The Mesaverde Formation was first described by W.H.Holmes in 1877 during the Hayden Survey. Holmes described the formation in the northern San Juan Basin as consisting of three units, which were a "Lower Escarpment" consisting of 40 m of ledge- and cliff-forming massive sandstone; a "Middle Coal Group" consisting of up to 300 m of thick slope-forming sandstone, shale, marl, and lignite; and an "Upper Escarpment" consisting of 60 m of ledge- and cliff-forming sandstone.[1] A.J. Collier redesignated these units in 1919 as the Point Lookout Sandstone, the Menefee Formation, and the Cliff House Sandstone, and raised the Mesaverde Formation to group rank.[2]
The Mesaverde Group is a Late Cretaceous stratigraphic group found in areas of Colorado, New Mexico, Utah, and Wyoming, in the Western United States.
The group is a single regression-transgression sequence in its type location in the San Juan Basin, dividing the older marine Mancos Shale and younger Lewis Shale deposited in the Western Interior Seaway. The Point Lookout Sandstone represents the regression, the Menefee Formation the subsequent fluvial delta deposits, and the Cliff House Sandstone the return of the sea. In other locations, such as along the Book Cliffs, the picture is more complicated, with multiple regression-transgression sequences from tectonic activity along the Sevier mountain front.[13] In the Cody area, the group is a simple regression sequence and remains at formation rank. Here the group is described as interbedded light gray sandstone and gray shale in the upper part; massive, light-buff, ledge-forming sandstone containing thin lenticular coal beds in the lower part.[14]
Formations
Mesaverde Gas Fields within the Uinta Basin and Piceance Basin
Dinosaur remains are among the fossils that have been recovered from the group, although none have yet been referred to a specific genus.[20]Deinosuchus has also been reported from Mesaverde outcrops in Wyoming.[21] In 2023, baenidturtle fossils tentatively assignable to Neurankylus sp. from the Mesaverde Formation were described.[22]
Fillmore, Robert (2011). Geological evolution of the Colorado Plateau of eastern Utah and western Colorado, including the San Juan River, Natural Bridges, Canyonlands, Arches, and the Book Cliffs. Salt Lake City: University of Utah Press. pp.224, 247–248. ISBN978-1-60781-004-9.
Fox, J.E. (1993). "Stratigraphic cross sections showing electric logs of Upper Cretaceous and older rocks, Powder River basin, southeastern Montana and northeastern Wyoming". U.S. Geological Survey Oil and Gas Investigations Chart. OC-135 to OC-138, Sections A-A' through F-F', G-G' through L-L', M-M' through R-R', S-S' through V-V'. doi:10.3133/oc135.
Holmes, W.H. (1877). "Report [on the San Juan District, Colorado]". In Hayden, F.V. (ed.). Ninth annual report of the United States Geological and Geographical Survey of the Territories, embracing Colorado and parts of adjacent territories, being a report of progress of the exploration for the year 1875; Part I, Geology. U.S. Geological and Geographical Survey of the Territories (Hayden). pp.237–276.
Spieker, E. M.; Reeside, J. B. (30 September 1925). "Cretaceous and Tertiary Formations of the Wasatch Plateau, Utah". Geological Society of America Bulletin. 36 (3): 435–454. Bibcode:1925GSAB...36..435S. doi:10.1130/GSAB-36-435.
Wahl, W.; Hogbin, J. (2003). "Deinosuchus material from the Mesaverde Formation of Wyoming: filling in a gap". Journal of Vertebrate Paleontology. 23: 107A.
Weishampel, David B.; Dodson, Peter; Osmólska, Halszka, eds. (2004). The Dinosauria (2nded.). Berkeley: University of California Press. ISBN0-520-24209-2.
