San Jose Formation Explained
The San Jose Formation is an Early Eocene (Wasatchian in the NALMA classification) geologic formation in the San Juan Basin of New Mexico and Colorado.[1]
Description
The San Jose Formation is mostly sandstone but with some mudstone beds. The formation was deposited by high-energy streams on a muddy floodplain that was the last preserved sedimentation episode in the San Juan Basin. Stream direction was from the northwest, north, and east towards the south.
The basal Cuba Mesa Member is found throughout the depositional basin and is a coarse-grained sheet sandstone. The Regina Member is floodplain mudstone and disconnected sheet sandstone that intertongues with the sandstone-dominated Ditch Canyon Member in the northwestern part of the basin and the Llaves Member on the east side of the basin. The uppermost member is the siltstone-dominated Tapicitos Member. The Cuba Mesa Member was deposited during subsidence in the basin center, while the later members were deposited during episodes of monoclinal folding along the Nacimiento Fault on the west escarpment of the Nacimiento Mountains.
Paleontology
The mudstone beds of the San Jose Formation are locally rich in fossils. These include the Almagre and Largo faunas of the early Eocene.
Fossil content
Among others, the following fossils have been reported from the formation:[1]
Mammals
- Primates
- Artiodactyls
- Carnivora
- Cimolesta
- Ferae
- Glires
- Hyaenodonta
- Insectivora
- Pantodonta
- Perissodactyla
- Placentalia
- Taeniodonta
- Theriiformes
Reptiles
- Snakes
- Turtles
- Lizards
- Paraglyptosaurus cf. yatkolai
- Lacertilia indet.
History of investigation
In late 1874, Edward Drinker Cope was a member of the Wheeler Survey but ignored orders from Wheeler to proceed north from the Chama River to Colorado. Instead, he headed south to explore the area north of the San Pedro Mountains, where fossils had been reported. He found early Eocene fossils in the badlands north of Regina, New Mexico and spent about seven weeks collecting fishes, reptiles, and what was then the oldest known mammal fossils in North America. He also collected the fossil of a giant flightless bird. Cope later wrote his father that this was "the most important find in geology I have ever made".
In 1948, G.G. Simpson visited the same area and assigned the fossil beds to the San Jose Formation. In 1967, the formation was divided (in ascending order) into the Cuba Mesa Member, Regina Member, Llaves Member, and Tapicitos Member.
See also
References
Bibliography
- Lichtig . A. . J. H. . Hutchison . S. G. . Lucas . 2018 . Additional records of turtles from the Eocene San Jose Formation, San Juan Basin, New Mexico . . 79 . 319–322.
- Lichtig . A. J. . S. G. . Lucas . 2015 . Turtles of the lower Eocene San Jose Formation, San Juan Basin, New Mexico . . 67 . 161–177.
- Book: Kues. Barry S.. Lewis. Claudia J.. Lueth. Virgil W.. A brief history of geological studies in New Mexico : with biographical profiles of notable New Mexico geologists. 2014. New Mexico Geological Society. 978-1-58546-011-3. First.
- Alroy . J . 2002 . Synonymies and reidentifications of North American fossil mammals . _ .
- Froehlich . D. J . 2002 . Quo vadis Eohippus? The systematics and taxonomy of the early Eocene equids (Perissodactyla) . . 134 . 2 . 141–256. 10.1046/j.1096-3642.2002.00005.x . free .
- Redline . A.D. . 1997 . Revision of the Wind River faunas, early Eocene of central Wyoming. 13. Systematics and phylogenetic pattern of early Eocene Hyopsodus (Mammalia: Condylarthra) . Annals of Carnegie Museum . 66 . 1 . 1–81. 10.5962/p.226625 . 90674869 . free .
- Williamson . T. E. . S. G. . Lucas . 1992 . Meniscotherium (Mammalia, Condylarthra) from the Paleocene-Eocene of Western North America) . . 1 . 1–75.
- Smith . Larry N. . Stratigraphy, sediment dispersal and paleogeography of the Lower Eocene San Jose Formation, San Juan Basin, New Mexico and Colorado . New Mexico Geological Society Field Conference Series . 1992 . 43 . 297–310 . 7 May 2020.
