ISSN:
1432-0967
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract The Kelly brecciated chondrite, originally classified as a polymict breccia, is actually a monomict breccia, based on conclusions from this study. Microprobe analyses of differently textured clasts are very similar to each other and also to well-known LL-type chondrites. Clast and matrix olivine compositions range between Fa27–31, well within the range of LL-chondrite olivine. A correlation was found between the degree of recrystallization and plagioclase composition; least recrystallized plagioclase is more Ca-rich than fully recrystallized plagioclase. Petrographic observations of shocked, annealed, and unshocked clasts coupled with particle size distribution measurements strongly indicate that Kelly is similar to lunar metabreccias in mode of formation, i.e., repeated mixing and accumulation of disaggregated surface rocks and impacting debris followed by partial annealing under moderate temperatures. At least three breccia generations are indicated. We propose that Kelly is an LL-chondrite parent body metabreccia that represents the final accumulation phase of the parent body. Only LL-type fragments were found in Kelly, which suggests that the parent body consisted of only LL-chondrites and was not a multi-shelled body of H-, L-, and LL-chondrites.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00385788
