ALHA77005 - Lherzolitic Shergottite
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Fact sheet

ALHA77005 - Lherzolitic Shergottite

This cumulate gabbroic rock (lherzolite) was found as a 483 g stone in the Allan Hills region of Antarctica. Isotopic techniques have dated it at 173±6 m.y. (Sm-Nd) and 185±11 m.y. (Rb-Sr). It has many similarities with another lherzolitic shergottite - LEW 88516 and both may have been ejected from Mars at the same time.

Only 5% of the outer surface of LEW 88516 still had a black fusion crust. The interior contains about 55% olivine, 35% pyroxene, 8% maskelynite (shock-melted plagioclase feldspar) and 2% opaque minerals. Grain size reaches 6 mm. Accessory amounts of ilmenite, chromite, whitlockite (Mg-rich apatite) and pyrrhotite are also present.

ALHA77005 appears to be more heavily shocked than other Martian meteorites and small patches of melt glass containing skeletal crystallites of olivine and chromite can be seen. The brown colour of the olivine may be due to shock-induced oxidation.

This description is based on the work of NASA scientist Charles Meyer - compiler of The Mars Meteorite Compendium.

-76.716, 159.667
About this collection

This collection of meteorites includes Shergottites, Nakhlites and Chassignites (or SNC meteorites) which originate from the surface of the planet Mars.

They carry unique signals of the surface of the planet that allows scientists to study the composition and age of Martian rocks. The collection includes a sample of the famous ALH84001 meteorite, evidence from which was used in 1996 to begin the debate of 'life on Mars?'. 


Sample details

Collection: Martian Meteorites
lherzolitic shergottite
Rock-forming mineral
Accessory minerals
Category guide  
Category Guide
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.
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.
Selecting one or more period, for example 'Jurassic'.
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.
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).
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: