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Traprock (or basalt) mountains, ridges, (or just traps) are elevated landscape features made of trap rock, most often basalt. Basalt, due to its high quantity of iron, is a characteristically dark-colored rock that weathers to shades of red and purplish-red when exposed to the air. Basalt is the substance of many elevated topographic features worldwide (hills, mountains, ridges, rock formations, etc.). Landscape features composed of basalt may include: *Elevated sections of prehistoric ocean floor that have been raised above sea level via plate tectonics *Prehistoric terrestrial lava floods that have become upended and/or exposed via faulting and erosion *Various surface volcanic landforms both recent and ancient. Because basalt has a tendency to fracture at abrupt angles, topographic features made of basalt often have a "postpile" appearance. Basalt ridges make up hundreds of square miles of topographic features in the northwestern United States, from Wyoming to Oregon. ==Notable landforms== Prominent basalt ridges, mountains, buttes, canyons, and other landscape features include: ===In the United States=== * The ridges and cliffs of the Columbia River Gorge in Oregon and Washington (state) * Basalt Mountain in Colorado, for which the town of Basalt, Colorado is named. * The Metacomet Ridge of Connecticut and Massachusetts. * The New Jersey Palisades and Watchung Mountains * Parts of California's inner coastal range. * Most of the Hawaiian Islands and their mountains are composed of basalt or similar volcanic rock. 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「traprock mountain」の詳細全文を読む スポンサード リンク
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