60015 (128) Cataclastic Anorthosite
We would like to thank the following for the use of this sample:
60015 is a highly-shocked ferroan anorthosite (~98% plagioclase. The plagioclase shows extensive evidence of shock (patchy and undulose extinction) and melting, but maskelynite is not reported. The highly-shocked plagioclase includes bubble-like melt inclusions with a very high index of refraction. Pyroxene grains are rounded and also show evidence of shock. Some orthopyroxene occurs as thin “stringers” along feldspar crystals. Pyroxene aggregates in the groundmass contain associated ilmenite, Cr-spinel, metallic iron and troilite (all in low abundance). No olivine is reported.
The sample weighed 5574 grams before analysis and is 3.5±0.05 billion years old (Ar/Ar).
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Our thin section is slightly thick so between crossed polars some plagioclase crystals are yellow instead of shades of grey.
Ma = Millions of years ago
Rock forming mineral:
- metallic iron,