040120d

Cross-bedded a very fine micaceous sandstone, crossbeds made obvious by bright pink mica flakes, most equant grains are quartz, Cretaceous Rodessa Formation, Citronelle oil field, South Alabama, 11,500 feet below the surface, thin section photomicrograph, crossed polarizers.

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.

082919c

Thin section photomicrograph of silty sandstone containing mica (bright particle in the center). Rodessa Formation in Citronelle oil Field, Alabama, scale bar 25 micrometers. Crossed polarizers. About 11,000 feet below the surface.

041919c

A ripple made of mica and quartz, bright colors are mica and quartz is gray, thin-section photomicrograph, crossed polarizers, Rodessa Formation, about 2 miles below the surface, Citronelle Field, Alabama.

040819c

Micaceous silty sandstone from more than 11,000 feet down in Citronelle Field, Alabama. Cross-polarized light.

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.

021519d

Mica, through a polarizing microscope.

A ripple, close-up and personal

Silty micaceous sandstone, cross laminated, crossed polarizers, muscovite and biotite mica. From 2 miles below the surface.

Yet more sandstone

Wavy muscovite (upper right) and large twinned plagioclase feldspar (lower half). Sandstone, Rodessa Formation, Citronelle field, South Alabama, about 2 miles below the surface.

Sandstone in thin section

Poorly sorted sandstone cemented by calcite (pink).

Muscovite (mica) in sandstone.

Both from the Cretaceous Rodessa Formation in Citronelle oil field, Alabama. About 2 miles below the surface. Both photos taken using crossed polarized light.

Rocks are pretty

 

Thin section photo of a mica flake, viewed with crossed polarizers. Surrounded by calcite cement.

Mica in sandstone

Laminated sandstone with mica

Sandstone never looked like this!

Actually, it did. This is micaceous sandstone from South Alabama. Note the scale in the lower right.

mica

Mica never gets old. Well, it wears the tens of thousands of millennia well.