Lithium and halogens in lunar samples

1977 ◽  
Vol 285 (1327) ◽  
pp. 49-54 ◽  
Keyword(s):  
Bulk Composition ◽  
Fluorine Content ◽  
The Other ◽  
The Moon ◽  
Rock Samples ◽  
A Value ◽  
Refractory Elements ◽  
Incompatible Elements ◽  
Lunar Samples ◽  
Mare Basalts

Lithium and the halogen elements F, Cl, Br and I have been measured in soils, breccias and rock samples from all Apollo missions. With the exception of the anorthosites, the fluorine content of the lunar samples is in the same range as for C l chondrites. Contrary to fluorine the other halogen concentrations show large variations. The lowest concentrations are found in the mare basalts of Apollo 15 and 17, the highest in some highland breccias. Lithium correlates well with some of the incompatible elements in both mare basalts and 'KREEP’-containing highland soils and breccias. From the observed ratios it is evident that in the bulk composition of the Moon Li is neither enriched nor depleted; it belongs to the group of non-refractory elements. From the correlation of Li with some refractory elements (Be, La, etc.) a value of 50:50 for the refractory to non-refractory portion of the Moon is inferred without any further assumption, thus confirming previous estimates of Wanke et al. (1974a, 1975)

Element correlations and the bulk composition of the Moon

1977 ◽  
Vol 285 (1327) ◽  
pp. 41-48 ◽  
Keyword(s):  
Solar Nebula ◽  
Bulk Composition ◽  
Experimental Studies ◽  
Primary Component ◽  
The Other ◽  
The Moon ◽  
Group Relations ◽  
Refractory Elements ◽  
Lunar Samples ◽  
Mechanical Mixtures

A great number of element correlations have been observed in lunar samples. It is known from theoretical and experimental studies that in the solar nebula the elements condensed in groups according to their condensation temperatures and chemical affinities. One of these groups - the refractory elements - is represented by the early condensates or high temperature condensates (h.t.c.). From element correlations and group relations we estimate the bulk Moon to contain about 50 % of h.t.c.; the other 50%, the non-refractory portion, consists mainly of (Mg, Fe)-silicates and minor phases of about chondritic composition. Recently we have found strong evidence that most of the lunar highland samples represent mechanical mixtures of a differentiated (feldspathic) lunar component and a primary component from the last accretion stage of the Moon. The contribution of the h.t.c. in this primary material is estimated to 21 %. Hence, an inhomogeneous accretion of the Moon is indicated. After the formation of a highly refractory core relatively more and more non-refractory material was added until the Moon reached its final mass. The composition of the primary matter observed in the lunar highlands gives us an important clue to the composition of the non-refractory portion of the Moon and thus leads to a more reliable estimation of the lunar bulk composition.

scholarly journals P-bearing olivines of lunar rocks: sources and localization in the lunar crust

2019 ◽  
Vol 64 (8) ◽  
pp. 803-825
Author(s):  
S. I. Demidovaa ◽  
M. O. Anosova ◽  
N. N. Kononkova ◽  
T. Ntaflos ◽  
F. Brandstätter
Keyword(s):  
Late Stage ◽  
The Moon ◽  
Local Distribution ◽  
Lunar Crust ◽  
Lunar Material ◽  
Incompatible Elements ◽  
Lunar Samples ◽  
Lunar Rocks ◽  
Mare Basalts

Fragments of P-bearing olivine have been studied in lunar highland, mare and mingled meteorites and in «Apollo-14», «Luna-16, -20, -24» lunar samples. Olivine contains up to 0.5 wt.% P2O5 and has variable MG# number. It is associated with anorthite, pyroxene and accessory spinel group minerals, Ti and Zr oxides, phosphates, troilite and Fe-Ni metal. Three possible sources of P-bearing olivine were found in lunar material: 1) highland anorthositic-noritic-troctolitic rocks enriched in incompatible elements and thought to be related to high-Mg suite rocks: 2) late-stage products of mare basalts crystallization; 3) unusual olivine-orthopyroxene intergrowths either of meteoritic or lunar origin. Enrichment in incompatible elements may be resulted from both crystallization processes (source 2) and KREEP assimilation (sources 1 and 3). However following metasomatic processes can lead to some addition of phosphorus and other elements. The rarity of P-bearing olivines points either to the low abundance or local distribution of their sources in the lunar crust. Association with mare basalts specifies the highland-mare boundary. The presence of the evolved rocks in the studied breccias suggests possible connection of some sources with recently discovered granitic domes in Procellarum Ocean. That means the P-bearing sources are mainly localized on the visible side of the Moon.

