The lunar meteorite Dhofar 1436 is dominated by solar wind type noble gases. Solar argon is equilibrated with “parentless” ⁴⁰Ar commonly known as lunar orphan argon. Ar‐Ar isochron analyses determined the lunar trapped ⁴⁰Ar/³⁶Ar ratio to 2.51 ± 0.04, yielding a corrected plateau age of 4.1 ± 0.1 Ga, consistent with the lunar Late Heavy Bombardment period. Lunar trapped and radiogenic argon components are all released at high temperatures (1200–1400 °C). Surprisingly, solar noble gases and lunar trapped argon can largely be released by crushing. Initial crushing steps mainly release elementally fractionated solar wind gases, while in advanced crushing steps, cosmogenic components dominate. Cosmogenic noble gases indicate irradiation at the lunar surface; they are less fractionated than solar wind species. We favor a scenario in which both solar and a large fraction of cosmogenic gases were acquired before the 4.1 Ga event, which caused shock metamorphism and formation of the regolith breccia. Sintering and agglutination along grain boundaries resulted in mobilization of solar wind, reimplanted, radiogenic, and cosmogenic noble gases, and resulted in their partial homogenization, fractionation, and retrapping in voids and/or defects accessible by crushing. An alternative scenario would be complete reset of the K‐Ar system 4.1 Ga ago accompanied by loss of all previously accumulated solar and cosmogenic noble gases. Later, the precursor of Dhofar 1436 became lunar regolith and accumulated solar and cosmogenic noble gases and reimplanted ⁴⁰Ar before its final formation of the polymict impact breccia. The C abundance of the step‐combusted Dhofar 1436 is 555.3 ppm, with δ¹³C of −28‰ to +11‰. Nitrogen contents released by crushing and combustion are 3.2 ppm and 20.8 ppm, respectively. The lightest nitrogen composition (δ¹⁵N = −79‰) is likely due to release from voids of shock metamorphic phases and is rather a result of the mobilization of nitrogen components that accumulated prior to the 4.1 Ga event.

中文翻译：

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Dhofar 1436月球陨石：40Ar-39Ar年表和挥发物，通过逐步燃烧和破碎方法揭示

月球陨石Dhofar 1436以太阳风型稀有气体为主导。太阳能氩气与通常称为月球孤儿氩的“无父母” ⁴⁰ Ar平衡。Ar‐Ar等时线分析确定了被困在月球上的⁴⁰ Ar / ³⁶Ar比值达到2.51±0.04，产生的校正高原年龄为4.1±0.1 Ga，与月球晚期重轰炸时期一致。捕集到的月球和放射性氩成分都在高温（1200–1400°C）下释放。出人意料的是，太阳稀有气体和月球捕获的氩气可以通过压碎而大量释放。最初的破碎步骤主要释放元素分馏的太阳风气体，而在高级破碎步骤中，宇宙成分占主导地位。宇宙产生的稀有气体表明在月球表面有辐射；它们比太阳风的种类少。我们赞成这样一种场景：在4.1 Ga事件之前，同时获取了太阳气体和大部分的宇宙气，这导致了冲击变质作用并形成了坚硬角砾岩角砾岩。沿晶界的烧结和凝集导致动员了太阳风，再注入的，辐射成因的和宇宙成因的稀有气体，并导致其部分均质化，分级分离，并重新陷于了空隙和/或可通过压碎进入的缺陷中。一种替代方案是完全重置4.1 Ga之前的K-Ar系统，同时损失所有先前累积的太阳和宇宙成因稀有气体。后来，Dhofar 1436的前身变成了月球长石，并积累了太阳和宇宙成因的稀有气体，并被重新植入。1 Ga以前伴随着所有先前累积的太阳和宇宙成因稀有气体的流失。后来，Dhofar 1436的前身变成了月球长石，并积累了太阳和宇宙成因的稀有气体，并被重新植入。1 Ga以前伴随着所有先前累积的太阳和宇宙成因稀有气体的流失。后来，Dhofar 1436的前身变成了月球长石，并积累了太阳和宇宙成因的稀有气体，并被重新植入。在最终形成多金属撞击角砾岩之前⁴⁰ Ar。与c丰度的步骤燃烧的佐法尔1436是555.3 ppm的，具有δ ¹³ -28‰至+ 11‰℃。压碎和燃烧释放的氮含量分别为3.2 ppm和20.8 ppm。最轻的氮组合物（δ ¹⁵ N = -79‰）很可能是由于从休克变质相的空隙释放和相当氮成分的动员之前4.1嘎事件累积的结果。