Chemistry of Yamato-791197 Antarctic meteorite: Evidence for its lunar highland origin

We report chemical data for 33 major, minor and trace elements in one clast, two matrices and two bulk samples of the Yamato-791197 meteorite by instrumental neutron activation analysis (INAA). Based on the well-established characteristic lunar and meteoritic ratios of FeO/MnO, (Cr)_2O_3/V and K/La, and the large-ion lithophile (LIL) element patterns, the Y-791197 meteorite is undoubtedly an anorthositic gabbro breccia of lunar highland origin. The similarity of chemical compositions of the Y-791197 and ALHA81005 meteorites suggests that both meteorites may have been ejected from the same lunar region. Based on the overall chemical abundances and the very low K_2O content, it is suggested that both meteorites originated from the far side of the moon. The similar Ir/Ni/Au ratios of the Y-791197 and ALHA81005 meteorites suggest that they may be related to one and the same impact event

Radionuclide disequilibria studies for investigating the integrity of potential nuclear waste disposal sites: subseabed studies.

This study of subseabed sediments indicates that natural radionuclides can be employed to define past long-term migration rates and thereby evaluate the integrity of potential disposal sites in ocean sediments. The study revealed the following conclusions: (1) the sedimentation rate of both the long and short cores collected in the North Pacific is 2.5 mm/1000 yr or 2.5 m/m.yr in the upper 3 meters; (2) the sedimentation rate has been rather constant over the last one million years; and (3) slow diffusive processes dominate within the sediment. Reworking of the sediment by physical processes or organisms is not observed