Martinot M, Besse S, Flahaut J, Quantin-Nataf C, Lozac'h L, van Westrenen W
Faculty of Science Vrije Universiteit Amsterdam Amsterdam The Netherlands.
Université Lyon 1, ENS-Lyon, CNRS, UMR 5276 LGL-TPE Villeurbanne France.
J Geophys Res Planets. 2018 Feb;123(2):612-629. doi: 10.1002/2017JE005435. Epub 2018 Feb 26.
Moon Mineralogy Mapper (M) spectroscopic data and high-resolution imagery data sets were used to study the mineralogy and geology of the 207 km diameter Humboldt crater. Analyses of M data, using a custom-made method for M spectra continuum removal and spectral parameters calculation, reveal multiple pure crystalline plagioclase detections within the Humboldt crater central peak complex, hinting at its crustal origin. However, olivine, spinel, and glass are observed in the crater walls and rims, suggesting these minerals derive from shallower levels than the plagioclase of the central peak complex. High-calcium pyroxenes are detected in association with volcanic deposits emplaced on the crater's floor. Geologic mapping was performed, and the age of Humboldt crater's units was estimated from crater counts. Results suggest that volcanic activity within this floor-fractured crater spanned over a billion years. The felsic mineralogy of the central peak complex region, which presumably excavated deeper material, and the shallow mafic minerals (olivine and spinel) detected in Humboldt crater walls and rim are not in accordance with the general view of the structure of the lunar crust. Our observations can be explained by the presence of a mafic pluton emplaced in the anorthositic crust prior to the Humboldt-forming impact event. Alternatively, the excavation of Australe basin ejecta could explain the observed mineralogical detections. This highlights the importance of detailed combined mineralogical and geological remote sensing studies to assess the heterogeneity of the lunar crust.
月球矿物学绘图仪（M3）光谱数据和高分辨率图像数据集被用于研究直径207千米的洪堡撞击坑的矿物学和地质情况。利用一种定制的M3光谱连续谱去除和光谱参数计算方法对M3数据进行分析，结果显示在洪堡撞击坑中央峰复合体中有多个纯结晶斜长石的探测结果，这暗示了其地壳起源。然而，在坑壁和坑缘中观测到了橄榄石、尖晶石和玻璃，这表明这些矿物的来源深度比中央峰复合体中的斜长石浅。在与位于撞击坑底部的火山沉积物相关的区域检测到了高钙辉石。进行了地质测绘，并通过撞击坑计数估算了洪堡撞击坑各单元的年龄。结果表明，这个底部断裂的撞击坑内的火山活动跨越了十亿多年。中央峰复合体区域的长英质矿物学特征（可能挖掘出了更深层的物质）与在洪堡撞击坑壁和坑缘中检测到的浅层镁铁质矿物（橄榄石和尖晶石）与月球地壳结构的一般观点不一致。我们的观测结果可以通过在形成洪堡撞击坑的撞击事件之前侵入斜长质地壳中的一个镁铁质深成岩体来解释。或者，澳大利亚盆地喷出物的挖掘也可以解释观测到的矿物学探测结果。这突出了详细的矿物学和地质遥感联合研究对于评估月球地壳非均质性的重要性。
