Abstract
Chemical zoning patterns in some iron, nickel metal grains from CH carbonaceous chondrites imply formation at temperatures from 1370 to 1270 kelvin by condensation from a solar nebular gas cooling at a rate of ~0.2 kelvin per hour. This cooling rate requires a large-scale thermal event in the nebula, in contrast to the localized, transient heating events inferred for chondrule formation. In our model, mass accretion through the protoplanetary disk caused large-scale evaporation of precursor dust near its midplane inside of a few astronomical units. Gas convectively moved from the midplane to cooler regions above it, and the metal grains condensed in these parcels of rising gas.
Original language | English (US) |
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Pages (from-to) | 839-841 |
Number of pages | 3 |
Journal | Science |
Volume | 288 |
Issue number | 5467 |
DOIs | |
State | Published - May 5 2000 |
Externally published | Yes |
ASJC Scopus subject areas
- General