Other
Scientific paper
Jul 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005psrd.repte..95t&link_type=abstract
Planetary Science Research Discoveries
Other
Core, Core Formation, Interior Earth, Cobalt, Nickel
Scientific paper
Formation of Earth's metallic core was one of the most important events in the history of the planet. Metallic iron is much denser than rock, so it sank to the middle, taking other elements that concentrate in metal rather than silicate (rock) with it. However, we do not understand everything about core formation. One particularly niggling puzzle is why cobalt (Co) and nickel (Ni) have the same concentration (relative to primitive carbonaceous chondrites) as one another in Earth's mantle. At low pressure these elements concentrate in metallic iron to different extents. Calculations show that if metal segregated from silicate at low pressure, nickel ought to be 100 times less abundant (normalized to chondrites) than cobalt, not equal.
Cosmochemists have tackled this problem by doing experiments at high pressure and temperature to map out how cobalt and nickel partitioning between metal and silicate differs compared to low pressure. However, the studies differ in their predictions of the behavior because of differences in the assumed pressure, temperature, and oxidation state during core formation. Nancy Chabot (Case Western Reserve University, now at the Johns Hopkins Applied Physics Laboratory), and David Draper and Carl Agee from the University of New Mexico addressed the discrepancies by designing a series of experiments over a wide range in temperature. Their results plot out the conditions under which metal can sink to the core while leading to the observed cobalt and nickel concentrations in the mantle. While the results do not lead to a unique solution, they point the way for further studies of other elements that tend to concentrate in metallic iron, and they show clearly that the equal nickel and cobalt concentrations in the mantle can be the product of core formation in the early Earth.
No associations
LandOfFree
Squeezing and Heating Rock to Scope Out How Metallic Iron Dribbled to the Center of the Earth does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Squeezing and Heating Rock to Scope Out How Metallic Iron Dribbled to the Center of the Earth, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Squeezing and Heating Rock to Scope Out How Metallic Iron Dribbled to the Center of the Earth will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1468951