Core 14220 and the lateral continuity of soils at Apollo 14 Station G

Nagle, J. S.

doi:10.1007/bf00899816

Cited by 5 publications

(2 citation statements)

References 3 publications

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“…Four extra large crystalline breccia fragments were present in the depth interval between 6 and 9 cm. Nagle [1980], in a study of the > 1 mm fraction, also recognized a lithic-rich unit at the base of this core, with abundant basalt and crystalline breccia fragments. Two agglutinates and one DMB >2 mm were also found in the drive tube.…”

Section: Modal Petrology Of 14220mentioning

confidence: 99%

The Apollo 14 Regolith: Petrology of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

Simon¹,

Papike²,

Laul³

1982

J. Geophys. Res.

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New modal data are presented for continuous polished thin sections from double drive tube 14210/14211, and single drive tube 14220, and for polished grain mounts of four soils from the double drive tube, one from the single drive tube, and the soils 14148 (trench top), 14149 (trench bottom), and 14141 (Cone Crater). Modal data show that the Cone Crater soil is immature, whereas the ‘smooth plains’ soils are mature and rich in agglutinates and breccias. Neither core exhibits any major variations with depth. Microprobe analyses of mineral and glass fragments are consistent with derivation of the soils predominantly from the local rocks, with ∼5–11% exotic mare component indicated by the modal data. About 4% of the glasses are SiO2‐ and K2O‐rich granitic glasses which are comminuted mesostasis from the local melt rocks. The soils are depleted in feldspar relative to the source rocks. The preferred explanation for this depletion is that feldspar is concentrated in the <10 μm fines and is consumed in the formation of agglutinates, regolith breccias, and feldspathic glass.

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Section: Modal Petrology Of 14220mentioning

confidence: 99%

The Apollo 14 Regolith: Petrology of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

Simon¹,

Papike²,

Laul³

1982

J. Geophys. Res.

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“…On the basis of examination under the binocular microscope, Nagle [1980b] distinguished six units and five glassrich zones. Modal data from continuous polished thin sections show that the bottom of the core is relatively rich in lithic fragments and that agglutinates gradually increase in abundance with decreasing depth.…”

Section: Apollo 14 Drive Tube 14220mentioning

confidence: 99%

The lunar regolith: Chemistry, mineralogy, and petrology

Papike

Simon²,

Laul

1982

Reviews of Geophysics

232

140

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The lunar regolith, a several meter thick layer of unconsolidated debris, forms the interface between the moon and its space environment. The regolith forms from lithic sources by the destructional processes of comminution and the constructional processes of agglutinate formation. In this manner a steady state soil can develop and will remain in a type of dynamic equilibrium until the system is disturbed by burial or mixing with new soil. Mixing takes place mainly on a local scale (vertically through meters and horizontally over several kilometers). Lateral transport is a relatively inefficient process, and therefore most of the lunar soil components were derived locally. There is no evidence for preferential transport of the finer soil fractions relative to the coarser fractions. The truly ‘exotic’ (derived at distances of tens of kilometers) component is generally in low abundance (≪1%). Therefore remotely sensed data should provide a reasonably accurate picture of bedrock geology. The chemical composition of the regolith varies with grain size. The <10 µm fraction is chemically fractionated from the bulk soil. In most cases the <10 µm fraction is enriched in Al2O3, CaO, Na2O, K2O, light rare earth elements, and Th and depleted in MgO, FeO, MnO, and Sc. These systematics are largely a result of simple comminution, with feldspar and friable mesostasis from local source rocks concentrating in the finest fraction. There is evidence that agglutinate glass forms preferentially by fusion of the finest soil fractions. Therefore agglutinate glass, like the <10 µm soil fraction, appears to be fractionated from bulk soil compositions. Highland soils are distinct from mare soils both chemically and petrologically. Soil samples collected near mare‐highland contacts are mixtures of the two lithologies. Mineral chemical systematics of monomineralic fragments in the lunar soil provide important clues to soil provenance. They can, in some cases, sort out the highland/mare contributions and, in special cases, can even further pinpoint a lithic source. In theory, lunar regolith cores can serve as solar probes, recording the sun's activity over billions of years. In practice, this has generally not been the case. The formation and evolution of most cores is still poorly understood. For most, we have not established how they formed, for example, how many depositional and erosional events were involved, what the time span involved in the accretion of the sampled soil column was, and how long that soil column has remained in situ. Without this information it is difficult, if not impossible, to read the sun's record. More interdisciplinary studies on cores must be carried out before they can be used as solar probes.

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The Apollo 14 Regolith: Chemistiy of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

Laul¹,

Papike²,

Simon³

1982

J. Geophys. Res.

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Chemical data for 31 major, minor, and trace elements were obtained by instrumental neutron activation analysis (INAA) for bulk and size fractions of drive tubes 14210/11 (39 cm) and 14220 (16.5 cm) and soils 14141, 14148, and 14149. Both cores are KREEPy and homogeneous in chemical composition. The meteoritic component varies from 3 to 7% in both cores. The heterogeneous Ni profiles suggest little in situ mixing of the cores since their emplacements. The bulk soils on the average contain 20% low‐K‐Fra Mauro basalt (LKFM) (62295), 10 to 15% mare basalt ( 14072), 6%anorthosite‐norite‐troctolite (ANT) and 59% high‐K KREEP. There are no significant intrasite chemical variations at the Apollo 14 site. Among the grain sizes, the coarse 1000–90, 90–20, and 20–10 μm fractions are similar in chemistry, but quite different from the < 10 μm fine fractions. The < 10 μm fine fractions comprise 5 to 15%of the bulk soils and are consistently more feldspathic and enriched in incompatible (LIL) elements relative to the coarse fractions. In the mature soils, agglutinates dominate the chemistry of the coarser fractions, and the similarity of LIL contents between the 1000–90 μm fractions and the < 10 μm fine fractions strongly suggests that agglutinates are derived from the fine fraction, which supports the F3 model of Papike et al [1981] Relative to the bulk soil, the < 10 μm fine fraction is enriched in Al2O3, CaO, Na2O, K2O, Ba, Sr, La(REE), Eu, and Th and depleted in MgO, FeO, Mn, and Sc. The observed varying degrees of enrichments and depletions can largely be explained by simple comminution of inesostasis and feldspar and their preferential incorporation into the finest fraction. Lateral mixing over short distances, simple comminution, and vertical mixing of the regolith are the dominant soil‐forming processes.

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Core 14220 and the lateral continuity of soils at Apollo 14 Station G

Cited by 5 publications

References 3 publications

The Apollo 14 Regolith: Petrology of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

The Apollo 14 Regolith: Petrology of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

The lunar regolith: Chemistry, mineralogy, and petrology

The Apollo 14 Regolith: Chemistiy of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

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