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Show 166 GEOLOGY OF THE HIGH PLATEAUS. pied by the beds which Powell has called Bitter Creek, lying upon the southern slopes of the Uinta Mountains. This determination does not rest upon identical fossils, for the two localities do not yield the same species; but upon the most decisive of all evidence, the known continuity of the beds. Between the Bitter Creek beds of the Uintas and those here assigned to the same epoch is an unbroken exposure along which the identity can be traced. The fossils found are Viviparus trocMformis (White), Hydrobia Utahensis (White), several undetermined species of Physa, Planorbis, and Limncea, and some plant remains. The total thickness of this series is about 2,200 feet, but varies a little in different sections. The following section was measured by Mr. E. E. Howell at the southwest angle of the plateau, and very well represents the general character of the whole formation. Feet. \a) Shaly limestone, containing Physa, Limncea, and Planorbis................ 250 (&) Gray and cream-colored limestone with Physa............................. 400 (c) Pale pink arenaceous limestone.......................................... 250 (d) Gray limestone, shaly and green at base, with Hydrobia, Physa, and Vivi- parus.......................................__......... .......... 350 (e) Cream-colored calcareous sandstone..................................... 350 (/) Gray limestone with Viviparus.......................................... 600 2,200 This series has been designated No. 3 in the various sections, and though it has not been connected with the Lower Tertiary beds in the southernmost of the High Plateaus its identity is probable in a high degree, so much so that it is taken for granted. The beds which overlie it are separated by a distinct plane of demarkation in the principal sections and by lithological characters. They are much more variable in their constitution and in their bedding. Its members are designated as series No. 2, and the following sections by Mr. Howell illustrate their characters: Series No. 2 (Tertiary), section No. 7 A: Feet. (a) Oream to gray shaly limestone, with fishes, Planorbis, Viviparus, and indistinct plant remains....................................................... 350 (b) Greenish calcareous shale..............................._____,......... 750 (c) Pale red, purple, and slate-colored marls, with occasional bands of calcareosu gray sandstone, fish-scales being found in some of the more calcareous members..............,........................................... 400 1,500 |
