| Description |
The Confusion Range lies in the western part of Millard and Juab Counties, west- central Utah. It i s bounded on the east and west by the White and the Snake Valleys, respectively. The range is 50 miles long from north to south and 7 to 10 miles wide. The stratigraphic section in the Confusion Range has been divided according to two schemes of stratigraphic nomenclature;one was suggested by Campbell (1951) and the other was proposed by Hose and Repenning (1959). According to the stratigraphic scheme proposed by Hose and Repenning, Upper Mississippian to Lower Triassic rocks are divided into six formations of which the Ely Limestone of Late Mississippian, Early and Middle Pennsylvanian, and Permian age i s the only formation related to the present study. A shale bed 18 - feet-thick, occurs 521 feet above the base of the Ely Formation. This shale bed contains the microfossils which are the subject matter of this report. The shale bed is overlain by a prominent limestone bed that contains the corals Crataniophyllum (Barbouria sp. of Hose and Repenning, 1959) which according to Hose and Repenning is 540 feet above the base of the Ely Formation. Forty species of Ostracoda, of which one is possibly new, belonging to 14 familie s and 23 genera, and 8 species of Foraminifera belonging to 4 families and 8 genera, and one species of Annelida were identified from the shale bed. The shale bed is characterized by the following ostracode genera: Bairdia, Hollinella, Healdia, Seminolites, Kirkbya, Ellipsella, Ectodemites and Glyptopleura. The genus Bairdia is represented by 5 species, Holinella by 4 species, the genera Healdia, Seminolites, and Kirkbya each is represented by 3 species, Ellipsella, Ectodemites, and Glyptopleura each is represented by one species . The ostracode species Hollinelladentata, Hollinella oklahomaensis, Seminoliteselon gatus, Kirkbya canyonensis, and Monoceratina ventrale are among the most characteristic guide fossils of the Pennsylvanian. The stratigraphic distribution of speciesis from Upper Mississippia t o Permian. The overlap of ranges of species suggests ageneral Pennsylvanian age and possibly Middle Pennsylvanian. The microfaunal assemblage from the shalebed suggestsa littoral to shallow marine environment and was benthonic. |
