Exercise: Note that the thin section photomicrograph of the limestone you see below is $100\%$ calcite. This is an oolitic lime grainstone $($oosparite$).$ Today, there is no porosity at all, which is common in many limestones$.$ The coarse crystals are calcite cement. The sample has been artificially stained so that Fe$-$poor calcite shows up as pink and Fe$-$rich calcite shows up as bluemauve. The Fe$-$rich and Fe$-$poor calcite cements form at different times.

Determine the order of events that affected the pore system over time, starting with deposition of ooids $($this is the paragenesis$).$

Although no porosity exists today, there were two stages in the paragenesis when pores existed.

A$.$ For the first stage, what was the origin of this porosity $($where was it located in the rock fabric and how did it form?$).$ What was the porosity in volume percent? What would you estimate as the permeability in millidarcies?

B$.$ For the second stage, what was the origin of this porosity $($where was it located in the rock fabric and how did it form?$).$ What was the porosity in volume percent? What would you estimate as the permeability in millidarcies?