ScienceActuallyDeep beneath Earth's surface, there’s an enormous amount of water trapped inside a special blue mineral called ringwoodite in the mantle.
John Vaccaro (johniac)SciTech Chronicles. . . . . . . . .Mar 19th, 2025
#Anchorage #CO2 #SO2 #magma #Nylon-6,6 #fermentation #Electrochemistry #Biorenewable #Bedmap3 #fast-warming #flow #sea-level #aquifers #Seismometers #uplift #subsidence #MTZ #subduction #ringwoodite #wadsleyite
gomli@kipuka #géologie
Découverte du jour, la #ringwoodite
Minéral hydraté (1.4%) solide, obtenu à partir de l'olivine, roche très commune dans les profondeurs. Il se trouverait dans une couche de transition entre le manteau supérieur et inférieur. Il pourrait y avoir selon les calculs l'équivalent de 1 à 2 océans mondiaux !
"« Je pense que cet océan souterrain pourrait être la source d’un cycle d’eau profonde, qui est en fait crucial pour le fonctionnement de notre planète », estime le Dr. Gu"
Note (kipuka) "Il ne s'agit pas d'eau moléculaire(H2O) mais de groupes hydroxyles(OH) inclus dans la struc. minérale"
https://www.nationalgeographic.fr/sciences/les-profondeurs-de-la-terre-cachent-un-gigantesque-ocean-solide
https://aus.social/@ksircombe/113124205623708267
Bill MinarikAt high pressures, fluorine-free topaz is stable: Topaz-OH. It's likely present only on recent Earth in our solar system: water, aluminous sediments (shales; pelites) from continental crust and cold subduction zones are all required.
Given these, Topaz-OH can potentially transport water into the mantle transition zone (where it's stored in #ringwoodite ) Figure from Huang et al (2020).
InoruOkay so as much as I love #kyanite's variable mohs, #ringwoodite just sounds way cool right now. So I voted for the latter.
(This is a close vote btw! The difference is only 11 votes as of when I voted! Vote #ringwoodite for potential water sequestered!)
via @MineralCup
GeologistsCatToday's #MinCup24 duell is #Kyanite /#Disthen Vs. #Ringwoodite. I am for several reasons in #TeamKyanite. One is the famous phase diagram: kyanite, #sillimanite, #andalusite. It's so famous even my humans know it
#mineral #MinCup #CatsOfMastodon
#mineral #MinCup #CatsOfMastodon
Why study and synthesize #Ringwoodite? Experiments (below, a diamond anvil pressure device that's transparent to visible light; Schmandt et al, 2014) and natural samples from the Earth's mantle (see ksircombe's posts: https://aus.social/@ksircombe/113124213223248687) suggest that there's an ocean or two worth of water stored in Earth's Ringwoodite. It's likely kept the planet habitable for the last 4.5 billion years.
Plus Ringwoodite is more Blue than #Kyanite !
#MinCup24 #Mantle #PlateTectonics #BlueMinerals
ksircombe (@[email protected])
Attached: 1 image 4/ Analysis of the ringwoodite from the diamond showed it contained 1.5% water. May not seem like a lot, but a lot of ringwoodite in the mantle means a lot of water down there too. This has big implications the origins of the oceans and how plate tectonics works. https://bib-pubdb1.desy.de/record/168146/files/10.1038_nature13080.pdf
We can make #Ringwoodite but measuring the pressure is hard. Yingwei Fei (CIW, Fei et al, 2004) pioneered combining the experiment with simple cubic crystals with well known volume changes with pressure. The volume of these cubic crystals is measured with synchrotron x-rays at the same time as the Ringwoodite is forming.
#MinCup24 #Synchrotron #Mantle
#MinCup24 #Synchrotron #Mantle
The Earth has a tremendous amount of #Ringwoodite, it's just difficult to get it to the surface unless encapsulated within another mineral. Making Ringwoodite big enough to see just requires a big press!
This is a 1500 ton press located at #Spring-8 in #Japan. It's bigger than it needs to be because it has a small gap in the WC anvils that allow synchrotron x-rays (intense, narrow beam) to penetrate the experiment, and because it's on actuators that position it to the micron.
#MinCup24 #Mantle
This is a 1500 ton press located at #Spring-8 in #Japan. It's bigger than it needs to be because it has a small gap in the WC anvils that allow synchrotron x-rays (intense, narrow beam) to penetrate the experiment, and because it's on actuators that position it to the micron.
#MinCup24 #Mantle
#Ringwoodite is a second chance for #Spinel (which lost out to #Vivianite earlier). Ringwoodite has the chemistry of olivine (Mg2SiO4) but the crystal structure of spinel (MgAl2O4).