61016 (217) - Melt rock with anorthosite cap
Collection:
Apollo 16
Click the microscope button to view a thin section for this sample.
Microscope
Click the microscope button to view a thin section for this sample.
Microscope

Fact sheet

61016 (217) - Melt rock with anorthosite cap

Sample 61016 is the largest sample returned by the Apollo missions. It is known as ‘Big Muley’, having been named after Apollo 16 field geology team leader Bill Muehlberger. There is evidence to suggest the sample was ejected from South Ray crater although it was found perched on the east rim of Plum Crater. The top side of the boulder is rounded with thin patina and numerous micrometeorite zap pits; the remainder of the sample was below the lunar soil surface. The melt rock (which formed during a meteorite impact) is dated at 3.97 billion years.

The thin section shows the sample to be a breccia consisting of shocked anorthosite attached to a piece of troctolitic ‘melt rock’. Its main lithology is characterised by clasts of maskelynite, a form of glass that is formed by cold transformation of the mineral plagioclase. The rock also contains glassy and devitrified lithic clasts containing maskelynite intergrown with olivine (in the troctolite portion of the rock).

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

Additional images
 
  • Astronaut sampling the lunar surface close to Plum crater
  • The Apollo 16 buggy close to Plum crater
About this collection
 
Apollo 16

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
maskelynite
glass
Accessory minerals
olivine
Category guide  
Category Guide
Title
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Description
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
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
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Timescale
Selecting one or more period, for example 'Jurassic'.
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
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample:

More from this collection

Apollo 16