Tuesday, May 5, 2015
Sillimanite, Kyanite, Andalusite Phase Diagram, Stellar Metamorphosis
The crank is at it again! haha!
This is a phase diagram with temperature/pressure alone to determine which mineral the Al2SiO5 will solidify into given the right temp/pressure.
During very late stages of star evolution, the aluminum, silicon and oxygen form bonds with each other in large quantities forming these three types of minerals. Nailing down which elements bonded with which first is the key, because then we can determine where in the atmosphere they probably formed before becoming their solid form.
As well, regardless of how "cranky" it may sound to modern geologists, this phase diagram literally means that if we find these minerals on the surface of the Earth (where you can pick them up with your hands), it means that at one point that area was around ~800 degrees C.
It also means that the atmosphere was much thicker because 1 GPa is ~9,800 atmospheres, and that's right on the surface ladies and gents. This is direct evidence for Earth's atmosphere having been vastly thicker, or the interior of a gas giant star.