scholarly journals The chlorine isotope fingerprint of the lunar magma ocean

2015 ◽  
Vol 1 (8) ◽  
pp. e1500380 ◽  
Author(s):  
Jeremy W. Boyce ◽  
Allan H. Treiman ◽  
Yunbin Guan ◽  
Chi Ma ◽  
John M. Eiler ◽  
...  
Keyword(s):  
Solar System ◽  
Isotope Ratios ◽  
Terrestrial Planets ◽  
The Moon ◽  
Magma Ocean ◽  
Chlorine Isotope ◽  
Important Stage ◽  
Lunar Basalts ◽  
Lunar Mare ◽  
Mare Basalts

The Moon contains chlorine that is isotopically unlike that of any other body yet studied in the Solar System, an observation that has been interpreted to support traditional models of the formation of a nominally hydrogen-free (“dry”) Moon. We have analyzed abundances and isotopic compositions of Cl and H in lunar mare basalts, and find little evidence that anhydrous lava outgassing was important in generating chlorine isotope anomalies, because 37Cl/35Cl ratios are not related to Cl abundance, H abundance, or D/H ratios in a manner consistent with the lava-outgassing hypothesis. Instead, 37Cl/35Cl correlates positively with Cl abundance in apatite, as well as with whole-rock Th abundances and La/Lu ratios, suggesting that the high 37Cl/35Cl in lunar basalts is inherited from urKREEP, the last dregs of the lunar magma ocean. These new data suggest that the high chlorine isotope ratios of lunar basalts result not from the degassing of their lavas but from degassing of the lunar magma ocean early in the Moon’s history. Chlorine isotope variability is therefore an indicator of planetary magma ocean degassing, an important stage in the formation of terrestrial planets.

scholarly journals Magnesium stable isotopes support the lunar magma ocean cumulate remelting model for mare basalts

2018 ◽  
Vol 116 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Fatemeh Sedaghatpour ◽  
Stein B. Jacobsen
Keyword(s):  
Isotopic Composition ◽  
Isotopic Fractionation ◽  
The Moon ◽  
Magma Ocean ◽  
Isotopic Analyses ◽  
Lunar Samples ◽  
Lunar Basalts ◽  
Mg Isotopes ◽  
Isotopic Variations ◽  
Mare Basalts

We report high-precision Mg isotopic analyses of different types of lunar samples including two pristine Mg-suite rocks (72415 and 76535), basalts, anorthosites, breccias, mineral separates, and lunar meteorites. The Mg isotopic composition of the dunite 72415 (δ25Mg = −0.140 ± 0.010‰, δ26Mg = −0.291 ± 0.018‰), the most Mg-rich and possibly the oldest lunar sample, may provide the best estimate of the Mg isotopic composition of the bulk silicate Moon (BSM). This δ26Mg value of the Moon is similar to those of the Earth and chondrites and reflects both the relative homogeneity of Mg isotopes in the solar system and the lack of Mg isotope fractionation by the Moon-forming giant impact. In contrast to the behavior of Mg isotopes in terrestrial basalts and mantle rocks, Mg isotopic data on lunar samples show isotopic variations among the basalts and pristine anorthositic rocks reflecting isotopic fractionation during the early lunar magma ocean (LMO) differentiation. Calculated evolutions of δ26Mg values during the LMO differentiation are consistent with the observed δ26Mg variations in lunar samples, implying that Mg isotope variations in lunar basalts are consistent with their origin by remelting of distinct LMO cumulates.

Exploring the Solar System

2018 ◽  
Author(s):  
Karel Schrijver
Keyword(s):  
Solar System ◽  
Planetary Systems ◽  
Interplanetary Dust ◽  
Terrestrial Planets ◽  
The Moon ◽  
System P ◽  
Asteroids And Comets

In this chapter, the author summarizes the properties of the Solar System, and how these were uncovered. Over centuries, the arrangement and properties of the Solar System were determined. The distinctions between the terrestrial planets, the gas and ice giants, and their various moons are discussed. Whereas humans have walked only on the Moon, probes have visited all the planets and several moons, asteroids, and comets; samples have been returned to Earth only from our moon, a comet, and from interplanetary dust. For Earth and Moon, seismographs probed their interior, whereas for other planets insights come from spacecraft and meteorites. We learned that elements separated between planet cores and mantels because larger bodies in the Solar System were once liquid, and many still are. How water ended up where it is presents a complex puzzle. Will the characteristics of our Solar System hold true for planetary systems in general?

Absolute time scale of lunar mare formation and filling

1977 ◽  
Vol 285 (1327) ◽  
pp. 151-158 ◽  
Keyword(s):  
Time Scale ◽  
Igneous Rock ◽  
The Moon ◽  
High K ◽  
Basalt Composition ◽  
Lunar Mare ◽  
Flow Activity ◽  
Mare Basalts ◽  
Low K ◽  
Eastern Edge

The high titanium basalts collected in the maria Tranquillitatis and Serenitatis crystallized 3.5-3.9 Ga ago. The ages of the low titanium rocks found in Oceanus Procellarum and on the eastern edge of mare Imbrium are lower, 3.1-3.4 Ga. There is, however, evidence that high-Ti basalts with lower ages and low-Ti basalts with higher ages occur on the Moon. The observed age spread of rocks even in limited areas suggests that lava flow activity in a basin lasted for several 100 Ma. The age variability of Apollo 11 basalts is particularly well documented: there are at least three different times of rock formation, two for the low-K and one for the high-K rocks. The ages of the oldest mare basalts 10003 (high-Ti, low-K rock) and 14053 (an igneous rock with low-Ti, low-K, high-Al mare basalt composition) of 3.91 ± 0.03 Ga and 3.95 ± 0.03 Ga respectively, suggest that mafic basalt flows had already begun to invade the older basins when the last basin-forming impacts occurred.

