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Oreodont Tuff

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Journal Article
Journal: GSA Bulletin
Published: 01 April 1990
GSA Bulletin (1990) 102 (4): 459–477.
... beds on the east. Facies distribution and sparse paleocurrent data suggest that the conglomeratic sequence was derived from sources to the south and southwest and that the finergrained beds were deposited in the more distal part of the basin to the east and northeast. The Oreodont Tuff, situated about...
Journal Article
Journal: GSA Bulletin
Published: 01 April 1990
GSA Bulletin (1990) 102 (4): 478–493.
... conventional 40 K- 40 Ar and 40 Ar/ 39 Ar single-crystal laser-fusion methods. Multiple analyses on minerals from 5 superposed tuffs yielded the following mean 40 K- 40 Ar ages: Rak Tuff at 16.3 ± 0.3 m.y., Oreodont Tuff at 15.9 ± 0.2 m.y., Dated Tuff at 14.8 ± 0.2 m.y., Hemicyon Tuff at 14.0 ± 0.1 m.y...
Series: GSA Special Papers
Published: 01 January 1990
DOI: 10.1130/SPE244-p69
... that blanketed both valleys and interchannel reaches. Fluvial sediments within the valleys include much spatially dispersed mammal bone that had been scavenged and subaerially weathered prior to burial. Waterholes, situated in or adjacent to the valleys, filled with tuff and carbonate mud containing freshwater...
Journal Article
Journal: AAPG Bulletin
Published: 01 August 1956
AAPG Bulletin (1956) 40 (8): 1899–1914.
... pyroclastic conglomerate, tuff, sandstone, and claystone of middle Miocene age, unconformably overlying all older rocks and unconformably overlain by rocks of middle Pliocene age. The name Teewinot formation is used for 5,000 feet or more of white limestone, pumicite, tuff, claystone, diatomite...
FIGURES
Journal Article
Published: 01 July 2010
Journal of the Geological Society (2010) 167 (4): 817–825.
... is locally defined by the Rak Tuff (16.3 ± 0.3 Ma). The concretions that bear ostracodes with soft tissues occur 62.5 m above the Rak Tuff, and approximately halfway between it and the Oreodont Tuff (15.8 ± 0.3 Ma). The silicified ostracodes therefore probably date to the latest Burdigalian, although...
FIGURES
Series: GSA Field Guide
Published: 01 January 2014
DOI: 10.1130/2014.0036(01)
EISBN: 9780813756363
..., Nebraska. The ash originated from the Bruneau-Jarbidge caldera in southwest Idaho, some 1600 km away, and it is geochemically matched with the Ibex Hollow tuff (11.93 Ma). Ashfall is a critical Clarendonian North American Land Mammal Age locality. More than 20 taxa—predominantly medium- and large-sized...
FIGURES | View All (15)
Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 01 June 2014
Lithosphere (2014) 6 (3): 157–176.
... Formation, which was derived from granitic rocks in the Hayfield Mountains to the north, sits unconformably on the Eocene Maniobra Formation. The northern basal conglomerate is overlain by more than 300 m of mostly red sandstone, conglomerate, mudrock and tuff. The basal conglomerate thins and fines...
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Image
Figure 2. Schematic stratigraphic sections. All age uncertainties are shown...
Published: 01 March 2005
because it is an important marker bed for basinwide correlation. The underscored ages for the Oreodont and Valley View Tuffs are considered the most robust because they are 40 Ar/ 39 Ar ages of sanidines. (B) Carnivore Canyon section and preferred age of the Hemicyon Tuff ( MacFadden et al., 1990 ). (C
Journal Article
Journal: GSA Bulletin
Published: 01 March 2005
GSA Bulletin (2005) 117 (3-4): 276–287.
... because it is an important marker bed for basinwide correlation. The underscored ages for the Oreodont and Valley View Tuffs are considered the most robust because they are 40 Ar/ 39 Ar ages of sanidines. (B) Carnivore Canyon section and preferred age of the Hemicyon Tuff ( MacFadden et al., 1990 ). (C...
FIGURES | View All (7)
Journal Article
Published: 01 June 2021
Rocky Mountain Geology (2021) 56 (1): 37–50.
... located between the southern Mosquito and Front ranges in central Colorado ( McIntosh and Chapin, 2004 ). The understudied Antero Formation is composed of widely scattered outcrops of algal limestone, tuffaceous sandstone, conglomerate, and shale alternating with layers of tuff derived from the Mount...
