scholarly journals A dry lunar mantle reservoir for young mare basalts of Chang’E-5

Nature ◽  
2021 ◽  
Author(s):  
Sen Hu ◽  
Huicun He ◽  
Jianglong Ji ◽  
Yangting Lin ◽  
Hejiu Hui ◽  
...  
Keyword(s):  
Mantle Reservoir ◽  
Mare Basalts

scholarly journals A dry lunar mantle reservoir for young mare basalts of Chang’E-5

2021 ◽  
Author(s):  
Sen Hu ◽  
Huicun He ◽  
Jianglong Ji ◽  
Yangting Lin ◽  
Hejiu Hui ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Isotope Composition ◽  
Water Abundance ◽  
Hydrogen Isotope Composition ◽  
Mantle Reservoir ◽  
Maximum Water ◽  
Spatio Temporal ◽  
Low Degrees ◽  
Mare Basalts ◽  
Water Contents

Abstract The distribution of water in the Moon’s interior carries key implications for the origin of the Moon1, the crystallisation of the lunar magma ocean2, and the duration of lunar volcanism2. The Chang’E-5 (CE5) mission returned the youngest mare basalt samples, dated at ca. 2.0 billion years ago3, from the northwestern Procellarum KREEP Terrane (PKT), providing a probe into the spatio-temporal evolution of lunar water. Here we report the water abundance and hydrogen isotope composition of apatite and ilmenite-hosted melt inclusions from CE5 basalts, from which we derived a maximum water abundance of 370 ± 30 μg.g-1 and a δD value (-330 ± 160‰) for their parent magma. During eruption, hydrogen degassing led to an increase in the D/H ratio of the residual melts up to δD values of 300-900‰. Accounting for low degrees of mantle partial melting followed by extensive magma fractional crystallisation4, we estimate a maximum mantle water abundance of 2-6 μg.g-1, which are too low for water contents alone to account for generating the Moon’s youngest basalts. Such modest water abundances for the lunar mantle are at the lower end of those estimated from mare basalts that erupted from ca. 4.0-2.8 Ga5, 6, suggesting the mantle source of CE5 basalts dried up by ca. 2.0 Ga through previous melt extraction from the PKT mantle during prolonged volcanic activity.

Systematics of Ni and Co in olivine from planetary melt systems; lunar mare basalts

1999 ◽  
Vol 84 (3) ◽  
pp. 392-399 ◽  
Author(s):  
J. J. Papike ◽  
G. W. Fowler ◽  
C. T. Adcock ◽  
C. K. Shearer
Keyword(s):  
Lunar Mare ◽  
Mare Basalts

scholarly journals A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang’E-3 mission

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Chunyu Ding ◽  
Zhiyong Xiao ◽  
Yan Su
Keyword(s):  
Lunar Regolith ◽  
Lava Tubes ◽  
Impact Ejecta ◽  
Comprehensive Comparison ◽  
Ground Penetrating ◽  
Shallow Crust ◽  
Low Permittivity ◽  
Mare Basalts ◽  
Subsurface Cavities ◽  
High Bulk

AbstractIn the radargram obtained by the high-frequency lunar penetrating radar onboard the Chang’E-3 mission, we notice a potential subsurface cavity that has a smaller permittivity compared to the surrounding materials. The two-way travel time between the top and bottom boundaries of the potential cavity is ~ 21 ns, and the entire zone is located within the continuous ejecta deposits of the Ziwei crater, which generally have similar physical properties to typical lunar regolith. We carried out numerical simulations for electromagnetic wave propagation to investigate the nature of this low-permittivity zone. Assuming different shapes for this zone, a comprehensive comparison between our model results and the observed radargram suggests that the roof of this zone is convex and slightly inclined to the south. Modeling subsurface materials with different relative permittivities suggests that the low-permittivity zone is most likely formed due to a subsurface cavity. The maximum vertical dimension of this potential cavity is ~ 3.1 m. While the continuous ejecta deposits of Ziwei crater are largely composed of pre-impact regolith, competent mare basalts were also excavated, which is evident by the abundant meter-scale boulders on the wall and rim of Ziwei crater. We infer that the subsurface cavity is supported by excavated large boulders, which were stacked during the energetic emplacement of the continuous ejecta deposits. However, the exact geometry of this cavity (e.g., the width) cannot be constrained using the single two-dimensional radar profile. This discovery indicates that large voids formed during the emplacement of impact ejecta should be abundant on the Moon, which contributes to the high bulk porosity of the lunar shallow crust, as discovered by the GRAIL mission. Our results further suggest that ground penetrating radar is capable of detecting and deciphering subsurface cavities such as lava tubes, which can be applied in future lunar and deep space explorations.

Geochemistry and Sr–Nd isotopic composition of Eocene lamphrophyre dykes, southeastern British Columbia

2003 ◽  
Vol 40 (6) ◽  
pp. 853-864 ◽  
Author(s):  
J H Sevigny ◽  
R J Thériault
Keyword(s):  
British Columbia ◽  
Limited Range ◽  
Calc Alkaline ◽  
Lithospheric Thinning ◽  
Enriched Mantle ◽  
Mantle Enrichment ◽  
Mantle Reservoir ◽  
Geochemical Analyses ◽  
Alkaline Lamprophyres

Mineral compositions, geochemical analyses, and Sr–Nd isotopic compositions are reported for alkaline and calc-alkaline lamprophyres collected along the southern margin of the Valhalla Complex, southeastern British Columbia. The lamprophyres were emplaced during Eocene extension and lithospheric thinning associated with tectonic denudation of the Valhalla Complex. SiO2 contents range from 44.4–51.6 wt.%, K2O from 1.3–3.7 wt.%, and volatile contents (H2O + CO2 + SO3) from 0.8–4.6 wt.%. MgO and Cr contents are 9.5–7.6 wt.% and 540–130 ppm, respectively, for samples with Mg#s between 0.69 and 0.65. Chrondrite-normalized rare-earth element patterns are strongly fractionated with Cen = 120–375 and Ybn = 8.4–12.7. Alkaline lamprophyres contain biotite ± kaersutite ± calcic plagioclase and exhibit a limited range in initial 87Sr/86Sr (0.7051–0.7057), initial εNd (–3.7 to –4.3), and TDM (766–796 Ma). Calc-alkaline lamprophyres contain F-rich phlogopite and sodic plagioclase, and exhibit a wider range in initial 87Sr/86Sr (0.7064–0.7090), initial εNd (–6.3 to –11.9), and TDM (917–1,614 Ma). Alkaline lamprophyres are interpreted as uncontaminated melts derived from a long-term, volatile, and incompatible element-enriched mantle reservoir. Mantle enrichment coincided with continental rifting of western North America (ca. 760 Ma). The enriched mantle reservoir remained isolated for ~700 Ma. Lamprophyres were generated by partial melting of the mantle reservoir in response to adiabatic decompression and lithospheric thinning during Eocene extension.

scholarly journals China's Chang'e-5 Landing Site: An Overview

2021 ◽  
Author(s):  
Yuqi Qian ◽  
Long Xiao ◽  
James Head ◽  
Carolyn van der Bogert ◽  
Harald Hiesinger ◽  
...  
Keyword(s):  
Thermal Evolution ◽  
Source Region ◽  
Landing Site ◽  
Volcanic Complex ◽  
The Moon ◽  
Age Variations ◽  
Specific Source ◽  
Scientific Significance ◽  
Lunar Chronology ◽  
Mare Basalts

<p><strong>Introduction</strong></p><p>The Chang’e-5 (CE-5) mission is China’s first lunar sample return mission. CE-5 landed at Northern Oceanus Procellarum (43.1°N, 51.8°W) on December 1, 2020, collected 1731 g of lunar samples, and returned to the Earth on December 17, 2020. The CE-5 landing site is ~170 km ENE of Mons Rümker [1], characterized by some of the youngest mare basalts (Em4/P58) on the Moon [2,3], which are never sampled by the Apollo or Luna missions [4]. This study describes the geologic background of the CE-5 landing site in order to provide context for the ongoing sample analysis.</p><p><strong>Northern Oceanus Procellarum</strong></p><p>Northern Oceanus Procellarum is in the northwest lunar nearside, and the center of the Procellarum-KREEP-Terrane [5], characterized by elevated heat-producing elements and prolonged volcanism. This region exhibits a huge volcanic complex, i.e., Mons Rümker [1], and two episodes of mare eruptions, i.e., Imbrian-aged low-Ti mare basalts in the west and Eratosthenian-aged high-Ti mare basalts (Em3 and Em4/P58) in the east [2]. The longest sinuous rille on the Moon [6], Rima Sharp, extends across Em4/P58. Both the Imbrian-aged (NW-SE) and Eratosthenian-aged (NE-SW) basalts display wrinkle ridges, indicating underlying structures, with different dominant orientations [2].</p><p><strong>Young Mare Basalts</strong></p><p>The Em4/P58 mare basaltic unit, on which CE-5 landed, is one of the youngest mare basalts on the Moon. Various researchers found different CSFD results; however, all of them point to an Eratosthenian age for Em4/P85 (1.21 Ga [2], 1.33 Ga [7,8], 1.53 Ga [3], 1.91 Ga [9]), and there are minor age variations across Em4/P58 [3]. Em4/P58 mare basalts have high-Ti, relatively high-olivine and high-Th abundances, while clinopyroxene is the most abundant mineral type [2,3]. Em4/P58 mare basalts cover an area of ~37,000 km<sup>2</sup>, with a mean thickness of ~51 m and volume of ~1450-2350 km<sup>3</sup> [3]. No specific source vents were found within the unit, and Rima Sharp is the most likely source region for the Em4/P58 mare basalts [3].</p><p><strong>Scientific Significance of the Returned Samples</strong></p><p>The scientific significance of the young mare basalts is summarized in our previous studies [2,3]. In [3], we first summarized the 27 fundamental questions that may be answered by the returned CE-5 samples, including questions about chronology, petrogenesis, regional setting, geodynamic & thermal evolution, and regolith formation (<strong>Tab. 1</strong> in [3]), especially calibrating the lunar chronology function, constraining the lunar dynamo status, unraveling the deep mantle properties, and assessing the Procellarum-KREEP-Terrain structures.</p><p><strong>References</strong></p><p>[1] Zhao J. et al. (2017) JGR, 122, 1419–1442. [2] Qian Y. et al (2018) JGR, 123, 1407–1430. [3] Qian Y. et al. (2021) EPSL, 555, 116702. [4] Tartèse R. et al. (2019) Space Sci. Rev., 215, 54. [5] Jolliff B. L. et al. (2000) JGR, 105, 4197–4216. [6] Hurwitz D. M. et al. (2013) Planet. Space Sci., 79–80, 1–38. [7] Hiesinger H. et al. (2003) JGR, 108, 1–1 (2003). [8] Hiesinger H. et al. (2011) Geol. Soc. Am., 477, 1–51. [9] Morota T. et al. (2011) EPSL, 302, 255–266.</p>

scholarly journals Melt inclusions from Permian-Triassic komatiites, northern Vietnam, reveal evidence for a deep hydrous mantle reservoir

2021 ◽  
Author(s):  
Charbel Kazzy ◽  
Alexander Sobolev ◽  
Andrey Gurenko ◽  
Evgeny Asafov ◽  
Eero Hanski ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Northern Vietnam ◽  
Mantle Reservoir

Reduction of mare basalts by sulfur loss

1976 ◽  
Vol 40 (9) ◽  
pp. 997-1004 ◽  
Author(s):  
Robin Brett
Keyword(s):  
Mare Basalts
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