Book contents
- Frontmatter
- Contents
- Contributors
- Preface
- PART I The Chronostratigraphy of the Uintan through Arikareean
- 1 Magnetic stratigraphy and biostratigraphy of the middle Eocene Uinta Formation, Uinta Basin, Utah
- 2 Biostratigraphy and magnetostratigraphy of the Bridgerian-Uintan Washakie Formation, Washakie Basin, Wyoming
- 3 Magnetic stratigraphy, sedimentology, and mammalian faunas of the early Uintan Washakie Formation, Sand Wash Basin, northwestern Colorado
- 4 Theoretical biochronology, the Bridgerian-Uintan boundary and the “Shoshonian Subage” of the Uintan
- 5 Middle Eocene mammalian faunas of San Diego County, California
- 6 Stratigraphy and paleomagnetism of the middle Eocene Friars Formation and Poway Group, southwestern San Diego County, California
- 7 Magnetostratigraphy of the upper middle Eocene Coldwater Sandstone, central Ventura County, California
- 8 Stratigraphy and paleomagnetism of the upper middle Eocene to lower Miocene (Uintan to Arikareean) Sespe Formation, Ventura County, California
- 9 Magnetostratigraphy of the Eocene-Oligocene transition in Trans-Pecos Texas
- 10 Magnetic stratigraphy of the Duchesnean part of the Galisteo Formation, New Mexico
- 11 Stratigraphy and vertebrate faunas of the Bridgerian-Duchesnean Clarno Formation, north-central Oregon
- 12 Eocene-Oligocene faunas of the Cypress Hills Formation, Saskatchewan
- 13 Magnetic stratigraphy of the White River Group in the High Plains
- 14 Magnetostratigraphy and biostratigraphy of the Eocene-Oligocene transition, southwestern Montana
- 15 The Whitneyan-Arikareean transition in the High Plains
- PART II Common Vertebrates of the White River Chronofauna
- Summary
- Index
1 - Magnetic stratigraphy and biostratigraphy of the middle Eocene Uinta Formation, Uinta Basin, Utah
Published online by Cambridge University Press: 06 July 2010
- Frontmatter
- Contents
- Contributors
- Preface
- PART I The Chronostratigraphy of the Uintan through Arikareean
- 1 Magnetic stratigraphy and biostratigraphy of the middle Eocene Uinta Formation, Uinta Basin, Utah
- 2 Biostratigraphy and magnetostratigraphy of the Bridgerian-Uintan Washakie Formation, Washakie Basin, Wyoming
- 3 Magnetic stratigraphy, sedimentology, and mammalian faunas of the early Uintan Washakie Formation, Sand Wash Basin, northwestern Colorado
- 4 Theoretical biochronology, the Bridgerian-Uintan boundary and the “Shoshonian Subage” of the Uintan
- 5 Middle Eocene mammalian faunas of San Diego County, California
- 6 Stratigraphy and paleomagnetism of the middle Eocene Friars Formation and Poway Group, southwestern San Diego County, California
- 7 Magnetostratigraphy of the upper middle Eocene Coldwater Sandstone, central Ventura County, California
- 8 Stratigraphy and paleomagnetism of the upper middle Eocene to lower Miocene (Uintan to Arikareean) Sespe Formation, Ventura County, California
- 9 Magnetostratigraphy of the Eocene-Oligocene transition in Trans-Pecos Texas
- 10 Magnetic stratigraphy of the Duchesnean part of the Galisteo Formation, New Mexico
- 11 Stratigraphy and vertebrate faunas of the Bridgerian-Duchesnean Clarno Formation, north-central Oregon
- 12 Eocene-Oligocene faunas of the Cypress Hills Formation, Saskatchewan
- 13 Magnetic stratigraphy of the White River Group in the High Plains
- 14 Magnetostratigraphy and biostratigraphy of the Eocene-Oligocene transition, southwestern Montana
- 15 The Whitneyan-Arikareean transition in the High Plains
- PART II Common Vertebrates of the White River Chronofauna
- Summary
- Index
Summary
ABSTRACT
The Uinta Formation in northeastern Utah was the original basis of the Uintan land mammal “age.” Magnetostratigraphic studies were conducted in four sections in the northeastern, north-central, and northwestern Uinta Basin. The uppermost Evacuation Creek Member of the Green River Shale, and all of unfossiliferous Uinta Formation unit “A,” was of normal polarity. This normal interval probably correlates with Chron C21n (46.3-47.8 Ma), as originally suggested by Prothero and Swisher (1992). Most of Uinta “B” was reversed (= Chron C20r, 43.8-46.3 Ma). A short normal zone spanning upper Uinta “B” and lower Uinta “C” probably correlates with Chron C20n (42.5-43.8 Ma). The upper part of the Uinta “C” and the lowermost portion of the Duchesne River Formation were also reversed (= C19r, 41.4-42.5 Ma), with normal (= C19n, 41.1-41.4 Ma) and reversed (= C18r, 40.0-41.1 Ma) magnetozones in the higher part of the Brennan Basin Member.
Although the original biostratigraphic data for most Uinta Basin collections are very poor, distinctions between the faunas of Uinta “B1,” “B2,” and “C” are possible. Uinta “B1” (the “Metarhinus zone” of Osborn, 1929) spans the interval 45–46 Ma, and is characterized by overlapping ranges of the brontotheres Sthenodectes and Metarhinus, the rhinocerotoids Hyrachyus eximius, Forstercooperia grandis and Triplopus obliquidens, and the agriochoerid oreodont Protoreodon parvus. Uinta “B2” (the “Eobasileus-Dolichorhinus zone” of Osborn, 1929), including White River Pocket, spans the interval 43-45 Ma, and is characterized by the overlapping ranges of the brontotheres Sphenocoelus, Metarhinus, Eotitanotherium, the chalicothere Eomoropus, the horse Epihippus gracilis, the creodont Oxyaenodon, and the artiodactyls Diplobunops, Oromeryx, and Leptotragulus.
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- Publisher: Cambridge University PressPrint publication year: 1996
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