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Wyandotte Caves, a pair of limestone caves located on the Ohio River in Harrison-Crawford State Forest in Crawford County, north-east of Leavenworth and from Corydon in southern Indiana, is a popular tourist attraction. Wyandotte Caves were designated a National Natural Landmark in 1972.〔(【引用サイトリンク】title= Wyandotte Cave )〕 They are now part of O'Bannon Woods State Park. The cave system is the 5th largest in the state of Indiana.〔(Indiana University Southeast Blue River Project )〕 The term "Wyandotte Caves" is used to refer to Wyandotte Cave (sometimes called the "Historic Cave") and Little Wyandotte Cave (also called Siberts Cave and sometimes called the "New Cave"), but the two caves are completely different. They are located very close to each other, and are owned and managed by the same entity. There the resemblance ends. ==Geological history and formations== Wyandotte Caves began to form in the Pliocene Era, about 2 million years ago.〔''Wyandotte Caves U.S. National Landmark, 2005'' (Wyandotte Caves U.S. National Landmark Backgrounder )〕 Like most of Southern Indiana's caves, the caves were formed when water dissolved limestone, causing hollow caves to form. The limestone which forms much of Southern Indiana's bedrock, and from which Wyandotte and other local caves are formed, was first deposited in the Mississippian epoch (360 Ma to 325 Ma), when Indiana was covered by a shallow inland sea. Although the glaciers of the Pliocene and Pleistocene periods did not quite reach as far south as the area now known as Crawford County, where Wyandotte and Marengo Caves are located, they dramatically influenced the development of those caves. The Ohio River was formed at this time, and today flows only minutes from Wyandotte Caves. The advancing and retreating glaciers destroyed the pre-existing Teays River, and the Ohio River was formed, draining the land that the Teays once drained. As the glaciers melted, the icy cold water flowing towards the Ohio River (which was then much higher than it is now) dissolved the limestone which is the bedrock for much of Southern Indiana, hollowing out caves such as Wyandotte. The main entrance to Wyandotte Cave is 220 feet (67 m) above the level of the Blue River. Wyandotte Cave is known for its long open passageways and large rooms. With 9.2 miles (14.806 km) of passageways on five levels it is one of the longest caves in Indiana. Included in its formations is Monument Mountain. At 135 feet (41.148 m) tall, Monument Mountain is considered to be the world's largest underground mountain. Wyandotte Cave is also home to a great many helictites, which are considered rare. The cave is also home to the tallest stalagmite in the world, known as the Pillar of the Constitution, but this is only visible on crawling tours. Long speleothems, formed by rainwater dissolving calcium carbonate, abound in Siberts Cave. The cave exhibits a wide variety of speleothems including; stalactites, stalagmites, columns, flowstone, flowstone colored with iron oxide known as cave bacon, flowstone known as cave draperies, soda straws, popcorn, and rimstone dams. The temperature inside both caves maintains a constant 52 degrees Fahrenheit (about 11 degrees Celsius). 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「Wyandotte Caves」の詳細全文を読む スポンサード リンク
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