@article{oai:nipr.repo.nii.ac.jp:00001565,
 author = {Kaneoka, Ichiro},
 journal = {Memoirs of National Institute of Polar Research. Special issue},
 month = {Dec},
 note = {P(論文), In order to examine the weathering effect on ^<40>(Ar)-^<39>(Ar) ages of Antarctic meteorites, the ^<40>(Ar)-^<39>(Ar) age patterns were compared for the outer and inner portions of two Antarctic meteorites (ALH-761,ALH-77288). The results indicate that the oxidized outer portions show anomalously old ^<40>(Ar)-^<39>(Ar) ages which exceed 4600Ma in the intermediate temperature fractions of around 800-1000℃. These old ^<40>(Ar)-^<39>(Ar) ages are accompanied by the increase of ^<36>(Ar), which is regarded to be mostly of atmospheric ^<36>(Ar). This might be explained by the incorporation of atmospheric Ar in hematite which was produced from goethite during neutron irradiation. The inner relatively fresh portions show the following plateau ages : ALH-761,64,4487±50Ma; ALH-77288,63,4497±40Ma.},
 pages = {259--274},
 title = {Investigation of the weathering effect on the 40Ar-39Ar ages of Antarctic meteorites},
 volume = {30},
 year = {1983}
}