05-22-2014, 05:39 PM
It turns out that in the lowest part of the mantle, perovskite has two phases — different ways of arranging its atoms. One "H-phase" has iron and a hexagonal structure, while the other phase is iron-free. The H-phase is more stable at the temperatures and pressures found close to the core, and is likely more common than the iron-free form of perovskite, said lead study author Li Zhang, a scientist at the Center for High Pressure Science and Technology Advanced Research in Shanghai.
The findings suggest that the mineral makeup of the bottom half of the lower mantle may be different than that of the top half, Zhang said. "The constitution of the Earth's lower mantle may be significantly different than previously thought," he said.
Geoscientists classify the inner Earth's layers according to the changes in rock type, which are often indicated by sudden changes in earthquake wave speeds. The discovery of the H-phase will spark a search through the deep Earth for places where perovskite changes over to the H-phase, the researchers said. [What is Earth Made Of?]
Discovering the new H-phase also opens up possibilities for improving models of Earth's interior, said Quentin Williams, a professor at the University of California, Santa Cruz, who was not involved in the studies. Researchers can now better explore how the transition from one mineral phase to another influences the planet's tectonic convection cycle, and whether there is a seismic signal of the change.
"The idea that 1,000 km above Earth's core, the material might separate into iron-rich and iron-poor minerals is quite new," Williams said.
http://news.yahoo.com/strange-rocks-foun...04291.html
I know it's more at the atomic level that this research discusses but I wonder if there is a correlation.
60.21 Questioner: Is the Earth solid all the way through from one side to the other?
Ra: I am Ra. You may say that your sphere is of an honey-comb nature. The center is, however, solid if you would so call that which is molten.
60.22 Questioner: And the honey-comb nature— are there third-density incarnate entities living in the honey-combed areas? Is this correct?
Ra: I am Ra. This was at one time correct. This is not correct at this present space/time.
The findings suggest that the mineral makeup of the bottom half of the lower mantle may be different than that of the top half, Zhang said. "The constitution of the Earth's lower mantle may be significantly different than previously thought," he said.
Geoscientists classify the inner Earth's layers according to the changes in rock type, which are often indicated by sudden changes in earthquake wave speeds. The discovery of the H-phase will spark a search through the deep Earth for places where perovskite changes over to the H-phase, the researchers said. [What is Earth Made Of?]
Discovering the new H-phase also opens up possibilities for improving models of Earth's interior, said Quentin Williams, a professor at the University of California, Santa Cruz, who was not involved in the studies. Researchers can now better explore how the transition from one mineral phase to another influences the planet's tectonic convection cycle, and whether there is a seismic signal of the change.
"The idea that 1,000 km above Earth's core, the material might separate into iron-rich and iron-poor minerals is quite new," Williams said.
http://news.yahoo.com/strange-rocks-foun...04291.html
I know it's more at the atomic level that this research discusses but I wonder if there is a correlation.
60.21 Questioner: Is the Earth solid all the way through from one side to the other?
Ra: I am Ra. You may say that your sphere is of an honey-comb nature. The center is, however, solid if you would so call that which is molten.
60.22 Questioner: And the honey-comb nature— are there third-density incarnate entities living in the honey-combed areas? Is this correct?
Ra: I am Ra. This was at one time correct. This is not correct at this present space/time.