Mare basalt petrogenesis and the composition of the lunar interior

1977 ◽  
Vol 285 (1327) ◽  
pp. 577-586 ◽  
Keyword(s):  
Experimental Investigation ◽  
Recent Literature ◽  
Bulk Composition ◽  
The Moon ◽  
Compositional Model ◽  
Earth’S Mantle ◽  
Source Regions ◽  
Lunar Interior ◽  
Wide Range ◽  
Mare Basalts

Mare basalts, which are believed to form by partial melting at considerable depths in the lunar interior, are capable of providing a wealth of information concerning the compositions of their source regions. Conversely, any acceptable estimate of the lunar bulk composition must in principle be able to provide source regions capable of yielding mare basalts. A wide range of lunar bulk compositions has been proposed in the recent literature. These differ principally in the proportions of involatile elements, e.g. Ca, A1, to elements of moderate volatility, e.g. Mg, Si, Fe. A detailed experimental investigation has been made of the capacity of the Taylor—Jakes compositional model (8.2 % A12O3) to provide source regions for mare basalts. It is demonstrated that this composition is much too rich in alumina to be acceptable. Other lunar bulk compositions even richer inA12O3 such as those advocated by Ganapathy & Anders, Wanke and co-workers and Anderson can likewise be rejected. In order to produce mare basalts, particularly the least fractionated varieties represented by some Apollo 12 and 15 basalts, lunar bulk compositions containing only about 4 % of A12O3 appear to be required. This is similar to the alumina content of the Earth’s mantle. The relative abundances of many other involatile elements, e.g. Ga, U, Ti, r.e.e., Zr, Ba, Sr, may likewise be similar in the Moon and in the Earth’s mantle. These relationships point towards a common origin for the Moon and for the Earth’s mantle.

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.

scholarly journals Lunar bulk chemical composition: a post-Gravity Recovery and Interior Laboratory reassessment

2014 ◽  
Vol 372 (2024) ◽  
pp. 20130242 ◽  
Author(s):  
G. Jeffrey Taylor ◽  
Mark A. Wieczorek
Keyword(s):  
Formation Processes ◽  
The Moon ◽  
Volatile Elements ◽  
Bulk Chemical Composition ◽  
Refractory Elements ◽  
The Earth ◽  
Lunar Samples ◽  
Mass Fractions ◽  
Bulk Chemical ◽  
Gravity Recovery

New estimates of the thickness of the lunar highlands crust based on data from the Gravity Recovery and Interior Laboratory mission, allow us to reassess the abundances of refractory elements in the Moon. Previous estimates of the Moon fall into two distinct groups: earthlike and a 50% enrichment in the Moon compared with the Earth. Revised crustal thicknesses and compositional information from remote sensing and lunar samples indicate that the crust contributes 1.13–1.85 wt% Al 2 O 3 to the bulk Moon abundance. Mare basalt Al 2 O 3 concentrations (8–10 wt%) and Al 2 O 3 partitioning behaviour between melt and pyroxene during partial melting indicate mantle Al 2 O 3 concentration in the range 1.3–3.1 wt%, depending on the relative amounts of pyroxene and olivine. Using crustal and mantle mass fractions, we show that that the Moon and the Earth most likely have the same (within 20%) concentrations of refractory elements. This allows us to use correlations between pairs of refractory and volatile elements to confirm that lunar abundances of moderately volatile elements such as K, Rb and Cs are depleted by 75% in the Moon compared with the Earth and that highly volatile elements, such as Tl and Cd, are depleted by 99%. The earthlike refractory abundances and depleted volatile abundances are strong constraints on lunar formation processes.

