Non-differentiated meteorites: CHONDRITES.

Those meteorites are fragments of "non-differentiated parent bodies". They have not been modified since creation of the solar system and thanks to isotopic analyses carried out on those meteorites, scientists have been able to measure the age of the solar system (and of the Earth as well), as 4.5 billion years.

The name "Chondrite" comes from the name of the small spheres that they contain, the chondrules, that can never be found in the structure of any terrestrial stone.

(TANEZROUFT 057 - C4 an)



There are several groups of chondrites:

- Ordinary chondrites (H, L, LL groups):

They are the most common meteorites (80 % of the total known meteorites).
They contain "free iron" (non oxidized) and are classified according to their iron content:

H Type (High) : between 12 and 21% iron

L Type (Low) : between 7 and 12% iron

LL Type (Low-Low) : less than 7% iron

An additional information about metamorphism is provided by a figure (between 3 and 7)

example : an L3 chondrite is slightly metamorphised and contains between 7 and 12% of Fe-Ni.

- Enstatite chondrites (EL and EH groups):

They are rare and their iron content is higher: up to 35% for EH.


- Carbonaceous chondrites (CI, CM, CO, CV, CK, CR... groups):

Those meteorites are also rare and are the most primitive ones. Their composition is very close to the one of the proto-solar cloud that origintated the solar system.

They contain carbon and low amount of iron, mostly under oxidized form.

Differentiated Meteorites

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