Hutcheon I D, Krot A N, Keil K, Phinney D L, Scott E R
Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94551, USA.
Science. 1998 Dec 4;282(5395):1865-7. doi: 10.1126/science.282.5395.1865.
Fayalite grains in chondrules in the oxidized, aqueously altered CV3 chondrite Mokoia have large excesses of radiogenic chromium-53. These excesses indicate the in situ decay of short-lived manganese-53 (half-life = 3.7 million years) and define an initial 53Mn/55Mn ratio of 2.32 (+/-0.18) x 10(-6). This ratio is comparable to values for carbonates in CI and CM chondrites and for several classes of differentiated meteorites. Mokoia fayalites formed 7 to 16 million years after Allende calcium-aluminum-rich inclusions, during hydrothermal activity on a geologically active asteroid after chondritic components had ceased forming in the solar nebula.
在氧化且经水蚀变的CV3球粒陨石莫科亚的球粒中的铁橄榄石颗粒含有大量过剩的放射性铬-53。这些过剩表明了短寿命锰-53（半衰期 = 370万年）的原位衰变，并确定了初始的53Mn/55Mn比率为2.32（±0.18）×10⁻⁶。该比率与CI和CM球粒陨石中的碳酸盐以及几类分异陨石的值相当。莫科亚铁橄榄石在阿伦德富钙铝包体形成700万至1600万年后形成，当时在太阳星云停止形成球粒陨石成分后，一颗地质活跃的小行星上发生了热液活动。
