Dakota
Description
Source: Wikipédia
The Dakota is a sedimentary geologic unit name of formation and group rank in Midwestern North America. The Dakota units are generally composed of sandstones, mudstones, clays, and shales deposited in the Mid-Cretaceous opening of the Western Interior Seaway. The usage of the name Dakota for this particular Albian-Cenomanian strata is exceptionally widespread; from British Columbia and Alberta to Montana and Wisconsin to Colorado and Kansas to Utah and Arizona. It is famous for producing massive colorful rock formations in the Rocky Mountains and the Great Plains of the United States, and for preserving both dinosaur footprints and early deciduous tree leaves.
Owing to extensive weathering of older rocks during the Jurassic and Triassic, the Dakota strata lie unconformably atop many different formations ranging in age from Precambrian to Early Cretaceous. With a few local exceptions, it is the oldest Cretaceous unit exposed in the northern Great Plains, including Kansas, Nebraska, Iowa, Minnesota, and Wisconsin, as well as the Desert Southwest. It generally consists of sandy, shallow marine or beach deposits with marine-influenced mudflat sediments, and occasional stream deposits.
Découvertes
Source: The Paleobiology Database
Site(s) correspondant(s) à cette formation: 8
J. B. White farm, Decatur : Nebraska - Burt 7478 12328 51467 61518 77268 farm of J. B. White, 3.22 km S of Decatur, NE Burt Co., near the Missouri River, eastern Nebraska, close to Iowa border- Condray Farm nodosaur : Kansas - Ottawa 7836 9210 13083 SW 1/4, section 8, T10S, R1W, on farm of Warren Condray, Ottawa Co., Kansas. 10 miles S of Miltonvale, KS.
- Republican River tracksite : Kansas - Clay 13083 13084 S 1/2, sec 9, T6S, R1E, on SW bank of Republican River about 50 miles from its mouth, near highest point of bluff and on projection within 100 yds of river; extreme NW Clay Co.
- south of Concordia : Kansas - Cloud 13083 S of Concordia, southern Cloud Co. (coordinates for Concordia)
- Jefferson County tracksite : Nebraska - Jefferson 51467 locality given only as "southern Jefferson County"
- Guthrie County dinosaur [PROXY] : Iowa - Guthrie 77268 SE portion of Guthrie Co.
- Dickinson county gravel pit [PROXY] : Iowa - Dickinson 77268 from a gravel pit in SE Dickinson Co.
- Akron gravel pit : Iowa - Plymouth 77268 gravel pit near Akron
Publication(s)
La base comprend 9 publication(s).
Source: The Paleobiology Database
- ↑1 2 E. H. Barbour. 1931. Evidence of dinosaurs in Nebraska. The Nebraska State Museum Bulletin 21(1):187-190
- ↑1 P. M. Galton and J. A. Jensen. 1979. Remains of ornithopod dinosaurs from the Lower Cretaceous of North America. Brigham Young University Geology Studies 25(3):1-10
- ↑1 2 3 R. M. Joeckel, J. M. Cunningham, and R. G. Corner, G. W. Brown, P. L. Phillips, G. A. Ludvigson. 2004. Late Albian dinosaur tracks from the cratonic (eastern) margin of the Western Interior Seaway, Nebraska, USA. Ichnos 11:275-284 (https://doi.org/10.1080/10420940490442377)
- ↑1 D. B. Weishampel and J. B. Weishampel. 1983. Annotated localities of ornithopod dinosaurs: implications to Mesozoic paleobiogeography. The Mosasaur 1:43-87
- ↑1 2 3 4 5 6 7 B. J. Witzke. 2001. The Age of Dinosaurs in Iowa. Iowa Geology 26:2-7
- ↑1 2 T. H. Eaton, Jr. 1960. A new armored dinosaur from the Cretaceous of Kansas. The University of Kansas Paleontological Contributions: Vertebrata 8:1-24
- ↑1 K. Carpenter and J. I. Kirkland. 1998. Review of Lower and middle Cretaceous ankylosaurs from North America. Lower and Middle Cretaceous Terrestrial Ecosystems, S. G. Lucas, J. I. Kirkland & J. W. Estep (eds.). New Mexico Museum of Natural History and Science Bulletin 14:249-270
- ↑1 2 3 4 G. A. Liggett. 2005. A review of the dinosaurs from Kansas. Transactions of the Kansas Academy of Science 108(1/2):1-14 (https://doi.org/10.1660/0022-8443(2005)108[0001:arotdf]2.0.co;2)
- ↑1 2 B. F. Mudge. 1866. Discovery of fossil foot-marks in the Liassic (?) Formation in Kansas. American Journal of Science 41(122):174-176 (https://doi.org/10.2475/ajs.s2-41.122.174)