(Mineralogical Society of America)
A very rare mineral that’s previously been found only in extraterrestrial meteorites has been discovered in Earth’s own rocks for the 1st time, lying in sedimentary-formation not so much far from shores of the Dead Sea
Allabogdanite, a phosphide mineral, was unknown to science until just a few of decades ago, after fragments of alittle iron meteorite were recovered from the Bolshoi Dolguchan River in Eastern Yakutia, Russia.
A sample of the fragments later revealed the presence of a latest or new mineral structure occurring as thin layers of crystals spread throughout the meteorite’s plessite mixture. The discoverers named it after Russian geologist Alla Bogdanova.
Subsequently, allabogdanite has been found in other meteorites too, suggesting that the rare mineral won’t be quite as exclusive as had been believed.
Even so, only being found in rocks rupture of the sky remains a special status all said – and yet now it seems allabogdanite also has Earthly origins we never knew about.
In a new study, scientists report the invention of allabogdanite within the Negev of Israel, located to the southwest of Dead Sea .
“The discovery of the high-pressure polymorph of (Fe,Ni)2P, allabogdanite within the surficial pyrometamorphic rocks of the Hatrurim Formation (the Mottled Zone) surrounding the Dead Sea basin in Israel is that the first terrestrial occurrence of a mineral previously only found in iron meteorites,” a team of researchers, led by crystallographer Sergey Britvin from St Petersburg University in Russia, explains in new paper.
While the Dead Sea’s allabogdanite won’t come from space , it still remains possible – perhaps – that it had been born out of some quite extraterrestrial event, the researchers say.
Analysis of the Hatrurim sample – and experiments exploring how it transitions from its low-pressure polymorph state, the mineral barringerite – suggest this terrestrial allabogdanite only forms under extremely high pressure: over 25 gigapascals.
“Such high pressures on Earth are often attained during catastrophic collisions with large meteorite impactors, or at the Earth’s mantle conditions, at a depth of quite 500 kilometers,” Britvin says.
However, as there is no evidence of huge meteorite collisions within the region – nor any signs that the rocks within the Mottled Zone have deep ties to Earth’s mantle – it isn’t exactly clear how this terrestrial allabogdanite came to be.
If we will locate other instances of terrestrial allabogdanite, it’d give us more to go-on. But until we will find another source of this unusual mineral on Earth, it’s hard to said more, the team concludes.
“Therefore, the origin of terrestrial allabogdanite within the rocks of the Mottled Zone remains unresolved and adds to the amount of mineralogical enigmas of this unusual metamorphic complex,” the researchers explain.
The findings were reported on American Mineralogist.
