76015 (102) Vesicular Micropoikilitic Impact Melt Breccia
Collection:
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Fact sheet

76015 (102) Vesicular Micropoikilitic Impact Melt Breccia

76015 is a very vesicular, crystalline-matrix breccia with with <0.1 mm to 5 cm long irregular vesicles that compose about 20% of the rock by volume. Some of the vugs and cavities are several centimetres across.

The poikilitic matrix of 76015 is a continuous network of interlocking pigeonite oikocrysts enclosing
tabular plagioclase (10-50 microns) and rounded olivine chadocrysts. Small amounts of small augite grains (20 microns) are found both within the pigeonite and between grains. Poikilitic ilmenite and armalcolite grains up to 200 microns long occur in the matrix. The vugs host some interesting minerals, including troilite, metallic iron, apatite, cristobalite and dendritic metallic copper.

The sample weighed 2819 grams before processing and analysis and has been dated at 3.93±0.04 billion years (Ar/Ar).

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

About this collection

Apollo 17, the final manned landing mission, had two objectives: to obtain samples of ancient rocks from the lunar highlands and to look for evidence of younger volcanic activity on the valley floor.

This small Collection contains material deriving from both periods, including igneous rocks around 4.3 billion years old from the lunar highlands as well as younger volcanic samples dating from about 3.6 billion years ago.

Apollo 17 was launched on 7 December 1972.

Sample details

Collection: Apollo 17
Type
metamorphic
Rock-forming mineral
olivine
pyroxene
plagioclase
glass
Accessory minerals
ilmenite
armalcolite
apatite
troilite
metallic iron
cristobalite
metallic copper
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: