The Farmington hypersthene chondrite is a dense, black meteorite that has been shocked and partly brecciated. It contains olivine (23% Fa), hypersthene (21% Fs), plagioclase (An10), kamacite, taenite, troilite, chromite, ilmenite and possibly clinohypersthene or pigeonite, merrillite and/or apatite and a titanium dioxide mineral. Some kamacite grains, sheathed by troilite, have globular shapes suggesting that they may have been molten. As temperatures decreased sulfur was introduced and reacted with the metal to form the troilite rims. Following this the meteorite was shocked, producing the black "breccia fragment" as well as the metal veins in the fragment. The electron microprobe analyzer indicates the metal throughout the meteorite is compositionally inhomogeneous, raising the possibility that it may not be indigenous. A chemical analysis, indicating that Farmington belongs to the L-group of chondrites, shows the following results: Fe 6.40, Ni 1.06, Co 0.09, FeS 4.79, SiO2 40.79, TiO2 0.17, Al2O2 1.75, FeO 15.15, MhO 0.28, MgO 24.84, CaO 1.92, Na2O 0.96, K2O 0.13, P2O5 0.30, H2O+ 0.09, H2O- 0.00, Cr2O3 0.55; total 99.27.
ASJC Scopus subject areas
- Geochemistry and Petrology