Abstract

The exploration of mafic anomaly in South Pole-Aitken (SPA, the largest confirmed) basin on the Moon provides important insights into lunar interior. The landing of Chang’e-4 (CE-4) and deployment of Yutu-2 rover on the discontinuous ejecta from Finsen crater enabled in-situ measurements of the unusual mineralogy in the central portion of SPA basin with visible and near-infrared imaging spectrometer (VNIS). Here we present detailed processing procedures based on the level 2B data of CE-4 VNIS and preliminary mineralogical results at the exploration area of Yutu-2 rover. A systematic processing pipeline is developed to derive credible reflectance spectra, based on which several spectral and mineral indices are calculated to constrain the mafic mineralogy. The mafic components in the soils and boulder around CE-4 landing site are concluded as clinopyroxene-bearing with intermediate composition and probably dominated by pigeonite although the possibility of mixing orthopyroxen (OPX) and calcic clinopyroxene (CPX) also exists. These mineralogical results are more consistent with a petrogenesis that the CE-4 regolith and rock fragment are derived from rapid-cooling magmatic systems and we interpret that the materials at the CE-4 landing site ejected from Finsen crater are probably recrystallized from impact melt settings.

中文翻译：

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Chang娥四号着陆点矿物学：可见和近红外成像光谱仪的初步结果

摘要

在月球上南极-艾特肯（SPA，已被确认的最大）盆地的镁铁质异常的勘探提供了对月球内部的重要见解。Fin娥四号（CE-4）的着陆以及Yutu-2漫游车在芬森陨石坑不连续的弹射点上的部署使原位用可见光和近红外成像光谱仪（VNIS）测量SPA盆地中部的异常矿物学。在此，我们根据玉-4 2号火星车勘探区的CE-4 VNIS 2B级数据和初步矿物学结果，介绍详细的处理程序。开发了一个系统化的处理管道以得出可靠的反射光谱，在此基础上，计算了一些光谱和矿物指数来约束镁铁质矿物学。CE-4着陆点周围土壤和巨石中的铁镁质成分被归结为具有斜辉石的中间成分，并且可能由皂石主导，尽管也存在将邻辉石（OPX）和钙化辉石钙化（CPX）混合的可能性。