Planktonic foraminifers of the lower Tertiary Roseburg, Lookingglass, and Flournoy Formations (Umpqua Group), southwest Oregon

Miles, G.A.

doi:10.1130/spe184-p85

Cited by 6 publications

(2 citation statements)

References 5 publications

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“…50-50.5 Ma). The Penutian, however, is time transgressive, ranging from 49 to 55 Ma (e.g., Miles, 1981). Palynostratigraphy of the lower Puget (Newman, 1981) suggests that this section is no older than 49 Ma.…”

Section: Low-altitude Assemblagesmentioning

confidence: 99%

Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America

Wolfe

Forest

Molnár

1998

Geological Society of America Bulletin

237

182

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Comparisons of the physiognomy of leaves from modern vegetation of known climates with that of Eocene and Oligocene fossil leaf assemblages from middle latitudes of western North America indicate paleoaltitudes comparable or higher than those at present. Using canonical correspondence analysis, a multivariate statistical approach that includes nonlinear relationships between characters and environmental parameters, we relate leaf physiognomy of fossil samples to modern vegetation of known environmental parameters, including moist enthalpy of the atmosphere, a thermodynamically conserved quantity of the atmosphere that varies with altitude. By estimating enthalpy values for both lowland leaf assemblages and coeval interior leaf assemblages, altitudes for the interior assemblages can be estimated to ±890 m. In northeastern Washington and southern British Columbia, the high Eocene altitudes indicate subsidence, or collapse, of an area undergoing crustal extension and may reflect an immediately preceding period of uplift that triggered the extension. Similarly, other areas that have undergone Cenozoic crustal extension appear to have been at least as high as they are at present. Three sites from the Rocky Mountains also indicate elevations at least as high as at present, and therefore suggest subsidence, either resulting from cooling of a hot upper mantle or erosion and isostatic compensation of surrounding terrain. High altitudes during Eocene and Oligocene time in western North America appear to have been normal, even in areas such as the Green River basin, and therefore cast doubt on the commonly inferred late Cenozoic uplift of that region.

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Section: Low-altitude Assemblagesmentioning

confidence: 99%

Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America

Wolfe

Forest

Molnár

1998

Geological Society of America Bulletin

237

182

View full text Add to dashboard Cite

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“…Planktonic foraminifers are usually more prevalent in early Tertiary strata than in other parts of the Tertiary. Studies by Miles (1977), McKeel (1972), and McKeel and Lipps (1975 are important contributions to information on these foraminifers. Taxa listed below typically occur in, although are not necessarily restricted to, faunas that are assigned to a pre-Ulatisian age:…”

Section: Pre-ulatisian Assemblagesmentioning

confidence: 99%

Pacific Northwest Tertiary benthic foraminiferal biostratigraphic framework—An overview

Rau

1981

Pacific Northwest Cenozoic Biostratigraphy

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A new pseudolivine gastropod genus from the lower Tertiary of North America

Squires

1989

J. Paleontol.

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A new genus, Calorebama, is proposed for a clade of pseudolivine gastropods (family Buccinidae) that has its earliest species in the lower Paleocene (Danian) of Alabama, its next earliest species in the upper Paleocene (Thanetian) of Alabama, and its subsequent species in the Eocene of California, Oregon, and Washington. Calorebama is characterized by an inflated biconical shape, a biangulate body whorl usually with strong nodes on the shoulder, and fine to medium spiral ribbing that is coarser anterior to the medial pseudolivine groove.Previously, these pseudolivines now being placed in Calorebama were assigned to the genus Pseudoliva. Study of the literature and every available museum specimen showed Calorebama to have five species and two subspecies, all of which have biostratigraphic integrity.Calorebama unicarinata (Aldrich) is the earliest species, and it, along with C. tuberculifera (Conrad), are the only known Gulf Coast species. Calorebama dilleri dilleri (Dickerson) is the earliest representative of the genus on the West Coast of North America, and it arrived during the early Eocene (Ypresian). Probable geographic isolation of C. dilleri dilleri in central and southern California resulted in lineage splitting and the appearance of C. dilleri lineata (Gabb), which phyletically evolved into C. inornata (Dickerson). Calorebama dilleri dilleri persisted in northern California and phyletically evolved into C. dilleri kirbyi (Clark), which similarly evolved into C. volutaeformis (Gabb).Calorebama inornata and C. volutaeformis, the youngest species of the genus, became widely distributed along the West Coast of North America before becoming extinct by the end of the earliest late Eocene.

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Planktonic foraminifers of the lower Tertiary Roseburg, Lookingglass, and Flournoy Formations (Umpqua Group), southwest Oregon

Cited by 6 publications

References 5 publications

Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America

Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America

Pacific Northwest Tertiary benthic foraminiferal biostratigraphic framework—An overview

A new pseudolivine gastropod genus from the lower Tertiary of North America

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