Title of article :
Tungsten isotopes in ferroan anorthosites: Implications for the age of the Moon and lifetime of its magma ocean
Author/Authors :
Touboul، نويسنده , , Mathieu and Kleine، نويسنده , , Thorsten and Bourdon، نويسنده , , Bernard and Palme، نويسنده , , Herbert and Wieler، نويسنده , , Rainer، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Pages :
5
From page :
245
To page :
249
Abstract :
New W isotope data for ferroan anorthosites 60025 and 62255 and low-Ti mare basalt 15555 show that these samples, contrary to previous reports [Lee, D.C., et al., 1997. Science 278, 1098–1103; Lee, D.C., et al., 2002. Earth Planet. Sci. Lett. 198, 267–274], have a W isotope composition that is indistinguishable from KREEP and other mare basalts. This requires crust extraction on the Moon later than ∼60 Myr after CAI formation, consistent with 147Sm–143Nd ages for ferroan anorthosites. The absence of 182Hf-induced 182W variations in the Moon is consistent with formation of the Moon at 62 −10 +90 Myr after CAI formation that has been inferred based on the indistinguishable 182W/184W ratios of the bulk Moon and the bulk silicate Earth. The uncertainties on the age of the Moon and the age of the oldest lunar samples currently hamper a precise determination of the duration of magma ocean solidification and are consistent with both an almost immediate crystallization and a more protracted timescale of ∼100 Myr.
Keywords :
accretion , cosmochemistry , moon , Thermal histories , Planetary formation
Journal title :
Icarus
Serial Year :
2009
Journal title :
Icarus
Record number :
2376570
Link To Document :
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