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The Rainwater Basin is a 4,200 mi.2 (10,900 km2) region of shallow lakes, marshes and other wetlands located south of the Platte River in south-central Nebraska. In the spring and fall months, millions of migratory birds pass through the region to feed and rest. The Rainwater Basin, along with the Platte River, is a major component of the Central Flyway of North America. These oval basins occur south of the Platte River on the loess-covered landscape of Nebraska. This area is often referred to as "God's Country" by residents. The Rainwater basins are the surface expression of elliptical depressions developed in fluvial sands and gravels buried by a blanket of several meter-thick loess. These basins are palimpsest landforms created by the draping of a younger loess blanket over these underlying depressions (Zanner and Kuzila 2001). The loess, which overlies these features, contains an intact sequence, from bottom to top, of Middle Wisconsinan Gilman Canyon Formation, Late Wisconsin Peoria Loess, Brady Soil, Holocene Bignell loess resting upon a Late Illinoian Sangamon Soil developed in the fluvial sand and gravels in which these depressions have developed〔Zanner, C. W., and M. S. Kuzila, 2001, (''Nebraska’s Carolina bays'' ). Geological Society of America Abstracts with Programs, v. 33, no. 6, pp. 438.〕 The intact layering of these different loesses and associated paleosols, which are each called “soil” by Zanner et al. (2007), prove that the loess has not been disturbed since it started accumulating over 27,000 years ago. Thus, these buried elliptical depressions are over 27,000 years old〔Zanner, C. W., W. Dort, Jr., and S. R. Bozarth, 2007, (''Holocene Bognell Loess Chronology. Stratigraphy and paleoenvironemntal reconstructions from within a loess table, Southwestern, Nebraska'' ). Geological Society of America Abstracts with Programs, v. 39, no. 3, pp. 73.〕 ==Rainwater Basin Wetland Management District== The Rainwater Basin Wetland Management District (WMD) currently manages 61 tracts of land, 59 of which are Waterfowl Production Areas (WPA) totaling 22,864 acres (92,52 km2) in the U.S. state of Nebraska. One of the remaining two areas is McMurtrey Wildlife Management Area that was transferred from the U.S. Military and is closed to public use. The other tract is the Platte River National Wildlife Management Area and this property is owned by the state of Wyoming and managed through a memorandum of understanding. WPAs are small isolated tracts of land scattered throughout the District. The Wetland Management District is managed from offices in Kearney, Nebraska. All of the federally managed land was acquired from willing landowners and purchased with the proceeds of duck stamps that are sold to hunters each year. 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「Rainwater Basin」の詳細全文を読む スポンサード リンク
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