Sandstone sparry

The less common late ferroan calcite cement is associated with a minus-cement porosity of <15% (Fig. 13C), indicating that it was precipitated after significant mechanical compaction. It consists of pervasive sparry calcite, which completely filled the remaining reduced intergranular pore space. Fracture-filling calcite cement occurs in grain fractures (Fig. 13D) and rock fractures. It is common below the Avalon Sandstone. 

Sparry calcite lens interbedded with the sandstone of the Mt. Eleming Eormation (Permian) and was not associated with coal. The lenticular calcite bed was about 5 cm thick and several tens of meters wide... 

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