Northwest Africa 482: A crystalline impact‐melt breccia from the lunar highlands
Northwest Africa 482: A crystalline impact‐melt breccia from the lunar highlands
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DOI：
10.1111/j.1945-5100.2002.tb01164.x
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发表时间：
2002-12
影响因子：
2.2
通讯作者：
I. Daubar;D. Kring;T. Swindle;A. Jull
中科院分区：
文献类型：
--
作者：
I. Daubar;D. Kring;T. Swindle;A. Jull
摘要：西北非洲482（NWA 482）是一个来自月球的结晶冲击熔融角砾岩，具有高地亲和力。再结晶基质和碎屑群均为高度非正相。碎屑都与含铁斜长岩系列有关，包括孤立的斜长石晶体和岩屑斜长岩、长斜长岩和尖晶石长斜长岩。钾，稀土元素和磷（KREEP）和月海岩性都不存在，将这颗陨石的源区限制在高地地形，几乎没有KREEP成分，最有可能在月球的远端。玻璃存在于穿过样品的冲击脉和几个大的熔体袋中，表明第二次撞击事件。
Abstract— Northwest Africa 482 (NWA 482) is a crystalline impact‐melt breccia from the Moon with highlands affinities. The recrystallized matrix and the clast population are both highly anorthositic. Clasts are all related to the ferroan anorthosite suite, and include isolated plagioclase crystals and lithic anorthosites, troctolites, and spinel troctolites. Potassium‐, rare‐earth‐element‐, and phosphorus‐bearing (KREEP) and mare lithologies are both absent, constraining the source area of this meteorite to a highland terrain with little to no KREEP component, most likely on the far side of the Moon. Glass is present in shock veins cutting through the sample and in several large melt pockets, indicating a second impact event.