Olivine-rich exposures in the South Pole-Aitken Basin
Olivine-rich exposures in the South Pole-Aitken Basin
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DOI：
10.1016/j.icarus.2011.12.012
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发表时间：
2012-03
期刊：
影响因子：
3.2
通讯作者：
S. Yamamoto;R. Nakamura;T. Matsunaga;Y. Ogawa;Y. Ishihara;T. Morota;N. Hirata;M. Ohtake;T. Hiroi;Y. Yokota;J. Haruyama
中科院分区：
文献类型：
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作者：
S. Yamamoto;R. Nakamura;T. Matsunaga;Y. Ogawa;Y. Ishihara;T. Morota;N. Hirata;M. Ohtake;T. Hiroi;Y. Yokota;J. Haruyama
根据日本月球探测器 Kaguya/SELENE 上的光谱剖面仪 (SP) 和多波段成像仪 (MI) 获得的光谱数据，研究了月球南极-艾特肯 (SPA) 盆地富含橄榄石暴露的分布和地质背景。富含橄榄石的暴露仅在薛定谔盆地和塞曼陨石坑的峰环或中心峰中发现，它们位于SPA盆地的外部区域，而不是在中心区域。在局部范围内，富含橄榄石的物质暴露在火山口壁或中心峰或峰环的倾斜壁上的滑坡特征上。另一个观测发现是，薛定谔盆地大部分富含橄榄石的地点，在千米尺度上富含橄榄石和富含斜长石的物质共存。富含辉石的物质存在于峰环外的新鲜火山口或富含橄榄石物质的中心峰中。基于这些结果，提出以下设想：（1）形成SPA盆地的撞击使月球上地幔和地壳大量融化，并将融化的物质分布到外部区域； (2)熔融物质的局部分异掩盖了SPA盆地中心区域的富橄榄石物质； （3）后来形成薛定谔陨石坑和塞曼陨石坑的撞击将富含橄榄石的物质再次挖掘并暴露在地表； (4) 空间风化和风化层园艺掩盖了暴露地点富含橄榄石的光谱，但最近倾斜墙壁上的小规模撞击或山体滑坡暴露了新鲜的富含橄榄石的物质，允许通过光谱遥感识别富含橄榄石的暴露。这表明，几个不同规模的事件在形成月球以及其他行星体上最初深层物质的表面分布方面发挥着重要作用。
The distribution and the geological context of the olivine-rich exposures in the South Pole-Aitken (SPA) Basin on the Moon were investigated based on the spectral data obtained from the Spectral Profiler (SP) and Multiband Imager (MI) onboard the Japanese lunar explorer Kaguya/SELENE. The olivine-rich exposures are found only in the peak rings or central peaks of the Schrödinger basin and Zeeman crater, which are located in the outer region of the SPA Basin and not in the center region. On a localized scale, the olivine-rich materials are exposed on landslide features on the crater walls or sloped wall of the central peaks or the peak rings. Another observational finding is the co-existence of olivine-rich and plagioclase-rich materials on a kilometer scale spanning most of the olivine-rich sites in the Schrödinger basin. Pyroxene-rich materials are found in fresh craters outside the peak rings or the central peaks with olivine-rich materials. Based on these results, the following scenario are proposed: (1) the impact to form the SPA Basin melted a large amount of the lunar upper mantle and crust, and distributed the melted materials to the outer region; (2) local differentiation of melted materials hid the olivine-rich materials in the center region of the SPA Basin; (3) later impacts that formed the Schrödinger and Zeeman craters excavated and exposed the olivine-rich materials to the surface again; and (4) space weathering and regolith gardening obscured the olivine-rich spectra at the exposure sites, but recent, small scale impacts or landslides on the sloped wall exposed fresh olivine-rich materials, allowing the identification of the olivine-rich exposures by spectral remote-sensing. This suggests that several, different scale events play an important role in forming the surface distributions of originally deep-seated materials on the Moon, as well as on other planetary bodies.