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Journal Article
Published: 01 May 2009
Journal of Paleontology (2009) 83 (3): 489–492.
... Nebraska and South Dakota, MacFadden, 2001 ). This is similar to the biostratigraphic assessment of the age of the Gaillard Cut L.F. for all of the known taxa of mammals except for the oreodont Merycochoerus matthewi , the latter of which potentially indicates and older (late Arikareean) age, and may...
FIGURES
Series: GSA Field Guide
Published: 01 January 2009
DOI: 10.1130/2009.fld015(07)
EISBN: 9780813756158
... against older lahar deposits, and the formation is characterized by laterally discontinuous and lithologically varied rocks, including lava flows, pumicious tuff, laharic breccia and conglomerate and lacustrine mudstone. Approximately 40 million years ago, the Clarno volcanic arc became inactive after...
Journal Article
Journal: Geology
Published: 03 January 2020
Geology (2020) 48 (3): 273–277.
....2015.06.057 . Scott , J. , and Bowring , S.A. , 2000 , High precision U/Pb geochronology of Oligocene tuffs from the White River Formation, Douglas, Wyoming [abstract] : Society of Vertebrate Paleontology, v. 20, Supplement, Abstracts of Papers of the Sixtieth Annual Meeting , p. 69A...
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Journal Article
Journal: Paleobiology
Published: 01 January 2004
Paleobiology (2004) 30 (4): 561–588.
... ungulates. Unexpectedly large variance in tooth dimensions of some taxa ( Fig. 4 ) can be interpreted as due to canine sexual dimorphism and molar polymorphism. Large variance within canines in black bears ( Ursus americanus ) and oreodonts ( Eporeodon occidentalis , Merycochoerus superbus...
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Journal Article
Journal: PALAIOS
Published: 30 April 2020
PALAIOS (2020) 35 (4): 175–190.
... abundance include oreodonts (three species), tayassuids (three species), palaeomerycids (two species), proboscideans (two genera), and rhinoceros (one species). The carnivore fauna is dominated by canids, with 13 species recognized in the formation. Other important carnivores are amphicyonids (four species...
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Journal Article
Journal: Geology
Published: 01 April 2004
Geology (2004) 32 (4): 297–300.
... Oligocene paleosols was 25 ± 8 cm (one standard deviation, after burial compaction of ∼80%), and the average amplitude within the Quaternary record near Kahlotus, Washington, was 21 ± 5 cm (uncompacted). Among 358 Oligocene paleosols observed near Kimberly, Oregon, between the 28.7 Ma John Day Tuff H...
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Series: GSA Special Papers
Published: 01 January 2008
DOI: 10.1130/2008.2435(05)
... . All the sites taken in this study (Table 1) were reversed in polarity, consistent with results from the Antero tuff reported by McIntosh and Chapin (2004 , Table 3, p. 227). As shown by Figure 2A , there was little overprinting of the magnetic signal, and only a single component of remanence...
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Series: GSA Special Papers
Published: 01 January 2008
DOI: 10.1130/2008.2435(08)
..., fragmentary fossils of a merycoidodontid oreodont ( MacGinitie, 1953 ), another small artiodactyl (? Leptomeryx ), brontothere tooth enamel fragments, and a Mesohippus jaw. Additionally, a vertebral fragment of a large brontothere and other miscellaneous bone fragments were recovered from the arkosic...
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Journal Article
Published: 01 March 2010
Journal of Paleontology (2010) 84 (2): 288–298.
... et al., 2008 ; Strong et al., 2008 ). Peccary fossils have so far been found only in the lower two-thirds of the Cucaracha Formation, below a welded tuff marker bed that correlates to the 100–105 m zone in our composite stratigraphic section ( Fig. 2 ). Underlying the Culebra Formation...
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Series: GSA Field Guides
Published: 04 September 2019
DOI: 10.1130/2019.0055(09)
EISBN: 9780813756554
... light-colored and well-stratified volcaniclastic lacustrine and fluvial strata of the Upper Oligocene to Lower Miocene oreodont-bearing Chalk Canyon formation ( Lander and Lindsay, 2011 ). The Chalk Canyon formation (informal name) and stratigraphically higher deposits (e.g., basaltic lava flows...
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