Figure 25—SEM photographs of primary and secondary porosity. 

(A). Primary porosity indicated by angular pore geometries.  Part of quartz overgrowth incompletely encloses patch of detrital matrix with microporosity.

(B). Dissolution of detrital matrix resulting in formation of secondary porosity.  Some primary porosity preserved between quartz grains. 

(C). Dolomite rhomb showing dissolution; primary and secondary porosity.