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19-583: The Wrangellia Terrane (named for the Wrangell Mountains , Alaska) is a crustal fragment ( terrane ) 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 , although this is not generally accepted. The term Wrangellia is confusingly applied to all of: Earlier geologists sometimes used

38-668: A 2,500 km (1,553 mi) long belt. Wrangellia collided and amalgamated with the Alexander Terrane by Pennsylvanian time. By the end of the Triassic, the Peninsular Terrane had also joined the Wrangellia composite terrane. A subduction zone existed on the west side of Wrangellia. Seafloor rocks too light to be subducted were compressed against the west edge of Wrangellia; these rocks are now known as

57-642: A song, "The Wrangell Mountain Song", in reference to the range. Mount Blackburn Mount Blackburn ( Ahtna : K’ats’i Tl’aadi ) is the highest peak in the Wrangell Mountains of Alaska in the United States . It is the fifth-highest peak in the United States and the twelfth-highest peak in North America . The mountain is an old, eroded shield volcano , the second-highest volcano in

76-715: Is one of the largest andesite shield volcanoes in the world, and also the only presently active volcano in the range. The Wrangell Mountains comprise most of the Wrangell Volcanic Field , which also extends into the neighboring Saint Elias Mountains and the Yukon Territory in Canada . The Wrangell Mountains are just to the northwest of the Saint Elias Mountains and northeast of the Chugach Mountains , which are along

95-423: Is that it is the 50th-most topographically prominent peak in the world. The western of Blackburn's two summits is the mountain's highest point, a fact that was not understood until the 1960s when new USGS maps were published. The first ascent of the west peak, and hence Mount Blackburn, was done on May 30, 1958, by Bruce Gilbert , Dick Wahlstrom , Hans Gmoser , Adolf Bitterlich , and Leon Blumer via

114-705: The Chugach Terrane . A complex fault system, known as the Border Ranges Fault , is the modern expression of the suture zone between Wrangellia and Chugach Terranes. Over time, plate tectonics moved this amalgamation of crust generally northeastward into contact with the North American continental margin. The Wrangellia composite terrane collided with and docked to North America by Cretaceous time. Strike-slip displacement, with Wrangellia travelling northward, continued after docking, although

133-571: The Kuskulana Glacier in less than 4 horizontal miles (6.4 km). Its other faces drop 8,000–10,000 ft (2,440–3,050 m), all in less than 8 miles (13 km). The toe of the Kuskulana Glacier , less than 12 miles (19 km) from the summit, lies at an elevation of 2,400 ft (730 m), giving a rise of 14,000 ft (4,270 m). While these figures speak to the peak's relief, one measure of its independence

152-528: The North (also called the Northwest) Ridge. This team made the first ascent of Blackburn but did not even know it at the time due to the incorrect identification of the highest point. Blumer's article in the 1959 American Alpine Journal is titled "Mount Blackburn – Second Ascent." Kennedy Peak , or East Blackburn , 16,286 ft (4,964 m), is the eastern summit and was originally thought to be

171-464: The U.S. behind Mount Bona and the fifth-highest in North America. It was named in 1885 by Lt. Henry T. Allen of the U.S. Army after Joseph Clay Stiles Blackburn , a U.S. senator from Kentucky . It is located in the heart of Wrangell – St. Elias National Park , the largest national park in the country. The mountain's massif is covered almost entirely by icefields and glaciers and is

190-574: The West Peak. Keen went on to write a famous article for the Saturday Evening Post titled, "First up Mount Blackburn." In 1912, Keen and Handy thought they were on Blackburn's highest point. Mount Blackburn represents the heavily eroded core of a shield volcano. Because it is shrouded in permanent ice, its internal structure cannot be determined. It is believed to have a summit caldera, greatly modified by glaciation. The oldest rocks in

209-599: The amount of post- accretion displacement is controversial. Wrangell Mountains 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 . The range takes its name from Mount Wrangell , which

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228-411: The area are granites, about 4.2 million years old, representing an intrusive mass. The majority of the mountain is 3.4 million year old granite, intruding between andesite flows. From this it is inferred that a caldera collapse took place between 4.2 and 3.4 million years ago, after which activity ceased. Today's standard route on the peak is the 1958 ascent route, the North (or Northwest) Ridge, which

247-468: The associated tectonic settings. It is composed of many rocks types, of various composition, age, and tectonic affinity, but the Late Triassic flood basalts are the defining unit of Wrangellia. These basalts , extruded onto land over 5 million years about 230 million years ago, on top of an extinct Pennsylvanian and Permian island arc, constitute a large igneous province , currently exposed in

266-792: The coast of the Gulf of Alaska . These ranges have the combined effect of blocking the inland areas from warmer moist air over the Pacific Ocean . The inland areas to the north of the Wrangell Mountains are therefore among the coldest areas of North America during the winter. The Wrangell Mountains include 12 of the 40+ Alaskan peaks over 13,000 feet (4,000 m) (see fourteeners and thirteeners ): Other prominent mountains include: The mountains are named after explorer, president of Russian-American Company , and admiral Ferdinand von Wrangel . American folk singer John Denver wrote

285-555: The highest point. The first ascent of this summit was made in 1912 by Dora Keen and George Handy via the Kennicott Glacier (on the south side of the mountain) and East Face. This heady exploit was ahead of its time. Dora Keen, driven by a deep desire for the climb, solicited miners from the nearby Kennecott Copper Mines , and forged a route up the heavily crevassed East Face to the East Peak, but did not traverse over to

304-729: The late Carboniferous—the two continental fragments remained isolated in the open ocean until they were accreted to Laurentia in the Middle Jurassic . 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

323-699: The other. This effectively dispersed continental fragments—the Alexander, Eastern Klamath, Northern Sierra and Okanagan terranes—westward along the shores of this ocean in a back-arc process similar to that of the present-day Scotia Plate between the South America Plate and the Antarctic Plate . During the Carboniferous , the Alexander terrane migrated westward into the northern Panthalassic Ocean where it merged with Wrangellia in

342-500: The principal source of ice for the Kennicott Glacier , which flows southeast over 20 miles (32 km) to just above the town of McCarthy . The mountain also contributes a large volume of ice to the north-flowing Nabesna Glacier and the Kuskulana Glacier system. Mount Blackburn is a large, dramatic peak, with great local relief and independence from higher peaks. Its west face drops over 11,000 ft (3,350 m) to

361-686: The term " Talkeetna Superterrane" to describe Wrangellia. There are two conflicting hypotheses about whether the Wrangellia Superterrane originated at polar or equatorial latitudes: Geological evidences indicate that the Caledonide closure of the Iapetus and Rheic Oceans along the Laurentian westcoast (modern coordinates) also opened an ocean between the northern margin of Laurentia and Baltica on one side and Siberia on

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