波浪谷

波浪谷（）是位於美國亞利桑那州的一個旅游勝地，靠近猶他州南部邊界。該地區位於科羅拉多高原内的的狼丘上。屬猶他州卡納布的土地管理局管理Bureau of Land Management (October 24, 2014). "Paria Canyon-Vermilion Cliffs – Wilderness Management Plan". BLM Website. Archived from the original on January 20, 2016. Retrieved January 18, 2016.。

該地區因其砂岩地層色彩繽紛、起伏的地表以及艱難徒步旅行而廣為人知。但由於地層脆弱而限制入境人數，採用每日抽籤系統（最多16人）及每月線上抽籤系統（最多48人）發放許可證Bureau of Land Management. "Coyote Buttes Permit Area". BLM Website. Archived from the original on April 12, 2012. Retrieved April 6, 2012. Bureau of Land Management. "BLM-AZ How to Obtain a Permit – Coyote Buttes Permit Area". BLM Website. Archived from the original on April 13, 2012. Retrieved April 6, 2012..

 地質學 
波浪谷由交叉的U形槽谷組成，這些槽谷是侏羅紀納瓦霍砂岩经侵蚀形成的U形槽。兩個主要槽寬62英尺（19m）、長118英尺（36m）及寬7英尺（2m）、長52英尺（16m）。最初，這些槽由不頻繁的水流沿納瓦霍砂岩內的節理面被侵蝕。它們形成後，由於水流縮小，槽現在幾乎完全被風侵蝕。在槽壁上有切入砂岩的侵蝕台階和凸起， 其方向與主要風的方向一致Loope, D.B.; Mason, J.A. (October 22, 2006). "Landforms generated by wind erosion of Navajo Sandstone outcrops at The Wave (Colorado Plateau, Utah / Arizona border.) Vol. 38, No. 7 (abstract: gsa.confex.com/gsa/2006AM/finalprogram/abstract_113067.htm)" (PDF). Geological Society of America Abstracts with Programs. p. 279. Archived from the original (PDF) on August 7, 2011. Loope, D.B., W.M. Seiler, J.A. Mason, and M.A. Chan (2008) Wind scour of Navajo Sandstone at The Wave (central Colorado Plateau, U.S.A.) Journal of Geology. vol. 116, pp. 173–183. 。

在波浪谷暴露了大面積風成砂岩内的交錯層理，由交替的顆粒流和風紋層組成。其有規律和循環交替的週期性代表了侏羅紀時期大型沙丘在沙漠中，被盛行風遷移的周期性變化。由於顆粒流和風紋層存在侵蚀差异（不同的抗侵蝕能力），因而造成在波浪谷中看到有規律和循環交替性的細脊和層理。根據這些砂岩的組成顆粒尺寸不同，它們的膠結程度亦不一樣。有的砂岩很軟及脆弱，尤其是細脊和肋紋。因此，遊客必須小心行走，以免它們遭到破壞Seiler, W.M. (August 1, 2008). "Jurassic Navajo sandstone of Coyote Buttes, Utah/Arizona : coloration and diagenetic history, preservation of a dinosaur trample surface, and terrestrial analogs to Mars (unpublished M.S. thesis, Dept. of Geology and Geophysics, University of Utah, Salt Lake City, Utah)". none. Archived from the original on March 5, 2012. Chan, M.A., and A.W. Archer (2000) Cyclic eolian stratification on the Jurassic Navajo Sandstone, Zion National Park: Periodicities and implications for paleoclimate. Archived April 21, 2016, at the Wayback Machine in D.A. Sprinkel, T.C. Chidsey, Jr., and P.B. Anderson, eds., pp. 607–18. Geology of Utah's Parks and Monuments.[dead link] Archived January 11, 2012, at the Wayback Machine Utah Geological Association, Salt Lake City, Utah. Caputo, M.V. (2003) Geology of the Paria Canyon-Vermilion Cliffs Wilderness, Utah and Arizona. in D.A. Sprinkel, T.C. Chidsey Jr., and P.B. Anderson, eds., Geology of Utah's Parks and Monuments. Archived January 11, 2012, at the Wayback Machine Utah Geological Association, Salt Lake City, Utah. 。

在某些地區，波浪谷内的納瓦荷砂岩具有變形的層理。這些變形層理在砂岩石化之前就已形成。這種變形很可能代表了這些沙子沉積後被恐龍踐踏和攪拌的結果。在北狼丘（North Coyote Buttes）地區的納瓦霍砂岩中發現了恐龍足跡和沙漠節肢動物（例如甲蟲和其他昆蟲）的化石洞穴Ekdale, A.A., R.G. Bromley, and D.B. Loope (2007) Ichnofacies of an ancient erg: a climatically influenced trace fossil association in the Jurassic Navajo Sandstone, Southern Utah, USA. in W. Miller, ed., 562–576, Trace Fossils. Concepts, Problems, Prospects. Elsevier, Amsterdam.。

 參考文獻 

Category:地球科學
Category:沉積學
Category:美國岩層