Evidence for a non-cosmogenic implanted C-14 component in lunar samples

被引:19
作者
Jull, AJT [1 ]
Lal, D [1 ]
Donahue, DJ [1 ]
机构
[1] UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV GEOL RES,LA JOLLA,CA 92093
关键词
D O I
10.1016/0012-821X(95)00163-7
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Experiments to determine if the presence could be confirmed of excess C-14 implantation in lunar soils and a rock surface sample were undertaken. Stepwise HF etchings of near-surface lunar soil 73221, collected from 0 to 0.5 cm depth and surface soil 10084, and a sample of surface scrapings from rock 68815 released appreciable amounts of C-14. Considering the amount of material dissolved, we find that the amounts of C-14 released are significantly in excess of the amounts that would be necessary for both galactic and solar cosmic-ray-produced C-14, even for the very surface. Further, there is an excess of C-14 released compared to deeper samples of rock and soil, based on our analyses of subsurface soils (73241 and 73261) from the same trench location of 73221, and earlier studies of C-14 in rock 68815 [1]. Based on the observed release pattern of C-14, we estimate that the excess C-14 in the lunar surficial samples may be released from depths of up to several microns. We conclude that this is an implanted solar component.
引用
收藏
页码:693 / 702
页数:10
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