Steens Mountain
| Steens Mountain | ||
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 Heading northwest from the Alvord desert |
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| height | 2956 m | |
| location | Oregon , USA | |
| Coordinates | 42 ° 39 '57 " N , 118 ° 33' 53" W | |
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The Steens Mountain is one of a fraction plaice with mining in the southeastern part of the US state of Oregon . It is located in Harney County on the edge of the Alvord Desert , from which it rises over 1,300 meters. Despite the enormous extension of around 80 kilometers, it is a single mountain, but it is often mistaken for a mountain range.
Due to its height and relatively heavy snowfall, there are several lakes in the area. The best known are Fish Lake ( Harney County ) on the Steens Mountain Loop with its popular camping area, and Mann Lake, popular with sport fishermen, at the northern end of the desert.
The mountain used to be called Snow Mountain . The name was changed in honor of Major Enoch Steen, who persecuted Indians around 1860 and engaged in skirmishes with them.
geology
The east side of Steens Mountain consists almost entirely of hundreds of superimposed basalt layers. They were formed by recurring volcanic activity 17 to 14 million years ago.
During volcanic activity, pole shifts took place, changes in the strength and direction of the earth's magnetic field, the course of which can be read from the magnetization of the ferrous lava, which has been frozen since cooling. The various layers of lava flow can be clearly seen on a 900 meter high steep slope. The analyzes showed that the earth's magnetic field was initially oriented to the south. It became 80 to 90 percent weaker and unpredictable. After 300 years it pointed north and got stronger again, but could not hold up. It became dramatically weaker again, this time for 3,000 years.
One of the lava layers initially showed inexplicable readings. The magnetization of the upper and lower areas, which were quickly cooled in contact with the ground or the air, points in one direction, while that of the interior, which cools more slowly, points in a direction deviating by 60 °. The cooling process, including the inside, must have taken place within about ten days. The interpretation as an extremely rapid change in the earth's magnetic field - actually physically impossible due to the electrical conductivity of the deep earth mantle - seemed to geologists in 2003 to have no alternative. After further sampling and, above all, laboratory experiments, they found the explanation in the special magnetic material properties.
Web links
- Steens Mountain on Peakbagger.com (English)
Individual evidence
- ^ A b Southeast Oregon Basin and Range , summitpost.org
- ↑ Victor E. Camp, Martin E. Ross, William E. Hanson: Genesis of flood basalts and Basin and Range volcanic rocks from Steens Mountain to the Malheur River Gorge, Oregon , Geological Society of America Bulletin, Volume 115, No. 1 , January 2003, pp. 105–128 ( abstract )
- ^ Andesitic and basaltic rocks on Steens Mountain , 1931-1977, USGS
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^ Magnetic Storm , Transcript from Nova (TV series) with Robert Coe from the University of California, Santa Cruz;
Date of first broadcast: November 18, 2003 ASTROSCIENCES RESEARCH NETWORK- Part 2 ( Memento of the original from July 12, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Transcript of the German version, nexworld.tv/blog, March 26, 2010 - ↑ Robert S Coe et al .: New Evidence does not Support Extraordinarily Rapid Field Change at Steens Mountain ( Memento of the original from August 8, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Contribution GP43A-1129 to the Fall Meeting 2012 of the AGU .
