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The Wrangellia terrane (named for the Wrangell Mountains, Alaska) is a crustal fragment extending from the south-central part of Alaska and along the Coast of British Columbia in Canada. Some geologists contend that Wrangellia extends southward to Oregon , [ 1 ] although this is not generally accepted.
The Wrangellia terrane, as one of the largest in Alaska formed beginning 300 million years ago in the Pennsylvanian and built up with basalt, carbonate and phyllite during the Triassic (these rocks are exposed from the Alaska Range to the Wrangell Mountains). Originating as a volcanic island arc, Wrangellia exhausted its magma supply and began ...
On the West coast of North America, the coast ranges and the coastal plain form the margin. Most of the land is made of terranes that have been accreted onto the margin. In the north, the insular belt is an accreted terrane, forming the margin. This belt extends from the Wrangellia Terrane in Alaska to the Chilliwack group of Canada. [6]
The Wrangell Mountains are a high mountain range of eastern Alaska in the United States.Much of the range is included in Wrangell-Saint Elias National Park and Preserve.The Wrangell Mountains are almost entirely volcanic in origin, and they include the second and third highest volcanoes in the United States, Mount Blackburn and Mount Sanford.
Siletzia, from Vancouver Island (Van) to the Klamath Mountains in Oregon.The shaded area shows near-surface extent as inferred from magnetic and gravitational studies (Silberling et al. 1987; Wells, Weaver & Blakely 1998), divided into the Crescent (CR) and Siletz (SZ) terranes; the crossed dashed lines are alternate locations of CR-SZ boundary.
Stikinia (in blue) at 330, 269, and 251 Ma, or before the breakup of Pangaea. At 269 Ma Stikinia is accompanied by the Wrangellia and Alexander terranes (west) and the East Klamath terrane (southeast). View centred on 60th meridian west.
Wrangellia Terrane; Wrekin Terrane; Y. Yakutat Block; Yukon–Tanana Terrane This page was last edited on 30 May 2015, at 22:36 (UTC). Text is available under the ...
The decline is attributed to early phases of the Wrangellia large igneous province enriching the ocean with osmium-188. Osmium-188 is preferentially sourced directly from the mantle, while osmium-187 is a radiogenic isotope supplied from eroded land.