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The Environment of West Virginia encompasses terrain and ecosystems ranging from arid plateaus to mountains. Most of West Virginia lies within the Appalachian mixed mesophytic forests ecoregion, while the higher elevations along the eastern border and in the panhandle lie within the Appalachian-Blue Ridge forests. West Virginia is situated in the Appalachian Mountains of the Upper South region of the 48 contiguous states. Usually considered part of the South Eastern United States, West Virginia is bounded on the northeast by Pennsylvania and Maryland, on the southeast by Virginia, on the northwest by Ohio, and on the southwest by Kentucky. A portion of the Appalachian Mountains stretches into eastern West Virginia, and in the state's northeastern corner, Spruce Knob is officially regarded as the tallest mountain in the Allegheny Mountains, a vast section of the Appalachians.〔(【引用サイトリンク】url=http://www.infoplease.com/ce6/us/A0803380.html )〕 West Virginia covers an area of , with of land and of water, making it the 41st-largest state in the United States. Generally, it is divided into four geographical regions: Ohio River Valley, Allegheny Plateau, Allegheny Highlands, and Potomac Section.〔(【引用サイトリンク】url=http://www.narr.com/west-virginia.html )〕 == Geology == (詳細はlava was deposited in the extreme eastern part of the State forming our oldest exposed rock, the Catoctin Greenstone. Later, perhaps about 800 million years ago, a narrow trough began to form in extreme eastern West Virginia. An arm of the sea entered and sediments accumulated. As time went on, this shallow sea transgressed westward. By the end of Cambrian time, about 300 million years later, this shallow sea covered essentially all of West Virginia. Marine deposition took place throughout most of this and the succeeding Ordovician Period. During this total interval of about 370 million years, most of the rocks exposed in Jefferson and eastern Berkeley counties and in scattered areas southwestward along the Virginia boundary were deposited. Rocks of the same age are found in abundance in the deep wells throughout the State. The Taconic Orogeny near the end of Ordovician time formed a high mountainous area east of West Virginia. During Middle and Late Devonian time the Acadian Orogeny, with the main uplift to the northeast, resulted in a further source for the predominantly clastic marine deposits of these epochs. However, near the end of Devonian time, the sea was rapidly retreating westward and the continental red beds of the Hampshire Formation were being deposited over most of the State. The sea made one more important intrusion into West Virginia during Middle Mississippian time, approximately 330 million years ago, resulting in the deposition of the Greenbrier Formation, predominantly limestone, the last marine deposit of significance in the State. At the close of Mississippian time, about 310 million years ago, West Virginia was essentially a land area, subject to erosion. Early in the succeeding Pennsylvanian Period, the area dropped to near sea level and for more than 50 million years continued to sink at about the same rate that deposition was taking place. Permian Period, roughly 270 to 225 million years ago, the Appalachian Orogeny began which played a major part in the formation of the Appalachian Mountains as we know them today. Never again has the sea invaded West Virginia. The oldest evidences of life found in West Virginia occur in rocks about 600 million years old, in the Antietam Formation of Lower Cambrian age. However, in this formation they are abundant and of forms that had already developed through a substantial part of all evolution that has taken place during the history of the earth. Evidences of life in other parts of the earth are found in rocks at least 3 billion years old. Fossils are found in increasing abundance and increasing stages of evolutional development in the rocks of all ages since earliest Cambrian time. 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「Environment of West Virginia」の詳細全文を読む スポンサード リンク
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