[Rockhounds] Volcano in Tanzania with weirdest, runniest magma on Earth is sinking into the ground

[axel.emmermann at telenet.be]

This lava is extremely rich in REE.
It looks black when freshly erupted but it turns white shortly thereafter.
It also weathers amazingly fast... 
The magma originates in the mantle rather than deeper in the Earth. Mantle magma is known for its REE-content.

Cheers
Axel

Axel Emmermann 
Mineralogische Kring Antwerpen 
Mineralogical Society of Antwerp 
Werkgroep Fluorescerende mineralen 
Workgroup Fluorescent Minerals 
[ http://fluo.mineralogie.be/index.html | http://fluo.mineralogie.be/index.html ] 
Bezoek Minerant op 4 & 5 mei 2024

----- Oorspronkelijk bericht -----
Van: "Kreigh Tomaszewski" <kreigh at gmail.com>
Aan: "Rockhounds at drizzle.com" <rockhounds at rockhounds.drizzle.com>
Verzonden: Zaterdag 3 augustus 2024 00:09:04
Onderwerp: [Rockhounds] Volcano in Tanzania with weirdest, runniest magma on Earth is sinking into the ground

A volcano in Tanzania with magma that erupts like a garden hose has been
steadily sinking into the ground for the past 10 years, a new study shows,
and the cause could be a deflating reservoir directly beneath one of the
volcano's two craters.

The new research reveals that the ground around the summit of Ol Doinyo
Lengai volcano, which sits along an active rift zone in East Africa,
subsided at a rate of 1.4 inches (3.6 centimeters) per year between 2013
and 2023. This means the *9,718-foot-tall (2,962 meters)*
<https://volcano.si.edu/volcano.cfm?vn=222120> volcano shrank by about 1.2
feet (36 cm) in the timeframe of the study, which was published June 8 in
the journal *Geophysical Research Letters*
<https://doi.org/10.1029/2023GL107673>.

Researchers used data from two satellite systems, Sentinel-1 and
Cosmo-SkyMed, to produce maps showing changes over time in the ground
around Ol Doinyo Lengai. Their maps indicate that a circular patch of
ground around the volcano's northern crater was "moving away from the
satellite with a steady rate of displacement over time," the researchers
wrote in the study.

Ol Doinyo Lengai is the only known volcano on Earth that is *actively
erupting* <https://doi.org/10.1016/j.jvolgeores.2023.107918> carbonatite
magma — extremely runny magma that is saturated with alkali elements, such
as calcium and sodium, and poor in silica. Most terrestrial magmas are rich
in silica, a compound made from bonded chains of silicon and oxygen that
binds molten rock together and *gives it a viscous consistency*
<https://www.livescience.com/planet-earth/volcanos/weird-new-device-measures-how-liquid-lava-is>.
But unlike those other magmas, whose weight is between 45 and 70% silica,
the magma that feeds Ol Doinyo Lengai contains less than 25% silica by
weight, according to *Erik Klemetti*
<https://denison.edu/people/erik-klemetti>, a volcanologist and associate
professor at Denison University in Ohio.

https://www.livescience.com/planet-earth/volcanos/volcano-in-tanzania-with-weirdest-runniest-magma-on-earth-is-sinking-into-the-ground
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