Location:

Altered alkali olivine basalts. Derbyshire, Britain

Alkali olivine basalts comprising olivine, titanaugite and plagioclase have been extensively altered to clay minerals and carbonates.

Major Minerals:

Ilmenite, titanomagnetite, secondary haematite-rich and TiO₂-rich alteration products, secondary haematite

Minor Minerals:

Secondary TiO₂ minerals (anatase), secondary pyrite, marcasite

Trace Minerals:

Include chrome-spinel, chalcopyrite

Textures:

Ilmenite forms lath-shaped crystals in subparallel domains. Titanomagnetite characteristically forms small skeletal crystals due to rapid crystallization, or larger crystals with oxidation-exsolution lamellae of ilmenite. Small euhedral chrome-spinels occur within olivine crystals or their pseudomorphs

Reference:

Ineson and Ixer, 1983