Figure F83. Photomicrograph of a silty sandstone in cross-polarized light to show components such as quartz (Q), biotite (B), and potassium feldspar (K) with cross-hatch twinning, as well as large enveloping crystals of carbonate (poikilotopic) cement (C; white where extinct) (Subunit 5B: Sample 210-1276A-54R-1, 63-66 cm).

Figure F83. Photomicrograph of a silty sandstone in cross-polarized light to show components such as quartz (Q), biotite (B), and potassium feldspar (K) with cross-hatch twinning, as well as large enveloping crystals of carbonate (poikilotopic) cement (C; white where extinct) (Subunit 5B: Sample 210-1276A-54R-1, 63-66 cm).