Opaque minerals in an Apollo 12 rock

Gibb, F. G. F.; Stumpfl, E. F.; Zussman, J.

doi:10.1016/0012-821x(70)90031-2

Cited by 19 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The single LA-ICP-MS analysis of olivine in 12003,312_C also indicates low concentrations of Ni and Co similar to those in 12052, although the Ti/V ratio of the 12003,312_C olivine is higher than those in the four available 12052 olivine analyses (Fagan et al 2013). Spinel compositions were reported for 12052 by Gibb et al (1970) and Haggerty and Meyer (1970). These are in good agreement with those measured in 12003,312_C (Fig.…”

Section: Typesupporting

confidence: 79%

“…12003 spinel compositions (a) are compared with those reported in other Apollo 12 samples (b) (Gibb et al. ; Haggerty and Meyer ; Brett et al. ; Brown et al.…”

Section: Resultsmentioning

confidence: 99%

“…Spinel compositions were reported for 12052 by Gibb et al. () and Haggerty and Meyer (). These are in good agreement with those measured in 12003,312_C (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…This may be due to unrepresentative sampling of the parent rock or compositional equilibration within the olivine modifying the initial phase compositions. (Gibb et al 1970;Haggerty and Meyer 1970;Brett et al 1971;Brown et al 1971;Cameron 1971;Champness et al 1971;El Goresy et al 1971;Keil et al 1971;Kushiro et al 1971;Reid 1971;Simpson and Bowie 1971;Taylor et al 1971;Weill et al 1971;Dungan and Brown 1977).…”

Section: Parent Melt Compositionsmentioning

confidence: 99%

See 3 more Smart Citations

Basaltic diversity at the Apollo 12 landing site: Inferences from petrologic examinations of the soil sample 12003

Snape

Joy

Crawford

et al. 2014

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-A detailed petrologic survey has been made of 17 basaltic chips (sized between 1 and 10 mm) from the 12003 soil sample as part of an ongoing study of basaltic diversity at the Apollo 12 landing site. An attempt has been made to classify these samples according to the well-established grouping of olivine, pigeonite, ilmenite, and feldspathic basalts. Particular attention has been paid to variations in major, minor, and trace element mineral chemistry (determined by electron microprobe analysis and laser ablation ICP-MS), which may be indicative of particular basaltic suites and less susceptible to sampling bias than bulk sample characteristics. Examples of all three main (olivine, pigeonite, and ilmenite) basaltic suites have been identified within the 12003 soil. One sample is identified as a possible new addition to the feldspathic suite, which currently consists of only one other confirmed sample. Identification of additional feldspathic basalts strengthens the argument that they represent a poorly sampled basaltic flow local to the Apollo 12 site, rather than exotic material introduced to the site by impact mixing processes. Three samples are identified as representing members of one or two previously unrecognized basaltic suites.

show abstract

Section: Typesupporting

confidence: 79%

“…12003 spinel compositions (a) are compared with those reported in other Apollo 12 samples (b) (Gibb et al. ; Haggerty and Meyer ; Brett et al. ; Brown et al.…”

Section: Resultsmentioning

confidence: 99%

“…Spinel compositions were reported for 12052 by Gibb et al. () and Haggerty and Meyer (). These are in good agreement with those measured in 12003,312_C (Fig.…”

Section: Discussionmentioning

confidence: 99%

Section: Parent Melt Compositionsmentioning

confidence: 99%

See 2 more Smart Citations

Basaltic diversity at the Apollo 12 landing site: Inferences from petrologic examinations of the soil sample 12003

Snape

Joy

Crawford

et al. 2014

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…(); Gibb et al. (); Haggerty and Meyer (); Keil et al. (); Kushiro and Haramura (); Reid (); Taylor et al.…”

Section: Resultsmentioning

confidence: 99%

An analysis of Apollo lunar soil samples 12070,889, 12030,187, and 12070,891: Basaltic diversity at the Apollo 12 landing site and implications for classification of small‐sized lunar samples

Alexander

Snape

Joy

et al. 2016

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-Lunar mare basalts provide insights into the compositional diversity of the Moon's interior. Basalt fragments from the lunar regolith can potentially sample lava flows from regions of the Moon not previously visited, thus, increasing our understanding of lunar geological evolution. As part of a study of basaltic diversity at the Apollo 12 landing site, detailed petrological and geochemical data are provided here for 13 basaltic chips. In addition to bulk chemistry, we have analyzed the major, minor, and trace element chemistry of mineral phases which highlight differences between basalt groups. Where samples contain olivine, the equilibrium parent melt magnesium number (Mg#; atomic Mg/[Mg + Fe]) can be calculated to estimate parent melt composition. Ilmenite and plagioclase chemistry can also determine differences between basalt groups. We conclude that samples of approximately 1-2 mm in size can be categorized provided that appropriate mineral phases (olivine, plagioclase, and ilmenite) are present. Where samples are fine-grained (grain size <0.3 mm), a "paired samples t-test" can provide a statistical comparison between a particular sample and known lunar basalts. Of the fragments analyzed here, three are found to belong to each of the previously identified olivine and ilmenite basalt suites, four to the pigeonite basalt suite, one is an olivine cumulate, and two could not be categorized because of their coarse grain sizes and lack of appropriate mineral phases. Our approach introduces methods that can be used to investigate small sample sizes (i.e., fines) from future sample return missions to investigate lava flow diversity and petrological significance.

show abstract

Mare Basalts: Crystal Chemistry, Mineralogy, and Petrology

Series¹

1977

1977, Reviews of Lunar Sciences

View full text Add to dashboard Cite

Lunar crustal rocks can be divided into two groups: the terra, or highland, types and the mare basalts.Interpretation of the highland samples is complicated by their derivative nature, which resulted from a series of crystallization, shock, and brecciation events. In contrast, mare basalts appear to be much less complicated and to have been rather uncompromised since their arrival at the lunar surface; thus a synthesis appears possible at this time. Although the mare basalts comprise less than 1% of the lunar crust, they contain much information about the thermal history of the moon and the nature of the lunar interior. It is now known that a complete suite of basalts, sampling all of the chemically and temporally distinct units, was not sampled by the Apollo and Luna missions. The mare basalts that have been studied have ages between 3.15 and 3.96 Gy. However, photogeologic evidence (crater counts and crater degradation studies) indicates that basalts as young as 2.5 Gy exist on the moon and were not sampled. The returned samples can be divided into two broad groups: the older, high-titanium group (ages, --•3.55-3.85 Gy; TiO•., 9-14 wt %) and the younger, low-titanium group (ages, 3.15-3.45 Gy; TiO•., 1-5 wt %). Basalts from Apollo 11 and 17 fall into the older, high-titanium group; basalts from Apollo 12 and 15 and Luna 16 fall into the younger, low-titanium group. The two major groups of basalts can be further subdivided on the basis of major-and minor-element chemistry. Within each of these subgroups a variety of grain sizes and textures, which result from different cooling histories, are present. Near-surface fractionation of these basalts involved mainly olivine in the low-titanium basalts and olivine plus iron-titanium oxides in the high-titanium basalts. The alkali-depleted mare basalts evolved by rapid cooling at the lunar surface under extremely reducing conditions (•10 -xa atm at 1150øC). This low oxygen fugacity resulted in reduced valence states for Ti (Ti 4+ • Ti a+) and Cr (Cr •+ -• CRY'+), which in turn affected both the chemistry and the stability of the mare basalt minerals. The most important mineralogical species in these rocks are the silicates (pyroxene, feldspar, and olivine) and the Fe-Ti oxides (ilmenite, spinel, and armalcolite). Models for the source regions of the mare basalts remain controversial. Three basic models for mare basalt source regions have been advanced. These include the cumulate source model (remelting of cumulates resulting from early lunar differentiation), the primitive source model (melting of deep undifferentiated mantle), and the assimilation model (primary melts are contaminated by assimilation). All of these models have problems. If one assumes that at least some of the lunar basalt samples arrived at the surface with unaltered chemistry, the high-pressure experimental phase equilibria approach can provide constraints on the nature of the source regions for these rocks. Results of these studies indicate that the low-and high-Ti mare basalt groups were derived fro...

show abstract

Opaque minerals in an Apollo 12 rock

Cited by 19 publications

References 6 publications

Basaltic diversity at the Apollo 12 landing site: Inferences from petrologic examinations of the soil sample 12003

Basaltic diversity at the Apollo 12 landing site: Inferences from petrologic examinations of the soil sample 12003

An analysis of Apollo lunar soil samples 12070,889, 12030,187, and 12070,891: Basaltic diversity at the Apollo 12 landing site and implications for classification of small‐sized lunar samples

Mare Basalts: Crystal Chemistry, Mineralogy, and Petrology

Contact Info

Product

Resources

About