Fonction : Chargée de recherche (CR)
Domaine(s) de recherche :
Planétologie (Mars, Lune, Mercure, Analogues terrestres), Spectroscopie VNIR, Télédetection, SIGs, Géologie de terrain
Thème(s) :
Coordonnées :
CRPG UMR 7358 CNRS-UL
15 rue Notre Dame des Pauvres
54500 Vandœuvre les Nancy – France
Email : jessica.flahaut@univ-lorraine.fr
Téléphone : +33 (0)3 83 59 42 15
Bureau : 208
Traitement d’images, Télédétection, SIGs
Planétologie / Missions Spatiales
Depuis 2023:
Wilk, K., J.L. Bishop, C.M. Weitz, M. Parente, A. M. Saranathan, Y. Itoh, C. Gross, J. Flahaut, F. Seelos (2024) Characterization of aqueous alteration and formation of salty exposures at Ius Chasma, Mars, Icarus, 408, 115800, doi : 10.1016/j.icarus.2023.11580.
Crawford, I. A., Anand, M., Barber, S., Cowley, A., Crites, S., Fa, W., Flahaut J. et al. (2023). Lunar resources. Reviews in Mineralogy and Geochemistry, 89(1), 829-868.
Flahaut, J., C.H. van der Bogert, I.A. Crawford & S. Vincent-Bonnieu (2023). Scientific perspectives on lunar exploration in Europe. npj Microgravity, 9(1), 50, doi:10.1038/s41526-023-00298-9.
Barthez, M., J. Flahaut, M. Guitreau, G. Ito & R. Pik (2023). Understanding VNIR plagioclase signatures on Mars through petrographic, geochemical and spectral characterization of terrestrial feldspar‐bearing igneous rocks. Journal of Geophysical Research: Planets, doi: 10.1029/2022JE007680.
2023 |
Flahaut, J., Payet, V., Fueten, F., Guitreau, M., Barthez, M., Ito, G., Allemand, P. New detections of feldspar-bearing volcanic rocks in the walls of Valles Marineris, Mars (Article de journal) Dans: Geophysical Research Letters, vol. 50, p. e2022GL100772, 2023. @article{Flahaut_etal2023,Plagioclase-bearing rocks were first detected in the vicinity of large impact basins on Mars using visible/near-infrared (VNIR) data. The geologic context is consistent with excavated plutons or ancient crustal outcrops. Our analyses reveal plagioclase outcrops exposed in a 200 m thick, sub-horizontal layer in the 8 km deep walls of the Valles Marineris canyon. These plagioclase-bearing rocks are consistent with either a sill, a volcano-clastic layer, or a porphyritic lava flow, in contrast with the previous understanding that plagioclase feldspar signatures must be indicative of nearly pure, anorthositic rocks inherited from a primary flotation crust or granitoids from either plutonic activity or ancient continental crust. We present here evidence of possibly effusive, volcanic rocks bearing plagioclase VNIR spectral signatures, expanding the geologic setting of these unique and uncommon martian rocks to include multiple lithologies. This has direct implications for Mars magmatic processes and for the nature of its crust. |
2022 |
Beck, N., Flahaut, J., Breton, S. En avant Mars ! Histoire et avenir de l’exploration martienne (Ouvrage) 2022. (BibTeX) @book{Beck_etal2022, |
Losekamm, M. J., Biswas, J., Chupin, T., Deiml, M., Deremetz, M., Evagora, A. M., Fau, G., Flahaut, J., Gancet, J., Glier, M., Gscheidle, C., M.,, Joulaud, Assessing the distribution of water ice and other volatiles at the Lunar South Pole with LUVMI-X: A mission concept (Article de journal) Dans: The Planetary Science Journal, vol. 3, p. 229, 2022. @article{Losekamm_etal2022,The search for exploitable deposits of water and other volatiles at the Moon’s poles has intensified considerably in recent years, due to the renewed strong interest in lunar exploration. With the return of humans to the lunar surface on the horizon, the use of locally available resources to support long-term and sustainable exploration programs, encompassing both robotic and crewed elements, has moved into focus of public and private actors alike. Our current knowledge about the distribution and concentration of water and other volatiles in the lunar rocks and regolith is, however, too limited to assess the feasibility and economic viability of resource-extraction efforts. On a more fundamental level, we currently lack sufficiently detailed data to fully understand the origins of lunar water and its migration to the polar regions. In this paper, we present LUVMI-X, a mission concept intended to address the shortage of in situ data on volatiles on the Moon that results from a recently concluded design study. Its central element is a compact rover equipped with complementary instrumentation capable of investigating both the surface and shallow subsurface of illuminated and shadowed areas at the lunar south pole. We describe the rover and instrument design, the mission’s operational concept, and a preliminary landing-site analysis. We also discuss how LUVMI-X fits into the diverse landscape of lunar missions under development. |
