Figure 40. Bivins Ranch No. 6-2, 5596.4 ft.  From base of shaly sandstone. Core porosity = 14.1 %; permeability_(air) = 4.2 md. Very thin clayey/micaceous lamination with several subrounded and equant (plagioclase feldspar) grains and secondary pores (blue).  Black grains (upper right) are small zircon grains. Calcite (C) occurs as a patchy carbonate cement.