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Blanchard, D. P.

Publications and source records attributed to Blanchard, D. P..

35 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Chemistry of orange/black soils from core 74001/2

Double core 74001/2 soils were studied. Bulk soils and the 90-150 micrometer and less than 20 micrometer size fractions of 13 soils from the core for both major and trace elements by instrumental neutron activation analysis were analyzed. The orange and black glassy soils in the core 74001/2 are homogeneous in composition and due to their unusual compositional characteristics probably have derived from a single source with the same composition. The top of the core has been reworked to a depth of about 5 cm. The reworked layer is marked by compositional differences in the first 3 cm which reflect the addition (at least 10%) of materials including mare basalt and a CaO-rich component. The maturity profile (I sub s/FeO) clearly indicates reworking depth of about 5 cm. It is likely that at least some of the ferro-magnetically active component (including agglutinitic glass) has been 'inherited' with the added material.

Blanchard, D. P.↗
NASA NTRS1977

Trace element distribution in mineral separates of the Allende inclusions and their genetic implications

Concentrations of the rare earth elements (REE), Sc, Co, Fe, Zn, Ir, Na, and Cr were determined for mineral separates of the coarseand fine-grained types (group I and II) of the Allende inclusions. These data in combination with other data suggest that the minerals in the coarse-grained inclusions (group I) crystallized in a closed system with respect to refractory elements although a totally molten stage is precluded. The data also indicate that fine-grained (group II) inclusions were formed by condensation from a super-cooled nebular gas; REE-rich clinopyroxene and spinel were formed earlier than REE-poor sodalite and nepheline. In addition, pre-existing Mg isotope anomalies in the coarse-grained inclusions must have been erased during the heating stage.

Nagasawa, H.↗
NASA NTRS1977

Chemistry of Apollo 12 mare basalts - Magma types and fractionation processes

Major and trace element data for a large suite of petrographically diverse Apollo 12 mare basalts are presented, and magma types sampled at the Apollo 12 site are characterized. The data confirm earlier classifications of the basalts into olivine, pigeonite, ilmenite, and feldspathic basalts. The olivine and pigeonite basalts are shown to be comagnetic and related by olivine fractionation. The other types, which differ in trace element and isotopic characteristics, are derived from different sources within the lunar interior. The spatial relations between the main basalt types are discussed in terms of local cratering events, and it is suggested that the younger ilmenite basalts overlie the olivine-pigeonite basalts. The role of olivine-dominated near-surface crystal fractionation in causing chemical variation is examined, and a relation between inferred cooling rate and the position of a sample in the fractionation sequence is determined.

Rhodes, J. M.↗
NASA NTRS1976

Drive tube 60009 - A chemical study of magnetic separates of size fractions from five strata

Each bulk soil and both the magnetic and nonmagnetic components of the 90-150 micron and below 20 micron fractions of five soils from drive tube 60009 were analyzed. Samples were analyzed for FeO, Na2O, Sc, Cr, Co, Ni, Hf, Ta, Th, La, Ce, Sm, Eu, Tb, Yb, and Lu by neutron activation analysis. Several samples were fused and analyzed for major elements by electron microprobe analysis. Compositional variations are not systematically related to depth. The compositions of the five soils studied are well explained by a two-component mixing model whose end members are a submature Apollo 16-type soil and an extremely immature anorthositic material similar to 60025. There is evidence that the anorthositic component had received a small amount of exposure before these soils were mixed. After mixing, the soils received little exposure suggesting mixing and deposition on a rapid time scale.

Blanchard, D. P.↗
NASA NTRS1975

Major and trace element chemistry of Boulder 1 at Station 2, Apollo 17

Twenty-seven samples from Boulder 1 at Station 2 are analyzed for major and trace elements by atomic absorption spectrophotometry and neutron activation analysis. Two types of matrix and several types of clast materials are characterized on the basis of their chemistry. It is shown that one matrix type is a common material at the Apollo 17 site, while the other is probably exotic to that site. The most unusual clast materials found are coarse norite (an old rock no longer found in millimeter fragments at the site) and pigeonite basalt (possibly a highland volcanic rock). It is concluded that the boulder-forming process combined materials from at least two different localities or vertical strata.

Blanchard, D. P.↗
NASA NTRS1975

Consortium studies of matrix of light gray breccia 73215

A description is presented of the preliminary results of interdisciplinary studies of matrix samples. The significance of the 73215 studies is considered and the relationship of 73215 to other Apollo 17 highland breccias is discussed. According to a tentative hypothesis 73215 is an aggregate of fragments plus melt generated in a very large impact, possibly the Serenitatis basin-forming event. If this is correct, studies of this sample will make it possible to date the Serenitatis event and will provide an insight into the breccia-forming processes associated with such events. Studies of the clasts in the breccia will provide an opportunity to formulate a partial characterization of the preimpact source terrain. An investigation of the deep lunar crust might perhaps also be possible.

