The John Day Formation is a series of rock strata exposed in the Picture Gorge district of the John Day River basin and elsewhere in north-central Oregon in the United States. The Picture Gorge exposure lies east of the Blue Mountain uplift, which cuts southwest–northeast through the Horse Heaven mining district northeast of Madras. Aside from the Picture Gorge district, which defines the type, the formation is visible on the surface in two other areas: another exposure is in the Warm Springs district west of the uplift, between it and the Cascade Range, and the third is along the south side of the Ochoco Mountains. All three exposures, consisting mainly of tuffaceous sediments and pyroclastic rock rich in silica, lie unconformably between the older rocks of the Clarno Formation below and Columbia River basalts above.[1]
Stratigraphy
The strata, which vary in age from 39 million years to 18 million years, were formed mainly from ashfalls from volcanoes due to a series of calderas now linked to the Yellowstone hotspot. Some of the major layers within the group exposed in the Picture Gorge district are the Big Basin Formation and Bridge Creek Beds (35 to 32 million years), the Turtle Cove Formation (30 to 28 million years), the Picture Gorge Ignimbrite (28.7 million years), the Kimberly Formation (28 to 25 million years), and the Haystack Formation (25 to 18 million years).[2]
Located in the general vicinity of what became the Cascade Range, the John Day volcanoes emitted large volumes of ash and dust, much of which settled in the John Day basin. The rapid deposition of the ash preserved the remains of plants and animals living in the region. Some of the solidified ash and the fossils they contain are found in the John Day Fossil Beds National Monument. Because ash and other debris fell during varied climatic and volcanic conditions and accumulated from many eruptions extending into the early Miocene (about 20 million years ago), the sediment layers in the fossil beds vary in their chemical composition and color.[3] The lowermost layer contains red ash, such as that exposed in the Painted Hills Unit of the national monument.[4] The layer above it is mainly pea-green clay. On top of the pea-green layer are buff-colored layers.[3]
Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Fossils found in the John Day Formation include a wide variety of plants and more than 100 species of mammals, including dogs, cats, oreodonts, horses, camels, and rodents.[5] Among the notable plant fossils are Metasequoia (Dawn Redwood), a genus thought to have gone extinct worldwide until it was discovered alive in China in the early twentieth century.[6]
Among the paleobiota found in the formation is the Daeodon, whose type species, Daeodon shoshonensis, has been found in the formation.[7]
Panorama of some of the John Day Formation strata exposed in the Painted Hills Unit of the John Day Fossil Beds National Monument
^Woodburne, M.O.; Robinson, P.T. (July 1977). "A New Late Hemingfordian Mammal Fauna from the John Day Formation, Oregon, and its Stratigraphic Implications". Journal of Paleontology. 51 (4). The Society of Economic Paleontologists and Mineralogists: 750–57. JSTOR 1303741.
^"The Geologic Formations of the John Day Basin" (PDF). Oregon Paleo Lands Institute. Retrieved September 23, 2011.
^ a bOrr, pp. 30–31
^Orr, pp. 30–31, 46
^"Geology Fieldnotes". National Park Service. Retrieved July 25, 2011.
^Orr, p. 46
^"John Day Fossil Beds National Monument" (PDF). NPShistory. US Department of the Interior. Retrieved 10 August 2022.
^ a b cSamuels, Joshua X. (2021-08-21). "The first records of Sinclairella (Apatemyidae) from the Pacific Northwest, USA". PaleoBios. 38 (1). doi:10.5070/p9381053299. ISSN 2373-8189. S2CID 236332341.
^ a b c d e f g h i j k l m n o p qWang, Xiaoming; Tedford, Richard H.; Taylor, Beryl E. (1999). "Phylogenetic systematics of the Borophaginae (Carnivora, Canidae). Bulletin of the AMNH ; no. 243". Bulletin of the AMNH (243). hdl:2246/1588.
^ a b cPeterson, Ryan; Samuels, Joshua; Rybcznskyi, Natalia; Ryan, Michael J; Maddin, Hillary C (April 2020). "The earliest mustelid in North America". Zoological Journal of the Linnean Society. 188 (4): 1318–1339.
^ a b cHunt, Robert M. (2009). "Long-legged pursuit carnivorans (Amphicyonidae, Daphoeninae) from the early Miocene of North America". Bulletin of the American Museum of Natural History (318). hdl:2246/5948.
^ a b c d e f g h i j k l mBarrett, Paul Z. (2016-02-09). "Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora)". PeerJ. 4: e1658. doi:10.7717/peerj.1658. ISSN 2167-8359. PMC4756750. PMID 26893959.
^ a b c d e f g h i j k l m n o p q r s t uWang, Xiaoming (1994). "Phylogenetic systematics of the Hesperocyoninae (Carnivora, Canidae)". Bulletin of the AMNH (221): 6–207. hdl:2246/829.
^ a b c d e f g h iTedford, Richard H.; Wang, Xiaoming; Taylor, Beryl E. (2009). Phylogenetic systematics of the North American fossil Caninae (Carnivora, Canidae). (Bulletin of the American Museum of Natural History, no. 325). [New York] : American Museum of Natural History. hdl:2246/5999.
^ a b c d eFamoso, Nicholas A.; Orcutt, John D. (2022). "First occurrences of Palaeogale von Meyer, 1846 in the Pacific Northwest, United States". Geodiversitas. 44 (14): 427–436. doi:10.5252/geodiversitas2022v44a14. S2CID 248235332.
