Chassigny is mineralogically similar to a terrestrial dunite – a rock made mostly of olivine, which formed deep underground from mantle material. Chassigny is composed of about 91% iron-rich olivine with intercumulous pyroxene, feldspar, and oxides. Cracks within it are filled with various carbonates and sulfates, which suggest the rock was exposed to liquid water before its arrival on Earth. Its crystallization age of 1.36 billion years and its composition, suggest a close relationship with the nakhlites and an origin in the same parent magma on Mars. However, Chassigny contains noble gas abundances that are different from those seen in other Mars meteorites or in the present martian atmosphere. If these gases derived from the martian mantle, as suspected, Chassigny must have originated within a magma pluton deep inside the martian crust.
Related categories METEORS AND METEORITES
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