Phase Chemistry, Structure, and Radiation Effects in Lunar Samples

Abstract

Phase chemistry, structure, and radiation effects were studied in rock, breccia, and soil samples. The regolith apparently developed in the final stages of accretion and was modified by later impact processes and radiation weathering. Exposure ages indicate transfer of buried igneous rock fragments to the near surface late in lunar history. With a few exceptions igneous rock fragments, soil, and breccia share the same distinctive chemistry, probably acquired before accretion of the moon. The igneous rocks texturally resemble basaltic achondrites, and the soil and breccias contain glassy spheres analogous to chondrules.

Asteroidal Theories and Experiments

“…The lunar igneous rocks were found by numerous investigators to show textural and chemical similarities to a specific type of meteorite, the basaltic achondrites. (See, for example, Arrhenius et al, 1970;Duke et al, 1970;Reid et al, 1970). However, these two types of objects have a distinctly different oxygen isotope composition (Taylor and Epstein, 1970) suggesting their origin in different environments.…”

Structural water in the Bench Crater chondrite returned from the Moon

“…Early reports of the mineralogy of lunar rocks were sprinkled with sightings of the hydrous minerals micas and amphiboles (Gay ef al., 1970; Dence et al, 197 1 ; Drever et al, Arrhenius et al, 1970), but these reports were never verified and have come to be regarded as erroneous. Iron oxyhydroxides, reported in a few samples such as the famous rusty lunar rock 66095, were generally shown later to contain only telluric H20 resulting from contamination with terrestrial air, either in the Apollo spacecraft or on the Earth (Freidman et al, 1970;Epstein and Taylor, 1974), although this point was debated by some (Haggerty, 1978).…”