The '''eogenetic substage''' (early diagenetic period) is the time from final deposition to the time when the sediment is buried below the zone of influence from surface processes. The eogenetic zone extends from the surface to the base of the zone of influence of surface processes. Even though the eogenetic substage may be geologically brief and the zone thin, the diagenesis that occurs is more varied and generally more significant than any other substage. Eogenetic processes are generally fabric selective. The major porosity change is reduction through carbonate or evaporite mineral precipitation. Internal sedimentation also reduces porosity. Although minor in comparison, the most important porosity creation process is selective solution of aragonite.<ref name=ch09r10 /> | The '''eogenetic substage''' (early diagenetic period) is the time from final deposition to the time when the sediment is buried below the zone of influence from surface processes. The eogenetic zone extends from the surface to the base of the zone of influence of surface processes. Even though the eogenetic substage may be geologically brief and the zone thin, the diagenesis that occurs is more varied and generally more significant than any other substage. Eogenetic processes are generally fabric selective. The major porosity change is reduction through carbonate or evaporite mineral precipitation. Internal sedimentation also reduces porosity. Although minor in comparison, the most important porosity creation process is selective solution of aragonite.<ref name=ch09r10 /> |