Global Mg/Si and Al/Si Distributions on the Lunar Surface Derived from Chang'E-2 X-ray Spectrometer

Dong, Wu-Dong; Zhu, Xiaoping; Zhu, M. H.; Xu, A.; Tang, Zesheng

doi:10.1088/1674-4527/16/1/004

Cited by 11 publications

(10 citation statements)

References 27 publications

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“…The results from Chang'e 2 XRS (Dong et al, 2016) indicate lower mafic abundance compared to LPGRS results (Fig. 5).…”

Section: Other Mafic Abundance Results Setsmentioning

confidence: 77%

“…The global median Al 2 O 3 found by Lunar Prospector's LPGRS, 24.7 wt% (Prettyman et al, 2006), implies a mafic abundance of 22.8%. The Chang'E-2 X-ray spectrometer (Dong et al, 2016) found 22.6 wt% Al 2 O 3 , implying for mafic abundance 27.4%, nearly three times the Kaguya SP result. The two X-ray result-sets essentially straddle the intermediate global result-set, LPGRS.…”

Section: Other Mafic Abundance Results Setsmentioning

confidence: 80%

“…In these comparisons, we will utilize results from the Lunar Prospector Gamma-Ray Spectrometer, LPGRS (Prettyman et al, 2006); the Kaguya GRS (Yamashita et al, 2012); and the Chang'e 2 X-ray spectrometer (Dong et al, 2016). Brief comparison will also be drawn with results from the Chang'e 1 Interference Imaging Spectrometer (Xia et al, 2019), and with X-ray spectrometer results, from the Apollo 15 and 16 missions (Adler et al, 1973;BVSP, 1981) and from the Chandrayaan-1 mission (Athiray et al, 2014;Narendranath et al, 2011).…”

Section: Methodology Orbital Data Sets Used In Comparisonsmentioning

confidence: 99%

“…The Chandrayaan-1 and Chang'e 2 X-ray spectrometers (XRSs) measured X-ray activity at broad ranges of energies inclusive of the most relevant 1-7 keV (Dong et al, 2016;Narendranath et al, 2011). A fortunate circumstance for Chang'e 2 XRS was that the Sun was in an active period with a number of solar flare events during the Chang'e 2 mission.…”

Section: Methodology Orbital Data Sets Used In Comparisonsmentioning

confidence: 99%

“…A fortunate circumstance for Chang'e 2 XRS was that the Sun was in an active period with a number of solar flare events during the Chang'e 2 mission. However, the spatial resolution of Chang'e 2 XRS was at best about 200 × 70 km (Dong et al, 2016), and the resultant map is based on the same ~600 km, "20 degrees" (of latitude) grid as a set of lowest resolution (best counting statistics) LPGRS maps (Prettyman et al, 2006).…”

Section: Methodology Orbital Data Sets Used In Comparisonsmentioning

confidence: 99%

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Ground truth constraints and remote sensing of lunar highland crust composition

Warren

Korotev²

2022

Meteorit & Planetary Scien

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We review constraints on the magnitude and possible causes of discrepancies, or at least major disparities, among global and near‐global data sets for lunar highland surface composition. When compared with data from other sources, reported mafic mineral abundance results from the Kaguya Spectral Profiler (Kaguya SP) spectral reflectance method for four Apollo 16 soils appear systematically low by a factor of 0.6, or an even more extreme factor (~1/3) if viewed in relation to the soils’ nonglass or CIPW mineralogy. Also, whether evaluated on a global median basis or on the basis of site‐by‐site comparison (for Apollo 16, Luna 20, and Apollo 17), the compositions found by the Kaguya SP technique show discrepancy, or at least disparity, versus other mafic abundance observations by that same factor of ~1/3. Spectral reflectance does not supply a simple bulk analysis of the target soil. The reflectance mineralogical signal is preponderantly determined by the nonglass fraction, and especially the masswise subordinate 10–20 µm grain size fraction. Literature data show that in anorthositic lunar soil, chemical composition is fractionated, more extremely anorthositic, for the nonglass component compared to the glass component. Also, the grain size fraction (10–20 μm) that most closely matches bulk reflectance has a significantly higher abundance of impact/agglutinitic glass than does the coarser material that dominates the soil mass. The Kaguya SP mafic abundance calibration needs adjustment by a factor of nearly 3 if results are to be interpreted as indicative of the mineralogy of the underlying crust. A claimed detection of several hundred lunar 500 m scale purest anorthosite (PAN; ≥98 vol% plagioclase) locales among millions of spectral reflectance observations is dubious, in part because with large data sets, compositional extremes are inevitably exaggerated as a byproduct of analytical uncertainty. Preponderance of PAN composition is rare among terrestrial layered intrusive anorthosites and is neither required nor expected for the flotation crust of a global magma ocean. Buoyant flotation and compaction would not suffice to yield pure plagioclase unless adcumulus growth was negligible, and trace element contents of ferroan anorthosites show that their mafic silicate components are for the most part of adcumulus, not “trapped melt,” derivation. A PAN‐dominated crust would imply a curiously fractionated (low) thorium/aluminum ratio for the crust, an implausibly high mantle/crust Th concentration ratio, and an oddly low Th/Al for the bulk Moon. Remote sensing techniques for planetary regolith composition are not easy to calibrate, particularly near the extremes of composition‐space and sensitivity.

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“…The results from Chang'e 2 XRS (Dong et al, 2016) indicate lower mafic abundance compared to LPGRS results (Fig. 5).…”

Section: Other Mafic Abundance Results Setsmentioning

confidence: 77%

Section: Other Mafic Abundance Results Setsmentioning

confidence: 80%