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Lake Nipigon (; (フランス語:lac Nipigon); (オジブウェー語:Animbiigoo-zaaga'igan)) is the largest lake entirely within the boundaries of the Canadian province of Ontario (since four of the five Great Lakes are split between the U.S. and Canada). It is sometimes described as the sixth Great Lake.〔http://www.wildernessinquiry.org/destinations/index.php?itinerary=nipigoncanoe〕 ==Geography and geology== Lying 260 metres (853 ft) above sea level, the lake drains into the Nipigon River and thence into Nipigon Bay of Lake Superior. The lake and river are the largest tributaries of Lake Superior. It lies about northeast of the city of Thunder Bay, Ontario.〔http://agora.lakeheadu.ca/agora.php?st=60〕 Lake Nipigon has a total area (including islands within the lake) of — compared to for Lake of the Woods. The largest islands are Caribou Island, Geikie Island, Katatota Island, Kelvin Island, Logan Island, Murchison Island, Murray Island, and Shakespeare Island. Maximum depth is . The lake is noted for its towering cliffs and unusual green-black sand beaches composed of the fine particles of a dark green mineral known as pyroxene. The lake basin provides an important habitat for woodland caribou. Abstract mafic rocks at Lake Nipigon give evidence of rift-related continental basaltic magmatism during the Midcontinent Rift System event, estimated at 1,109 million years ago. Great sills up to thick are also related with the rifting event, forming cliffs hundreds of meters high. The mafic and ultramafic intrusions centered on Lake Nipigon represent a ''failed arm'' of the main rift called the Nipigon Embayment. 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「Lake Nipigon」の詳細全文を読む スポンサード リンク
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