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The Palisades, also called the New Jersey Palisades or the Hudson River Palisades, are a line of steep cliffs along the west side of the lower Hudson River in northeastern New Jersey and southern New York in the United States. The cliffs stretch north from Jersey City approximately 20 mi (32 km) to near Nyack, New York. They rise nearly vertically from near the edge of the river, and are approximately 300 feet high at Weehawken and increasing gradually to 540 feet high near their northern terminus.〔("Township of Palisade" ) on the Bergen County website〕 From Fort Lee north the Palisades are part of Palisades Interstate Park and are a National Natural Landmark. The Palisades are among the most dramatic geologic features in the vicinity of New York City, forming a canyon of the Hudson north of George Washington Bridge, as well as providing a vista of the skyline. They are located in the Newark Basin, a rift basin located mostly in New Jersey. ''Palisade'' is derived from the same root as word ''pale'', ultimately from the Latin word ''palus'', meaning stake. The Lenape called the cliffs "rocks that look like rows of trees", a phrase that became "Weehawken", the name of a town in New Jersey that sits at the top of the cliffs across from Manhattan. ==Geology== (詳細はbasalt cliffs are the margin of a diabase sill, formed about 200 million years ago〔Tirella, Tricia. "Spotlight on North Bergen". ''Palisade'' magazine; Summer 2010; Page 16.〕 at the close of the Triassic Period by the intrusion of molten magma upward into sandstone.〔Brannen, Peter. ("Headstone for an Apocalypse" (op-ed) ) ''New York Times'' (August 6, 2013)〕 The molten material cooled and solidified before reaching the surface. Water erosion of the softer sandstone left behind the columnar structure of harder rock that exists today. The cliffs are about 300 ft (100 m) thick in sections and originally may have reached to 1,000 ft (300 m). The end Triassic extinction event that coincided with the formation of the Hudson Palisades, Central Atlantic Magmatic Province, 200 million years ago ranks second in severity of the five major extinction episodes that span geologic time.〔〔Chu, Jennifer. ("Huge and widespread volcanic eruptions triggered the end-Triassic extinction" ) ''MIT News'' (March 21, 2013)〕 The most severe extinction in the past 500 million years was the Permian–Triassic extinction event, informally known as the Great Dying〔("The Great Dying': MIT Insights into the Most Severe Mass Extinction in Earth’s History" ) ''The Daily Galaxy'' (November 24, 2013)〕〔Chandler, David L. ("Ancient whodunit may be solved: The microbes did it!" ) ''MIT News'' (March 31, 2014)〕 coincided with flood basalt eruptions that produced the Siberian Traps, which constituted one of the largest known volcanic events on Earth and covered over 770,000 sq mi (2,000,000 km2) with lava. Franklyn Van Houten did trailblazing research on a rock formation known as the Newark Basin. His discovery of a consistent geological pattern in which lake levels rose and fell is now known as the "Van Houten cycle".〔Structural Geology & Tectonics Group ("Van Houten cycle" (illustration) ) on the Rutgers University website〕〔Olsen. ("Milankovich Cycles in Early Mesozoic Rift Basins of Eastern North America Provide Physical Stratigraphy and Time Scale for Understanding Basin Evolution" ) from ''Lamont Newsletter 13'' (1986) pp.6-7, on the Lamont-Doherty Earth Observatory website〕〔MacPherson, Kita. ("Franklyn Van Houten, expert on sedimentary rocks, dies at 96" ) ''News at Princeton'' (September 14, 2010) on the Princeton University website〕〔Chalker, Georgette E. ("Franklyn Bosworth Van Houten 1914-2010" ) Princeton University Department of Geosciences website (February 10, 2011)〕 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「The Palisades (Hudson River)」の詳細全文を読む スポンサード リンク
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