Ito, G., Flahaut, J., Gonzalez-Maurel, O., Godoy, B., Payet, V., Barthez, M. Remote sensing survey of Altiplano-Puna volcanic complex rocks and minerals for planetary analog use (Article de journal) Dans: Remote Sensing, vol. 14, no. 9, p. 2081, 2022. @article{Ito_etal2022,The Altiplano-Puna Volcanic Complex (APVC) of the Central Andes is an arid region with extensive volcanism, possessing various geological features comparable to those of other solar system objects. The unique features of the APVC, e.g., hydrothermal fields and evaporite salars, have been used as planetary analogs before, but the complexity of the APVC presents a wealth of opportunities for more analog studies that have not been exploited previously. Motivated by the potential of using the APVC as an analog of the volcanic terrains of solar system objects, we mapped the mineralogy and silica content of the APVC up to 100,000 km2 in northern Chile based on a combination of remote sensing data resembling those of the Moon and Mars. The band ratio indices of Landsat 8 Operational Land Imager multispectral images and mineral classifications based on spectral hourglass approach using Earth Observing-1 Hyperion hyperspectral images (both in the visible to shortwave infrared wavelengths) were used to map iron-bearing and alteration minerals. We also used Hyperion imagery to detect feldspar spectral signatures and demonstrated that feldspar minerals can be detected on non-anorthosites, which may influence interpretations of feldspar spectral signatures on Mars. From the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Emissivity Dataset, we derived the silica percentage of non-evaporite rocks within errors of approximately 2--3 wt.% SiO2 for those in the 60--70 wt.% range (about 8 wt.% errors for the 50--60 wt.% range). Based on an integrated assessment of the three datasets, we highlighted three regions of particular interest worthy of further field investigation. We also evaluated the benefits and limitations of all three remote sensing methods for mapping key minerals and capturing rock diversity, based on available samples and existing geological maps. |
2020 |
Schnuriger, N., Flahaut, J., Martinot, M., Chevrel, S. D. Long-lived volcanism expressed through mare infilling, domes and IMPs in the Arago region of the Moon (Article de journal) Dans: Planetary and Space Science, vol. 185, p. 104901, 2020. @article{Schnuriger_etal2020,Mare Tranquillitatis corresponds to the deposit of successive Early to Late Imbrian basaltic units filling the Tranquillitatis basin on the Moon. The present study focuses on the western half of the mare, in the vicinity of the Arago crater (6.16textdegreeN, 21.42textdegreeE). High resolution datasets from recent remote sensing missions were used to reconstruct the geologic history of the area, which includes a variety of geological features such as: 8 extrusive domes, numerous wrinkle ridges, a sinuous rille and 37 Irregular Mare Patches (IMPs). We performed crater counting to date the domes emplacement and estimated the domes lava rheologic properties (plastic viscosities, lava effusion rates, and durations of effusion) using their geometric characteristics. As a result we classify the Arago domes into three groups: E1-type domes (Arago 1 and 8), H1-type domes (Arago 4 to 7), and B-type domes (Arago 2 and 3) respectively emplaced $null$textasciitilde $null$3.7 $null$Ga, textasciitilde3.4 $null$Ga, and textasciitilde2.8 $null$Ga ago. IMPs are observed in the younger mare unit and on the top of the Arago 6 dome; they likely correspond to a late stage of waning mare volcanism in the area. Both IMPs and domes have a composition similar to the surrounding mare in the VNIR spectral domain, consistent with mafic materials. The exceptionally long-lived volcanism and its diversity recorded in the Arago region may be related to both a Th-rich anomaly reported nearby and to the large-scale magma center responsible for the Lamont positive Bouguer anomaly. In addition, volcanic features of the Arago region are superimposed on a Ti-rich mare unit visited by the Apollo 11 crew 175 $null$km to the south at Tranquility Base. The geological and historical richness of this region makes it a compelling site for future science and/or In Situ Resources Utilization (ISRU) driven missions to the Moon. |
