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In geology, a terrane (/ t ə ˈ r eɪ n, ˈ t ɛr eɪ n /; [1] [2] in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or "sutured" to crust lying on another plate. The crustal block or fragment preserves its distinctive geologic history, which is different from the ...
Denali is the highest mountain in North America. Most of Alaska consists of terranes accreted by collisions with island arcs carried in over the last 160 million years. [21] These terranes were caused by the subduction of the Farallon, Kula, and Pacific plates sequentially. [21]
Rocks of Wrangellia (the individual terrane, not the composite terrane) were originally created in the Pennsylvanian to the Jurassic somewhere, but probably near the equator, in the Panthalassic Ocean off the west coast of Laurentia (North American craton) as island arcs, oceanic plateaus, and rock assemblages of the associated tectonic settings.
Other Peri-Gondwanan terranes, sometimes called "Greater Avalonia", include Carolina in the Appalachian and the deep bedrock of Florida in North America, Oaxaquia and Yucatán in Mexico, and the Chortis Block in Central America. [2] The North American terranes of Ganderia and Carolinia are sometimes grouped with Avalonia because they were ...
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The Yakutat Terrane is currently colliding with the continental margin below the central Gulf of Alaska. During the Neogene the terrane's western part was subducted after which a sediment wedge accreted along the northeast Aleutian Trench. This wedge incorporates sediment eroded from the continental margin and marine sediments carried into the ...
Initially, Arkansas bauxite met 90% of US aluminum demand. Underground mining before and during World War II gave way to open pit mining in the 1960s. During the war, up to six million tons were mined in 1943. Arkansas bauxite mines were often passed over in favor of higher quality bauxite reserves in the Caribbean and mining ceased in 1982.
As with related peri-Gondwanan terranes (e.g., Avalonia and Gander), the Carolina Terrane played a major role in the tectonic evolution of the east coast of North America during the Paleozoic. It represents the largest exotic terrane in the Appalachians, and underlies an enormous area of the southeastern United States.