a few canons that 

 drain westward, especially in those connecting with Beaver Creek. They 

 are also excellently exhibited in Fanny Peak, which is composed of the 

 serrated and broken edges of the red sandstones standing vertically. 



In the southern end of the Hills in the canons of Red Canon and 

 Amphibious Creeks the silicious limestone (3) is overlaid by over 200 feet 

 (estimated) of red and pink sandstones, which are somewhat calcareous and 

 contain occasional beds of limestone. Similar beds at the springs on Minne 

 Katta Creek have a measured thickness of 300 feet. At the latter place a 

 few fragments of crinoid stems Avere found in some of the limestones. 



On the eastern side of the Hills, especially in the canons of Rapid and 

 Box Elder Creeks, where most excellent sections of the entire series are 

 visible, these upper beds were studied with great care. They are there 

 more calcareous than on Amphibious Creek and consist of an alternation of 

 pink and red sandstones and limestones, an accurate measurement of 

 which is given on a subsequent page. On Box Elder Creek a few fossils 

 were found in the limestones about 1 1 5 feet above the base of the alternat- 