Meurisse, A., Flahaut, J., Reiss, P., Carpenter, J. D. Preface to the special issue on textquotelefttextquoteleftSpace resourcestextquoterighttextquoteright (Article de journal) Dans: Planetary and Space Science, vol. 185, p. 1042894, 2020. @article{Meurisse_etal2020, |
Martinot, M., Flahaut, J., Besse, S., Quantin-Nataf, C., Westrenen, W. Mineralogical survey of the anorthositic Feldspathic Highlands Terrane crust using Moon Mineralogy Mapper data (Article de journal) Dans: Icarus, vol. 345, p. 113747, 2020. @article{Martinot_etal2020,Spectroscopic data from the Moon Mineralogy Mapper (M) instrument are used to study the mineralogy of the central peak or peak ring of 75 craters located in the lunar anorthositic Feldspathic Highlands Terrane (FHT-a), as defined by Jolliff et al. (2000). The thickness of South-Pole Aitken (SPA) ejecta at the location of the selected craters is estimated. Crustal thickness models are used with empirical cratering equations to estimate the depth of origin of the material excavated in the studied central peaks, and its distance to the crust-mantle interface. The goal of this survey is to study the composition of the FHT-a crust, and the extent of its potential lateral and vertical heterogeneities. High-Calcium Pyroxene (HCP) and featureless spectra are mostly detected throughout the entire FHT-a, whereas the number of pure plagioclase detections is small. No relationship between the central peak composition and the distance to SPA or the depth within the SPA ejecta is observed. The SPA ejecta material cannot be spectrally distinguished from crustal material. We interpret the paucity of plagioclase spectra in the FHT-a, which contrasts with more frequent plagioclase detections in the central peaks of craters sampling the crust in younger lunar terranes using identical spectroscopic techniques Martinot et al. (2018b), as a possible effect of terrane maturation, or of mixing with mafic components that mask their signature in the visible near-infrared. Overall, the FHT-a appears homogeneous laterally. However, data hint at a pyroxene compositional change with increasing depth, from high-calcium content in the upper crust towards less calcic compositions with increasing depth, which is consistent with prior studies of the architecture of the lunar crust. |
Flahaut, J., Carpenter, J., Williams, J. P., Anand, M., Crawford, I. A., Westrenen, W., Füri, E., Xiao, L., Zhao, S. Regions of interest (ROI) for future exploration missions to the lunar South Pole (Article de journal) Dans: Planetary and Space Science, vol. 180, p. 104750, 2020. @article{Flahaut_etal2020,The last decades have been marked by increasing evidence for the presence of near-surface volatiles at the lunarpoles. Enhancement in hydrogen near both poles, UV and VNIR albedo anomalies, high CPR in remotely sensedradar data have all been tentatively interpreted as evidence for surface and/or subsurface water ice. Lunar waterice and other potential cold-trapped volatiles are targets of interest both as scientific repositories for under-standing the evolution of the Solar System and for exploration purposes. Determining the exact nature, extent andorigin of the volatile species at or near the surface in the lunar polar regions however requiresin situmeasure-ments via lander or rover missions. A number of upcoming missions will address these issues by obtainingin situdata or by returning samples from the lunar surface or shallow subsurface. These all rely on the selection ofoptimal landing sites. The present paper discusses potential regions of interest (ROI) for combined volatile andgeologic investigations in the vicinity of the lunar South Pole. We identified eleven regions of interest (including abroad area of interest (>200 km-200 km) at the South Pole, together with smaller regions located near Cabeus,Amundsen, Ibn Bajja, Wiechert J and Ideltextquoterightson craters), with enhanced near-surface hydrogen concentration(H>100 ppm by weight) and where water ice is expected to be stable at the surface, considering the