Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.; Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637, USA.
Sci Adv. 2017 Jan 11;3(1):e1602365. doi: 10.1126/sciadv.1602365. eCollection 2017 Jan.
Establishing the age of the Moon is critical to understanding solar system evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined. We present uranium-lead dating of Apollo 14 zircon fragments that yield highly precise, concordant ages, demonstrating that they are robust against postcrystallization isotopic disturbances. Hafnium isotopic analyses of the same fragments show extremely low initial Hf/Hf ratios corrected for cosmic ray exposure that are near the solar system initial value. Our data indicate differentiation of the lunar crust by 4.51 billion years, indicating the formation of the Moon within the first ~60 million years after the birth of the solar system.
确定月球的年龄对于了解太阳系的演化和包括地球在内的类地行星的形成至关重要。然而，尽管其重要性不言而喻，但月球的年龄从未被准确确定过。我们展示了对阿波罗 14 号锆石碎片的铀铅定年，这些碎片产生了高度精确、一致的年龄，证明它们不受结晶后同位素干扰的影响。对同一碎片的铪同位素分析显示，经过宇宙射线暴露校正后的初始铪/铪比值极低，接近太阳系的初始值。我们的数据表明，月球地壳的分化发生在 45.1 亿年前，这表明月球的形成时间在太阳系诞生后的约 6000 万年之内。