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.

scholarly journals Coordinated analysis of space weathering characteristics in lunar samples to understand water distribution on the Moon

2021 ◽  
Vol 27 (S1) ◽  
pp. 2260-2262
Author(s):  
Alexander Kling ◽  
Michelle Thompson ◽  
Jennika Greer ◽  
Philipp Heck
Keyword(s):  
Water Distribution ◽  
Space Weathering ◽  
The Moon ◽  
Lunar Samples

Effect of Catfish Bone Paste on the Properties of Steamed Bread

2014 ◽  
Vol 881-883 ◽  
pp. 757-760
Author(s):  
Xiao Qing Ren ◽  
Li Zhen Ma ◽  
Xin Yi He
Keyword(s):  
Weight Loss ◽  
Specific Volume ◽  
Cell Structure ◽  
The Other ◽  
Gas Cell ◽  
A Value ◽  
Crumb Structure ◽  
Steamed Bread ◽  
Different Levels ◽  
Structure Properties

The objective of this study was to examine the effect of different levels of catfish bone paste to flour on the physicochemical, textural and crumb structure properties of steamed bread. Six different levels (0, 1, 3, 5, 7,10 %) of catfish bone paste to flour were used in the formulation of the steamed bread. The results showed that the weight loss and TTA of steamed bread decreased with an increase in the levels of the catfish bone paste. On the other hand, the pH increased with an increase in the levels of the catfish bone paste. The specific volume, hardness, chewiness and gas cell structure in the crumb of steamed bread with catfish bone paste at 5% supplementation level were better. Thus, a value of 5% catfish bone paste was considered a better level for incorporation into the steamed bread.

scholarly journals Bayesian constraints on the origin and geology of exo-planetary material using a population of externally polluted white dwarfs

2021 ◽  
Author(s):  
John H D Harrison ◽  
Amy Bonsor ◽  
Mihkel Kama ◽  
Andrew M Buchan ◽  
Simon Blouin ◽  
...  
Keyword(s):  
Solar System ◽  
White Dwarf ◽  
Bayesian Model ◽  
Total Mass ◽  
White Dwarfs ◽  
Bulk Composition ◽  
Planetary Systems ◽  
The Moon ◽  
Planetary Bodies ◽  
Nearby Stars

Abstract White dwarfs that have accreted planetary bodies are a powerful probe of the bulk composition of exoplanetary material. In this paper, we present a Bayesian model to explain the abundances observed in the atmospheres of 202 DZ white dwarfs by considering the heating, geochemical differentiation, and collisional processes experienced by the planetary bodies accreted, as well as gravitational sinking. The majority (>60%) of systems are consistent with the accretion of primitive material. We attribute the small spread in refractory abundances observed to a similar spread in the initial planet-forming material, as seen in the compositions of nearby stars. A range in Na abundances in the pollutant material is attributed to a range in formation temperatures from below 1,000 K to higher than 1,400 K, suggesting that pollutant material arrives in white dwarf atmospheres from a variety of radial locations. We also find that Solar System-like differentiation is common place in exo-planetary systems. Extreme siderophile (Fe, Ni or Cr) abundances in 8 systems require the accretion of a core-rich fragment of a larger differentiated body to at least a 3σ significance, whilst one system shows evidence that it accreted a crust-rich fragment. In systems where the abundances suggest that accretion has finished (13/202), the total mass accreted can be calculated. The 13 systems are estimated to have accreted masses ranging from the mass of the Moon to half that of Vesta. Our analysis suggests that accretion continues for 11Myrs on average.

scholarly journals Ultraviolet Albedo of Comet West (1976 VI)

1980 ◽  
Vol 90 ◽  
pp. 263-266
Author(s):  
P. D. Feldman
Keyword(s):  
Solar Radiation ◽  
Solar Spectrum ◽  
Ultraviolet Spectrum ◽  
The Moon ◽  
Lunar Dust ◽  
Cometary Dust ◽  
A Value ◽  
Dust Coma ◽  
Spectrometer Slit ◽  
The Continuum

The ultraviolet spectrum of Comet West (1976 VI) in the range 1200-3200 Å was recorded by rocket-borne instruments on March 5.5, 1976. At the time of launch, r = 0.385, Δ = 0.84 and the phase angle was 78°. Longward of 2100 Å the continuum of solar radiation scattered by cometary dust is detected and is found to closely follow the solar spectrum. Since the dust coma is completely included in the spectrometer slit, the ultraviolet albedo can be determined relative to the visible and this ratio is found to be ≈0.3 at 2700 Å. There is evidence for a further decrease in albedo near 2200 Å. Using a visible albedo of 0.2 gives a value of 0.06 for the cometary albedo at 2700 Å, a value similar to that found for the moon and lunar dust in this spectral region.

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