Zhou Tinghong, Tarduno John A, Cottrell Rory D, Neal Clive R, Nimmo Francis, Blackman Eric G, Ibañez-Mejia Mauricio
Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627 USA.
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 USA.
Commun Earth Environ. 2024;5(1):456. doi: 10.1038/s43247-024-01551-z. Epub 2024 Sep 6.
Single crystal paleointensity (SCP) reveals that the Moon lacked a long-lived core dynamo, though mysteries remain. An episodic dynamo, seemingly recorded by some Apollo basalts, is temporally and energetically problematic. We evaluate this enigma through study of ~3.7 billion-year-old (Ga) Apollo basalts 70035 and 75035. Whole rock analyses show unrealistically high nominal magnetizations, whereas SCP indicate null fields, illustrating that the former do not record an episodic dynamo. However, deep crustal magnetic anomalies might record an early lunar dynamo. SCP studies of 3.97 Ga Apollo breccia 61016 and 4.36 Ga ferroan anorthosite 60025 also yield null values, constraining any core dynamo to the Moon's first 140 million years. These findings suggest that traces of Earth's Hadean atmosphere, transferred to the Moon lacking a magnetosphere, could be trapped in the buried lunar regolith, presenting an exceptional target for future exploration.
单晶古强度（SCP）表明，月球缺乏长期存在的核心发电机，尽管谜团仍然存在。一些阿波罗玄武岩似乎记录的间歇性发电机在时间和能量方面存在问题。我们通过研究约37亿年（Ga）的阿波罗玄武岩70035和75035来评估这个谜团。全岩分析显示名义磁化强度高得离谱，而SCP表明磁场为零，这说明前者并未记录间歇性发电机。然而，深部地壳磁异常可能记录了早期月球发电机。对39.7亿年的阿波罗角砾岩61016和43.6亿年的富铁斜长岩60025的SCP研究也得出零值，将任何核心发电机的存在时间限制在月球形成的最初1.4亿年。这些发现表明，地球冥古宙大气的痕迹转移到缺乏磁层的月球上，可能被困在埋藏的月球风化层中，这为未来的探索提供了一个特殊目标。
