040120b

Micaceous very fine sandstone, thin section photomicrograph, scale bar 100 µm, crossed polarizers, equant particles mostly quartz, curved sheet-like particles muscovite mica, Rodessa Formation, Cretaceous, Citronelle Field, 11,500 feet below the surface, South Alabama.

021919c

Cross laminae of mica (bright colors and shades of brown) and quartz (gray and white). Thin section photomicrograph. 2.5 mm wide field of view.