Extraterrestrial Mineralogy: Two major igneous events in the evolution of the Moon

1977 ◽  
Vol 286 (1336) ◽  
pp. 439-451 ◽  
Keyword(s):  
Large Scale ◽  
Bulk Composition ◽  
Large Body ◽  
Uranium Content ◽  
The Moon ◽  
Lunar Crust ◽  
Crust And Upper Mantle ◽  
Lunar Basalts ◽  
Initial Melting ◽  
Mare Basalts

An understanding of the origin of the Moon is strongly dependent upon a knowledge of its bulk composition and thermal history. Both aspects require a detailed consideration of the composition and origin of the lunar crust and of the mantle-derived lunar basalts. The evidence for two major igneous events is discussed, the first being a large-scale melting and fractionation into crust and mantle at —4.6 to —4.5 Ga, and the second a partial melting of the uppermost mantle at —3.8 to — 3.2 Ga. The distribution of uranium is used to place constraints on the minimum extent of initial melting and on the depth at which the mare basalts were generated, using recent lunar heatflow data for a bulk-Moon uranium content of 30 parts/10 9 . The model favours melting of at least 90 % by volume, and a concentration of the high U-contents of the crust and upper mantle by formation of a thick lower mantle of mafic adcumulates ‘barren’ in heat-producing elements. The ‘fertile’ mafic orthocumulates from which the mare basalts were generated are restricted by the model to depths of less than 200 km. A downward revision of the bulk U-content of the Moon results in down-scaling of the other refractory lithophile elements by analogy with the solar-nebula condensation models. This means that the bulk Moon is fairly close in composition to that of the Earth’s mantle, including its iron content but excluding the volatile elements which are strongly depleted in the Moon. Low contents of siderophile and chalcophile elements, and high contents of lithophile refractory elements in the lunar basalts are attributable to the large-scale fractionation into a core, mantle and crust. The hypothesis of an origin for the Moon by fission from a proto-Earth is revived. Earth layering by a heterogeneous accretion sequence would account for non-equilibrium between core and mantle (e.g. nickel distribution) and an outer veneer of volatile-rich condensate that would contribute to subsequent generation of a granitic crust. Early collision with a large body may have caused fission and formation of a proto-Moon from the Earth’s iron-poor, proto-mantle, with loss of volatiles. Early melting of most of the proto-Moon led to strong fractionation such that the crust and mantle-derived basalts appear to have more extreme compositions, relative to Earth basalts, than is indicated by the likely bulk composition of the Moon.

Re-evaluating 142Nd/144Nd in lunar mare basalts with implications for the early evolution and bulk Sm/Nd of the Moon

2009 ◽  
Vol 73 (20) ◽  
pp. 6421-6445 ◽  
Author(s):  
Alan D. Brandon ◽  
Thomas J. Lapen ◽  
Vinciane Debaille ◽  
Brian L. Beard ◽  
Kai Rankenburg ◽  
...  
Keyword(s):  
Early Evolution ◽  
The Moon ◽  
Lunar Mare ◽  
Mare Basalts

scholarly journals Crustal porosity reveals the bombardment history of the Moon

2021 ◽  
Author(s):  
Ya Huei Huang ◽  
Jason Soderblom ◽  
David Minton ◽  
Masatoshi Hirabayashi ◽  
Jay Melosh
Keyword(s):  
Solar System ◽  
Surface Expression ◽  
Orbital Evolution ◽  
Terrestrial Planets ◽  
The Moon ◽  
Planetary Evolution ◽  
History Of ◽  
Giant Impacts ◽  
Formation And Evolution ◽  
Lunar Basins

Abstract Planetary bombardment histories provide critical information regarding the formation and evolution of the Solar System and of the planets within it. These records evidence transient instabilities in the Solar System’s orbital evolution, giant impacts such as the Moon-forming impact, and material redistribution. Such records provide insight into planetary evolution, including the deposition of energy, delivery of materials, and crustal processing, specifically the modification of porosity. Bombardment histories are traditionally constrained from the surface expression of impacts — these records, however, are degraded by various geologic processes. Here we show that the Moon’s porosity contains a more complete record of its bombardment history. We find that the terrestrial planets were subject to double the number of ≥20-km-diameter-crater-forming impacts than are recorded on the lunar highlands, fewer than previously thought to have occurred. We show that crustal porosity doesn’t slowly increase as planets evolve, but instead is generated early in a planet’s evolution when most basins formed and decreases as planets evolve. We show that porosity constrains the relative ages of basins formed early in a planet’s evolution, a timeframe for which little information exists. These findings demonstrate that the Solar System was less violent than previously thought. Fewer volatiles and other materials were delivered to the terrestrial planets, consistent with estimates of the delivery of siderophiles and water to the Moon. High crustal porosity early in the terrestrial planets’ evolution slowed their cooling and enhanced their habitability. Several lunar basins formed early than previously considered, casting doubt on the existence of a late heavy bombardment.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

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
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