^Hunt, Robert M. (2001). "Small Oligocene amphicyonids from North America (Paradaphoenus, Mammalia, Carnivora)". American Museum Novitates (3331): 1–20. doi:10.1206/0003-0082(2001)330<0001:BAOTLL>2.0.CO;2. hdl:2246/2884. S2CID 83979855.
^ a b cStirton, R. A.; Rensberger, John M. (1964). "Occurrence of the insectivore genus Micropternodus in the John Day formation of Central Oregon". Bulletin of the Southern California Academy of Sciences. 63: 57–80.
^ a bKorth, William W. (1994). "Middle Tertiary Marsupials (Mammalia) from North America". Journal of Paleontology. 68 (2): 376–397. Bibcode:1994JPal...68..376K. doi:10.1017/S0022336000022952. ISSN 0022-3360. JSTOR 1306077. S2CID 130386546.
^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk blKorth, W.; Samuels, J. (2015). "New Rodent Material from the John Day Formation (Arikareean, Middle Oligocene to Early Miocene) of Oregon". Annals of Carnegie Museum. 83 (1): 19–84. doi:10.2992/007.083.0102. S2CID 85780261.
^ a bLucas, Spencer G.; Emry, Robert J.; Foss, Scott E. (1998). "Taxonomy and distribution of Daeodon, an Oligocene-Miocene entelodont (Mammalia: Artiodactyla) from North America". Proceedings of the Biological Society of Washington. 111: 425–435. ISSN 0006-324X.
^ a b c d e f g h i j k l m nSchultz, C. Bertrand (Charles Bertrand); Falkenbach, Charles H.; Laboratories, American Museum of Natural History Frick; Museum, University of Nebraska State (1954). "Desmatochoerinae, a new subfamily of oreodonts. article 2". Bulletin of the AMNH. 105. hdl:2246/424.
^ a b cStilson, Kelsey; Hopkins, Samantha; Davis, Edward Byrd (February 2016). "Osteopathology in Rhinocerotidae from 50 Million Years to the Present". PLOS ONE. 11 (2): e0146221. Bibcode:2016PLoSO..1146221S. doi:10.1371/journal.pone.0146221. PMC4739690. PMID 26840633.
^ a b c dStilson, Kelsey T.; Hopkins, Samantha S. B.; Davis, Edward Byrd (2016-08-02). "Correction: Osteopathology in Rhinocerotidae from 50 Million Years to the Present". PLOS ONE. 11 (8): e0160793. Bibcode:2016PLoSO..1160793S. doi:10.1371/journal.pone.0160793. ISSN 1932-6203. PMC4970714. PMID 27483016.
^ a b cMarriott, Katherine; Prothero, Donald R.; Beatty, Brian (August 2022). "Systematics of the nothokemadine camels (Artiodactyla: Camelidae)". New Mexico Museum of Natural History and Science Bulletin. 89: 295–302.
^ a b c d e f g h iPROTHERO, DONALD R. (2021-05-28). THE SYSTEMATICS OF NORTH AMERICAN PECCARIES (MAMMALIA: ARTIODACTYLA: TAYASSUIDAE). New Mexico Museum of Natural History and Science.
^ a bProthero, D. (2016). "A new genus of hesperhyine peccary (Artiodactyla: Tayassuidae) from the late Oligocene of Oregon". New Mexico Museum of Natural History and Science Bulletin. 74: 205–211. S2CID 6287992.
^ a bCoombs, Margery C.; Hunt, Robert M.; Stepleton, Ellen; Albright, L. Barry; Fremd, Theodore J. (2001). "Stratigraphy, Chronology, Biogeography, and Taxonomy of Early Miocene Small Chalicotheres in North America". Journal of Vertebrate Paleontology. 21 (3): 607–620. doi:10.1671/0272-4634(2001)021[0607:SCBATO]2.0.CO;2. ISSN 0272-4634. JSTOR 20061990. S2CID 131128421.
^ a bCoombs, Margery C.; Hunt Jr, Robert M. (2015). "New material of Moropus (Perissodactyla, Chalicotheriidae, Schizotheriinae) from the early Hemingfordian Rose Creek Member of the John Day Formation, Oregon, U.S.A." Journal of Vertebrate Paleontology. 35 (6): e1009992. Bibcode:2015JVPal..35E9992C. doi:10.1080/02724634.2015.1009992. S2CID 129074972.
^ a b c d eSchultz, C. Bertrand (Charles Bertrand); Falkenbach, Charles H. (1947). "Merychyinae, a subfamily of oreodonts. article 4". Bulletin of the AMNH. 88: 165–285. hdl:2246/396.
^ a bHembree, Daniel I. (April 30, 2007). "Phylogenetic revision of Rhineuridae (Reptilia: Squamata: Amphisbaenia) from the Eocene to Miocene of North America". The University of Kansas Paleontological Contributions (15): 1–20. doi:10.17161/PCNS.1808.3763. S2CID 59354440.
^ a bBerman, David S. (1976). "A New Amphisbaenian (Reptilia: Amphisbaenia) from the Oligocene-Miocene John Day Formation, Oregon". Journal of Paleontology. 50 (1): 165–174. ISSN 0022-3360. JSTOR 1303648.
Bibliography
Orr, Elizabeth L., and Orr, William N. (1999). Geology of Oregon, 5th ed. Dubuque, Iowa: Kendall/Hunt Publishing Company. ISBN0-7872-6608-6.