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The Glen Canyon Group is a geologic group of formations that is spread across the U.S. states of Nevada, Utah, northern Arizona, north west New Mexico and western Colorado. It is sometimes called the Glen Canyon Sandstone in Colorado and Utah.〔GEOLEX database〕 There are four formations within the group. From oldest to youngest, these are the Wingate Sandstone, Moenave Formation, Kayenta Formation, and Navajo Sandstone.〔Harshbarger, J. W., C. A. Repenning, and J. H. Irwin. 1957. Stratigraphy of the uppermost Triassic and the Jurassic rocks of the Navajo country. U.S. Geological Survey, Reston, VA. Professional Paper 291.〕 Part of the Colorado Plateau and the Basin and Range,〔GEOLEX database〕 this group of formations was laid down during the Late Triassic and Early Jurassic, with the Triassic-Jurassic boundary within the Wingate Sandstone.〔Lucas, S. G., A. B. Heckert, J. W. Estep, and O. J. Anderson. 1997. Stratigraphy, biostratigraphy, and sequence stratigraphy of the Upper Triassic Chinle Group, Four Corners region. Pages 81-107 in Anderson, O. J., B. Kues, and S. G. Lucas, editors. Mesozoic geology and paleontology of the Four Corners Region. New Mexico Geological Society, Socorro, NM. New Mexico Geological Society, 48th Field Conference.〕〔Lucas, S. G., A. B. Heckert, and L. H. Tanner. 2005. Arizona’s Jurassic fossil vertebrates and the age of the Glen Canyon Group. Pages 95-104 in Heckert, A. B. and S. G. Lucas (editors). Vertebrate paleontology in Arizona. New Mexico Museum of Natural History and Science, Albuquerque, NM. Bulletin 29.〕 The top of the Glen Canyon Group is thought to date to the Toarcian stage of the Early Jurassic. Asterisks ( *) below indicate usage by the U.S. Geological Survey. ==Subunits== Group rank (alphabetical):〔 *Kayenta Formation (AZ,CO *,UT *), *Moenave Formation (AZ *,NV *,UT *), *Navajo Sandstone (AZ *,CO *,NM *,UT *), *Wingate Sandstone (AZ *,CO *,NM *,UT *) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Glen Canyon Group」の詳細全文を読む スポンサード リンク
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