NWA 2737 b - Chassignite
Collection:
Martian Meteorites
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

NWA 2737 b - Chassignite

NWA 2737 was found in several pieces (totaling 611 grams) in 2000 in the Moroccan Sahara and is also known as the “Diderot” meteorite. It originally crystallized 1.38 billion years ago (Sm-Nd age), and was severely shocked about 170 million years ago (Ar-Ar plateau age).

The meteorite mainly consists of olivine (90%) which is unusually black in hand specimen and brown in thin section. These colours are shock-induced. Minor minerals in NWA 2737 are pyroxene (augite and pigeonite) and chromite.  Accessory species include alkali feldspar (sanidine), chlorapatite and kaersutite. Calcite and aragonite occur in cracks and interstices between the other minerals. Laihunite (a high density ferric iron-rich variety of olivine) is also reported. Melt inclusions are found in the olivine.

This description draws on the work of NASA scientist Charles Meyer - compiler of The Mars Meteorite Compendium. A pdf document describing NWA 2737 is available.

Note that the thin section was embedded in a mixture of moutnign medium and sand grains to support it while thin sections were cut so the quartz in the periphery of the section is from Earth.

Map
 
34.033333, -6.85
Description:
Exact location unknown, Morocco
Precision:
Poor
About this collection
 
Martian Meteorites

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
Type
meteorite
Category
Dunite chassignite
Rock-forming mineral
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:
Southern Illinois

More from this collection

Martian Meteorites