present-daysurface thermal regime. Identifying more specific landing sites for individual missions is critically dependent onthe missiontextquoterights goals and capabilities. We present detailed case studies of landing site analyses based on the missionscenario and requirements of the upcoming Luna-25 and Luna-27 landers and Lunar Prospecting Rover case study.Suitable sites with promising science outcomes were found for both lander and rover scenarios. However, therough topography and limited illumination conditions near the South Pole reduce the number of possible landingsites, especially for solar-powered missions. It is therefore expected that limited Sun and Earth visibility at lati-tudes>80textdegreewill impose very stringent constraints on the design and duration of future polar missions. |
Aerts, J. W., Riedo, A., Melton, D. J., Martini, S., Flahaut, J., Meierhenrich, U. J., Meinert, C., Myrgorodska, L., Lindner, R., Ehrenfreud, P. Biosignature analysis of Mars soil analogs from the Atacama Desert : Challenges and implications for future missions to Mars (Article de journal) Dans: Astrobiology, vol. 20, no. 6, 2020. @article{Aerts_etal2020,The detection of biosignatures on Mars is of outstanding interest in the current field of astrobiology and drives various fields of research, ranging from new sample collection strategies to the development of more sensitive detection techniques. Detailed analysis of the organic content in Mars analog materials collected from extreme environments on Earth improves the current understanding of biosignature preservation and detection under conditions similar to those of Mars. In this article, we examined the biological fingerprint of several locations in the Atacama Desert (Chile), which include different wet and dry, and intermediate to high elevation salt flats (also named salars). Liquid chromatography and multidimensional gas chromatography mass spectrometry measurement techniques were used for the detection and analysis of amino acids extracted from the salt crusts and sediments by using sophisticated extraction procedures. Illumina 16S amplicon sequencing was used for the identification of microbial communities associated with the different sample locations. Although amino acid load and organic carbon and nitrogen quantities were generally low, it was found that most of the samples harbored complex and versatile microbial communities, which were dominated by (extremely) halophilic microorganisms (most notably by species of the Archaeal family Halobacteriaceae). The dominance of salts (i.e., halites and sulfates) in the investigated samples leaves its mark on the composition of the microbial communities but does not appear to hinder the potential of life to flourish since it can clearly adapt to the higher concentrations. Although the Atacama Desert is one of the driest and harshest environments on Earth, it is shown that there are still sub-locations where life is able to maintain a foothold, and, as such, salt flats could be considered as interesting targets for future life exploration missions on Mars. |
2019 |
Mangold, N., Flahaut, J., Ansan, V. The surface composition of terrestrial planets (Article de journal) Dans: Oxford Research Encyclopedias Planetary Science, 2019. @article{Mangold_etal2019,Planetary surface compositions are fundamental to an understanding of both the interior activity through differentiation processes and volcanic activity and the external evolution through alteration processes and accumulations of volatiles. While the Moon has been studied since early on using ground-based instruments and returned samples, observing the surface composition of the terrestrial planets did not become practical until after the development of orbital and in situ missions with instruments tracking mineralogical and elemental variations. The poorly evolved, atmosphere-free bodies like the Moon and Mercury enable the study of the formation of the most primitive crusts, through processes such as the crystallization of a magma ocean, and their volcanic evolution. Nevertheless, recent studies have shown more diversity than initially expected, including the presence of ice in high latitude regions. Because of its heavy atmosphere, Venus remains the most difficult planetary body to study and the most poorly known in regards to its composition, triggering some interest for future missions. In contrast, Mars exploration has generated a huge amount of data in the last two decades, revealing a planet with a mineralogical diversity close to that of the Earth. While Mars crust is dominated by basaltic material, recent studies concluded for significant contributions of more felsic and alkali-rich igneous material, especially in the ancient highlands. These ancient terrains also display widespread outcrops of hydrous minerals, especially phyllosilicates, which are key in the understanding of past climate conditions and suggest a volatile-rich early evolution with implications for exobiology. Recent terrains exhibit a cryosphere with ice-rich landforms at, or close to the surface, of mid- and high latitudes, generating a strong interest for recent climatic variability and resources for future manned missions. While Mars is certainly the planetary body the most similar to Earth, the observation of specific processes such as those linked to interactions with solar wind on atmosphere-free bodies, or with a thick acidic atmosphere on Venus, improve our understanding of the differences in evolution of terrestrial bodies. Future exploration is still necessary to increase humankindtextquoterights knowledge and further build a global picture of the formation and evolution of planetary surfaces. |
Guitreau, M., Flahaut, J. Record of low-temperature aqueous alteration of Martian zircon during the late Amazonian (Article de journal) Dans: Nature Communications, vol. 10, no. 1, p. 2457, 2019. @article{Guitreau+Flahaut2019,Several lines of evidence support the presence of liquid water on Mars at different times. Among those, hydrated minerals testify to past aqueous weathering processes that can be precisely studied in Martian meteorites such as NWA 7533/7034. Bringing constraints on the timing of weathering of the Martian crust would help understand its evolution, the availability of liquid water, and the habitability of Mars. Here we present a new method based on U--Th--Pb isotope systems to assess if zircon crystals underwent low-temperature aqueous alteration, such as exemplified by Hadean-aged detrital crystals from Western Australia. Data for NWA 7533 zircons show evidence for aqueous alteration and modeling of U--Th--Pb isotope system evolution indicates that the latest alteration event occurred during the late Amazonian (227--56 Ma). This finding largely expands the time duration over which liquid water was available near the Martian surface, thereby suggesting that Mars might still be habitable. |
Flahaut, J., Bishop, J. L., Silvestro, S., Tedesco, D., Daniel, I., Loizeau, D. The Italian Solfatara as an analog for Mars fumarolic alteration (Article de journal) Dans: American Mineralogist, vol. 104, p. 1565–1577, 2019. @article{Flahaut_etal2019,The first definitive evidence for continental vents on Mars is the in situ detection of amorphous silica-rich outcrops by the Mars Exploration Rover Spirit. These outcrops have been tentatively interpreted as the result of either acid sulfate leaching in fumarolic environments or direct precipitation from hot springs. Such environments represent prime targets for upcoming astrobiology missions but remain difficult to identify with certainty, especially from orbit. To contribute to the identification of fumaroles and hot spring deposits on Mars, we surveyed their characteristics at the analog site of the Solfatara volcanic crater in central Italy. Several techniques of mineral identification (VNIR spectroscopy, Raman spectroscopy, XRD) were used both in the field and in the laboratory on selected samples. The faulted crater walls showed evidence of acid leaching and alteration into the advanced argillic-alunitic facies, with colorful deposits containing alunite, jarosite, and/or hematite. Sublimates containing various Al and Fe hydroxyl-sulfates were observed around the active fumarole vents at 90 textdegreeC. One vent at 160 textdegreeC was characterized by different sublimates enriched in As and Hb sulfide species. Amorphous silica and alunite assemblages that are diagnostic of silicic alteration were also observed at the Fangaia mud pots inside the crater. A wide range of minerals was identified at the 665 m diameter Solfatara crater that is diagnostic of acid-steam heated alteration of a trachytic, porous bedrock. Importantly, this mineral diversity was captured at each site investigated with at least one of the techniques used, which lends confidence for the recognition of similar environments with the next-generation Mars rovers. |