James, O. B.↗
NASA NTRS1975

Chemistry of agglutinate fractions in lunar soils

Agglutinates are aggregates of crystalline grains and lithic fragments bonded together by glass. It is thought that glassy agglutinates are formed at the upper surface of the lunar regolith by impact-related melting and welding of soil particles, in response to meteoroid and micrometeoroid bombardment. A description is presented of an investigation in which bulk soils were separated into 'agglutinate' and 'nonagglutinate' fractions. The obtained fractions were analyzed for major, minor, and trace elements. The obtained chemical data for agglutinate and nonagglutinate fractions of lunar soils indicate that agglutinitic glass is enriched in mafic and most lithophile elements relative to the bulk soils. A model involving preferential melting and assimilation of mesostasis material and mafic soil components is proposed to account for the observed chemical data. It is suggested that glassy agglutinates may form more readily in mafic soils than in more feldspathic ones. Such selectivity should be most effective between mare and highland soils, but may possibly operate on a more local scale.

Rhodes, J. M.↗
NASA NTRS1975

A geochemical and petrographic study of 1-2-mm fines from Apollo 17

Samples of fines less than 1-mm and 155 1-2 mm particles from several Apollo 17 sites were analyzed for Na, Sc, Cr, Mn, Fe, Co, Ni, Hf, Ta, Th, and REE. Products of comminution and construction are present in the 1-2 mm particles, and the compositions of the rock fragments clearly indicate the general chemical characteristics of their parent rock types. The likely sources of materials for the glassy particles are considered. Glasses are enriched over their parent soils in Fe, Sc, Mn, and Cr, and are relatively enriched in light REE, so that some chemical fractionation accompanies glass-forming processes. Elements were determined by instrumental neutron activation analysis.

Blanchard, D. P.↗
NASA NTRS1974

Major and trace element concentrations in samples from 72275 and 72255

Analytical data have been obtained for Co, Sc, Hf, Zn, Cr, Ga, Rb, Cs, Ni, major elements, and rare earth elements in eight samples from boulder 1. The data for trace elements were obtained by radiochemical neutron activation analysis. Major elements, except Na and Mn, were obtained by atomic absorption spectral photometry. Values for Na and Mn were obtained by neutron activation analysis of the same powder that was later dissolved to provide the atomic absorption analyses.

Haskin, L. A.↗
NASA NTRS1973

Major and trace elements in igneous rocks from Apollo 15.

The concentrations of major and trace elements have been determined in igneous rocks from Apollo 15. All materials analyzed have typical depletions of Eu except for minerals separated from sample 15085. Four samples have concentrations of trace elements that are similar to those of KREEP. The samples of mare basalt from Apollo 15 have higher concentrations of FeO, MgO, Mn, and Cr and lower concentrations of CaO, Na2O, K2O, and rare-earth elements (REE) as compared to the samples of mare basalt from Apollos 11, 12, and 14. The samples can be divided into two groups on the basis of their normative compositions. One group is quartz normative and has low concentrations of FeO while the other is olivine normative and has high concentrations of FeO. The trace element data indicate that the samples of olivine normative basalt could be from different portions of a single lava flow.

Helmke, P. A.↗
NASA NTRS1973

Rare earths, other trace elements and iron in Luna 20 samples.

The results of the analysis by neutron activation of six samples from the Luna 20 mission and one sample of less than 1 mm fines from Apollo 16 are reported. The concentrations of the rare-earth elements (REE) in the samples of fines from Luna 20 and Apollo 16 are less than those found for corresponding materials from the mare areas but a negative Eu anomaly is still present. The concentrations of the REE in fines from Luna 20 are only about two-thirds as great as in the sample of Apollo 16 fines, but the concentration of Co, Sc and Cr are greater by factors ranging from 1.5 to 2.3.

Helmke, P. A.↗
NASA NTRS1973

Major and trace element abundances in samples from the lunar highlands

Analyses for major elements, REE, Co, Cr, Cs, Ga, Hf, Ni, Rb, Sc, and Zn have been done on samples of Apollo 16 rocks 60025, 60335, 64455, 65015, 67075, and 67629 and on fines 60601, 61221, 61241, 64501, 65701, 67601, and 69941. FeO, Na2O, REE, Co, Cr, Hf, and Sc have been determined in four 4-5 mg chips from 65015 and 20 individual, 2.5-9.5 mg fragments from 65702. It appears that trace element characteristics of small fragments are similar to those of larger rocks. No simple mixing relationship was found among KREEP basalts, VHA basalts, anorthosites, fines, and meteorites. Balances could not be simultaneously achieved for Al2O3 and LIL elements, using analyzed samples as end members for mixing models. Most samples analyzed have negative Eu anomalies, in contrast to the positive anomalies expected for plagioclase cumulates. Most samples may be derived from LIL-rich liquids that flowed into highland valleys.

Haskin, L. A.↗