Engineering Papers⌕ Search

Engineering topics

Boynton, W. V.

Publications and source records attributed to Boynton, W. V..

113 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Fractionation in the solar nebula - Condensation of yttrium and the rare earth elements

The condensation of Y and the rare earth elements (REE) from the solar nebula may be controlled by thermodynamic equilibrium between gas and condensed solids. Highly fractionated REE patterns may result if condensates are removed from the gas before condensation is complete. It is found that the fractionation is not a smooth function of REE ionic radius but varies in an extremely irregular pattern. Both Yb and Eu are predicted to be extremely depleted in the early condensate without the requirement of condensation in the divalent state. The model is discussed with respect to a highly fractionated pattern observed by Tanaka and Masuda (1973), in a pink Ca-Al-rich inclusion from the Allende meteorite and can account for the abundances of each REE determined. According to the model this inclusion represents a condensate from a previously fractionated gas rather than from a gas of solar composition. Before the condensation of this inclusion, an earlier condensate was formed and was removed from equilibrium with the gas.

Boynton, W. V.↗
NASA NTRS1975

Volatiles on the surface of Apollo 15 green glass and trace-element distributions among Apollo 15 soils

Zn, Ge, Cd, In, and Au have been detected in surficial deposits on Apollo 15 green-glass spherules, and it is suggested that these deposits are condensates from the magmatic gas phase which was responsible for the pneumatic expulsion of the green glass from the lunar interior. Thermodynamic data indicate that chlorides and fluorides were the dominant forms of the volatile metals. The Ar-40x content of a nongreen-glass soil fraction is greater than that found in green-glass. Mare and low-K Fra Mauro basalts seem to be the most prominent components of Apollo 15 soil. The correlation of Zn with Ar-40x and with Pb-204 is studied, and the distribution of quartz-normative and olivine-normative basalts is considered.

Chou, C.-L.↗
NASA NTRS1972

Bulk, rare earth, and other trace elements in Apollo 14 and 15 and Luna 16 samples.

Measurement of 24 and 34 bulk, minor, and trace elements in lunar specimens by instrumental and radiochemical neutron activation analysis shows greater Al2O3, Na2O, and K2O abundances and higher TiO2, FeO, MnO and Cr2O3 depletions in Apollo 14 soil samples as compared to Apollo 11 samples and to most of Apollo 12 samples. The uniform abundances in 14230 core tube soils and three other Apollo 14 soils indicate that the regolith is uniform to at least 22 cm depth and within about 200 m from the lunar module.

Laul, J. C.↗
NASA NTRS1971

Bulk, rare earth and other trace elements in Apollo 14 and 15 and Luna 16 samples

The chemical abundances were measured by instrumental and radiochemical neutron activation analysis in a variety of lunar specimens. Apollo 14 soils are characterized by significant enrichments of Al2O3, Na2O and K2O and depletions of TiO2, FeO, MnO and Cr2O3 relative to Apollo 11 and to most of Apollo 12 soils. The uniform abundances in 14230 core tube soils and three other Apollo 14 soils indicate that the regolith is uniform to at least 22 cm depth and within approximately 200 m from the lunar module. Two Luna 16 breccias are similar in composition to Luna 16 soils. Four Apollo 15 soils (LM, STA 4, 9, and 9a) have variable compositions. Interelement correlations between MnO-FeO, Sc-FeO, V-Cr2O3 and K2O-Hf negate the hypothesis that howardite achondrites may be primitive lunar matter, argue against the fission hypothesis for the origin of the moon, and precludes any selective large scale volatilization of alkalies during lunar magmatic events.

Laul, J. C.↗