South Pole–Aitken basin ejecta reveal the Moon’s upper mantle

Melosh, H. J.; Kendall, J. D.; Horgan, B.; Johnson, Brandon C.; Bowling, T. J.; Lucey, P. G.; Taylor, G. J.

doi:10.1130/g39375.1

Cited by 137 publications

(149 citation statements)

References 20 publications

Supporting

Mentioning

126

Contrasting

Order By: Relevance

“…This is consistent with the recent study by Melosh et al (2017), who proposed that the lunar upper mantle has a large LCP component instead of olivine signatures. However, olivine detections are scarce in the craters studied here (only 3 craters out of 36) and does not appear to have a major role in the transition from the crust to the mantle.…”

Section: Spinel and Olivine Detectionssupporting

confidence: 93%

“…On the contrary, Lemelin et al (2015) used Kaguya Multiband Imager data, and found no clear evidence of increasing mafic content with depth within the crust. Melosh et al (2017) combined the results of the simulation with spectroscopic observations of the SPA ejecta blanket and concluded that the lunar upper mantle has a large LCP component. They proposed several origins for the OOS lithologies: they might represent components of the deep crust or even the crust-mantle interface, or alternatively have an exogenic origin.…”

Section: Introductionmentioning

confidence: 99%

“…They also found evidence for the presence of mafic plutons in the crust. Melosh et al (2017) 3-D modeled the largest lunar impact basin (SPA, with a diameter exceeding 2,200 km Howard et al, 1974;Spudis et al, 1994), and showed that the SPA impact event sampled the upper mantle. Pieters et al (2011) used spectroscopic data from the Moon Mineralogy Mapper (M 3 ) instrument to study the Moscoviense impact basin and described so-called OOS rock types, defined by high abundances of Orthopyroxene, Olivine, and Mg-rich Spinel.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compositional Variations in the Vicinity of the Lunar Crust‐Mantle Interface From Moon Mineralogy Mapper Data

et al. 2018

View full text Add to dashboard Cite

Moon Mineralogy Mapper spectroscopic data were used to investigate the mineralogy of a selection of impact craters' central peaks or peak rings, in order to characterize the lunar crust‐mantle interface, and assess its lateral and vertical heterogeneity. The depth of origin of the craters' central peaks or peak rings was calculated using empirical equations, and compared to Gravity Recovery and Interior Laboratory crustal thickness models to select craters tapping within +10/−20 km of the crust‐mantle interface. Our results show that plagioclase is widely detected, including in craters allegedly sampling lower crustal to mantle material, except in central peaks where Low‐Calcium Pyroxene was detected. Olivine detections are scarce, and identified in material assumed to be derived from both above and below the crust‐mantle interface. Mineralogical detections in central peaks show that there is an evolution of the pyroxene composition with depth, that may correspond to the transition from the crust to the mantle. The correlation between High‐Calcium Pyroxene and some pyroxene‐dominated mixture spectra with the location of maria and cryptomaria hints at the existence of lateral heterogeneities as deep as the crust‐mantle interface.

show abstract

Section: Spinel and Olivine Detectionssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compositional Variations in the Vicinity of the Lunar Crust‐Mantle Interface From Moon Mineralogy Mapper Data

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Model simulations of a large impact event at the angle 30°–60° suggest that an SPA‐scale event should penetrate through entire lunar crust and excavate mantle materials (Melosh et al, ). Yet the region inside the SPA does not show strong spectral signatures of olivine (Lucey, ), which has been thought to be the major component of the lunar mantle.…”

Section: Introductionmentioning

confidence: 99%

Geologic History of the Northern Portion of the South Pole‐Aitken Basin on the Moon

et al. 2018

View full text Add to dashboard Cite

We conducted a detailed photogeological analysis of the northern portion of the South Pole‐Aitken (SPA) basin (10–60°S, 125–175°W) and compiled a geological map (1:500,000 scale) of this region. Our new absolute model age for the Apollo basin, 3.98 + 0.04/−0.06 Ga, provides a lower age limit for the formation of the SPA basin. Some of the plains units in the study area were formed by distal ejecta from remote craters and basins. The characteristic concentrations of FeO and TiO2 of other plains are indicative of their volcanic origin. The oldest volcanic materials occur near the center of the SPA basin and have an Early Imbrian age of ~3.80 + 0.02/−0.02 Ga. Late Imbrian volcanic activity occurred in and around the Apollo basin. In total, the volcanic plains cover ~8% of the map area and cannot account for the extensive SPA iron signature. The sources of the signature are the oldest materials on the SPA floor (FeO ~11–14.5 wt%). In contrast, the ejecta composing the SPA rim are significantly poorer in FeO (<7.5 wt%). The signature could be related to the differentiation of the SPA impact melt. However, the spatial segregation of the ancient iron‐rich and iron‐poor materials suggests that the SPA iron signature predated the basin. Thus, the signature might be explained by a pre‐SPA lunar crust that was stratified with respect to the iron concentrations, so that the SPA impact excavated the upper, iron‐poorer portion of the crust to form the SPA rim and exposed the deeper, iron‐richer portion on the floor of the basin.

show abstract

“…Figure a shows the age just after the formation of the megaregolith on the lunar primordial crust composed of PAN, which was formed during the Lunar Magma Ocean (LMO). In this scenario, we assume that the megaregolith in the FHT originated from the ejecta of huge impact basins such as the SPA or the putative Procellarum impact basin [ Hawke et al , ; Nakamura et al , ; Lucey et al , ; Melosh et al , ].…”

Section: Discussionmentioning

confidence: 99%

Featureless spectra on the Moon as evidence of residual lunar primordial crust

et al. 2015

View full text Add to dashboard Cite

We report the global distribution of areas exhibiting no absorption features (featureless or FL) on the lunar surface, based on the reflectance spectral data set obtained by the Spectral Profiler onboard Kaguya/SELENE. We found that FL sites are located in impact basins and large impact craters in the Feldspathic Highlands Terrane, while there are no FL sites in the Procellarum regions nor the South Pole‐Aitken basin. FL sites in each impact basin/crater are mainly found at the peak rings or rims, where the purest anorthosite (PAN) sites are also found. At the local scale, most of the FL and PAN points are associated with impact craters and peaks. Most of the FL spectra show a steeper (redder) continuum than the PAN spectra, suggesting the occurrence of space weathering effects. We propose that most of the material exhibiting a FL spectrum originate from space weathered PAN. Taking into account all the occurrence trends of FL sites on the Moon, we propose that both the FL and PAN materials were excavated from the primordial lunar crust during ancient basin formations below the megaregolith in the highlands. Since the FL and PAN sites are widely distributed over the lunar surface, our new data may support the existence of a massive PAN layer below the lunar surface.

show abstract

South Pole–Aitken basin ejecta reveal the Moon’s upper mantle

Cited by 137 publications

References 20 publications

Compositional Variations in the Vicinity of the Lunar Crust‐Mantle Interface From Moon Mineralogy Mapper Data

Compositional Variations in the Vicinity of the Lunar Crust‐Mantle Interface From Moon Mineralogy Mapper Data

Geologic History of the Northern Portion of the South Pole‐Aitken Basin on the Moon

Featureless spectra on the Moon as evidence of residual lunar primordial crust

Contact Info

Product

Resources

About