- Sullivan . R. M. . S. G. . Lucas . 1988 . Fossil Squamata from the San José Formation, Early Eocene, San Juan Basin, New Mexico . . 62 . 631–639.
- Beard . K. C . 1987 . Jemezius, a new omomyid primate from the early Eocene of northwestern New Mexico . . 16 . 6 . 457–468. 10.1016/0047-2484(87)90034-0 .
- Flanagan . K. M . 1986 . Early Eocene rodents from the San Jose Formation, San Juan Basin, New Mexico . Contributions to Geology, University of Wyoming Special Paper . 3 . 197–220.
- Krishtalka . L. . R. K. . Stucky . 1986 . Early Eocene artiodactyls from the San Juan Basin, New Mexico, and the Piceance Basin, Colorado . Contributions to Geology, University of Wyoming Special Paper . 3 . 183–196.
- Schoch . R. M . 1986 . Systematics, Functional Morphology and Macroevolution of the Extinct Mammalian Order Taeniodonta . . 42 . 1–320.
- Korth . W.W. . 1984 . Earliest Tertiary evolution and radiation of rodents in North America . Bulletin of Carnegie Museum of Natural History . 24 . 1–71. 10.5962/p.228603 . 198239228 . free .
- Bown . T.M. . Schankler . D . 1982 . A review of the Proteutheria and Insectivora of the Willwood Formation (lower Eocene), Bighorn Basin, Wyoming . U.S. Geological Survey Bulletin . 1523 . 10.3133/b1523. free .
- Lucas . S. G. . R. M. . Schoch . E. . Manning . 1981 . The Systematics of Forstercooperia, a Middle to Late Eocene Hyracodontid (Perissodactyla: Rhinocerotoidea) from Asia and Western North America . . 55 . 826–841.
- Book: Osborn . Henry Fairfield. Henry Fairfield Osborn. 1931. 1978. Cope: Master Naturalist: Life and Letters of Edward Drinker Cope, With a Bibliography of His Writings. Ayer Com C. M. Bauer, 1916, U.S. Geol. Survey Prof. Paper 98-Ppany Publishing. Manchester, New Hampshire. 978-0-405-10735-1.
- Gingerich . P. D. . E. L. . Simons . 1977 . Systematics, phylogeny, and evolution of early Eocene Adapidae (Mammalia, Primates) in North America . . 24 . 245–279.
- Baltz . E.H. . Stratigraphy and regional tectonic implications of part of Upper Cretaceous and Tertiary rocks, east-central San Juan Basin, New Mexico . U.S. Geological Survey Professional Paper . Professional Paper . 1967 . 552 . 10.3133/pp552. free .
- Simpson . George Gaylord Simpson . G. G . 1951 . Hayden, Cope, and the Eocene of New Mexico . Proceedings of the Academy of Natural Sciences of Philadelphia . 103 . 1–21.
- Simpson . G. G. . The Eocene of the San Juan Basin, New Mexico; Part 2 . American Journal of Science . 1948b . 246 . 6 . 363–385 . 10.2475/ajs.246.6.363. 1948AmJS..246..363S . free .
- Simpson . G. G. . The Eocene of the San Juan Basin, New Mexico. Part 1 . American Journal of Science . 1948a . 246 . 5 . 257–282 . 10.2475/ajs.246.5.257. 1948AmJS..246..257S .
- Denison . R.H. . 1938 . The broad-skulled PseudoCreodi . New York Academy of Science Annals . 37 . 163–256. 10.1111/j.1749-6632.1937.tb55483.x . 129936019 .
- Hay . O. P . 1904 . On some fossil turtles belonging to the Marsh Collection in Yale University Museum . . Fourth Series . 18 . 106 . 261–276. 10.2475/ajs.s4-18.106.261 . 1904AmJS...18..261H .
- Cope . Edward Drinker Cope . E. D . 1875 . Systematic Catalogue of Vertebrata of the Eocene of New Mexico, Collected in 1874 . Geographical Explorations and Surveys West of the 100th Meridian, Engineer Department, U. S. Army . 5–37.
Notes and References
- http://www.fossilworks.org/cgi-bin/bridge.pl?action=displayStrata&geological_group=&formation=San%20Jose&group_formation_member=San%20Jose San Jose Formation
