60215 (31) Cataclastic Anorthosite (brecciated)
Collection:
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Fact sheet

60215 (31) Cataclastic Anorthosite (brecciated)

60215 is actually a polymict breccia, because it contains clasts of material other than anorthosite. However, the largest portion is almost pure white and very plagioclase rich. Low Ni, Co and C contents suggest that the main portion of 60215 can be considered “pristine”. The rock was apparently originally encased in black glass, which has been eroded or chipped away by micrometeorite bombardment.

The anorthositic portion is both highly shocked and cataclastic. The brown mottled fragments are also of plagioclase composition (probably devitrified maskelynite) in which abundant, minute (<1 mm) mafic inclusions occur. Plagioclase fragments are relatively coarse, while pyroxene fragments are rare and generally less than 0.1 mm across, except for one texturally-distinct, millimeter-size, shocked and strongly zoned pigeonite clast. This clast has granular exsolution due to partial inversion, and has minor intergrown olivine. A second, smaller fragment adjacent to this pigeonite is extremely Fe rich (Wo20En55). These two zoned pyroxene fragments appear to be exotic. Low-Ca pyroxene compositions are heterogeneous; subordinate high-Ca pyroxene is more homogeneous. Rare chromite and olivine are also present.

The sample weighed 386 grams before analysis.

Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/

About this collection

The Apollo 16 landing site was in the hilly region around Descartes crater in the lunar highlands. The landing spot was chosen to allow the astronauts to gather geologically older lunar material (Descartes Formation and the Cayley Formation) than the samples obtained in the first four landings, which were in or near lunar maria.

The mission lasted 11.1 days, with a stay on the lunar surface of 71 hours. The crew were on the lunar surface for 20.2 hours during which they traversed approximately 27 kilometers and collected approximately 96 kilograms of samples.

Apollo 16 was launched on 16 April 1972.

Sample details

Collection: Apollo 16
Type
metamorphic
Rock-forming mineral
plagioclase
feldspar
Category guide  
Category Guide
Title
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Description
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Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
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Timescale
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Theme
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
Category
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
Owner
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We would like to thank the following for the use of this sample: