083019b

Calcite cement (pale pink) dissolving feldspar and quartz in a very fine sandstone, Rodessa Formation, Citronelle oil Field, Alabama, about 11,000 feet below the surface, thin section, scale bar 100 micrometers, crossed polarizers.

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.

040819c

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