39Ar-40Ar ages of eucrites and thermal history of asteroid 4 Vesta
نویسندگان
چکیده
منابع مشابه
AR-AR AGES OF EUCRITES AND THE THERMAl HISTORY OF ASTEROID 4-VESTA
New Ar-Ar ages of several cumulate and unbrecciated eucrites cluster at ~4.48 Gyr. We suggest that this age cluster was produced by interruption of eucrite metamorphism within the Vesta parent asteroid by a giant impact, which excavated and rapidly cooled these meteorites. We see no evidence for younger formation ages of the cumulate eucrites, as previously proposed. Introduction. Several obser...
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Planetary scientists are pretty sure that almost all of the HED meteorites come from the fourth-largest asteroid, 4 Vesta. HED stands for the three types of rocks that make up the group. As cosmochemists have studied the meteorites over the years, their view of the geologic history of the asteroid has become progressively more complicated. Jean-Alix Barrat and Marcel Bohn (CNRS and University o...
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The asteroid 4 Vesta is the only known differentiated asteroid with an intact internal structure, probably consisting of a metal core, an ultramafic mantle, and a basaltic crust. Considerable evidence suggests that the HED meteorites are impact ejecta from Vesta, and detailed studies of these meteorites in terrestrial laboratories, combined with ever more sophisticated remote sensing studies of...
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Introduction: Recent work on chronology seem to point to older ages for eucrites: which favor a magma ocean model for Vesta. [1] indicate a Pb-Pb age for the eucrite Asuka 881394 of 4.566 + 0.3 Ga. Whole rock isochrons of eucrites based on Hf-W, Al-Mg and Mn-Cr [2-4] indicate somewhat younger ages at around 4.564 Ga (or about 3.5 Myrs after CAI formation). From the perspective of thermal modeli...
متن کاملThe case for a younger Imbrium basin: New 40Ar-39Ar ages of Apollo 14 rocks
Petrographically and chemically well-characterized rocks of the Apollo 14 landing site (12 impact melt breccias, 3 clast-free impact melt rocks, 2 granulitic rocks, 1 cataclastic noritic anorthosite, 1 shocked gabbronorite, 1 mare basalt, and 1 plagioclase single crystal) have been dated by the 40Ar-39Ar technique. The samples represent two different formations at the Apollo 14 site: (1) small ...
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ژورنال
عنوان ژورنال: Meteoritics & Planetary Science
سال: 2003
ISSN: 1086-9379,1945-5100
DOI: 10.1111/j.1945-5100.2003.tb00035.x