Aerts, J. W., Spanning, R. J. M., Flahaut, J., Molenaar, D., Bland, P. H., Genge, M. J., Ehrenfreund, P., Martins, Z. Microbial communities in sediments from four mildly acidic ephemeral salt lakes in the Yilgarn Craton (Australia) -- Terrestrial analogs to ancient Mars (Article de journal) Dans: Frontiers in Microbiology, vol. 10, 2019. @article{Aerts_etal2019,The Yilgarn Craton in Australia has a large number of naturally occurring shallow ephemeral lakes underlain by a dendritic system of paleodrainage channels. Processes like evaporation, flooding, erosion, as well as inflow of saline, often acidic and ion-rich groundwater contribute to the (dynamic) nature of the lakes and the composition of the sediments. The region has previously been described as an analog environment for early Mars due to its geological and geophysical similarities. Here, we investigated sediment samples of four lake environments aimed at getting a fundamental understanding of the native microbial communities and the mineralogical and (bio)chemical composition of the sediments they are associated with. The dominant mineral phases in the sediments were quartz, feldspars and amphiboles, while halite and gypsum were the only evaporites detected. Element analysis revealed a rich and complex image, in which silicon, iron, and aluminum were the dominant ions, but relative high concentrations of trace elements such as strontium, chromium, zirconium, and barium were also found. The concentrations of organic carbon, nitrogen, and phosphorus were generally low. 16S amplicon sequencing on the Illumina platform showed the presence of diverse microbial communities in all four lake environments. We found that most of the communities were dominated by extremely halophilic Archaea of the Halobacteriaceae family. The dynamic nature of these lakes appears to influence the biological, biochemical, and geological components of the ecosystem to a large effect. Inter- and intra-lake variations in the distributions of microbial communities were significant, and could only to a minor degree be explained by underlying environmental conditions. The communities are likely significantly influenced by small scale local effects caused by variations in geological settings and dynamic interactions caused by aeolian transport and flooding and evaporation events. |
2018 |
Schmidt, G., Fueten, F., Stesky, R., Flahaut, J., Hauber, E. Geology of Hebes Chasma, Mars: 1. Structure, Stratigraphy, and Mineralogy of the Interior Layered Deposits (Article de journal) Dans: Journal of Geophysical Research (Planets), vol. 123, no. 123, p. 2893–2919, 2018. @article{Schmidt_etal2018,Hebes Chasma is an 8‐km deep, 126 by 314 km, isolated basin that is partially filled with massive deposits of water‐altered strata called interior layered deposits (ILDs). By analyzing the ILDtextquoterights structure, stratigraphy, and mineralogy, a depositional history of Hebes Chasma is interpreted. Three distinct ILD units were found and are informally referred to as the Lower, Upper, and Late ILD. These units are distinguished by their layer thicknesses, layer attitudes, mineralogies, and erosional landforms. The Lower and Upper ILDs comprise the chasmatextquoterights 7.5‐km tall, 120 by 43 km, central mound, and the Late ILD is located in the valley between the central mound and the chasmatextquoterights northern wall. A horizontal unconformity separates the Lower and Upper ILDs, and layer attitudes revealed large‐scale shallow folding within the Lower ILD. All ILDs are characterized by both monohydrated and polyhydrated sulfates signatures. Erosional landforms such as hummocks, polygons, and debris flows suggest past glacial activity within the chasma. A scenario involving several ash fall events during various stages of chasma formation is proposed as the dominant setting throughout Hebestextquoteright geologic history. |
