Correlation and ages of Cenozoic chronostratigraphic units in Oregon and Washington

Armentrout, John M.

doi:10.1130/spe184-p137

Cited by 66 publications

(44 citation statements)

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“…Sandstone and siltstone of the Astoria Formation un-conformably overlie the Nye Mudstone (Snavely et al, 1980 (Barnes, 1987a;Armentrout, 1981) and has been assigned to the Newportian Molluscan Stage (Addicott, 1976;Armentrout, 1981), which has been correlated with the Saucesian Foraminiferal Stage (Addicott, 1976;Armenurout et al, 1983, chart). Two other fossil pinnipeds have been recovered from the Astoria Formation.…”

Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

“…Marine siltsone and fine-grained sandstone of the Nye Mudstone overlie by gradational contact the Yaquina Formation (Snavely et al, 1980). The Nye Mudstone is late Oligocene to early Miocene in age and has been assigned to the Pillarian Molluscan Stage (Addicott, 1976;Armentrout, 1981), which has been correlated with the Saucesian Foraminiferal Stage (Armentrout et al, 1983, chart). The Nye Mudstone can be correlated with the middle and late Arikareean and early Hemingfordian, approximately 25-18 Ma (Figure 2).…”

Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

“…This formation has been assigned to the Juanian Molluscan Stage (Addicott, 1976;Armentrout, 1981) and Zemorrian Foraminiferal Stage (Armentrout et al, 1983, chart). The Yaquina Formation has produced, in addition to pinnipeds, desmostylians (Domning et al, 1986), cetaceans (Emlong, 1966;Barnes, 1987b), and a single land mammal, an anthracothere.…”

Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

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New Enaliarctos* (Pinnipedimorpha) from the Oligocene and Miocene of Oregon and the Role of "Enaliarctids" in Pinniped Phylogeny

Berta¹

1991

Smithsonian Contributions to Paleobiology

117

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.-Three new species of the pinnipedimorph Enaliarctos* are described from the marine late Oligocene and early Miocene (Arikareean and Hemingfordian or early Barstovian correlatives) of coastal Oregon. Enaliarctos tedfordl, new species, is based on a partial cranium from the late Oligocene Yaquina Fonnation. A related new species, Enaliarctos emlongi, is founded on a nearly complete cranium, jaws, and associated skeletal elements from the late Oligocene to early Miocene Nye Mudstone. A third new species, Enaliarctos barnesi, is based on a partial cranium and jaws from late Oligocene or early Miocene rocks near the contact between the Yaquina Formation and the Nye Mudstone. Another skull, from the Nye Mudstone, is referred to a previously described species, Enaliarctos mitchelli Barnes, 1979. Three of these species, E. mitchelli, E. emlongi, and E. tedfordl form a monophyletic clade, united by reduced cheek teeth cingula and short metacone of the upper camassial. The major trend observed in Enaliarctos over 10 million years of history is an intermediate stage in the transformation to homodonty evidenced by premolarization of the upper camassial and molars and reduction and simplification of cusps on the lower camassial.Cladistic analysis of 52 cranial and dental characters suggests the following phylogenetic hypotheses: (1) the subfamily "Enaliarctinae" (= "Enaliarctidae") is paraphyletic, (2) monophyly of the genus Enaliarctos* is questioned although the status of this taxon as sister taxon to other pinnipeds is affirmed, (3) other "enaliarctid" pinnipeds, Pteronarctos and Plnnarctidlon, are assigned to less inclusive pinniped clades {Pteronarctos -I-all other pinnipeds and Pinnarctidion + Desmatophoca, Allodesmus, and the Phocidae).OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The trilobite Phacops rana Green.

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Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

Section: Location Stratigraphy and Correlationmentioning

confidence: 99%

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New Enaliarctos* (Pinnipedimorpha) from the Oligocene and Miocene of Oregon and the Role of "Enaliarctids" in Pinniped Phylogeny

Berta¹

1991

Smithsonian Contributions to Paleobiology

117

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“…Currently some workers are placing essentially all of the Narizian Stage in the middle Eocene (Armentrout, 1981). In order that conformity be maintained with past usage we have chosen to place the stage in the upper Eocene.…”

Section: Lower and Middle Eocene Rocks Penutian (?) And Ulatisian Stmentioning

confidence: 99%

Foraminiferal biostratigraphy and correlations in the Gulf of Alaska Tertiary Province

Rau¹,

Plafker²,

Winkler³

1983

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INTRODUCTIONAs part of ongoing research by the U.S. Geological Survey on the geology and resource potential of the Gulf of Alaska Tertiary Province, a vast amount of data has been accumulated over the past 25 years on the lithology and paleontology of bedded rocks in the province. This report brings together available information on the occurrence, age, and paleoecological significance of benthonic foraminifers and presents correlations based on these data from 16 measured stratigraphic sections and 12 exploratory wells. Relatively few reports employing modern taxonomic methods developed during the past 40 years have been published on foraminiferal

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“…The oldest possible age (47.1 Ma) according to these determinations for the rocks referable to the Franklinian stage ( fig. 2) would place the base of the Puget Group in the early middle Eocene subepoch or the early Lutetian age using the scales of Armentrout (1981), others (1978, 1985), Haq and others (1987), and Cande and Kent (1992). Although the youngest radiometric age reported as acceptable by Turner and others (1983) is 41.2±1.8 Ma, this date was determined on the basis of ash partings approximately 1,100 m below the top of the type section.…”

Section: Stratigraphy Of the Puget Groupmentioning

confidence: 99%

Paleoecological and floristic heterogeneity in the plant-fossil record; an analysis based on the Eocene of Washington

Burnham¹

1994

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Correlation and ages of Cenozoic chronostratigraphic units in Oregon and Washington

Cited by 66 publications

References 0 publications

New Enaliarctos* (Pinnipedimorpha) from the Oligocene and Miocene of Oregon and the Role of "Enaliarctids" in Pinniped Phylogeny

New Enaliarctos* (Pinnipedimorpha) from the Oligocene and Miocene of Oregon and the Role of "Enaliarctids" in Pinniped Phylogeny

Foraminiferal biostratigraphy and correlations in the Gulf of Alaska Tertiary Province

Paleoecological and floristic heterogeneity in the plant-fossil record; an analysis based on the Eocene of Washington

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