Rapid accretion and differentiation of iron meteorite parent bodies inferred from super(1) super(8) super(2)Hf- super(1) super(8) super(2)W chronometry and thermal modeling

New high-precision W isotope measurements are presented for 33 iron meteorites from 8 magmatic groups (IC, IIAB, IID, IIIAB, IIIE, IIIF, I VA and IVB), 2 non-magmatic groups (IAB-IIICD and IIE), and one ungrouped iron (Deep Springs). All magmatic irons have epsilon super(1) super(8) super(2)W values...

Full description

Saved in:
Bibliographic Details
Published in:Earth and planetary science letters 2008-08, Vol.273 (1-2), p.94-104
Main Authors: Qin, L, Dauphas, N, Wadhwa, M, Masarik, J, Janney, P E
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:New high-precision W isotope measurements are presented for 33 iron meteorites from 8 magmatic groups (IC, IIAB, IID, IIIAB, IIIE, IIIF, I VA and IVB), 2 non-magmatic groups (IAB-IIICD and IIE), and one ungrouped iron (Deep Springs). All magmatic irons have epsilon super(1) super(8) super(2)W values that are, within errors, equal to, or less radiogenic than, the Solar System initial of -3.47+/-0.20. A method was developed to correct the measured epsilon super(1) super(8) super(2)W values of magmatic iron meteorites for the presence of cosmogenic effects produced during space exposure to galactic cosmic rays. The corrected data provide new constraints on the timing of metal-silicate differentiation in iron meteorite parent bodies, which must have taken place within a few million years (
ISSN:0012-821X
DOI:10.1016/j.epsl.2008.06.018