Qian, Y. Q., Xiao, L., Zhao, S. Y., Zhao, J. N., Huang, J., Flahaut, J., Martinot, M., Head, J. W., Hiesinger, H., Wang, G. X. Geology and Scientific significance of the Rümker region in Northern Oceanus Procellarum: Chinatextquoterights ChangtextquoterightE‐5 Landing region (Article de journal) Dans: Journal of Geophysical Research (Planets), vol. 123, no. 6, 2018. @article{Qian_etal2018,The Rümker region (41‐45textdegree N, 49‐69textdegree W) is located in northern Oceanus Procellarum of the Moon. Mons Rümker is the most distinctive geological feature in the area. The region is characterized by prolonged lunar volcanism (Late Imbrian Period to Eratosthenian Period), forming multiple geologic units in the area, including very low‐Ti to low‐Ti mare basalts, high‐Ti mare basalts, and volcanic complexes. Each geologic unit has distinct element composition and mineral assemblages. The Rümker region, overlying the Procellarum KREEP Terrain, was selected as the landing region for Chinatextquoterights ChangtextquoterightE‐5 lunar sample return mission. Pre‐landing analysis of the geologic context and scientific potential are reported in this contribution. We conducted detailed geological mapping using image, spectral and altimetry data. Fourteen geological units were defined, a geologic map was constructed, and the geologic history was outlined. The western mare units (Im1, Im2, Im3) are Imbrian‐aged (textasciitilde3.4‐3.5 Ga) representing the major stage of lunar mare eruptive volcanism. The eastern young mare units (Em3, Em4; <2 Ga) are among the youngest mare basalts on the Moon. They have never been explored in situ or studied in the laboratory. We suggest that samples returned from the eastern mare unit (Em4) could answer many fundamental questions and that this unit should be listed as the top priority landing site for ChangtextquoterightE‐5 sample return mission. |
Martinot, M., Flahaut, J., Besse, S., Quantin-Nataf, C., Westrenen, W. Journal of Geophysical Research: Planets Compositional Variations in the Vicinity of the Lunar Crust-Mantle Interface From Moon Mineralogy Mapper Data (Article de journal) Dans: Journal of Geophysical Research (Planets), vol. 123, p. 3220–3237, 2018. @article{Martinot_etal2018,Moon Mineralogy Mapper spectroscopic data were used to investigate the mineralogy of a selection of impact craterstextquoteright 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 craterstextquoteright 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. |
Huang, J., Xiao, Z., Flahaut, J., Martinot, M., Head, J., Xiao, X., Xie, M., Xiao, L. Geological characteristics of Von Kármán Crater, Northwestern South Pole‐Aitken Basin: ChangtextquoterightE‐4 Landing site region (Article de journal) Dans: Journal of Geophysical Research (Planets), 2018. @article{Huang_etal2018,Von Kármán crater (diameter =textasciitilde186 km), lying in the northwestern South Pole‐Aitken basin, was formed in the pre‐Nectarian. The Von Kármán crater floor was subsequently flooded with one or several generations of mare basalts during the Imbrian period. Numerous subsequent impact craters in the surrounding region delivered ejecta to the floor, together forming a rich sample of the SPA basin and farside geologic history. We studied in detail the targeted landing region (45.0--46.0textdegreeS, 176.4--178.8textdegreeE) of the 2018 Chinese lunar mission ChangtextquoterightE‐4, within the Von Kármán crater. The topography of the landing region is generally flat at a baseline of textasciitilde60 m. Secondary craters and ejecta materials have covered most of the mare unit, and can be traced back to at least four source craters (Finsen, Von Kármán L, Von Kármán Ltextquoteright and Antoniadi) based on preferential spatial orientations and crosscutting relationships. Extensive sinuous ridges and troughs are identified spatially related to Ba Jie crater (diameter = textasciitilde4 km). Reflectance spectral variations due to difference in both composition and physical properties are observed among the ejecta from various‐sized craters on the mare unit. The composition trends were used together with crater scaling relationships and estimates of regolith thickness to reconstruct the subsurface stratigraphy. The results reveal a complex geological history of the landing region, and set the framework for the in‐situ measurements of the CE‐4 mission, which will provide unique insights into the compositions of farside mare basalt, SPA compositional zone, including SPA compositional anomaly and Mg‐pyroxene annulus, regolith evolution and the lunar space environment. |