南土狼丘
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南土狼丘（英语：Coyote Buttes South）是位于美国亚利桑那州的一个旅游胜地，靠近犹他州北部边界。与波浪谷及白袋地区两旅游胜地均位于科罗拉多高原内的帕里亚峡谷-朱红悬崖荒野区的狼丘上。属犹他州卡纳布大阶梯-埃斯卡兰特国家纪念区的土地管理局管理[1]。
该地区因早期河流切割形成许多孤立的小丘，并出露其色彩鲜明的砂岩地层[2]，而广为人知。出露的风成砂岩呈现大规模的交错层理，加上由差异风化所造成的凹凸层面，更引人入胜。由于地层脆弱而限制入境人数，发放许可证采用每日现场抽签系统（最多16人）及每月线上抽签系统（最多48人）[3][4]。
在南土狼丘也可以看到如同白袋地区的花椰菜岩，但是棕色的，分布在小丘顶上。大部分出露在南土狼丘的砂岩都呈现厚层交错层理的叠加。在区域地质剖面其沉积层面趋近水平，代表无区域性构造运动。也证实了科罗拉多高原的稳定性构造。同理恐龙脚印在水平地面上，而不在斜坡上，也证实该地区的构造稳定性。在此地不同程度的风蚀地貌显出不同程度的差异侵蚀. 从初始的凹凸层理，深切层理到只剩下的骨架。 有的呈现出洋葱状剥离。也有形同波浪谷的地貌，但规模较小。
地质
[编辑]南狼丘如同波浪谷及白袋地区一样，均由侏罗纪纳瓦荷砂岩（Navojo Sandstone）组成并暴露了大面积风成砂岩内的叠加交错层理[5]。每一套交错层理由有规律的交替颗粒流和风纹层组成[6]，并和上下套由沉积层面隔开。每一套交错层理方向和倾斜角与上下套不同，代表了侏罗纪时期沙丘在沙漠中，被盛行风吹移的变化[7]。由于颗粒流和风纹层具不同的抗侵蚀能力而造成差异侵蚀。这些差异在南狼丘壁上造成凹凸不平的层面， 有的凸出层面可以形成长板凳，让游客坐着休息。由于这些砂岩的组成颗粒尺寸不同，它们的胶结程度亦不一样[8]。有的砂岩很软及脆弱[9][10][11]。
图集
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参考文献
[编辑]- ^ 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.
- ^ VERLANDER, J.E. (1995), The Navajo Sandstone. Geology Today, 11: 143-146. https://doi.org/10.1111/j.1365-2451.1995.tb00943.x)
- ^ 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.
- ^ William E. Freeman, G. S. Visher; Stratigraphic analysis of the Navajo Sandstone. Journal of Sedimentary Research 1975;; 45 (3): 651–668. doi: https://doi.org/10.1306/212F6E06-2B24-11D7-8648000102C1865DWilliam E. Freeman, G. S. Visher; Stratigraphic analysis of the Navajo Sandstone. Journal of Sedimentary Research 1975;; 45 (3): 651–668. doi: https://doi.org/10.1306/212F6E06-2B24-11D7-8648000102C1865D)
- ^ Ralph E. Hunter, David M. Rubin（1983）Interpreting Cyclic Crossbedding, with An Example from the Navajo Sandstone, Editor(s): M.E. Brookfield, T.S. Ahlbrandt, Developments in Sedimentology, Elsevier,Volume 38,1983,Pages 429-454,ISSN 0070-4571,ISBN 9780444422330, https://doi.org/10.1016/S0070-4571(08)70808-2. (https://www.sciencedirect.com/science/article/pii/S0070457108708082)
- ^ John E. Marzolf(1983), Changing Wind and Hydrologic Regimes During Deposition of the Navajo and Aztec Sandstones, Jurassic (?), Southwestern United States.Editor(s): M.E. Brookfield, T.S. Ahlbrandt, Developments in Sedimentology,Elsevier,Volume 38,1983, Pages 635-660,ISSN 0070-4571,ISBN 9780444422330, https://doi.org/10.1016/S0070-4571(08)70816-1.(https://www.sciencedirect.com/science/article/pii/S0070457108708161) )
- ^ Schultz, R. A., C. H. Okubo, and H. Fossen (2010), Porosity and grain size controls on compaction band formation in Jurassic Navajo Sandstone, Geophys. Res. Lett., 37, L22306, doi:10.1029/2010GL044909. )
- ^ 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.