| Autor: |
Th. Graf, P. Pellas, Rainer Wieler, Robert N. Clayton, Peter Signer, A. Pedroni, Marc J.-F. Suter, C. Fieni, S. Vogt, J.C. Laul |
| Rok vydání: |
1989 |
| Předmět: |
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| Zdroj: |
Geochimica et Cosmochimica Acta. 53:1449-1459 |
| ISSN: |
0016-7037 |
| Popis: |
Noble gases and cosmic-ray tracks were determined on light, solar-gas-free inclusions of the solar-gas-rich H4 chondrite Fayetteville. 10 Be, 26 A1, major and trace element concentrations as well as oxygen isotope ratios complete the data set. One exceptional inclusion is an L-chondrite xenolith, identified by its oxygen isotope signature and the concentration of metallic Fe-Ni. Oxidized Fe of this inclusion equilibrated with the host early in the history of Fayetteville's parent body. Track density variations indicate that the majority of Fayetteville's inclusions were irradiated as pebbles in the parent body by solar flare particles for about 10 4 -10 6 years. The L-chondritic inclusion contains an unequivocal excess of GCR produced He and Ne relative to the remaining inclusions. This clast, as well as two more solar-gas-free samples suffered a GCR exposure on the parent body lasting some 10 million years or longer. This exposure is comparable in length to the residence times of solar-gas-rich matrix samples in the GCR active zone of the Fayetteville parent regolith. Probably the other inclusions also were irradiated by GCR during at least several million years prior to the separation of the meteoroid from the parent body. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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